Full text of DOI:10.1046/j.1365-2044.2001.01918-10.x

Anaesthesia, 2001, 56, pages 272±296
................................................................................................................................................................................................................................................
Correspondence
The role of the anaesthetist:
replacement brain
reversible chemical coma and then rate is too fast or too slow. I am getting
take over the functions that the brain angina. I am dehydrated. I am bleeding too
would normally perform. This task much.'
involves both the cerebral functions
The present-day anaesthetist has many
roles outside the operating theatre,
such as in intensive care, on obstetric
units, acute and chronic pain manage-
ment, teaching, education and resusci-
tation. We shall always be primarily
associated, however, with our role of
providing anaesthesia for patients
undergoing surgical procedures; yet
we are very poor at explaining our
function in this role. As Professor
Strunin points out, only 55% of the
general public think that we are
medically qualified (Strunin. Anaesthesia
2000; 55: 941±2). I have been asked if
I started as a porter and then gained
promotion! Some patients even ask if I
am going to be present during the
operation. This may explain why some
anaesthetists would prefer to be called
intensivists or chronic pain doctors for
example.
and the practical functions that an
anaesthetist normally performs. The
ease with which these tasks are
performed depends on the anaesthe-
tist's skills, knowledge, training and
mental state. The following examples
may help to elaborate this surrogate
brain role.
Disability and environment
`My neck is badly positioned. I am in pain. I
am cold. My pressure areas need attention. I
am developing clots in my calf veins.' The
list is endless.
The pre-operative visit is a crucial
part of the process. This is when we
perform the vital medical evaluation of
our patient. To which areas of the
Airway and breathing
body do
I need to give special
We analyse the competence and ade-
quacy of the airway and breathing.
`What type of airway is best for me?'
(face-mask, laryngeal mask, tracheal,
bronchial tube, venturi system, etc.).
`What type of breathing am I to perform?'
(spontaneous, assisted, one-lung venti-
lation, insufflation, etc.). `Am I breathing
at the right rate? Is my breathing deep
enough? Have I enough oxygen in my
circulation?'
attention? Will cerebral perfusion (of
the original not the replacement brain)
be a problem? Will the cardiovascular
system be a problem? Will the airway
or breathing be a problem? Will the
hepatic or renal function be a problem?
Will there be excessive loss of blood or
clotting factors? Will the endocrine
system be a problem? Are all these in
optimal condition? In some cases, we
have to refer the patient for further
tests in order to perform a complete
evaluation.
The need for a complete knowledge
of the effects of the drugs that we plan
to administer to a patient is obvious.
We also need to have a good working
knowledge of the surgery and a good
understanding of the surgeon perform-
ing the operation. This enables us to
predict the trauma and hazards the
Depending on the operation and the
patient, we establish and act upon
acceptable parameters. Simple pulse
oximetry and capnography may suffice
for decision-making, but blood gas
analysis may be necessary in some
cases (e.g. complex general surgery or
thoracic and cardiac surgery).
The surgeons simply want a patient
to lie still, have an optimal view of
their operating field plus a zero turn-
around time. The patient simply wants
to be unaware of the operation and to
be alive at the end. Neither truly
appreciates what we do and we are
bad at explaining it to our own
trainees and other medical practi-
tioners, let alone the general public. Circulation
I have heard mixed views on the We apply parameters for heart rate and patient, and therefore we, will face
success of the recent National Anaes- blood pressure. In addition, in some during the course of an operation; for
thesia Day.
cases we need to decide on the example, blood loss during hepatic
So what is the role of the anaes- adequacy of blood volume, haemato- surgery, cardiovascular changes during
thetist in theatre? It is surely very easy crit, acid base balance, clotting func- cardiac surgery, the need for hypoten-
to explain. We are the patients' tion and ionic composition. `My Blood sive anaesthesia or long and short
replacement brain. We induce a pressure is too high or too low. My heart operations due to the speed of the
All correspondence should be addressed to Professor M. Harmer, Editor of Anaesthesia, Department of Anaesthetics, University of
Wales College of Medicine, Heath Park, Cardiff CF14 4XN, UK.
Letters (two copies) must be typewritten on one side of the paper only and double spaced with wide margins. Copy should be
prepared in the usual style and format of the Correspondence section. Authors must follow the advice about references and other
matters contained in the Notice to Contributors to Anaesthesia printed at the back of each issue. The degree and diplomas of each
author must be given in a covering letter personally signed by all the authors.
Correspondence presented in any other style or format may be the subject of considerable delay and may be returned to the author for
revision. If the letter comments on a published article in Anaesthesia, please send three copies; otherwise two copies of your letter will suffice.
272
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................................................................................................................................................................................................................................................
surgeon. We are constantly monitoring or when anaesthetic staff have disas- the true sense of the word. Whilst the
the patient's vital signs during an trously changed in the middle of an drugs and tools used in anaesthesia
operation. However, we also need to operation.
I
fundamentally have changed little,
monitor the progress of the surgery so think that our College and induction of and arousal from anaes-
that we can anticipate critical events Association are performing a good thesia are now a minor part of our
and perform pre-emptive measures. job of improving our image. It is work. Surgery has become more com-
This may explain why it is sometimes obviously
important
that
we plex and patients have become older
frustrating when we cannot see what enlighten the public and others in and sicker. Nowadays, caring for the
the surgeon is doing under the the medical profession of our role patient before, during and after the
microscope or deep in the abdominal outside the theatre complex. How- pharmacological exposure, surgical
or thoracic cavity.
ever, when 43% of our time is spent assault and associated physiological
Webster clearly illustrated the pro- performing routine operating theatre disturbance is our major role. We
blems of calling ourselves peri-opera- work, it is important that we explain have evolved into peri-operative phy-
tive physicians [1]. I agree with his this role more clearly. I feel that the sicians and the term anaesthetist has
misgivings. We think highly of physi- best way of explaining my role to become an anachronism.
cians such as the neurologists and patients is by telling them that `A
According to the `Snapshot' survey
cardiologists because of their under- general anaesthetic puts you into a last year, in-theatre work only accounts
standing of the brain and heart. Yet reversible coma and I will be your for about 50% of our time. A substantial
we do not emphasise our role as the replacement brain for the duration of proportion of the specially has moved
surrogate brain during general or, in your operation.'
some instances, regional anaesthesia.
A. Vohra
into the field of intensive care medicine
where they undertake a similar type of
work on the very sickest patients. Again,
rendering the patient insensible is a
minor part of their activity. Trauma
management in the A & E Department
is a variant of this.
The other substantial area of the
non-theatre clinical activity is pain
management. It departs substantially
from the above two roles. The phar-
macological expertise and the ability to
perform anaesthetic techniques (blocks
etc.) are valuable skills. Perhaps the
most important are the communication
skills honed in theatre during the
everyday experience of communicating
with anxious, distressed, difficult and
sometimes strange patients (and sur-
geons).
Some have gone even further and
immersed themselves in palliative care.
This is a long way from the operating
room, yet the process by which it
occurs has a logic to it. On occasions,
I have found myself, on the same day,
working in the operating room, ICU
and Accident department whilst also
caring for a patient, in pain, dying of
cancer.
Can we then still call ourselves
anaesthetists or are we merely practi-
cing anaesthesia (rendering insensible)
whilst we spend most of our time
undertaking a range of other activities?
Are anaesthetists already peri-operative
physicians in contrast to the `peri-
operative physicians' proposed by
The physician can ponder over various
Manchester Royal Infirmary,
Manchester M13 9WL, UK
E-mail: avohra@compuserve.com
medical aberrations, institute treatment
and wait for a response that can take
hours or days to occur. We do similar
processing, but with response times of
seconds and minutes rather than
hours. Presenting our role as the
replacement or surrogate brain will
make it easier for the public, and
perhaps other medical professionals to
understand what we do (its not just
one big syringe and one small syringe
followed by a cup of coffee and The
Times crossword). It also makes it
easier to teach trainee anaesthetists to
appreciate why they need to see
patients pre-operatively and to under-
stand the operation so that their brain
can be ready to cope with the
anaesthetic period and beyond.
This concept would explain why
two different anaesthetists can have
two quite different outcomes even
when using, apparently, the same
anaesthetic drugs and technique. It is
another reason for re-emphasizing the
importance of training, teaching and
experience. Whose brain do you want
to look after you when you undergo
Reference
1 Webster NR. The anaesthetist as peri-
operative physician. Anaesthesia 2000;
55: 839±40.
Anaesthesia, what's in a name?
We all recognise the difficulty that the
rest of the world has in identifying just
what an anaesthetist is. In his editorial
(Strunin. Anaesthesia 2000; 55: 941±2),
Professor Strunin wrestles with the
name itself and considers new ways of
publicity. However, I believe that the
major cause lies within our specialty
and is more fundamental than we care
to think. It is we ourselves who have
problems with our identity.
Thirty years ago the role of the
anaesthetist was clear. His job was to
render the patients insensible for the
surgeon to operate on and almost all of
his time was within the confines of the
operating theatre. The public had some
idea of his identity, though not of his
credentials or his importance. He was
the one who put you to sleep and
woke you up. He was an anaesthetist in
general anaesthesia?
A
consultant
anaesthetist, a trainee anaesthetist or a
nurse anaesthetist? It explains why one
anaesthetist will be happy to anaes-
thetise a patient that another would
not. It clarifies why critical incidences
can occur due to fatigue, distractions
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Anaesthesia, 2001, 56, pages 272±296
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others as a peripatetic trouble-shooter
[1]?
The dawn of a new century is an
I
would like to highlight several probability of significant ITU mortality.
important issues. As it was, all members of the `team' did
1 The number of extra staff required a good job without loss of life.
appropriate time to look at our to deal with the situation in a large
specially and to see how its role is intensive care unit/theatre complex was
J. Mitchell
Harefield Hospital,
Middlesex UB9 6JH, UK
changing within the broader pattern of significant,
notably
anaesthetists,
health care that is evolving in our anaesthetic support staff, perfusionists,
hospitals. If we can spot where it will and non-clinical backup from the
be in 10 years time, might it not be Estates Department. We were fortunate
even further from the original concept that the incident occurred in the middle
of the anaesthetist so beloved by the of a weekday with all staff immediately
surgeons. That was the `gasser' who available. It is important to establish
kept a steady stream of patients flowing quickly who is in charge from both a
through the operating theatre and did clinical and a non-clinical perspective so
Complete power failure 2
We were most interested to read the
letter concerning complete power
failure (Tye & Chamley. Anaesthesia
2000; 55: 1133±4), but were disap-
pointed that no reference was made to
uninterruptible power supplies (UPS).
These devices provide mains-level
voltage for a limited period of time
after complete power failure. Although
they are not new, only relatively
recently have Office Grade UPSs
been improved to Medical Grade
standards by reducing the earth leak-
age currents to allowable limits. Most
medical-grade UPSs are of the order
of 300 VA rated, which is calculated
by multiplying the mains voltage (V)
by the current consumption in amps
(A). In the UK, many monitors have a
VA rating of 240 V  1 A ˆ 240.
This would give a maximum run
time after power failure of 300/
240 ˆ 1.25 h.
nothing else.
that sensible decisions can be made
Anaesthesia has changed over the last quickly regarding treatment priorities
30 years and is going in new direc- and the potential need to evacuate the
tions. It is no surprise that the outside area.
world cannot grasp what we are all
about.
2 The hospital telephone exchange
had stopped working and there was
What's in a name? Well, the term no internal or external telephone
anaesthesia doesn't cover my work ± communication. Extensive use was
which is sad as I am rather fond of the made of personal mobile telephones
title anaesthetist.
(which of course had little opportu-
nity to interfere with medical equip-
ment).
W. Notcutt
James Paget Hospital,
Great Yarmouth NR31 6LA, UK
3 In common with the majority of
intensive care units in the UK, we
depend on electrically driven ventila-
tors. We had brought a number of gas-
driven ventilators of the minute
volume divider type (Blease Brompton
Manley) back into service to cover the
potential problems that had been pre-
dicted for the New Year, and these
were deployed during this incident. It
was notable that some of the more
junior intensive care nurses had not
seen such ventilators in use before.
Reference
1 Goldhill DR. Introducing the Post-
Operative Care Team. British Medical
Journal 1997; 314: 389.
For approximately £700, a 300 VA
rated device (and a little more for a
600 VA device) can be purchased
allowing uninterrupted monitoring of
the patient. A further device may be
required to power a ventilator.
Many hospitals test their generators
regularly, and this has to be done at
times of peak usage (i.e. during operat-
ing lists). The impact of momentary or
medium-term power failures can be
eliminated by UPSs and we believe
they should be available in all operating
theatre suites.
Complete power failure 1
I read with interest the letter (Tye & There were no problems with the
Chamley. Anaesthesia 2000; 55: 1133± pipeline supply of oxygen or air
4) describing their experience of a during this incident.
complete power failure as a result of
4 We were fortunate that this inci-
construction work. Such events are dent occurred in daylight hours. Some
fortunately rare but may occur with natural light was available in the ITU
no obvious precipitating factor. At and elsewhere. It was clear that it would
about midday on a weekday in the be very difficult to manage the situation
middle of January this year, there was a in the dark with only a handful of
total power failure at this hospital, torches.
W. J. Fawcett
H. Blowers
which affected the 18-bed adult inten-
5 The ambient temperature in some
sive care unit in particular. The cause areas rapidly fell to approach that out-
was found to be fatigue of an old side (which was about average for
component in the main switching January).
G. Wilson
Royal Surrey County Hospital,
Guildford GU2 7XX, UK
relay, which stopped both the mains
What was clear from this incident was
electrical supply and the backup gen- that had there really been a problem
erator supply to a large part of the with the much-hyped `millennium' bug
hospital. Looking back at the incident, we would have been struggling with the
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The Combitubew should be
redesigned for anaesthetic use
use. Anesthesia and Analgesia 2000; 90:
improvements to enhance its current
958±62.
use in anaesthesia:
1 The pharyngeal balloon is rather 5 ASA Task Force on Management of the
We read with great interest the article
(Hartmann et al. Anaesthesia 2000; 55:
670±5), in which the authors
described the use of the Combitube
(ETC) for gynaecological laparoscopy.
We are also finishing a similar study
in elective patients and we would like
to comment on ETC use in anaes-
thesia.
First, we congratulate the authors
because they have provided an alter-
native to tracheal intubation for this
type of surgery. In our country, airway
management for gynaecological laparo-
rigid and could produce pharyngeal
trauma, especially during prolonged
surgery. Shifting to a high-volume/
low-pressure balloon could solve this
problem.
2 The tube should be bent without
kinking its upper end.
3 A softer material for the tube
would be an advantage
According to a recent publication
which suggests that re-sterilisation is
possible [6], we re-use the ETC without
problems.
No other device provides good
ventilation, airway protection, allows
Difficult Airway. Practice Guidelines
for Management of the Difficult
Airway. A Report by the ASA Task
Force on Management of the Difficult
Airway. Anesthesiology 1993; 78: 597±
602.
6 Lipp M, Jaehnichen G, Golecki N,
Fecht G, Reichl R, Heeg P.
Microbiological, microstructure, and
material science examinations of
reprocessed Combitubes after multiple
reuse. Anesthesia and Analgesia 2000; 91:
693±7.
scopy remains
a challenge, mainly
because we consider that no other
device other than a tracheal tube can
be used. Although published experi-
ence using laryngeal mask airway for
gynaecological laparoscopy is available
[1], we prefer not to use it for this
type of surgery. We think that the
laryngeal mask airway does not pro-
vide reliable protection of the airway
against gastric content regurgitation in
patients undergoing gynaecological
laparoscopy. Wide variation in gastric
content volume among patients is an
important issue, especially when gas-
troesophageal reflux may not be clini-
cally apparent. Other considerations
are: high airway pressures may develop
during surgery and the laryngeal mask
airway may fail to provide adequate
ventilation under this condition, and
laryngeal mask airway fixation is not
reliable and displacements might
occur.
blind or laryngoscopic insertion, auto- Supplementary oxygenation
matic and reliable fixation, and is so
useful in the difficult airway. Thus,
we strongly encourage the manufac-
turers to develop a new special model
for anaesthesia use. Minor changes to
with the laryngeal mask
airway 1
We read with interest the paper on the
administration of oxygen via the laryn-
such a remarkable device would make geal mask airway in the recovery room
it more feasible for anaesthetic (Peyton et al. Anaesthesia 2000; 55:
situations.
992±9). Whilst congratulating them
on their excellent study in which they
directly compared the efficacy of a
number of oxygen delivery devices,
we would like to comment on a
number of issues that this study has
raised.
R. M. Urtubia
Mutual de Seguridad Hospital,
C.CH.C.,
Alameda 4848,
Santiago, Chile
J. Medina
We agree that end-tidal oximetry, as
first described by Myles and collea-
gues, is the optimum method of
measuring oxygen delivery in this
setting, since they have shown the
end-tidal oxygen concentration to
approximate closely to the alveolar
oxygen concentration [1]. However,
Peyton and colleagues were incorrect
to state that other studies did not use
this method since our description of
the breathing system filter or heat and
moisture exchanger as an oxygen
delivery device also used end-tidal
oximetry [2]. In our clinical study of
Padre Hurtado Hospital,
Esperanza 2150,
Santiago, Chile
References
1 Bapat PP, Verghese C. Laryngeal mask
airway and the incidence of
Second, similar to Hartmann et al.
and contrary to previous reports [2],
we have observed a very low incidence
of mild and transient postoperative
pharyngeal symptoms with the ETC
regurgitation during gynecological
laparoscopies. Anesthesia and Analgesia
1997; 85: 139±43
2 Oczenski W, Krenn H, Dahaba AA,
et al. Complications following the use
of the Combitube, tracheal tube and
37
F SA, either using blind or
laryngoscopical insertion techniques
[3, 4].
laryngeal mask airway. Anaesthesia 1999; 40 patients, we sampled gas from a
catheter positioned just above the
laryngeal opening of the laryngeal
Third, ETC is a reliable device in
managing failed intubations [5] in the
anaesthesia setting and is a feasible
device for elective patients. Thus, we
are including ETC in many more
elective surgical procedures, including
gynaecological laparoscopy. However,
we feel that ETC needs some
54: 1161±65
3 Urtubia RM, CaÂrcamo CR, Montes
JM. Complications following the use of mask airway, and not, as they implied,
the Combitube, tracheal tube and
at the filter's orifice. At an oxygen
laryngeal mask airway. Anaesthesia 2000; flow rate of 4 l.min21, we found an
55: 597.
4 Urtubia RM, Aguila CM, Cumsille
MA. Combitubew, A study for proper
end-tidal oxygen concentration of
36.2%, which is slightly greater than
was found in this paper (27.5%).
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They also stated that the achievement
of a high end-tidal oxygen concentra-
tion is important to patient safety.
Whilst this and other studies [3, 4]
have confirmed the superior perfor-
mance of the T-bag compared to other
devices, how much this improves
patient safety is debatable, as the
amount of time gained before desatura-
tion in the event of apnoea or airway
obstruction is likely to be minimal.
However, the T-bag does have the
advantage that movement of the
rebreathing bag confirms spontaneous
respiratory effort. We would also argue
that it is only necessary to provide
sufficient oxygen to maintain adequate
oxygen saturation in order to overcome
the effects of reduced functional residual
capacity, ventilation-perfusion mis-
match and diffusion hypoxia. In any
case, patient safety can only be assured
by continuous observation and
monitoring.
Whilst not wishing to be seen as
biased, the advantage of using breath-
ing system filters as oxygen delivery
devices is their convenience. In this
age where cost-effectiveness is an
important consideration, re-using the
filter (approximate cost £1.50) may
result in significant savings. In our
hospitals, T-pieces are used to provide
supplementary oxygen through the
laryngeal mask airway at an approx-
imate cost of £1.10 per patient (the
T-bag costs approximately £1.50).
However, it is also important to realise
that any adverse event that results from
the use of the filter as an oxygen
delivery device is the responsibility of
the anaesthetist concerned since this
contravenes the Medical Device
Directive regulations, as highlighted
by Wilkes & Vaughan [5]. Whether
any manufacturer would wish to
obtain approval for their filters to be
used in this way remains to be seen,
since the cost incurred would be
significant.
bound to mention is that of product
liability regulations. It should be noted
that anaesthetic circuit filters are not
covered by product liability regulations
for use as routes of oxygen supple-
mentation as described in the paper by
Peyton et al. The Consumer Protection
Act sees this as a modification to a
piece of equipment and that the
`designing' anaesthetist takes on the
entire responsibility for the work done
and any consequences [4]. By advertis-
ing your idea to colleagues in other
hospitals, you become a manufacturer
and the full rigour of regulations might
apply. The Medical Devices Regulations
that regulates every aspect of medical
equipment development became law in
January 1995 and was implemented in
June 1998 [5].
References
1 Myles PS, Heap M, Langley M.
Agreement between end±tidal oxygen
concentration and the alveolar gas
equation, pre±and post
cardiopulmonary bypass. Anaesthesia
and Intensive Care 1993; 21: 240.
2 Orme RML'E, Williams M.
Supplementary oxygen and the
laryngeal mask airway ± evaluation of a
heat±and±moisture exchanger.
Anaesthesia and Intensive Care 1999; 27:
509±11.
3 Martin J, Brimacombe JR. Oxygen
enrichment during emergence with
the laryngeal mask, the `T±bag' versus
the T±piece. Anaesthesia 1997; 52:
1195±8.
4 Poh J, Brimacombe J. A comparison of
the T±piece, Venturi T±piece and T±
bag for emergence with the laryngeal
mask. Anaesthesia and Intensive Care
1998; 26: 526±8.
W A. Marchant
The Middlesex Hospital,
London, UK
5 Wilkes AR, Vaughan RS. The use of
breathing system filters as oxygen±
delivery devices. Anaesthesia 1999; 54:
552±8.
I. Calder
The Royal Free Hospital,
Hampstead, London, UK
References
1 Newton NI. Supplementary oxygen ±
potential for disaster. Anaesthesia 1991; 46:
905±6.
Supplementary oxygen with the
laryngeal mask airway 2
We read with interest the article on
oxygen supplementation with the lar-
yngeal mask airway, comparing four
devices (Peyton et al. Anaesthesia 2000;
55: 992±9), and congratulate them on
this study.
2 Newton NI, Adams AP. Excessive
airway pressure during anaesthesia.
Anaesthesia 1978; 33; 689±9.
3 Brimacombe J, Berry A. Barotrauma
and the laryngeal mask airway.
Anaesthesia 1994; 49: 1009.
We feel that it would be worth 4 Grant LJ. Regulations and safety in
raising two small points. Firstly, the
potential for barotrauma when
medical equipment design. Anaesthesia
1998; 53: 1±3
facemask or circuit filter is used to 5 Anon. Medical Device Regulations 1994
a
administer oxygen through a laryngeal
mask airway in an anaesthetised
patient should the filter or facemask
(SI 1994 no. 3017). 1994.
become obstructed. This theoretical The self-regulating bag
risk has been raised previously [1, 2],
although there have been no reports At the end of a neurosurgical case, I
of barotrauma during anaesthesia with had deepened anaesthesia and was
the laryngeal mask airway. This is allowing the patient to breathe spon-
thought to be due to the low- taneously prior to extubation. The
pressure seal, formed by the laryngeal patient was breathing through a long
mask airway and periglottic tissues extension attached to a circle breath-
protecting the patient from baro- ing system. The reservoir bag was
R. M. L'E Orme
Kettering General Hospital,
Kettering NN16 8UZ, UK
M. Williams
Queen Alexandra Hospital,
Portsmouth PO6 3LY, UK.
trauma [3]. placed on top of the soda lime
The second point that we feel canister, in a position to allow easy
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................................................................................................................................................................................................................................................
visual and tactile confirmation of
spontaneous
respiration
(Fig. 1).
Respiration was smooth, but I had
to re-open the APL valve several
times as the bag kept becoming
`tight' despite a low fresh gas flow;
the valve was fully opened and no-
one else was interfering with it. On
close inspection, I readily discovered
the cause of the problem ± the bag
itself was lying right next to the APL
valve and with each inflation the
movement of the bag rubbed against
the valve and turned it in a clockwise
direction (Fig. 1). This led to
a
stepwise increase in end-expiratory
pressure, and eventually closed the
valve off completely. No harm
occurred to the patient. This is yet
another example of why the anaes-
thetist must be attentive to detail at
all times, especially at the busy period
at the end of an operation.
Figure 1
N. Smith
The National Hospital for Neurology
and Neurosurgery,
London WC1N 3BG, UK
E-mail: nataliesmith@btinternet.com
A new device to facilitate
awake oral fibreoptic
intubation
of cuff are not in the barrel (Fig. 2).
This simulates the position of a tracheal
tube cuff that is not fully through the
glottis. With successive 10-ml incre-
ments of air, the cuff can be seen
herniating out of the barrel of the
syringe, simulating herniation of the
cuff through the glottis (Fig. 3 with
20 ml of air in the cuff; Fig. 4 with
30 ml of air).
Our experience suggests that where
there are persistent cuff leaks, the
possibility of cuff herniation should be
considered. Early laryngoscopy allows
re-positioning of the tube or re-intuba-
tion if herniation of the cuff is
occurring.
We wrote to Portex to ask whether
cuff herniation had been reported to
them previously and were informed that
it had not, although more than 1
million Soft-Seale tubes have been
sold. Despite an absence of reports,
however, we suggest that cuff herniation
is a relatively common problem in
clinical use and we hope that our
letter draws attention to it.
Fibreoptic-guided, orotracheal intuba-
tion is facilitated by use of airway aids
such as the Ovassapian [1], Berman
[2] and Bronchoscope intubating air-
ways. These devices help to keep the
tip of the fibrescope in the midline
and act as a conduit for guiding it
towards the larynx. They are also
useful for awake, oral fibreoptic
intubation where they have the addi-
tional advantage of acting as a bite
block to prevent damage to the
fibrescope [3]. They may, however,
provoke coughing, retching and
vomiting in the awake patient when
fully inserted in the mouth, especially
when the gag reflex is not fully
obtunded. We wish to report the
use of a device called `Safe Bite'e
(AMS Ltd Milton Keynes, UK) for
use as an airway aid for oral fibreoptic
intubation. This device has recently
been introduced for preventing
damage to laryngeal mask airways in
patients recovering from general
anaesthesia.
Herniation of tracheal tube
cuffs: a simple teaching model
Herniation of tracheal tube cuffs
through the glottis seems to be occur-
ring with increasing frequency in inten-
sive care; we have seen it on at least five
occasions in the last year.
Typically, a leak is noticed when a
tracheal tube with a large-volume, low-
pressure cuff is being used. Usually,
more air is injected into the cuff and the
leak stops for a short time. With a
recurrence of the leak, more air is
injected and eventually it becomes
clear that the cuff has herniated upwards
through the glottis and re-intubation
becomes necessary.
A simple teaching model demon-
strates convincingly what happens and
suggests how the problem can be
avoided or managed. A tracheal tube
with a large-volume, low-pressure cuff
(such as the Portex Soft-Seale) is
placed in the empty barrel of a 20-ml
syringe so that the proximal 3±4 mm
D. Wright
M. Baruch
Western General Hospital,
Edinburgh EH4 2XU, UK
A 51-year-old female patient was
schedule for a right total maxillectomy
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Anaesthesia, 2001, 56, pages 272±296
................................................................................................................................................................................................................................................
Figure 3
Figure 2
Figure 4
advantage of a reduced size (Fig. 5).
This prevents it from touching the
sensitive areas of the back of the throat
and prevents gagging. Indeed, it is easily
tolerated without local anaesthesia, as is
seen in Fig. 6 with one of us (J.O.C.)
demonstrating it. Our patient under-
went two further awake oral fibreoptic
intubations with the technique
described.
for excision of a non-Hodgkin lym- tracheal intubating fibrescope was
phoma that had been treated unsuc- then inserted through the `Safe Bit'
cessfully with radio and chemotherapy. and directed in the midline towards the
She was predicted to have difficult epiglottis. Further topical anaesthesia to
laryngoscopy due to limited mouth the supraglottic and infraglottic regions
opening and a Mallampati grade 3 was achieved with the `spray as you
airway. An awake, oral fibreoptic go' technique through the working
intubation was therefore planned. channel of the fibrescope with 1.5-ml
After a full explanation of the proce- boluses of lidocaine 4%. Once the tip
dure the night before the operation, of the fibrescope entered the trachea, a
she was premedicated with morphine 6.5-mm ID preformed oral RAE tube
10 mg and scopolamine 0.2 mg intra- was successfully railroaded over the
muscularly 1 h before the intubation insertion cord of the fibrescope, its
was performed. Lidocaine 4% 4 ml position checked fibreoptically and
was sprayed into the back of her with end-tidal carbon dioxide mon-
throat to numb her tongue and itoring. The patient was anaesthetised
oropharynx. She then received mid- and paralysed and the `Safe Bite' was
azolam 1 mg and a target-controlled then peeled from the tracheal tube,
infusion of propofol 1% aiming for a which was then secured.
J. Otero-Carrasco
K. Moaz
M. T. Popat
The John Radcliffe Hospital,
Oxford OX3 9DU, UK
References
concentration of 1 mg.ml21. A `Safe
The `Safe Bite' can be opened from
1 Ovassapian A. A new fibreoptic
intubating airway. Anesthesia and
Analgesia 1987; 66 (Suppl.): S132:
32.
Bite' was inserted into her mouth and the side and peeled back from the
she tolerated this without gagging fibrescope and the tracheal tube just
or vomiting. An Olympuse LF-2 like a Berman airway, but has the
278
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................................................................................................................................................................................................................................................
2 Smith JE, Mackenzie AA, Scott Knight
VCE. Comparison of two methods of
fibrescope guided tracheal intubation.
British Journal of Anaesthesia 1991; 66:
546±50.
3 Popat MT, Chippa JH, Russell R.
Awake fibreoptic intubation following
failed regional anaesthesia for Caesarean
section in a parturient with Still's
disease. European Journal of
Anaesthesiology 2000; 17: 211±14.
Transparent obstruction of RAE
tube
A
12-kg, 23-month-old child was
scheduled for tonsillectomy and ade-
noidectomy on a routine ENT list. He
had a history of partial respiratory
obstruction but no sleep apnoea. In
the anaesthetic room with his mother,
he appeared relaxed following an oral
premed of midazolam 6 mg. After one
failure to cannulate his rather mobile
veins, he was induced with sevoflur-
ane. A guedel airway was needed
while he was deepened, then a 22-g
cannula was inserted in his right foot.
His trachea was intubated with a 4.5-
mm RAE tracheal tube, which had
been taken from a fresh packet and
lubricated with KY jelly.
Figure 5
continued uneventfully breathing iso- either of blood or another foreign
flurane on a T-piece.
Because his adenoids were so large,
no tonsillectomy was done, but he still further examination and the lot
oozed a little in recovery and needed number noted. The obstruction was a
some manual ventilation with a face- very flexible clear membrane that
mask. He was closely observed post- blocked the whole lumen. It was
operatively for signs of any inhalation, quite tough, but after showing it to a
body, but he recovered well.
The tracheal tube was retained for
At this point, he became impossible
to ventilate. The intubation had been
straightforward and so the tube was
withdrawn in case of malposition.
After manual ventilation, he was
again intubated and the same thing
occurred except that a small amount
of gas could be passed using higher
inflation pressures. There was no
audible wheeze or cutaneous signs of
a reaction. The obstruction was so
obviously related to the intubation
that it was decided to extubate him
again, and on much closer inspection
of the tube a small clear foreign body
was seen in the lumen. Figure 7 shows
the whole tube and Fig. 8 shows the
obstructed section magnified with
and without KY lubricant. It was
very easy to confuse the obstruction
with surface lubricant. Another packet
was opened and the next RAE tube
worked perfectly and the anaesthetic Figure 6
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Anaesthesia, 2001, 56, pages 272±296
................................................................................................................................................................................................................................................
product is subsequently packed on a
Multivac machine, which seals top and
bottom webs of the pack by a heat
process. It is important to note that
there is no glue involved at this stage
either.
When we received the sample in
February of this year there was no
indication on the Complaint Report
that
a
lubricant had been used;
however, in the above letter it is
reported that KY jelly had been used.
We sent KY jelly to an outside test
house for testing and a comparison was
made between it and the contaminant
found in the original RAE Tracheal
Tube (Complaint Sample). The con-
clusion from the independent test
house revealed that: `Both samples
were very similar and can be said to
originate probably from a similar
source' (i.e. ± they are both hydrogels).
Figure 7 Whole RAE tube after cleaning, showing the obstruction at 8 cm.
number of colleagues, who bent and
moved the tube, it became looser,
though it was not removed. As no
harm had come to the patient, the
Medical Devices Agency recom-
mended sending the tube back to
the manufacturers, Mallinkrodt, for
examination.
In due course, the report from
Mallinkrodt stated that the sticky sub-
stance was alcohol based and was not
used anywhere in their manufacturing
process. The implication was that it may
have been introduced locally. As far as
we are concerned, this was impossible as
the tube had been taken out of fresh
packet and only come into contact with
KY lubricant, which contains no alco-
hol. It looked more like a lump of glue,
which might have been used to seal the
packets.
R. Tackley
Torbay Hospital,
Torquay TQ2 7AA, UK
Reference
1 Foreman MJ, Moyes DG. Anaesthetic
breathing circuit obstruction due to
blockage of the tracheal tube connector
by a foreign body. Anaesthesia and
Intensive Care 1999; 27 : 73±5.
A reply
The reported complaint described an
incident whereby the RAE Tracheal
tube had an obstruction down the
main lumen causing problems when
ventilating the patient. In the above
letter regarding this issue, the complai-
nant stated that the contaminant
`looked more like a lump of glue
which might have been used to seal
the packets'. An extensive examination
was carried out on the returned
sample. The substance that was
obstructing the lumen was found to
be tacky and thick in nature. This
substance is foreign to our production
process. Uncuffed tracheal tubes do not
come in contact with any glue-related
substance, as there is no bonding
required in their manufacture. The
No similar case has been reported in
spite of 46 000 similar tubes being sold
in the UK.
We are all aware of possible foreign
bodies in tracheal tubes, and one of
the advantages of transparent breath-
ing circuits is meant to be the easier
identification of obstructions [1]. This
episode should draw attention to the
extra care needed to identify trans-
parent foreign bodies in reusable
tubes.
Figure 8 (a) Magnified section without
lubricant; (b) with lubricant.
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................................................................................................................................................................................................................................................
From the analysis it would seem likely Because ambient pressure oxygenation atypical oxygenated shunt situation.
that the contaminant involved in this of the non-ventilated lung inevitably This will result in a small further
complaint was a lubricant, e.g. KY delays hypoxic pulmonary vasocon- increase in the already relatively large
Jelly.
striction (HPV), pulmonary blood arterial to end-tidal CO2 gradient that
On our Instructions For Use we flow through the lung is maintained is seen during thoracic surgery [4].
supply with this product it states under and the tidal gas movement will result Therefore, in clinical situations where
the `Warning Precautions (General)' in either CO2 re-breathing (in
a
there is a delay in the lung collapsing
section, that if the tracheal tube is `closed' reservoir-bag system) or some away from the chest wall [2, 5], an
lubricated prior to intubation, it is CO2 elimination (in an `open' T-piece arterial blood gas measurement may be
essential to verify that lubricant does system). Recorded examples of both required to guide the level of minute
not enter and occlude the tube lumen, CO2 re-breathing and elimination, volume ventilation. In theory, the small
thereby preventing ventilation.
from two patients prior to thoraco- increase in gradient will be marginally
We would like to highlight that scopic surgery, are given in Fig. 9. Gas greater with a `re-breathing' system
fact that this is the first complaint of sampling ports were sited on the than with an `open, non-rebreathing'
this nature that we have ever received respective double-lumen tube (DLT) system.
with this product having marketed connectors, and tidal CO2 and tidal O2
For anaesthetists who might be con-
and distributed the RAE range of (shown as percentages) were recorded sidering using a reservoir-bag system
products for the past 15 years in via a single gas sampling line that was without the added safety of an incor-
Europe.
switched alternately from the ventilated porated in-let valve [1], of much greater
to the non-ventilated lung. importance is the need to ensure that
In Patient A, an ambient pressure thoracoscopic access ports are not air-
oxygen reservoir-bag was attached to tight when surgical suction is being used
the non-ventilated lung and the tidal [2].
Mallinckrodt Medical
Cornamaddy, Athlone,
Co. Westmeath, Ireland
CO2% recorded from this lung
Finally, it is worth noting that once
increased progressively as the partial the lung has collapsed, very likely to the
pressure of CO2 in the reservoir-bag point at which small airways closure
approached that of the mixed venous occurs, the need for ambient pressure
blood. At the same time, the tidal O2% oxygenation no longer exists. This
fell progressively as the partial pressure belief is based in part on the observation
of N2O in the reservoir-bag also that once the thoracic cavity is opened
approached that of the mixed venous to ambient air, and in the absence of
blood. In Patient B, the non-ventilated pleural adhesions, air-flow obstruction
lung was opened to air and the tidal or emphysema, the reservoir-bag is seen
O2% recorded from this lung fell to expand over 30±60 s as the lung
rapidly towards the percentage present collapses down due to its inherent
in the ambient air, while the tracing of elastic recoil. Then, unlike the situation
tidal CO2% was similar to the end-tidal before the thoracic cavity is opened,
CO2 tracing recorded from the venti- there is no noticeable progressive reduc-
lated lung. Thus, when a clamped-off tion with time in the volume of gas in
DLT connector to a non-dependent the reservoir-bag. Thus, most or all
lung is detached from the DLT itself further collapse of the non-ventilated
before the thoracic cavity is opened, lung is a consequence of ongoing
some on-going CO2 elimination from gaseous uptake from within the lung
that lung will result. This small com- (absorption atelectasis). In spite of this,
ponent of CO2 elimination is likely to we still choose to leave the reservoir-bag
be greater when using ambient pressure attached while surgery is proceeding.
oxygenation, because, as already stated, We do this not in the belief that it will
HPV is delayed and pulmonary blood further prevent the entrainment of air
flow through the expanded, non-ven- and therefore nitrogen into the non-
Administering ambient
pressure oxygenation to the
non-ventilated lung during
thoracoscopic surgery
We are pleased to see that Baraka et al.
have embraced the concept of attach-
ing an ambient pressure oxygen source
to the non-ventilated lung during
thoracoscopic surgery (Baraka et al.
Anaesthesia 2000; 55: 602±3). The
Mapleson
E system oxygen source
they describe, which utilises a 10-
l.min21 oxygen supply, a T-piece and
a length of wide-bore tubing, has
obvious merit. It will achieve the
desired exclusion of ambient air and
therefore nitrogen from the non-venti-
lated lung. Second, being an `open' T-
piece system rather than a possibly
`closed' [1] reservoir-bag system [2], it
will not carry the potential risk of
negative pressure lung damage in the
event that surgical suction is applied
during thoracoscopic surgery being
performed using airtight access ports
[2]. Third, the 10-l.min21 oxygen flow
will eliminate `re-breathing' of the tidal
gas movement that occurs out of and
back into the non-ventilated lung
before the chest is opened and before
the lung can collapse down [3].
tilated lung is therefore maintained.
ventilated lung, but rather to enable
For those anaesthetists wishing to immediate identification of any leakage
experience the several practical clinical of ventilating gases past the DLT
advantages of using an oxygen reser- bronchial cuff. Gas leakage past the
voir-bag system [2], we advise that bronchial cuff is seen when surgical
until the non-ventilated lung is able to traction on the lung or bronchus
collapse down, ambient pressure oxy- threatens to dislodge the DLT from
genation via this lung creates an the relevant main bronchus. Complete
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Anaesthesia, 2001, 56, pages 272±296
................................................................................................................................................................................................................................................
Figure 9 Tidal O2 and CO2 concentra-
tions (percentages) recorded from the
ventilated and non-ventilated lungs of
two patients, one (Patient A) with an
ambient pressure O2 reservoir connected
to the non-ventilated lung and the other
(Patient B) with the non-ventilated lung
opened to air. 1. Airway connector to
non-dependent lung clamped-off at end-
expiration, so initiating single-lung ven-
tilation. 2. A second clamp placed across
the DLT lumen itself, so isolating the
non-ventilated lung. 3. (In Patient A
only) Ambient pressure O2 reservoir
connected to the still-isolated (clamped-
off) non-ventilated lung. 4. (In Patient A
only) Gas sampling line switched from
the ventilated lung to the O2 reservoir. 5.
(In Patient A only) Clamp removed from
the DLT, so connecting the non-venti-
lated lung with the O2 reservoir. 6. Gas
sampling switched from the non-venti-
lated to the ventilated lung. 7. Gas
sampling switched from the ventilated
to the non-ventilated lung. 8. (In Patient
B only) Period of gas sampling from the
non-ventilated lung that is not yet
opened to air. 9. (In Patient B only)
DLT lumen to the non-ventilated lung
clamped-off and the DLT connector
detached, so opening gas sampling to
ambient air. 10. (In Patient B only)
Clamp removed from the DLT, so
connecting the non-ventilated lung to
the ambient air.
on the ambient pressure oxygen
reservoir. Anaesthesia 1999; 54: 1023±4.
2 Pfitzner J, Peacock MJ, Daniels BW.
Ambient pressure oxygen reservoir
apparatus for use during one±lung
anaesthesia. Anaesthesia 1999; 54: 454±
8.
Snowdon SL, Russell GN. Variation in
the arterial to end±tidal PCO2
difference during one±lung anaesthesia.
British Journal of Anaesthesia 1994; 72:
21±4.
dislodgement in the course of thoracic
surgery, although rarely reported, is well
recognised and certainly best avoided.
J. Pfitzner
M. J. Peacock
B. W. Daniels
The Queen Elizabeth Hospital,
Adelaide, South Australia 5011
5 Pfitzner J, Peacock MJ, Tsirgiotis E,
Walkley IH. Lobectomy for cavitating
lung abscess with haemoptysis, strategy
for protecting the contralateral lung and
also the non±involved lobe of the
ipsilateral lung. British Journal of
3 Pfitzner J, Peacock MJ, McAleer PT.
Gas movement in the non±ventilated
lung at the onset of single±lung
ventilation for video±assisted
thoracoscopy. Anaesthesia 1999; 54:
437±43.
References
1 Pfitzner J, Carne HD, Taylor EC. One±
lung anaesthesia, response to questions
4 Ip Yam PC, Innes PA, Jackson M,
Anaesthesia 2000; 85: 791±4.
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................................................................................................................................................................................................................................................
Light wand guided tracheal
intubation through the
intubating laryngeal mask
incidence of oesophageal intubation in concept of a probable cause and best
the ILM-LW group was zero. We correction tactic, whereas ours is based
wonder if this frequency concerns the on the concept of starting with simple
first intubating attempt or the final manoeuvres and avoiding size changes.
We read with interest the article
comparing blind (BL) and lightwand-
guided (LW) tracheal intubation
through the intubating laryngeal mask
(ILM) (Kihara et al. Anaesthesia 2000;
55: 427±31). According to their
results, the authors report that the
ILM-LW intubating technique is
superior to the ILM-BL technique,
since it improves the success rate (100%
vs. 93%) and diminishes either the
number of adjusting manoeuvres
required or the duration of the intu-
bating procedure.
These results are in agreement with
those reported in a similar randomised,
double cross over comparative study [1],
using a prototype flexible lightwand
(FLW) [2]. However, Kihara et al. do
not clarify whether in the ILM-LW
group the lateral glow misplacement
and/or the absence of glow in the neck
was followed by specific LW adjusting
manoeuvres, or did they apply the same
sequence of BL adjusting manoeuvres as
in the ILM-BL group. Additionally, we
would like to ask whether the intuba-
tion time reported included not only
the time for successful intubation but
also the time required for proper ILM
placement.
outcome.
Both these concepts have some merit.
A comparative study is required to
determine which of these concepts/
manoeuvring sequences, if any, is best.
Second, `insertion time' was from
commencement of insertion of the
ILM to capnographic confirmation of
tracheal intubation. If insertion failed,
the time was excluded from the
analysis of insertion time. Finally, the
0% incidence of oesophageal intuba-
tion in the lightwand group refers to
the final outcome. Some initial oeso-
phageal intubation events may have
gone unrecorded since we only con-
nected the anaesthesia circuit when the
light glow was seen at the sternal notch
and tracheal placement likely. Interest-
ingly, on all occasions when the light
glow was seen at the sternal notch,
tracheal intubation was subsequently
confirmed, suggesting that this is a
reliable sign for successful tracheal
intubation with the lightwand/ILM
technique.
V. Dimitriou
G. S.Voyagis
Gennimatas and Sotiria Hospitals,
Athens, Greece
References
1 Dimitriou V, Voyagis GS. Light-guided
tracheal intubation using a prototype
illuminated flexible catheter through
the intubating laryngeal mask. European
Journal of Anaesthesiology 1999; 16: 448±
53.
2 Dimitriou V, Voyagis GS. Use of a
prototype flexible lighted catheter for
guided tracheal intubation through
the intubating laryngeal mask.
Anesthesia and Analgesia 1999; 89:
257±8.
3 Dimitriou V, Voyagis GS. Light-
guided intubation via the intubating
laryngeal mask using a prototype
illuminated flexible catheter. Clinical
experience in 400 patients. Acta
Anaesthesiologica Scandinavica 2000; 44:
1002±6.
S. Kihara
S. Watanabe
Saiseikai General Hospital,
3 3-10 Futabadai, Mito,
Ibaraki 311-4198, Japan
A reply
In a recent study [3], the ILM-LW
intubating method was performed in
a larger series of patients (n ˆ 400).
We found that the success rate was
independent of factors usually predict-
ing difficult laryngopscopy, since this
was similar in patients with either
normal (372/373, 99.7%) or poten-
tially difficult airways (27/27, 100%)
[3]. Absence of glow in the neck was
noticed during the first intubating
attempt in 19 of 400 patients
(4.8%). In all these cases, accidental
oesophageal intubation occurred and
it was confirmed by capnography.
However, 18 of 19 patients were
finally intubated successfully during
the second or third intubating
attempt, resulting in a final incidence
of persistent oesophageal intubation of
1/400 (0.25%). In the paper of Kihara
and colleagues, it is reported that the
J. Brimacombe
We thank Drs Dimitriou and Voyagis
for their valuable comments concern-
ing our paper comparing intubation
through the intubating laryngeal mask
airway (ILM) with and without a
lightwand. We will respond to each
of their questions in turn.
University of Queensland,
Cairns Base Hospital,
The Esplanade,
Cairns 4870, Australia
Reference
lateral neck and/or was absent, we 1 Dimitriou V, Voyagis GS. Light-guided
First, if the light glow was seen in the
performed manoeuvres that were iden-
tical to the blind intubation group. For
example, if a glow was seen initially in
the lateral neck, we performed an
extension manoeuvre (Dimitriou and
Voyagis would have performed a twist-
intubation via the intubating laryngeal
mask using a prototype illuminated
catheter. Acta Anaesthesiologica
Scandanavica 2000; 44: 1002±6.
ing manoeuvre [1]). If this occurred a Full circle
second time, we performed an `up±
down' manoeuvre (Dimitriou and I was interested to read the letter
Voyagis would have performed another `Iatrogenic foreign body in the
twisting manoeuvre [1]). The sequence bronchus' (Dutta et al. Anaesthesia
of adjusting manoeuvres proposed by 2000; 55: 1036±7), and was reminded
Voyagis and Dimitriou is based on the of a similar occurrence that I reported
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................................................................................................................................................................................................................................................
in 1967 [1]. This involved the loss at there might be an underlying malig- chest X-ray as well as antero-posterior
laryngoscopy, into the oesophagus and nancy. She was therefore listed for and lateral neck views performed before
subsequently to the colon, of the urgent admission and surgery. The admission.
complete metal nozzle from a spray consultant gynaecologist concerned
I met the patient the following week
bottle of lidocaine. As a result of this discussed the case with me as the on the morning of surgery. She
mishap, the makers modified their intended anaesthetist during the appeared fit and well and weighed
spray by having the nozzle perma- course of a routine list. He was anxious 80 kg. She had an obvious goitre, but
nently fixed to the actuator valve.
that she be operated on the following clinically appeared euthyroid, and
In the same report, I also referred to week in view of the possible malig- indeed had no symptoms of oesopha-
another incident involving the use of a nancy. During the discussion, I learned geal or tracheal obstruction. Examina-
Rogers laryngeal spray a year earlier [2], that she was also due to undergo a total tion of her head and neck revealed
and to my personal experience of losing thyroidectomy in the near future for a normal dentition, a slightly receding
the atomiser button of a Macintosh multinodular goitre. Correspondence mandible, and a Mallampati grade 2
laryngeal spray into the depths of the in her case notes confirmed this and airway. It therefore came as a surprise
bronchial tree.
Whilst it is somewhat disappoint- mechanical obstruction. Otherwise she cervical spine X-rays. The AP film
ing to learn that similar problems was `fit and well'. revealed some suprasternal narrowing
can, and still do, occur over 30 years For a variety of reasons it was not of the trachea with deviation to the
indicated that she had no symptoms of to discover the appearances of her
later, it is perhaps not all that possible to arrange to see the patient right (Fig. 10). The lateral view, how-
surprising given that most things within the time frame proposed. We ever, showed marked anterior deviation
come round full circle if you wait agreed that she would be admitted onto of the pharynx and trachea with
long enough!
the ward on the day of surgery (as is the extensive soft tissue shadowing poster-
norm), but that she should have a plain ior to the larynx and trachea (Fig. 11).
J. G. Francis
Exeter EX3 0QT, UK
References
1 Francis JG. A wandering spray nozzle.
British Journal of Anaesthesia 1967; 1:
813.
2 Bowen RA. Hazard of anaesthesia.
British Medical Journal 1966; 1: 862.
Anterior deviation of the
trachea
I was interested to read the recent
letter concerning difficult intubation in
a patient with a tracheal diverticulum
and 908 deviation of the trachea
(Davies. Anaesthesia 2000; 55: 923±5).
The author states that he could find no
previous reports in the literature of
such marked tracheal deviation.
I
would like to add to the literature by
reporting a case with which I was
recently involved.
A 49-year-old woman with menor-
rhagia had been referred by her GP to
one of our gynaecologists for further
investigation and management. On
examination, a large pelvic mass was
discovered, and although ultrasound
scan suggested that the mass was due
to fibroids, there was concern that
Figure 10
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Because it is our policy not to under-
take difficult or high-risk patients in
our isolated gynaecology unit, we
decided not to proceed with the case
that day. She was rebooked to have her
operation two weeks later, an awake
fibre-optic intubation being the obvious
choice for airway management.
In the meantime, she had an MRI
scan of her neck performed, which
revealed that the tracheal deviation was
due to thyroid tissue extending behind
the pharynx, larynx and upper part of
the oesophagus, with associated nar-
rowing of the trachea (Fig. 12). There
was some discussion between the
gynaecology and surgical teams regard-
ing which operation should be per-
formed first. It was even proposed that
the two should be performed at the
same time, since it was suggested that
instrumentation of such a distorted
airway could cause postextubation dif-
ficulties if the gynaecological surgery
was undertaken alone. In the end,
however, she underwent hysterectomy
and bilateral salpingo-oophorectomy,
and histology revealed only benign
disease. Intubation was achieved with
a 6-mm reinforced tracheal tube using
Figure 11
an awake fibre-optic technique. Sur-
gery and anaesthesia were both
uneventful, and the patient made a
problem-free recovery. At the time of
writing, she is awaiting her total
thyroidectomy.
I also have been unable to find any
previous reports of marked anterior
deviation of the larynx and trachea. In
addition, I have been unable to find any
literature about retro-tracheal spread of
thyroid tissue, although retrosternal,
spread and total intrathoracic thyroid is
well recognised, as is ectopic retro-
tracheal [1] and intratracheal [2] thyroid
tissue.
The airway management of this case
was fairly straightforward, armed with
the X-ray information, but it serves to
remind that patients with major airway
distortion can still be symptom-free.
Appropriate pre-operative investigation
is required for all patients presenting
for thyroid surgery to ensure that
airway management presents no
unpleasant surprises in the anaesthetic
room.
Figure 12
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Anaesthesia, 2001, 56, pages 272±296
................................................................................................................................................................................................................................................
2 Kock HJ, Pietsch M, Krause U, Wilke
H, Eigler FW. Implanted vascular access
systems, Experience in 1500 patients
with totally implanted central venous
access port systems. World Journal of
Surgery 1998; 22: 12±16.
I. J. Crabb
Gloucestershire Royal NHS Trust,
Gloucester GL1 3NN, UK
References
1 Salvatori M, Rufini V, Corsello SM et al.
Thyrotoxicosis due to ectopic
3 Van der Hem KG, Meijer S, Werter CJ,
Van Groeningen CJ. Spontaneous
catheter fracture and embolisation of a
totally implanted venous access port.
Netherlands Journal of Medicine 1991; 38:
262±4
retrotracheal adenoma treated with
radioiodine. Journal of Nuclear Biology and
Medicine 1993; 37: 69±72.
2 Myers EN, Pantangco IP. Intratracheal
thyroid. Laryngoscope 1975; 85: 1833±40.
Aortic cross-clamping in sickle
cell disease
Mishaps with a central venous
cannula in the ICU
We read with interest the correspon-
dence on the emergency repair of a
large tender abdominal aortic aneurysm
in a patient with sickle cell trait (Heames
& Vincent. Anaesthesia 2000; 55: 1034).
We, too, recently anaesthetised a patient
with sickle cell disease for a procedure
requiring aortic cross-clamping.
We wish to report an unusual case of
disconnection from a central venous
cannula (CVC) in a patient on the
intensive care unit (ICU). A 66-year-
old man had been transferred from the
Figure 13
decided to leave the CVC in for 2 h to
allow the clotting to normalise whilst
nursing the patient supine. His condi-
tion remained stable throughout and he
went on to be discharged back to the
satellite hospital.
high-dependency area in
a satellite
hospital to our ICU for further manage-
ment of respiratory failure secondary
to fluid overload due to congestive
cardiac failure (CCF) after a myocardial
infarction 6 weeks previously.
Our case was slightly different in
that it was a 68-year-old woman with
haemoglobin SC disease (HbSC dis-
ease) who presented for coronary
artery bypass graft surgery. Like the
authors, we found very little published
literature on major vascular surgery in
patients with sickle cell disease, and
none at all on coronary artery bypass
grafting in sickle cell disease, although
there was some on cardiac valve
replacement in this patient population.
Although patients with HbSC disease
have a milder clinical course than those
with homozygous haemoglobin S dis-
ease (HbSS disease), with symptoms
occurring later [1] and a longer median
survival [2], we, too, were concerned
about the potential problems of cardio-
pulmonary bypass and vascular stasis.
After reviewing the available litera-
ture, and having prolonged discussions
with our haematologists, we decided
on a management strategy for this
patient. She was exchange transfused
This case highlights the need to be
vigilant to the possible hazards that
may occur with multilumen CVCs
and the various risks that we need to
consider whilst utilizing them on the
ICU. A literature search reveals no
previous reports of similar mechanical
failure during the short-term use of
CVCs, although there are reports of
fractures in the long-term use of
implanted subcutaneous central venous
catheters [1±3]. The exact nature of the
mechanical failure is being investigated
by the manufacturer; the results of
this investigation will allow a more
thorough risk assessment.
The CCF had worsened when his
cardiac rhythm changed to an atrial
flutter tacchyarryhthmia. With manage-
ment including intubation and ven-
tilation, diuresis, anticoagulation and
cardioversion, his condition began to
improve. A trans-thoracic echocardio-
gram was performed to assess left
ventricular function and for the pre-
sence of thrombus. On confirmation of
the absence of intracardiac thrombus,
M.W. went to instruct the patient's
nurse to discontinue the intravenous
heparin infusion. On entering the
cubicle, it was noted that a streak of
fresh blood was dripping down the
patient's chest. On further investigation,
it was found that the medial `pigtail' of
the four lumens to the right subclavian
venous CVC (Arrow 8.5F 20 cm anti-
biotic-coated quad-lumen CVC) had
become disconnected/unplugged from
the base where the four lumens come
together (Fig. 13). The patient was
immediately laid head down whilst the
heparin infusion was stopped and the
faulty lumen was occluded to prevent
entrainment of air. On balance, it was
M. Williams
B. Siggers
Queen Alexandra Hospital,
Portsmouth PO6 3LY, UK
(to a total haemoglobin of 10.1 g.dl21
,
and HbA of 61%) pre-operatively and
kept well hydrated. During anaesthe-
sia, the inspired fractional concentra-
tion of oxygen was maintained at 0.5.
Normothermia was maintained whilst
on cardiopulmonary bypass, and an
References
1 Vadlamani P, Dawn B, Berry MC.
Catheter fracture and embolisation
from totally implanted venous access
ports. Angiology 1998; 49: 1013±16.
286
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................................................................................................................................................................................................................................................
intermittent cross-clamp fibrillation that they are using a score of hypnosis successfully for my own anaesthetic
technique used with cross-clamp to titrate a mixture of hypnotic and recording purposes.
times of 9 min and 7 min, so mini- analgesic agents in their infusion group
C. Stonell
mizing blood stasis in the coronary and then drawing conclusions about
Colchester General Hospital,
vessels. The case proceeded unevent- the adequacy of hypnosis. In other
Colchester CO4 5JL, UK
fully and the patient was discharged words, as their infusion varies, the level
of hypnosis and analgesia will vary. In
home well after 7 days.
In our opinion, the basic principles of contrast, their volatile group receive a
anaesthesia in sickle cell disease, of measured amount of analgesia. Second,
keeping patients warm, well hydrated, in their discussion they state `episodes
well oxygenated and mildly alkalotic [3] of light anaesthesia occurred in
to avoid conditions leading to relative response to sudden surgical stimuli'.
regional hypoxia, increased sickling, and This would appear to be more due to
compromised oxygen delivery to tis- inadequate analgesia than inadequate
sues, should be extended to when these hypnosis. A sudden spike in the BIS
patients undergo surgery requiring car- score from a satisfactory, stable baseline,
A reply
Thank you for the opportunity to
respond to the points raised in the
above letter. In stating first that BIS is a
score of hypnosis and not analgesia,
and then that the stability of BIS may
be maintained using alfentanil, an
analgesic, Dr Stonell seems to want to
have his cake and eat it. Confusion in
this area has been partly resolved by
recent work, summarised below and
published while our manuscript was in
preparation.
In volunteers, alfentanil does not
appear to affect Cp50 or BIS50
(respectively, the propofol concentra-
tion and BIS associated with a 50%
probability of loss of consciousness)
[1]. The conclusion is that alfentanil
does not exert a significant additional
hypnotic effect under these circum-
stances. In another study, tracheal
diopulmonary bypass.
coincident with surgical stimulus, is
suggestive of inadequate analgesia,
while the level of hypnosis may be
adequate. Hence, an increase in the
analgesic component may have been
required, while not necessarily increas-
ing the hypnotic component, some-
thing they would have been unable to
do with their infusion mixture. Alter-
natively, an infusion with a higher
concentration of alfentanil may have
been more suited to the type of
surgery.
W. A. Marchant
S. Wright
The Middlesex Hospital,
London W1N 8AA, UK
References
1 Williams S, Maude OH, Serjeant GR.
Clinical presentation of sickle cell
haemoglobin SC disease. Journal of
Pediatrics 1986; 109: 586.
2 Platt OS, Brambilla DJ, Rosse WF, et al.
Mortality in sickle cell disease: Life
expectancy and risk factors for early
death. New England Journal of Medicine
1994; 330: 1639.
While closed-loop anaesthesia is an
exciting prospect, it entails more than
infusing a drug, or combination of
drugs, to achieve a certain score on a
monitor that is only monitoring one
aspect of the anaesthetic, in this case
hypnosis. Using such an approach, we
run the risk of over-sedating patients
while providing inadequate analgesia. I
suggest their study would have been
more meaningful if they had separated
their infusions and been able to titrate
each individually: using Propofol to
achieve an adequate BIS score, and
alfentanil, or another short-acting
opioid, to provide adequate analgesia
and maintain stability of the BIS score.
This study also serves as a reminder
that the attending anaesthetist is still the
single most important patient monitor
in any operating theatre.
intubation caused
a rise in BIS,
which is attenuated in a dose-related
fashion by pre-administration of remi-
fentanil [2]. The authors of this study
concluded that a change in bispectral
index is as sensitive as haemodynamic
responses after a painful stimulus for
detecting deficits in the analgesic
component of anaesthesia.
Dr Stonell's second point concerns
episodes of light anaesthesia and the
limitations of our intravenous techni-
que. He quotes us incorrectly in his
letter. Our discussion states: `episodes
of light anaesthesia occurred in all
groups in response to sudden surgical
stimuli'. In other words, these episodes
were noted in patients receiving iso-
flurane/N2O/morphine as well as
propofol/alfentanil anaesthesia. The
use of a measured amount of analgesia
in the former group, rather than a
variable one in the latter, is noted by
Dr Stonell with apparent approval.
However, the effect of a bolus dose
of morphine, administered at induc-
tion, declines intra-operatively and is
3 Neumayr L, Koshy M, Haberkern C,
et al. Surgery in patients with
Haemoglobin SC Disease. American
Journal of Hematology 1998; 57: 101±18.
Close loop anaesthesia using
bispectral index
I read the paper describing closed loop
control of anaesthesia using bispectral
index (Morley et al. Anaesthesia 2000;
55: 953±9) with interest, and would
like to comment on two points which
concern me.
Bispectral index monitoring (BIS) is
based upon EEG analysis and produces
a dimensionless number from 0 to 100.
As the authors correctly state, this is a
score of hypnosis. It is not a measure of
analgesia, although, to some extent,
this can be derived from the trend of
the BIS score. It therefore concerns me
Finally, I would like to thank Dr
Derrick for making his program `Moni-
tor' available for download over the
internet. It is one of very few anaes-
thesia recording software programs
available for the Apple Macintosh
platform, and one that I have used
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Anaesthesia, 2001, 56, pages 272±296
................................................................................................................................................................................................................................................
responses after orotracheal intubation.
Anesthesia and Analgesia 2000; 90:
161±7.
no more titrated to analgesic require-
ments than is a variable rate alfentanil
infusion.
care and the genesis of peripheral
nerve injury' [4]. This was also the
conclusion of the article of which
Caplan was a co-author in 1990 [5],
which is in fact cited by Sawyer. That
article called for `prospective studies',
and we now have two carefully
conducted large prospective studies
[1, 2] not cited by Sawyer (to be
fair, one is a recent publication). A
most important feature of this study of
lower extremity neuropathies was that
such neuropathies are sensory and
present early, which is contrary to
the catchall statement in the Sawyer
review.
Sawyer and colleagues did cite an
editorial by Stoelting [6] with a similar
cautious sentiment: `a conclusion that
postoperative ulnar nerve palsy is always
a preventable complication cannot be
supported by available evidence and our
current understanding of the problem'.
I regret that they did not take this
message from that editorial, rather than
reproduce a figure that looks very much
like Stoelting's figure 2, without
acknowledgement.
I know we should avoid damage to
our patient's peripheral nerves, by
avoiding what could be harmful features
such as excess pressure, and abnormal
positions for long periods. It is perhaps
even more important that we should
avoid being shot in the foot by the
assertion that all peri-operative nerve
injuries are `essentially avoidable'. This
review has not provided any direct
evidence that this is so: and scientifically
the evidence that we have will rarely be
able to do so. In fact, the review article
has cited evidence that some injuries do
`just happen', presumably caused by
effects that we do not realise, and
probably cannot control. Does one of
the authors, who is the Medical Direc-
tor of the Medical Protection Society,
truly wish to stand by the assertion that
in essence all peri-operative nerve
injuries are indefensible, particularly on
the basis of the evidence adduced in this
review?
Dr Stonell suggests that our study 3 Munglani R, Andrade J, Sapsford DJ,
might have been more meaningful if
we had been able to titrate a separate
alfentanil infusion to provide adequate
analgesia. He does not indicate how
intra-operative analgesia might be
measured in order to effect this
titration. The fact is that intra-opera-
tive signs of light anaesthesia are often
the same as those of inadequate
analgesia ± namely a rise in arterial
pressure and heart rate, and increased
BIS. That the two states are intimately
associated is further indicated by
evidence that painful stimuli at light
levels of anaesthesia may enhance
cognitive function [3]. This phenom-
enon is recognised, perhaps unwit-
tingly, by the many anaesthetists who
respond to cardiovascular `evidence' of
intra-operative light anaesthesia by
increasing inspired volatile concentra-
tions as well as administering a bolus
of opiate analgesic.
The diagnosis of inadequate analge-
sia ultimately depends on observation
by the anaesthetist of surgical events,
information that is clearly unavailable
to a closed-loop controller. Even with
this advantage, the anaesthetists admin-
istering isoflurane in our study were
unable to out-perform the controller
in terms of number of episodes of
light anaesthesia.
Baddeley A, Jones JG. A measure of
consciousness and memory during
isoflurane administration: the coherent
frequency. British Journal of Anaesthesia
1993; 71: 633±41.
Are peri-operative peripheral
nerve lesions preventable?
At first sight, the review of peripheral
nerve injuries associated with anaes-
thesia (Sawyer et al. Anaesthesia 2000;
55: 980±91) appears to be a useful
account of an important condition,
which often presents considerable
medicolegal challenge. Unfortunately,
I think that one of its main conclud-
ing statements is wrong, and poten-
tially very
profession.
damaging
to
our
The authors conclude: `Although
they (peripheral nerve injuries)
account for a small proportion of
medicolegal claims, they are difficult
to defend, being essentially avoidable'.
However, throughout their article they
quote individual cases, small series,
and reviews which could not and do
not support this contention. In most
cases, clinicians are being wise after
the event and reporting putative
mechanisms. In many cases the
mechanism is likely, but in others the
mechanism suggested might be incor-
rect. In retrospect, much `evidence' is
necessarily suspect. Their citation of
the relevant literature in this review is
necessarily restricted, but the balance
May I thank Dr Stonell on Dr
Derrick's behalf for his kind comments
regarding `Monitor'.
A. P. Morley
St Thomas' Hospital,
London SE1 7EH, UK
is unhelpful. In particular,
I was
surprised by the age and source of
the references. Excluding the duplicate
reference (citations 10 and 57), the
article cites 66 sources, of which only
12 are less than 10 years old, and only
seven of those are original reports. It
does not cite two recent prospective
studies [1, 2] and experimental data
[3]. In an editorial comment on this
latter study, Caplan wrote: `(it is) ¼ a
humbling reminder that we have a
References
1 Iselin-Chaves IA, Flaishon R, Sebel PS,
et al. The effect of the interaction of
propofol and alfentanil on recall, loss of
consciousness, and the bispectral index.
Anesthesia and Analgesia 1998; 87: 949±
55.
2 Guignard B, Menigaux C, Dupont
X, Fletcher D, Chauvin M. The
G. B. Drummond
Royal Infirmary,
Edinburgh EH3 9YW, UK
effect of remifentanil on the bispectral limited understanding of the relations
index change and hemodynamic
between conventional peri-operative
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Correspondence
................................................................................................................................................................................................................................................
The recent papers referred to by Dr
Drummond [1, 3, 4], but unpublished
at the time our artricle was submitted,
support this view. Whilst we are
cognisant of the length of time from
submission to publication, we were
unable to review these articles. Dr
Drummond correctly takes us to task
for failing to acknowledge the source
of figure 4, for which we apologise.
However, it was modified from an
original article by Wadsworth [5] and
not by Stoelting [6] as cited by Dr
Drummond.
References
References
1 Warner MA, Warner DO, Matsumoto
JY, et al. Ulnar neuropathy in surgical
patients. Anesthesiology 1999; 90:
54±9.
1 Prielipp RC, Morrell RC, Walker FO,
Santos CS, Bennett J, Butterworth J.
Ulnar nerve pressure. Influence of arm
position and relationship to
somatosensory evoked potentials.
Anesthesiology 1999; 91: 345±54.
2 Cheng FW. Perioperative ulnar nerve
injury±A continuing medical and
liability problem. ASA Newsletter 1998;
62: 10±11.
2 Warner MA, Warner DO, Harper M,
Schroeder DR, Maxson PM. Lower
extremity neuropathies associated with
lithotomy positions. Anesthesiology
2000; 93: 938.
3 Prielipp RC, Morell RC, Walker FO,
et al. Ulnar nerve pressure. Influence of
arm position and relationship to
somatosensory evoked potentials.
Anesthesiology 1999; 91: 345±54.
4 Caplan RA. Will we ever understand
perioperative neuropathy?
3 Warner MA, Warner DO, Harper M,
Schroeder DR, Maxson PM. Lower
extremity neuropathies associated with
lithotomy positions. Anesthesiology
2000; 93: 938±42.
The time of onset of peri-operative
peripheral neuropathy has been
a
subject for much debate. In the article
quoted by Dr Drummond [3], in
relation to lower extremity peri-opera-
tive peripheral neuropathy, Warner
et al. stated that `prolonged duration
of time in lithotomy positions, espe-
cially for more than 2 hours, was
strongly associated with these neuro-
pathies'. Lower extremity neuropathies
did indeed present early, within 4 h of
completion of the anaesthetic and 14
out of 15 neuropathies resolved within
6 months. The same group of inves-
tigators prospectively studied ulnar
neuropathy [7] with interesting results.
They found that symptoms developed
2±7 days after surgery and in four
patients symptoms resolved within
6 weeks; however, three patients still
had residual symptoms 2 years later.
These authors also observe: `None of
the neuropathies were present within
the first 2 postoperative days'.
The experimental observations of
Prielipp et al. [1] also showed that
pressure on the ulnar nerve at the
elbow was greatest with the forearm
in pronation and least in supination.
Referring to this last study, Caplan
[4] in the same article quoted by
Dr Drummond, wrote: `Until we
have a better ability to predict and
monitor ulnar nerve injury, these
findings can serve as guides for clinical
decision making.' Our sentiments
entirely!
4 Caplan RA. Will we ever understand
perioperative neuropathy?
Anesthesiology 1999; 91: 335±6.
5 Kroll DA, Caplan RA, Posner K, Ward
RJ, Cheney FW. Nerve injury
associated with anesthesia.
Anesthesiology 1999; 91: 335±6.
5 Wadsworth TG. The cubital tunnel and
the external compression syndrome.
Anesthesia and Analgesia 1974; 53: 303±
8.
Anesthesiology 1990; 73: 202±7.
6 Stoelting RK. Postoperative ulnar
nerve palsy ± is it a preventable
complication? Anesthesia and Analgesia
1993; 76: 7±9.
6 Stoetling RK. Postoperative ulnar
nerve palsy ± is it a preventable
complication? Anesthesia and Analgesia
1993; 76: 7±9.
7 Warner MA, Warner DO, Matsumoto
JY, Harper M, Schroeder DR, Maxson
P. Ulnar neuropathy in surgical patients.
Anesthesiology 1999; 90: 54±9
A reply
Thank you for the opportunity to
reply to Dr Drummond's letter. We
agree that in the genesis of nerve
injuries, the mechanisms of injury are
putative and unknown. It was to this
end that our suggestions for avoiding
possible predisposing factors, as
described in our review article, were
directed. This would be the safest
course of action for an anaesthetist in
clinical practice to follow until further
research, such as that undertaken by
Prielipp et al. [1], could be undertaken
to elucidate a mechanism of neural
injury. We have not stated that all peri-
operative nerve injuries are avoidable,
or that they can be wholly prevented,
rather that an awareness of predisposing
factors may reduce the frequency with
which they occur. We have stated that
nerve injuries are `difficult to defend'
rather than `indefensible' and this is
borne out by the fact that ` ¼
payment was made in about half of
the claims (for peri-operative ulnar
neuropathy) where care was judged
appropriate' [2].
Peripheral nerve injuries
I read the recent review article on
peripheral nerve injuries (Sawyer et al.
Anaesthesia 2000; 55: 980±91) with
great interest. Most of the neurolo-
gical damage described in the article
resulted from poor surgical position-
ing, which caused either direct
pressure or traction on the nerve
trunk. I would like to report a case
where significant, but thankfully tem-
porary, damage was unwittingly
inflicted on a major peripheral nerve
by anaesthetic considerations alone.
A 52-year-old woman undergoing
free-flap reconstruction of an intra-
oral carcinoma was anaesthetised
supine and both arms adequately
padded with gel supports in the
crucifix position. Direct arterial pres-
sure was monitored via a 20-g cannula
in the left radial artery. Shortly after
R. J. Sawyer
M. N. Richmond
J. Jarratt
J. Hickey
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Anaesthesia, 2001, 56, pages 272±296
................................................................................................................................................................................................................................................
commencement of surgery, the arterial catheters but who were new to CSEs. epidural analgesia for many of our
trace became markedly damped and a Both patients were anxious and com- obstetric patients.
satisfactory waveform could only be plained bitterly of pain when their skin
H. Parry
re-established by extending the wrist. was infiltrated with lidocaine. When
Watford General Hospital,
This position was maintained through- they complained of severe pain as the
Watford WD18 0HB, UK
out the operation (some 5 h) by use of spinal needle was introduced, it was in
a roll of crepe bandage and adhesive each case assumed that the pain they
tape (Fig. 14) without any further were experiencing was no worse than
monitoring problems. On the follow- that of skin infiltration with local
ing day, the patient complained of anaesthetic. The anaesthetists con-
numbness and weakness in the left cerned believed they were using the
Epidural failures and trainees'
performance
hand and examination revealed
a
L223 or L324 space but in each case a
We read with interest the paper
attempting to correlate obstetric epi-
dural performance with psychomotor
aptitude (Dashfield et al. Anaesthesia
2000; 55: 744±9) and were shocked
by the quoted `failure rate' of 1 in 5
epidurals, which seemed to improve
little with time. This seems much
higher than the failure rate of trainees
at Kingston Hospital, which for the
last seven novices has been two failures
for the first 10 epidurals, then 1.7,
0.85, 0.4 and 0.5 for each subsequent
10. We therefore wish to raise several
points.
We judge success of epidural inser-
tion as the establishment of good
analgesia without technical problems.
We question the validity of using
success or failure of the epidural over
the duration of labour as a measure of
the trainee's performance of epidural
anaesthesia. The authors hinted that
good analgesia throughout labour was
perhaps too `stringent' a measure, and
complete median nerve palsy on that magnetic resonance imaging (MRI)
side. Fortunately, this gradually but scan carried out following evidence of
completely resolved over the next few nerve damage showed a lesion at T12±
days.
L1. It was concluded that the spinal
In retrospect, it is clear that over- needle had been inserted at an inap-
extension of the wrist exerted traction propriately high level and that clinical
on the median nerve and possibly negligence had occurred resulting in
compression of it within the carpal permanent neurological damage. The
tunnel itself. In my experience, mon- patients continue to suffer pain, hyper-
itoring of the radial arterial waveform sensitivity and parathesia in one leg,
often requires a little wrist extension to and one of them also has greatly
produce a reliable trace but, in the light reduced power.
of the above case, I would urge caution
as to both the degree of extension and concerned had been using inappropri-
the length of time for which it is ately high spaces for some time but as
It is my opinion that the anaesthetists
applied.
long as they were performing only
epidural analgesia no problem occurred.
Since these cases, we have been very
careful not to use too cephalad a space.
If there is any doubt we feel a CSE
is contraindicated and use epidural
analgesia alone. Thankfully, we have
had no further similar cases, although
we continue to use combined spinal
P. J. Hilton
Morriston Hospital,
Swansea SA6 6NL, UK
Spinal cord damage
I would like to report two cases of
damage to the spinal cord similar to
those described by the editorial `Logic
in the safe practice of spinal anaesthesia'
(Reynolds. Anaesthesia 2000; 55: 1045±
6).
Until April 1994, either spinal or
epidural analgesia was used at Watford
General Hospital for those obstetric
patients requesting regional anaesthesia.
In April 1994, the combined spinal
epidural technique (CSE) was intro-
duced using a Portex pack and the
needle through needle technique.
During the following 18 months, two
patients suffered permanent severe
damage to the spinal cord because the
needles were inserted at too cephalad
an interspace. The blocks were per-
formed by anaesthetists with 8 or 10
years experience of siting epidural
Figure 14 .
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Correspondence
................................................................................................................................................................................................................................................
we feel that this is an important epidurals than in their first 20, one
The conclusions of our study
limitation of the study. It is a harsh trainee performed the same, two remain the same; psychomotor abilities
measure and makes no allowance for trainees performed marginally better, appear to be poor determinants of
the successfully inserted epidural that and the four remaining trainees who trainees' initial proficiency at obstetric
works well initially but subsequently improved a lot seem to be responsible epidural anaesthesia or of trainees'
provides insufficient analgesia. Audit for the observed improvement in mean rates of progress during early obstetric
data can shed some light on the size failure rate. We believe the fact that training.
of this problem.
useful improvement was seen in less
A. Dashfield
J. Coghill
J. Langton
Derriford Hospital,
Plymouth PL6 8DH, UK
At Kingston Hospital over a 27- than half the trainees studied is either
month period to June 2000, there evidence of inadequate supervision
were 3625 epidurals performed, of (highly unlikely) or evidence that the
which 95.8% produced good initial measure of success or failure of an
analgesia. Of those that failed to epidural over the course of a labour is
achieve good initial analgesia, 35% not valid for assessing competence of
were inserted too late or abandoned insertion.
Reference
because of an urge to push, 50%
We would be very interested to
1 Kestin IG. A statistical approach to
measuring the competence of
anaesthetic trainees at practical
procedures. British Journal of Anaesthesia
1995; 75: 805±9.
had persistent perineal, one-sided or learn the rate at which performance
back pain, and possible failed epidural improved when measured against the
identification was responsible for 15%. establishment of analgesia, and any
Of the 3473 women who achieved relationship between the psychomotor
good analgesia at the initial insertion, tests and this measure, which we feel is
17.6% subsequently had analgesia pro- a far more relevant test of operator
blems. Expressed as a proportion of all competence.
epidurals inserted, the problems were:
P. Dill-Russell
R. G. W. Stacey
Should epidurals be avoided in
acupunctured patients?
one-sided pain 6.8%, perineal pain
6.6%, catheter migration out of space
Kingston Hospital,
Kingston-upon-Thames,
Surrey KT2 7QB, UK
1.8%, other causes of abdominal pain
1.2% and back pain 1.1%. This
population, if not correctly managed,
would be unlikely to re-establish
analgesia, and would count in the
Although acupuncture is becoming
accepted among pain clinicians, an
in situ needle technique called `Oki-
bari' in Japanese is not known well.
In this technique, fine metallic needles
are used to puncture the skin and left
present study as failed epidurals despite
the fact that a successful epidural had
been performed. It is interesting to
note that this figure of almost 20% is
close to the failure rate of 1 in 5
found in this study. This begs the
question about what contribution late
failures made to the overall failure rate
in the current study.
Postnatal assessment of all women
with successfully established epidural
analgesia revealed 6.9% who rated
their analgesia as poor. Internal review
of the reasons for these failures has
shown withholding top ups in late
labour and failure to get an anaesthetist
to review a failing epidural to be the
main causes. Clearly, it would be unfair
to attribute these situations outlined
above, where analgesia was initially
good, as failures due to lack of technical
proficiency.
A reply
Thank you for the interest in our in the subcutaneous tissues. We report
study. As we pointed out in our paper, a rare case in which a massive number
good analgesia throughout labour was of needles were found on chest X-ray;
a `stringent' measure of success or with the result that epidural cannula-
failure of an epidural. The reason we tion was abandoned.
chose this outcome measure was that
An 82-year-old woman was sched-
it had previously been used and uled for distal gastrectomy. She had
accepted in a peer reviewed journal received acupuncture for her backache
[1]. We based the number of epidural for 20 years. Her chest and abdominal
procedures we studied for each trainee X-rays revealed hundreds of fine
on Kestin's finding that 47 epidural metallic needles around the vertebrae
procedures were required before an (Fig. 15). We feared that performing
acceptable success rate was achieved; an epidural in this situation might lead
thus our end point had to be the same. to complications, such as spinal cord
We have re-examined our data and injury and pneumothorax. We there-
correlated psychomotor test scores fore abandoned placement of an
against the success rate of establishing epidural catheter and we chose only
analgesia. The correlation between the general anaesthesia. Her intra- and
means of the first 25 and 50 consecutive postoperative courses were uneventful.
epidurals and a eye-hand co-ordination
There were several complications
or information management task was associated with acupuncture, such as
also not significant, suggesting that late pneumothorax [1], abscess [2], haema-
failures of epidural analgesia were less toma with subarachnoid haemorrhage
important than Dill-Russell and Stacey [3] and spinal cord injury [4]. If we
The mean failure rate used in this study
hides some interesting observations. The
data in Table 2 reveal that three trainees
performed worse in their final 20
suggest.
had attempted an epidural puncture,
q 2001 Blackwell Science Ltd
291

Correspondence
Anaesthesia, 2001, 56, pages 272±296
................................................................................................................................................................................................................................................
Figure 15 Chest (a) and abdominal (b) X-rays show hundreds of needles left around the vertebrae.
the American Medical Association 1974;
229: 1422.
some of the needles in her back might
have advanced and migrated deeply. In
such a case, there is no guarantee of
safety during the epidural procedure.
We would like to stress the importance
of pre-operative X-rays, especially in
the patient who had received acu-
anaesthetic solution to produce satis-
factory operating conditions for catar-
act surgery (Frow et al. Anaesthesia
2000; 55: 750±5). In cases of peri-
bulbar and subtenon anaesthesia, prop-
tosis and lid fullness associated with
the sensation of a full orbit have been
used as end point markers for the
injectate volume [1]. However, publi-
cation of any study reporting use of
2 Yazawa S, Ohi T, Sugimoto S, Satoh S,
Matsukura S. Cervical spinal epidural
abscess following acupuncture:
successful treatment with antibiotics.
Internal Medicine 1998; 37: 161±5.
puncture to the back. If needles are 3 Keane JR, Ahmadi J, Gruen P. Spinal
epidural hematoma with subarachnoid
hemorrhage caused by acupuncture.
left in situ, epidural puncture may be
contraindicated.
American Journal of Neuroradiology 1993; an objective criterion instead of a
K. Koga
A. Shigematsu
UOEH, Kitakyushu,
807-8555 Japan
E-mail: kkoga@med.uoeh-u.ac.jp
14: 365±6.
subjective one would be well received,
especially by trainee anaesthetists. I
would like to make the following
comments.
Though complete ocular akinesia is
not considered to be absolutely neces-
sary for cataract surgery [2], it is used as
the main index of the quality of
anaesthesia such that supplemental
injections are given to secure maximum
eye immobility. In the present study, the
reported rate of supplemental injection
4 Shiraishi S, Goto I, Kuroiwa Y,
Nishio S, Kinoshita K. Spinal cord
injury as a complication of an
acupuncture. Neurology 1979; 29:
1188±90.
T. Noguchi
Y. Shiga
Chikuho Rosai Hospital,
820-088 Fukuoka, Japan
E-mail: nogutaka@dL.dion.ne.jp
Total upper eyelid drop as an
endpoint marker of peribulbar
anaesthesia
References
1 Kuiper JJ. Pneumothorax as
I read with interest the recent article (10.2%) is similar to that observed by
others [3, 4]. Hence, this technique
does not seem to offer any additional
describing a novel approach to deter-
complication of acupuncture. Journal of mine the optimal volume of local
292
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Anaesthesia, 2001, 56, pages 272±296
Correspondence
................................................................................................................................................................................................................................................
3 Ahmad S, Ahmad A, Benzon HT.
Clinical experience with the
advantage with regard to supplemental
injection.
reviewed [1], although we do acknowl-
edge the two studies she has quoted.
Her comments on the intra-ocular
pressure increases are correct in that no
proven link has been shown to exist
between transient intra-ocular pressure
rises and volumes injected. However,
pain on injection, triggering of the
oculocardiac reflex and ischaemic optic
neuropathy have been linked to this by
others [2±4].
The last point raised concerning the
supposed lack of a qualitative explana-
tion for the statistically significant
negative correlation between injectate
volume and intra-ocular pressure rise is
invalid since a possible explanation was
included in the discussion, based on
our clinical experience. We do, how-
Peribulbar block for ophthalmologic
surgery. Regional Anesthesia 1993; 18:
184±8.
It is a commonly observed fact that
intra-ocular pressure rises acutely after
injection and subsequently tends to
decrease towards the pre-injection
level [5, 6]. The authors report a
mean rise of 6.9 mmHg after injection
4 Loots JH, Koorts AS, Venter JA.
Peribulbar anesthesia. A prospective
stastitical analysis of the efficacy and
predictability of bupivacaine and a
lignocaine mixture. Journal of Cataract
and Refractive Surgery 1993; 19: 72±6.
5 Bowman R, Liu C, Sarkies N.
lntraocular pressure changes after
Peribulbar injections with and without
ocular compression. British Journal of
Ophthalmology 1996; 80: 394±7.
of
a mean anaesthetic volume of
9.1 ml. Several authors who adminis-
tered predetermined volumes of injec-
tate have reported average rises of
intra-ocular pressure of similar magni-
tude [7, 8].
The authors have emphasised the
fact that in procedures involving
injection of fixed volumes of local 6 Morgan JE, Chandra A. lntraocular
anaesthetic, the injected volume may
be excessive for a particular patient
and may dangerously increase the
intra-ocular pressure. Although there
pressure after peribulbar anaesthesia: is
the Honan balloon necessary? British
Joumal of Ophthalmology 1990; 68: 227± ever, feel this does warrant further
9.
attention to assess whether statistical
is a tendency for transient intra-ocular 7 Stevens J, Giubilei M, Lanigan L, et al. significance can be linked to clinical
pressure to rise with increase in
injectate volume, no direct relation-
ship has been reported. Moreover, the
fears that a larger injection volume
Sub-tenon, retrobulbar, peribulbar local significance and see if our result can be
anaesthesia: the effect upon intraocular duplicated.
pressure. European Journal of Implant and
M. W. O. Frow
Refractive Surgery 1993; 5: 25±8.
Central Middlesex Hospital,
London NW10 7NS, UK
may cause a substantial increase in 8 Meyer D, Hamilton RC, Loken RG,
intra-ocular pressure jeopardising the
retinal blood supply and impairing the
surgical field have not been confirmed
[9].
Inclusion of a qualitative explanation
of the reported negative correlation
between the injectate volume and the
rise in intra-ocular pressure would have
enhanced the significance of the
observed relationship.
Gimble HV. Effect of combined
peribulbar and retrobulbar injection of
large volumes of anesthetic agents on the
intra-ocular pressure. Canadian Journal of
Ophthalmology 1992; 27: 230±2.
References
1 Bowman R, Liu C, Sarkies N.
Intraocular pressure changes after
peribulbar injections with and without
ocular compression. British Journal of
Ophthalmology 1994; 78: 605±7.
2 Davis II DB, Mandel MR. Efficacy and
complication rate of 16, 224
9 Gillart T, Bazin JE, Raynaud C et al.
Effect of injection pressure on the
success rate of Peribulbar block.
Anaesthesia 1996; 51: 779±81.
S. Verma
Queen Charlotte Hospital,
London W6 0XG, UK
consecutive peribulbar blocks: a
prospective multicenter study. Journal of
Cataract and Refractive Surgery 1994; 20:
327±37.
A reply
We thank Dr Verma for taking an
interest in our paper and giving us the
opportunity to reply to the points
raised.
She is correct in her observation that
our technique confers no additional
advantage in terms of the level of
akinesia achieved. Our aim was not to
describe a superior technique for peri-
bulbar block in this regard, but one
which is at least as good as other
techniques employed.
3 Bedi A, Carabine U. Peribulbar
anaesthesia: a double-blind comparison
of three local anaesthetic solutions.
Anaesthesia 1999; 54: 67±71.
4 Rubin AP. Complications of local
anaesthesia for ophthalmic surgery.
British Journal of Anaesthesia 1995; 75:
93±6.
References
1 Ripart J, Lefrant JY, Bruno V, et al.
Ophthalmic regional anesthesia: Medial
canthus episcieral (sub-tenon)
anesthesia is more efficient than
peribulbar anesthesia. Anesthesiology
2000; 92: 1278±85.
2 Woodward DK, Leung ATS, Tse MWI,
et al. Peribulbar anaesthesia with 1 %
ropivacaine and hyaluronidase 300 IU/
ml: comparison with 0.5% bupivacaine,
2% lidocaine and hyaluronidase 50 IU/
ml. British Journal of Anaesthesia 2000;
75: 618±20.
Concerning the mean rise in intra-
ocular pressure of 6.9 mmHg immedi- Anaesthetic menu: a step too
ately after injection without the use of far?
external ocular compression techniques,
we felt that this did compare favourably We read with interest the letter (Wood &
with the bulk of the literature we Raghavan. Anaesthesia 2000; 55: 1039)
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Anaesthesia, 2001, 56, pages 272±296
................................................................................................................................................................................................................................................
concerning soya bean oil in propofol reached and as yet there is no proven a three-way tap into the line of a
and could not understand their general- `sound scientific basis' on this issue. giving set administering diclofenac
isation about genetically modified sub- However, there has been enough con- sodium (75 mg/3 ml in 100 ml
stances in propofol.
cern regarding the potential effects on normal saline) also results in the
While it may be true that some of health to warrant the introduction of formation of this white precipitate,
the soya bean oil source may have a legislation on labelling in September regardless of whether normal saline is
genetically modified source, to brand 1998. The safety of genetically modified buffered with 0.5 ml of 8.4% sodium
propofol as genetically modified is products has been questioned so it bicarbonate as suggested by the man-
stretching things a bit far in our would seem reasonable to exercise ufacturer's data sheet. This is
opinion. While one can offer an some caution in their use from now on. hitherto unreported reaction between
alternative induction agent to most Until firm conclusions are reached, two commonly used intravenous
a
anaesthetic patients, it may be difficult perhaps it would be wiser for man- drugs. Whether the precipitate is
to find a suitable short-acting sedative ufacturers to use soya bean oil in harmful if it enters the systemic
with a similar pharmacological profile their products that is not from a circulation is unclear.
in the case of intensive care use, genetically modified source as this
G. Ackland
where propofol is the first choice would be quite possible. If the drugs
Barnet General Hospital, UK
sedative for short-term sedation. were labelled accordingly, we would
What about the countless number of then be able to give accurate infor-
patients who have received propofol mation to patients when required
over the last 6 years, without consult- regarding the origins of the drugs
ing them? Taken a step further, what we are using.
Incidence of anaphylaxis under
anaesthesia
about the origins of soya bean oil in
If in the future genetically modified
other lipid-based solutions such as substances are found to be harmful,
diazemuls and intravenous lipid emul- an open approach to informing
sions (TPN)? What about their alter- patients wherever possible now
natives? Imagine yourself offering (or would surely prevent accusations of
being forced to offer!) this information arrogance and the desire to litigate in
and trying to suggest an alternative to the future.
The recent letter rightly pointed out
the need for current UK epidemiolo-
gical data on the incidence and out-
come
of
anaphylactic
and
anaphylactoid reactions in patients
under local and general anaesthesia
(Watkins et al. Anaesthesia 2000; 55:
1127±8). It is no longer satisfactory to
extrapolate from data derived from
publications in other countries,
though comparison is of great interest.
UK data need to be collected, collated
and published as part of audit, possibly
combining sources from the Commit-
tee on Safety of Medicines yellow card
system, the Royal College of Anaes-
thetists Critical Incident System with
diazemuls to the parents of a fitting
C. C. Wood
child!
V. Raghavan
In this increasingly litigious and
Mayday University Hospital,
paranoid world such generalisation
Thornton Heath CR7 7YE, UK
without a sound scientific basis can
only make matters worse.
S. Dhileepan
Physical incompatibility
A. Patel
between atracurium and
Kingston Hospital,
intravenous diclofenac
Surrey KT2 1QB, UK
I should like to report the finding of the laboratory results and interpreta-
physical imcompatibiliy between atra- tion, NADRAS (National Adverse
curium bresylate (Tracrium, Glaxo- Drug Reaction Advisory Service).
Wellcome) and intravenous diclofenac There is currently no feedback for
References
1 Anon. ABPI Compendium of Data Sheets
1999±2000: Diprivan 1%, 2%, 1781±
3. Zeneca.
sodium (Voltarol, Geigy).
clinicians though drug-specific infor-
Voltarol ampoules contain diclofenac mation can be obtained from the
sodium, mannitol, sodium metabisul- Committee on Safety of Medicines
phite (E223), benzyl alcohol, propylene (CSM).
2 Anon. ABPI Compendium of Data Sheets
1999±2000: Diazemuls, 356. Dumex.
glycol, sodium hydroxide and water,
whilst atracurium exists solely in aqu- least six major anaphylactic reactions in
eous solution.
the past 212 years all confirmed with
Inadvertent drawing up of intrave- elevated blood tryptase levels, four
In this hospital, there have been at
A reply
The medical profession is frequently
accused of arrogance and of withhold- nous diclofenac into a syringe pre- with positive skin prick test positive.
ing information regarding medical viously used to administer atracurium Four presented with sudden onset of
treatments and drugs from the public bresylate results in the formation of a pulselessness and/or cyanosis, one with
on the basis that doctors know best.
Conclusions on the safety of geneti-
cally modified products have yet to be injection of atracurium bresylate via general anaesthesia and one under
white precipitate.
a bradycardia and three with severe
Similarly, at room temperature, bronchospasm. Five patients were under
294
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Anaesthesia, 2001, 56, pages 272±296
Correspondence
................................................................................................................................................................................................................................................
Britain and Ireland. Management of a
Patient with Suspected Anaphylaxis
during Anaesthesia. Sample of
Operating Procedure/Guideline.
February. 1998.
subarachnoid block. One died and one [8] on Suspected Anaphylactic Reac-
has short-term memory loss. Two were tions Associated with Anaesthesia
for Caesarean section under general (Continuing Medical Education Day
anaesthesia and one manual removal of 7/9/2000). What is also needed, as
placenta under spinal anaesthesia. Drugs Watkins et al. suggest, is a centre to co-
implicated were succinylcholine (four), ordinate all records of suspected ana-
atracurium (one), amoxycillin with phylactic and anaphylactoid reactions,
Clavulanic acid (one). Is this incidence together with laboratory and skin test
in one DGH representative of the results with a view to regular publica-
How should we manage the
electronically tagged patient?
UK?
tion of results. Meanwhile, the College
It needs to be reiterated that Audit Representative in each depart-
patients experiencing an anaphylactic ment might in 2001 collect data on all
or anaphylactoid reaction under anaphylactic reactions observed under
anaesthesia present with a variety of anaesthesia in their department for
signs [1, 2] and that these may not all future reference.
A 25-year-old man recently presented
as a day case for an elective plastic
surgical procedure to a previous hand
laceration. Medically he was a fit ASA
I patient but he informed staff that he
was wearing an electronic tagging
device. Since this was due to be
removed in approximately 1 month, it
was decided to postpone the operation
until after this date as little was known
about these devices and possible
complications.
Electronic monitoring is a system of
home detention for offenders being
brought into effect in the light of an
ever-increasing prison population. An
electronic tag radio frequency `trans-
mitter' the size of a wristwatch is
worn around the ankle or wrist. This
is the `Personal Identification Device'.
It is electronically linked to a receiver
connected to the phone socket in the
place of curfew. The continuous trans-
mission of the tag is picked up by the
receiver and checked intermittently by a
central monitoring centre that dials the
client's phone. The system therefore
cannot `track' a client but can detect
whether a person is within range of
the receiving unit at any time.
appear at once [3]. Whittington and
R. M. Foxell
Fisher in a study of 555 patients state
West Dorset General Hospital,
that `cardiovascular manifestations are
Dorchester DT1 2JY, UK
the most common feature, that any
system may be the only system
involved and that the full constellation
References
of systems does not occur in every
1 The Association of Anaesthetists of
patient' [4]. A high index of suspicion
Great Britain and Ireland and the
British Society of Allergy and
is required even if only signs from
one system are noted, for early
diagnosis with prompt and thorough
treatment. In 10% of cases cardiovas-
cular collapse is the sole presenting
feature [1].
Clinical Immunology. Suspected
Anaphylactic Reactions Associated with
Anaesthesia, revised edition. London:
AAGBI, 1995.
2 Currie M, Webb RK, Williamson JA,
Treatment in patients presenting, for
Russel WJ, Mackay P. Clinical
anaphylaxis: an analysis of 2000 incident
example, with sudden onset of severe
hypotension (which as Watkins et al.
point out may coincide with the time
of patient transfer to the operating
reports. Anaesthesia and Intensive Care
1993; 21: 621±5.
3 Manthri PR, Wildsmith JAW.
Histaminoid reactions associated with
theatre) needs to be commenced
rapidly. Cardiac massage will be of
rocuronium. British Journal of
Anaesthesia 1999; 82: 823.
limited effect without immediate
intravenous fluids and drug therapy.
General and axial local anaesthesia will
4 Whittington T, Fisher Anaphylactic,
anaphylactoid reactions. In: Bovill JG,
contribute to the effects of vasodilata-
ed. Drug Interaction. London: Bailliere
Tindall, 1998: 311.
tion seen in anaphylaxis. In a recent
report [5], 8 litres of crystalloid were
It is well known that interference
with implanted medical devices such as
pacemakers [1] and implantable defi-
brillators [2] can occur on exposure to
magnetic fields emitted by electronic
article surveillance systems (shoplifting
gates) whose radiation can include
radiofrequency, magnetic and pulsed
electromagnetic fields. There is also
evidence of interference by mobile
communication devices in close proxi-
mity to medical devices [3], and cellular
phones have been banned from operat-
ing theatres and intensive care units in
the past.
5 Heier T, Cuttormsen AB. Anaphylactic
reactions during induction of
administered over 2 h together,
sequentially, with ephedrine, epinephr-
ine, phenylephrine and metaraminol to
a patient experiencing an anaphylactic
reaction to rocuronium, in order to
maintain the CVP . 0. Epinephrine,
which is the basis of drug treatment
for awake patients exhibiting the
symptoms and signs of an anaphylactic
reaction, may for some anaesthetised
patients need to be supplemented by
an alpha constrictor [6, 7].
anaesthesia using rocuronium for
muscle relaxation: a report of 3 cases.
Acta Anaesthesiologica Scandinavica 2000;
44: 775±81.
6 Neal SMCD, Manthri PR, Gadiyar V,
Wildsmith JAW. Histaminoid reactions
associated with rocuronium. British
Journal of Anaesthesia 2000; 84: 108±
11.
7 Higgins DJ, Cayari P. Methoxamine in
the management of severe anaphylaxis.
Anaesthesia 1999; 54: 1126.
The Association of Anaesthetists has
recently announced that it will review
their current report [1] and guidelines
The Home Office Electronic
Monitoring Department states that
8 Association of Anaesthetists of Great
q 2001 Blackwell Science Ltd
295

Correspondence
Anaesthesia, 2001, 56, pages 272±296
................................................................................................................................................................................................................................................
An unusual method of
diagnosing postoperative sore
throat
A 32-year-old engineer presented for
elective arthroscopy on a weekend. He
was assessed pre-operatively and was
noted to have a Mallampati 1 airway
and was generally fit and well. He
elected to receive a general anaesthetic.
After induction with propofol, a size 5
laryngeal mask was placed uneventfully
using the standard technique.
The operative course was uneventful
and, immediately after the surgery, the
patient was comfortable and did not
complain of difficulty swallowing or a
sore throat. However, 2 days after the
surgery, he telephoned the anaesthetic
department complaining that he had a
sore throat that had not improved over
the weekend and that `the floppy thing
at the back of my throat has turned
Figure 16
yellow!' Despite his graphic description
and worries, he was not keen to brave
the Seattle traffic and come to the
electronic monitoring equipment is knowledge of these devices but acted
not known to affect products such as as we thought best in the circumstances.
department. Instead, he reasoned he
could take some pictures with his
newly acquired digital camera and e-
mail them to us. After a few minutes,
we received the fruits of his labours. It
appeared from the pictures (Fig. 16)
that he had an ischaemic uvular. Over
the next few days (and a series of
pictures) the uvular demarcated and
separated.
pacemakers or communication sys-
tems. However, the Personal Identifi- interest to anaesthetists and medical
cation Device is radiofrequency personnel, allowing better management
I hope this information will be of
a
transmitter and therefore could con- of this group of patients in the future. I
tribute to radiofrequency noise and am grateful to Stephen Crunkhorn at
possibly interfere with sophisticated the Home Office for his help and
electronic equipment, although there advice.
are no reports of this happening.
J. Tye
Offenders are advised to contact the
University Hospital Birmingham
NHS Trust,
Uvular trauma has been reported
after general anaesthesia with laryn-
geal masks [1]. The necrosis that our
monitoring contractor prior to
a
hospital admission for removal of the
equipment. Certification from medical
staff is normally required to account
for any curfew hours that have been
missed. Once the offender returns
home, officers would visit to re-install
the personal identification device. In
an emergency, it would be acceptable
for the medical staff to cut the strap
with a normal pair of scissors and the
Control Centre would automatically
record this.
Birmingham, UK
patient
experienced
presumably
occurred as a result of compression
of the uvular by the tip of the
laryngeal mask being folded over, and
remains an unusual complication.
More unusual still was the method
of diagnosis. Yet another useful use
of e-mail!
References
1 Dodinot B, Godenir JP, Costa AB.
Electronic article surveillance: a possible
danger for pacemaker patients. PACE
1993; 16: 46±53.
M. Sanders
2 McIvor ME et al. Study of pacemaker
and Implantable Cardioverter
1722 NE 56th Street,
Seattle, WA 98105, USA
E-mail: mksander@u.washington.edu
Defibrillator Triggering by Electronic
Article Surveillance Devices (SPICED
TEAS). PACE 1998; 21: 1847±61.
Our patient should probably have
contacted his monitoring department to
have the device removed before the
scheduled surgery but there was 3 MDA. MDA Device Bulletin DB
Reference
obviously some communication break-
down. As medical staff, we were also
at fault due to a complete lack of
9702. Electromagnetic Compatibility of
Medical Devices with mobile
communications.
1 Lee JJ. Laryngeal mask and trauma
to uvula. Anaesthesia 1989; 44:
1014±15.
296
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