Full text of DOI:10.1046/j.1365-2044.2003.306519.x

Anaesthesia, 2003, 58, pages 280–300
.....................................................................................................................................................................................................................
Correspondence
Flow through disposable
alternatives to the laryngeal
mask
flowthroughtheshaftisaidedbythelarge
inner diameter (8 mm at a minimum) or gas flow through the different airways
impeded by possible turbulent flow we used a mechanical lung model
In order to compare the resistance to
through the rectangular ÔshaftÕ. (Drager LS 800) in which the compli-
¨
We therefore conducted a study to ance (C) and resistance (R) was set to
There are now various disposable alter-
natives to the laryngeal mask, including compare the resistance to gas flow low values in order to allow for a high
the Portex Soft-Seal laryngeal mask through the SLIPA, the standard laryn- flow rate on expiration, and to mimic a
airway, the Streamlined Pharynx Air- geal mask, the Portex Soft Seal laryngeal clinical scenario where an additional
way Liner (SLIPA) and the disposable mask airway and a Portex tracheal tube increased resistance imposed by an air-
laryngeal mask airway Unique.
(TT). The airways and TT were chosen way may have clinical implications.
The SLIPA has been designed to to represent comparable sises (a size 3 A maximum expiratory flow rate of
provide an inexpensive single-use alter- laryngeal mask, a size 3 Portex Soft Seal 122 l.min)1 was thus achieved. By
native to the laryngeal mask [1]. It is boot laryngeal mask airway, a size 53 SLIPA using a calibrated 30 L syringe, the true
shaped with a toe, bridge and heel and an 8-mm TT). If the relationship compliance of the mechanical lung was
(Fig. 1). The distal boot shaped part of between flow and pressure is not linear, it calculated (22 ml.cmH2O)1). In this
the SLIPA is connected to a proximal would imply turbulent flow. A flow of mechanical lung model, the ÔtrachealÕ
ÔshaftÕ, which in cross-section is rectan- 30 l.min)1 was generated through these pressure is measured, digitised at 300 Hz
gular. This shaft is connected to the airways, and there was no significant and recorded using a computer program
breathing system proximally by a round drop in pressure between the distal and (LungSense, University of Stellenbosch).
connection with an inner diameter of proximal openings, suggesting that the It was thus possible to plot the airway
7 mm.Thecross-sectionareaoftheÔshaftÕ airways pose minimal resistance at pressures against time during deflation
varies from 8 mm · 29 mm for the 30 l.min)1 and therefore turbulent (Fig. 2). Since the mechanical lung
smallest SLIPA to 8 mm · 33 mm for flow could not be a factor at these flow model does not have a natural expo-
the largest. It is not known to what extent rates.
nential drop during the terminal phase
30
25
7mm ID connection
“boot”
20
8mm
15
lma
33mm
8mm
portex
10
slipa
5
0
1
0.3
0.6
0
Shaft
Time (sec)
Narrowing in shaft connecting to
“boot”
Figure 2
Figure 1
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.
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280
Ó 2003 Blackwell Publishing Ltd

Anaesthesia, 2003, 58, pages 280–300
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Correspondence
Table 1 Time constant and calculated resistance for the different airways.
consent form for postoperative analgesia
is limited to that of providing evidence
of the process of consent taking place.
Similar evidence is provided by making
a written note of the proposed anaes-
thetic technique and the possible com-
plications discussed with the patient.
This record could be written on the
anaesthetic chart without the need for
an extra form.
Equation from linear regression of a pressure drop
Resistance; cm
H2O.ml)1.s
from 20 cm H2O to 10 cm H2O
s (s)
SLIPA
p ¼ 3.176 – (11.90 t)
0.084 0.038
0.088 0.040
0.098 0.045
*
Portex Soft Seal
Standard laryngeal mask airway
8 mm ETT
R2 for all the gradients was > 0.98 p: pressure
p ¼ 3.241 – (11.36 t)
*
p ¼ 3.278 – (10.20 t)
*
p ¼ 3.276 – (8.69 t)
0.115 0.052
*
t: time s: time constant
Considering Prof Harmer’s fictitious
patient who refused an epidural be-
cause of the possible associated inser-
tion of a urinary catheter, the patient is
perfectly at liberty to do so; in addi-
tion, it is clear from case-law that he
does not have to explain his reasons for
refusing any option that he has been
offered [4].
Finally, I would partly concur with
Prof Harmer’s suggestion of pre-
operative anaesthetic assessment clinics.
As I have discussed, consent is a process
not a piece of paper and needs time for
the patient to appreciate the options
available. I feel that providing patients
with a large amount of anaesthetic
information on the day of surgery may
pressure them into accepting the option
suggested by the anaesthetist. This is an
example of medical paternalism and if it
continues, then I feel that a case invol-
ving inadequate anaesthetic information
disclosure is inevitable. Therefore, we
must adopt methods of providing
patients with adequate information
about our techniques prior to the final
pre-operative visit of the anaesthetist.
Solutions include both pre-operative
anaesthetic assessment clinics and pre-
operative information leaflets.
General principles of consent
of deflation due to the properties of a
metal spring, the time constant (s) for
I read with interest the editorial ÔCon-
sent and ethics in postoperative pain
management (Harmer. Anaesthesia 2002;
57: 1153–4). Prof Harmer is incorrect
in saying that the General Medical
Council’s advice [1] on obtaining con-
sent is intended primarily for surgical
procedures. Our legal responsibilities as
anaesthetists regarding consent have not
changed; however, cliniciansÕ percep-
tions of consent has. Consent derives
from the principle of autonomy; in law
this was stated by Justice Cardozo in
Schloendorff v Society of New York
Hospital [2], ÔEvery human being of
adult years and sound mind has a right
to determine what shall be done with
his own bodyÕ. This principle of auton-
omy is not limited to surgery and
therefore anaesthetists have a duty to
gain consent before performing any
procedure, be it a general, regional or
local anaesthetic. We do this every day
in our practice when we explain to
patients what is going to occur in the
anaesthetic room. Without valid con-
sent, we are assaulting our patients and
we leave ourselves open to a civil action
based in trespass. This does not occur
for the simple reason that consent forms
are not the process of consent. This is
clearly stated by Bristow J in Chatterton
v Gerson [3], ÔÔ… that getting the
patient to sign a pro forma expressing
each airway was calculated for
a
decrease from 20 cm H2O to 10 cm
H2O by plotting the natural logarithm of
pressure against time and performing a
linear regression to obtain the slope of the
regression line.
Regression yielded the equations for
the different airways as shown in
Table 1. The time constant (s) is the
inverse of the slope. From the equation
s ¼ C · R the resistance (R) for each
airway using this model could then be
calculated.
Comparing the four curves in Fig. 2
using One Way Repeated Measures
Analysis of Variance, there was a statisti-
cally significant difference (p < 0.001)
among the airways, and using Tukey’s
Test it was shown that there was a
significant difference between all airways
(p < 0.001).
In conclusion, despite the irregular
shape of the SLIPA, it does not pose a
greater resistance to airflow in a mechan-
ical lung model set at Ôworst scenarioÕ
clinical setting than the laryngeal mask
airway, the Portex Soft Seal laryngeal
mask airway and a 8-mm TT. The
difference in resistance among the dif-
ferent airways is statistically, but not
clinically significant.
C. M. Danbury
Royal Berkshire Hospital,
Reading RG1 5AN, UK
E-mail: chris.danbury@rbbh-tr.nhs.uk
G. J. Coetzee
University of Stellenbosch,
Tygerberg 7505,
References
1 General Medical Council. Seeking
patient’s consent. The ethical considerations.
General Medical Council. London
1998.
consent …ÕÕ should be
a valuable
South Africa
reminder to everyone of the need for
explanation and consent. But it would
be no defence to an action based on
trespass to the person if no explanation
had in fact been given. The consent
would have been in form only, not in
reality… The duty of a doctor is to
explain what he intends to do, and
its implicationsÕ. Thus, the role of a
E-mail: gertcoetzee@telkomsa.net
2 Schloendorff v Society of New York
Hospital. 211 NY 125 (1914).
3 Chatterton v Gerson and Another.
[1981] QB 432, at 443.
Reference
1 Miller D. M, Lavelle M. A streamlined
pharynx airway liner: a pilot study in 22
patients in controlled and spontaneous
ventilation. Anesthesia and Analgesia
2002; 94: 759–61.
4 In re T. (Adult: Refusal of Treatment).
[1993] Fam. 95, at 102.
Ó 2003 Blackwell Publishing Ltd
281

Correspondence Anaesthesia, 2003, 58, pages 280–300
.....................................................................................................................................................................................................................
of all national and international societies
Second, we want to correct some
Editor’s reply
in the field of TCM to make the TCM- misunderstandings of Kam and Liew.
therapies as safe as possible. The focus The raw ingredients quoted in the
should be on two important points: review cannot cause toxic reaction in
proper education of therapists and good the ordinary patient for the following
I am delighted that my editorial has led
to a heightening of awareness and
would agree with Dr Danbury’s obser-
vations. I would correct his initial
assertion that I stated the advice Ôis
intended primarily for surgical proce-
duresÕ as the precise words were Ôwhilst
the advice might be intendedÕ because
that is the main slant of most consent
documents. I would not disagree with
Dr Danbury that any procedure per-
formed on a patient should be done
with consent.
quality of drugs.
reasons: Aconitum species are not
Most reported cases of severe side- allowed to be sold unprepared except
effects of TCHM are caused by incor- to pharmacies and thus can only reach a
rect treatment. Typical examples are the patient in illegal ways. Datura was only
two cases of nephropathy induced by added to the Chinese materia medica in
Aristolochia in Great Britain in 1999. the last century, when it still was used in
Both patients were treated over a period Europe for asthma. Although it is now
of 2–6 years with the same formula by also listed in the Chinese pharmaco-
general practitioners with no education poeia, it is no part of any traditionally
in TCM or TCHM [4]. Such a long applied prescriptions. As for Venenum
period of TCHM-treatment with the Bufonis and Podophyllum (correctly
same formula is very uncommon. Com- spelled ÔGui JiuÕ), they are also rarely
bined with the lack of proper know- used remedies, which are only applied
ledge by the therapist, this long period externally. An accidental ingestion, as
of intake could be responsible for the suggested by the authors, is less likely
nephropathies rather than the Aristolo- than a mistaken ingestion of amphet-
M. Harmer
Editor-in-Chief
In defence of traditional
Chinese herbal medicine
Kam and Liew have reviewed the side- chia itself. Only therapists with proper amine instead of aspirin because of the
effects and complications of traditional training should be allowed to treat similar spelling.
Chinese herbal medicine (TCHM) patients. Unfortunately, political pres-
The review tends towards exagger-
(Kam & Liew. Anaesthesia 2002; 57: sure has forced German officials to halve ation, especially if single case reports
1083–9). As members of the German the time of TCM-training in conflict with nearly no evidential value are
taskforce on quality control of Chinese with the suggestions of almost all quoted, such as the 87-year-old-patient
herbs of the German Scientific Society German TCM-societies.
of Traditional Chinese Medicine
(DWGTCM e.V.) we would like to
who had a possible adverse effect due to
We are grateful to Kam and Liew in the consumption of too much garlic.
highlighting the problems of getting We want to correct the authors’ link
clarify some points in this review article. herbs of good quality. Most of these between TCHM and the 5-element-
First, we want to thank our dear difficulties could be easily solved in the theory. The prescription of Chinese
colleagues P.C.A. Kam and S. Liew for few countries where the herbs origin- herbs is usually made with other theor-
pointing out the importance of herbal ate (especially China): toxic contamin- ies but not the 5-element-theory.
traditional Chinese medicine (TCM) in ation, blended herbs, non-proper
The reported side-effects of TCHM
so many different countries. The im- preparation, incorrect handling of are not specific. Every therapy has its
pressive numbers support our estima- herbs and incorrect labelling. The own Ôpros and consÕ. Dealing with
tion that more than 1.5 billion people major way of applying Chinese herbs problems of Ôalternative medicineÕ
all over the world are trusting in the is still the herbal decoction (in China > should avoid both Ôuncritical enthusi-
80%), not the patent remedy that was asm… (and) uninformed scepticismÕ [5].
efficacy and safety of TCM. Taking into
account this widespread use of TCM, described by Kam and Liew as the
To focus more on valid data of
the number of reported severe side- main form of application. The quoted TCHM interactions with general
report from Clinical Pharmacology and anaesthesia should be the centre of our
effects is relatively low. This is even
more impressive when compared with Drug Safety checked without excep- attention. In the opinion of the anaes-
the number of side-effects seen with tion only patent remedies, in which thetists in our group, the interactions of
conventional medications. For example 1.53% (32 of 2080) had contaminants TCHM with anaesthesia are more
1 in 200 patients treated with NSAIDs of conventional medications and 2% commonly due to reduced coagulation
for longer than 2 months die of gastro- heavy metal contaminants. This can be (especially after heart-surgery) and dee-
intestinal bleeding [1]. The new Cox- attributed to illegal drug companies per sedation during regional anaesthesia.
2-inhibitors are not much better: only 1 before 1997 located in Hong Kong. For example, salvia milthiorriza and
out of 12 patients treated with these For this reason, the Chinese FDA has ginkgo biloba do have real effects on
very expensive drugs benefits in terms not only closed some of these factories, blood coagulation and thus should not
but also requires from any herbal be taken prior to surgery as with other
of prevented fatal gastrointestinal bleed-
ing compared to conventional NSAIDs pharmaceutical company proof of platelet-inhibitors. But the lowering of
[2]. Both non-selective and selective GMP (Good Manufacturing Practice) blood viscosity is the desired therapeutic
Cox-2-inhibitors can cause renal failure by the end of 2003 and will close any effect, not an adverse or side-effect of
[3]. Nevertheless, it should be the goal company that fails to do so.
these drugs. As for the ÔGinseng abuse
282
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Anaesthesia, 2003, 58, pages 280–300
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Correspondence
3 Ahmad SR, Kortepeter C, Brinker A,
Chen M, Beitz J. Renal failure associ-
ated with the use of celecoxib and
rofecoxib. Drug Safety 2002; 25: 537–
44.
SyndromeÕ with mood elevation and
nervousness, it can be said that Gin-
sengoids Rg1, Rc, etc. have a known
interaction with caffeine, which is why
prescribers of Ginseng with a proper
education in their field, warn their
patients not to take caffeine-containing
beverages during the treatment period.
Our group recommends discontinuing
TCHM, especially if taken with west-
ern drugs, before anaesthesia.
To evaluate these clinical impressions
we invite all anaesthetists to report their
experiences to our homepage http://
www.dwgtcm.com/English/english.html.
Hospitals should look to cooperate with
patients taking herbal remedies and their
therapists. As Kam and Liew have
stated, there is only a tiny amount of
research into Chinese herbs, as no major
western pharmaceutical companies are
lobbying or financing this kind of
research. In the Peoples Republic of
China, 30 years of scientific research has
been done, some with impressive
results, but remains mostly untranslated
and thus ignored.
herbal medicines should be included in
any pre-operative assessmentÕ, and this
includes traditional Chinese and Indian
herbal medications [1].
We agree that THCM is linked to
many theories as suggested in our paper,
and not only to the 5-element theory.
We hope that we have increased the
awareness of anaesthetists to the poten-
tial drug interactions and adverse effects
of traditional Chinese herbal medica-
tions, and call for international and
national regulation of all herbal medi-
cations (natural remedies, and tradi-
tional Chinese, Indian (ayurvedic) and
other cultural herbal medicines).
4 Lord GM, Tagore R, Cook T, Gower
P, Pusey CD. Nephropathy caused by
Chinese herbs in the UK. Lancet 1999;
354: 481–2.
5 Traditional Medicine Team at WHO,
Zhang X. WHO Traditional Medicine
Strategy 2002–05, Geneva, 2002: 2.
A reply
We thank Dr Hosbach and colleagues
for their interest in our review article
and for the opportunity to respond.
It is clear from their comments that
traditional Chinese herbal medicines
(THCM) are widely used throughout
the world. The aim of our article was to
increase the awareness of anaesthetists to
the adverse effects and the contaminants
in THCM. The main problem is that the
prescription and preparation of THCM
is not controlled in many countries.
Because of the absence of strict interna-
tional and national regulations, patients
have access to various traditional med-
icines that have not been evaluated for
safety by good preclinical animal studies,
controlled clinical studies and post mar-
keting surveillance. This is compounded
by the failure or reluctance of many
patients to disclose the THCM they
take, and frequently the exact herb (as a
dried herb or as a tablet) that is dispensed
by the traditional Chinese physician is
not revealed to the patient.
Although western literature on
THCM is restricted to case reports,
we suggest that the adverse effects of
THCM are probably under-reported.
So far, literature from the Peoples
Republic of China that suggests
impressive results from THCM are not
evidence based and ⁄ or poorly con-
trolled. Given that healthcare profes-
sionals and patients are ignorant of the
possibility of interactions between Chi-
nese herbal remedies and anaesthesia,
and also the possibility of added con-
taminants, the most important step is to
increase the awareness of these potential
adverse effects to all concerned. We
support the views of Drs A Sehgal and
J E Hall that Ôquestioning regarding any
P. C. A. Kam
S. Liew
University of New South Wales,
Kogarah, NSW, Australia
E-mail: p.kam@unsw.edu.au
Reference
1 Sehgal A, Hall JE. Herbal medicines –
harmless or harmful? Anaesthesia 2002;
57: 947–8.
Herbal prescriptions are medica-
tions and any medication that has a
main effect may have undesired side-
effects too. It is to the credit of Kam and
Liew that their review will encourage
anaesthetists world-wide to focus on
potential herb anaesthesia interactions.
Transoesophageal
echocardiography during
surgery for intra-atrial masses
We would like to report the following
case of difficulty with diagnosis of a
right atrial mass. An 80-year-old-lady
was referred to our cardiothoracic unit
for urgent resection of a right atrial
myxoma. She had recently been seen in
the medical outpatient clinic complain-
ing of increasing shortness of breath
during the preceding 3 months. On
examination, she was noted to have a
systolic cardiac murmur radiating to the
carotids and bilateral pitting oedema at
the ankles. An ECG showed sinus
rhythm and her full blood count
I. Hosbach
G. Neeb
S. Hager
S. Kirchhoff
B. Kirschbaum
German Scientific Society of
Traditional Chinese Medicine,
Osnabrueck, Germany
E-mail: hosbach@dwgtcm.com
References
1 Moore RA. The hidden costs of arth-
ritis treatment and the cost of new
therapy – the burden of non-steroidal
anti-inflammatory drug gastropathy.
Rheumatology 2002; 41 (Suppl. 1): 7–15.
2 Laine L, Bombardier C, Hawkey CJ
et al. Stratifying the risk of NSAID-
related upper gastrointestinal clinical
events: results of a double-blind out-
comes study in patients with rheuma-
toid arthritis. Gastroenterology 2002; 123:
1006–12.
showed
a microcytic hypochromic
anaemia. A transthoracic echocardio-
gram (TTE) was performed. This was
reported by a consultant cardiologist as
showing moderate mitral regurgitation
and a mass in the right atrium that
appeared to be pedunculated and
attached to the intra-atrial septum
(IAS) (Fig. 3). The diagnosis of a right
atrial myxoma was made and she was
transferred for urgent surgery.
Ó 2003 Blackwell Publishing Ltd
283

Correspondence Anaesthesia, 2003, 58, pages 280–300
.....................................................................................................................................................................................................................
The surgical plan was to use bicaval
General anaesthesia was induced and both atria, the IAS and the inferior
venous bypass lines to facilitate a right the TOE probe inserted by the anaes- and superior caval veins. In this view,
atrial incision and use transoespha- thetist whilst the patient was prepared the right atrial mass was clearly seen to
geal echocardiography (TOE) intra- and draped. As part of the standard be arising from the inferior vena cava
operatively to assess the surgical TOE examination [1] a bicaval view (IVC) and to not be attached to the
result.
was obtained (Fig. 4) demonstrating IAS. This contradicted the diagnosis of
atrial myxoma and surgery was aban-
doned prior to incision. A CT scan
performed the following day showed a
renal hypernephroma with extension
into IVC.
Intraoperative TOE has been recom-
mended for the evaluation of removal
of intracardiac tumours [2]. In this case,
TOE prevented an unnecessary opera-
tion and potentially averted technical
difficulties and morbidity that may have
occurred had the IVC been cannulated
as planned. However, Leibowitz et al.
suggest that TOE should be considered
in the diagnostic assessment of patients
with right atrial masses, even when
these masses have been demonstrated
with TTE [3]. On the basis of this case,
we believe that TOE should be consid-
ered for all cases of suspected right atrial
tumour prior to surgical referral. In our
patient, such a policy would have
avoided an unnecessary anaesthetic.
Figure 3 A transthoracic image showing a mass in the right atrium that appears to be
pedunculated and attached to the intra-atrial septum.
A. Mellor
J. Clark
N. J. Morgan-Hughes
P. C. Braidley
Northern General Hospital,
Sheffield S7 5UA, UK
References
1 Shanewise JS, Cheung AT, Aronson S
et al. ASA ⁄ SCA Guidelines for Per-
forming a Comprehensive Intra-
operative Multiplane Transesophageal
Echocardiography Examination:
Recommendations of the American
Society for Intraoperative Echocardio-
graphy and the Society of Cardio-
vascular Anesthesiologists Task Force
for Certification in Perioperative
Transesophageal Echocardiography.
Anesthesia and Analgesia 1999; 89:
870–84.
2 Practice guidelines for perioperative
transesophageal echocardiography.
American Society of Anesthesiologists
and the Society of Cardiovascular
Anesthesiologists Task Force on
Transesophageal Echocardiography.
Anesthesiology 1996; 84: 986–1006.
Figure 4 A transoesophageal bicaval view demonstrating both atria and the inferior and
superior caval veins. In this view the right atrial mass is clearly seen to be arising from the
inferior vena cava.
284
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Correspondence
20.8 mmol.l)1, Creatinine 1.13 lmol.l)1, than in children but is considered along
3 Leibowitz G, Keller NM, Daniel WG,
Bicarbonate 18 mmol.l)1
,
Alkaline with stridor and the inability to lie flat a
Freedberg RS, Tunick PA, Stottmeister
C, Kronzon I. Transesophageal versus
transthoracic echocardiography in the
evaluation of right atrial tumors.
American Heart Journal 1995; 130:
1224–7.
Phosphate 133, ALT 35, Albumin strong predictor of the need for airway
30 g.l)1 and CRP of 21. Full blood intervention [1,2]. Even enthusiasts of
count
revealed:
Haemoglobin conservative management acknowledge
113 g.l)1, WBC 2.6 and Platelets 135. that airway intervention can be expec-
The patient was noted to be lympho- ted to be required in around 15–20% of
paenic.
adult patients [1,2]. Patients can often
His chest X-ray was unremarkable be managed conservatively but there are
and blood cultures later produced no other cases where unexpected airway
A sore throat in a dialysis
patient
growth.
loss has occurred [3]. I believe it is
He was treated empirically with important that such cases are reported so
intravenous fluids and timentin 3.1 g, that the literature accurately reflects the
although the diagnosis was not clear at incidence of this complication.
I would like to present my recent
experience with a tragic case of epi-
glottitis.
this time. Approximately 1 h after the
initial assessment, the patient developed immunosuppressed as a result of his
a hoarse voice and complained of renal failure not being optimally treated.
This patient was undoubtedly
A 34-year-old-man presented to the
emergency department having been
referred by his GP. He gave a 24-h
history of sore throat, malaise, nausea,
vomiting and sweating. His nausea had
improved and he had eaten following
his arrival in the emergency depart-
ment. He was short of breath on
exertion but not at rest with no cough
or sputum. The patient suffered from
chronic renal failure and was currently
treated with peritoneal dialysis. He had
not dialysed that day but the previous
day his peritoneal fluid was clear. He
was suffering from chronic renal failure
secondary to IgA nephropathy. In the
past, he had undergone two failed renal
transplants, a parathyroidectomy and
had been on haemodialysis. He was
currently treated with lisinopril and
amlodipine for hypertension.
Supplementary history was obtained
from his dialysis unit. He had suffered
recurrent episodes of peritonitis and
vancomycin-resistant enterococci infec-
tion. He had been advised to recom-
mence haemodialysis but had not
followed this advice.
On examination, he was sat by his bed,
apyrexial, alert and orientated, with an
oxygen saturation of 96% in room air.
His respiratory rate was 18.min)1, talking
freely without distress, pulse 110 beats.-
min)1, blood pressure 110 ⁄ 60 mlHg,
and was noted to be cool peripherally.
Examination of his chest was unremark-
able. The abdomen was noted to be soft
with multiple striae, a dialysis catheter in
situ and was non-tender to palpation.
Examination of his throat showed it to be
mildly erythematous but nil else.
increased difficulty in breathing.
It is likely this contributed to his
Senior assistance was sought from the demise. Overwhelming sepsis compli-
anaesthetic department, intensive care cated this case resulting in acute lung
unit and the on-call general surgeon. injury and septic shock. I hope to
The patient was given nebulised epi- increase awareness that epiglottitis may
nephrine 5 mg repeatedly and dexa- prove fatal even after the airway is
methasone 8 mg intravenously. The secured.
patient’s condition continued to deteri-
S. Williams
orate with increasing respiratory distress
Nambour General Hospital,
and stridor.
Queensland 4560,
An inhalational induction was per-
Australia
formed with sevoflurane and the trachea
E-mail: steven85@doctors.org.uk
intubated with a size 7 tracheal tube with
the aid of a bougie. The epiglottis and
surrounding structures were noted to be
swollen at laryngoscopy. The patient
became hypotensive post intubation
requiring inotropes and fluids. He was
transferred to the intensive care unit
where he was treated with vancomycin
1 g, gentamicin 320 mg and ceftriaxone
2 g. Infusions of epinephrine, norepi-
nephrine and vasopressin were com-
menced sequentially. The patient was
commenced on renal replacement ther-
apy with haemodialafiltration. However,
under recognised, life threatening con-
he failed to respond to any of the
interventions and died of refractory sep-
tic shock approximately 12 h after his
arrival in the emergency department.
A swab was taken from the epiglottis,
culture of which showed group A
Streptococci sensitive to penicillin. A
post mortem examination was in keep-
ing with the diagnosis of epiglottitis.
Adult epiglottitis typically presents
with severe sore throat and difficulty
swallowing usually in a pyrexial patient
[1,2]. The presence of respiratory dis-
tress at presentation is more variable
References
1 Herbert PC, Ducic Y, Boisvert D,
Lamothe A. Adult epiglottitis in a
Canadian setting. Laryngoscope 1998;
108: 64–9.
2 Frantz TD, Rasgon BM, Quesenberry
CP Jr. Acute epiglottitis in adults.
Analysis of 129 cases. Journal of the
American Medical Association 1994; 272:
1358–60.
3 Ames WA, Ward VMM, Tranter
RMD, Street M. Adult epiglottitis: an
dition. British Journal of Anaesthesia
2000; 85: 795–7.
Cocaine and pulmonary oedema
Dr Symons has drawn attention to the
anaesthetic problems that may be asso-
ciated with illicit drug abuse (Symons.
Anaesthesia 2002; 57: 1142). This prob-
lem may be more widespread than
hitherto suspected. Recent correspond-
ents have described cases of acute
pulmonary oedema in healthy adults at
His biochemistry revealed: Na
137 mmol.l)1, K 3.7 mmol.l)1, Urea
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285

Correspondence Anaesthesia, 2003, 58, pages 280–300
.....................................................................................................................................................................................................................
artificial ventilation? Anaesthesia 1997;
52: 956–62.
the time of anaesthesia without obvious ventilation, improve cardiovascular sta-
cause (Norman. Anaesthesia 2002; 57: bility and reduce mortality. Magnesium
206, Dodd. Anaesthesia 2002; 57: 726). offers the possibility of all three and its
It has been overlooked that cocaine use has been described in a small
smokers are at risk of acute pulmonary number of case reports [1] and uncon-
oedema [1, 2] and that this may present trolled case series [2,3]. The authors of
during anaesthesia in the manner des- this recent series report remarkable
3 James MF, Manson ED. The use of
magnesium sulphate infusions in the
management of very severe tetanus.
Intensive Care Medicine 1985; 11: 5–12.
4 James MF. Magnesium sulphate for the
control of spasms in severe tetanus.
Anaesthesia 1998; 53: 605–6.
cribed by Norman and Dodd [3, 4].
success with its use, and conclude by
Acute pulmonary oedema in a young recommending its use as a first line
otherwise healthy adult without predis- agent in tetanus.
posing risk factors must alert the anaes-
Magnesium poses real risks including
Minor or major?
thetist to the possible diagnosis of muscle weakness, paralysis and cardio-
cocaine abuse. This possibility must vascular side-effects. Reservations have
always be investigated fully. Experience already been expressed in this journal
shows that when such a complication regarding its safety, particularly in set-
arises, unless a non-negligent cause can tings where facilities for ventilation are
be demonstrated, lawyers and their not available [4]. Given these very real
medical expert advisers may attempt to concerns, it is vital that the drug is
identify or surmise some relevant error carefully evaluated before recommend-
or minor misjudgement by the anaes- ing its widespread use. Our own
We read with interest the paper (Fikkers
et al. Anaesthesia 2002; 57: 1094–7),
looking at the results of performing
percutaneous tracheostomy using the
Ciaglia Blue RhinoTM technique. In
100 patients, they managed to achieve a
headline complication rate of 36.7%
(36/98), of which 6.1% were classified
as major. We agree with them that it is
important to distinguish between major
and minor complications as many of the
complications reported in previous
papers about percutaneous tracheosto-
my are of minimal or no clinical
consequence to the patient; for exam-
ple, minor bleeding from the skin edges.
We do disagree, however, with their
classification of what constitutes a major
or minor complication. To classify
posterior tracheal wall puncture as a
minor complication is wrong – it is this
very complication which is most feared
during percutaneous tracheostomy, as it
may lead to posterior tracheal wall tear,
pneumothorax, pneumomediastinum or
tracheo-oesophageal fistula formation
[1–3]. It is for this very reason that
many authors have advocated the use of
fibre-optic bronchoscopy during the
procedure to minimise the risk of this
occurring [4]. We would also contend
that accidental extubation, subcuta-
neous emphysema, puncture of the
tracheal tube, difficult tube placement
and air leakage constitute major com-
plications. Recalculating their major
complication rate raises it from the
original 6.1% to 21%. Despite the use
of a bronchoscope, the authors still
thetist, and claim compensation.
experience with magnesium is that it
may be helpful in controlling spasms and
cardiovascular parameters, but the results
are by no means clear and we remain very
concerned about the risks of profound
muscle weakness and hypotension.
C. Hutter
City Hospital
Nottingham NG5 1PB, UK
References
Drs Attygalle and Rodrigo state that
when designing the study they consid-
ered it Ôunfair to subject patients to
conventional therapyÕ. We, however,
argue that with the available evidence,
magnesium remains a potentially exci-
ting treatment for tetanus, but one that
carries a substantial risk of causing more
harm. A carefully designed double blind
randomised controlled clinical trial of
sufficient sample size is still required to
establish the evidence for magnesium’s
efficacy and its safety profile. Until the
results from such a trial are available, we
believe magnesium cannot be advocated
as a first line treatment in tetanus.
1 Hoffman CK, Goodman PC. Pulmon-
ary edema in cocaine smokers. Radiol-
ogy 1989; 172: 463–5.
2 Ettinger NA, Albin RJ. A review of the
respiratory effects of smoking cocaine.
The American Journal of Medicine 1989;
87: 664–8.
3 Bird DJ, Markey JR. Massive pul-
monary edema in a habitual crack
cocaine smoker not chemically positive
for cocaine at the time of surgery.
Anesthesia and Analgesia 1997; 84:
1157–9.
4 Singh PP, Dimich I, Shamsi A. Intra-
operative pulmonary oedema in a
young cocaine smoker. Canadian Jour-
nal of Anaesthesia 1994; 41: 961–4.
C. L. Thwaites
J. J. Farrar
The Hospital for Tropical Diseases,
Ho Chi Minh City,
Viet Nam
Magnesium sulphate as a first
line therapy in the management
of tetanus
E-mail: lthwaites@hcm.vnn.vn,
jeremyjf@hcm.vnn.vn
We were delighted to read the paper
(Attygalle & Rodrigo. Anaesthesia 2002;
57: 811–17) indicating renewed interest
References
in the treatment of tetanus, a disease 1 Williams S. Use of Magnesium to treat report a very high complication rate,
that still affects up to 1000 000 people a tetanus. British Journal of Anaesthesia
year. Most tetanus occurs where facil-
2001; 88: 152.
ities for ventilation are limited, and 2 Attygalle D, Rodrigo N. Magnesium
far in excess of the rate seen in our ICU
where bronchoscopy is not routinely
used – our complication rate in 220
there is a desperate need for new
treatments that diminish the need for
sulphate for control of spasms in severe patients (up to the end of 2001) with
the Blue RhinoTM technique is 6.4%
tetanus. Can we avoid sedation and
286
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Anaesthesia, 2003, 58, pages 280–300
.....................................................................................................................................................................................................................
Correspondence
learning curve. Intensive Care Medicine
2002; 28: 59–62.
(14/220) – 8 bleeds, 1 subcutaneous
emphysema, 1 posterior tracheal wall
injury, 2 difficult insertions, 1 cuff leak,
1 procedure abandoned.
oscillating the tube to ensure that the
needle has not impaled the tube. In our
opinion, it does not constitute a major
problem either.
5 Johnson JL, Cheatham ML, Sagraves
SG, Block EF, Nelson LD. Percutane-
ous dilational tracheostomy: a compar-
ison of single- versus multiple-dilator
techniques. Critical Care Medicine 2001;
29: 1251–4.
We agree with the authors that
procedure time is not important in the
performance of a percutaneous trache-
ostomy – safety is paramount, not
speed. We would therefore ask why
they, like several others, have timed
their procedures? [5]. They also state
that the use of a Crile’s forceps for blunt
dissection shortened their procedure
time. Is this either statistically significant
or clinically relevant? The use of blunt
dissection increases tissue trauma,
increasing the incidence of bleeding
and wound infection and so is not part
of the procedure in our ICU. For easier
passage of the dilator, we recommend
maintaining the wet conditions on the
hydrophilic coating during insertion
and an adequate initial incision. We
wish the authors continued success with
the Blue RhinoTM technique of percu-
taneous tracheostomy, and I expect that
their complication rate will fall as they
gain experience. We strongly advise
them, however, to abandon blunt dis-
section and learn to push a little harder
with the dilator!
Timing of the procedure. We agree that
this is usually not very important and is
influenced, for example, by the
procedure being performed by less
A reply
experienced
colleagues
under
We thank Drs Morgan and Roberts for
their interest in our study. Dealing with
the points raised sequentially:
supervision, as is often the case in a
teaching hospital like ours. But
sometimes the duration of the
procedure, and particularly the time
that the patient is not adequately
ventilated, may be critical in patients
with severe respiratory difficulties. Also
in emergency situations, percutaneous
techniques may be used [4,5]. In those
circumstances, the fastest procedure may
be desirable [6]. Therefore, timing of the
procedure was and is of interest.
Minor and major complications. We care-
fully registered all the problems we
encountered, even those problems that
were easily overcome. We defined major
complications as those requiring surgical
or medical intervention. Posterior wall
puncture, seen at bronchoscopy, in this
context constitutes a minor event. The
use of bronchoscopy creates a direct view
of the posterior tracheal wall. In cases of
imminent puncture of the posterior
tracheal wall, puncture can be avoided.
This is the main reason why we routinely
advocate bronchoscopy [1]. We choose
to speak of ÔpunctureÕ and not of Ôper-
forationÕ, which can be devastating [2]. It
is important to note that this would
remain unrecognised without perform-
ing bronchoscopy. Pneumothorax only
can happen if the puncture is off the
midline and perforates the posterior
tracheal wall. Understandably, we always
take precautions to avoid accidental
extubation, but it is only a real problem
in cases of difficult intubation. The two
patients where accidental extubation has
happened were easily re-intubated. The
only case where subcutaneous emphys-
ema was impressive was related to the use
of a fenestrated tube [3]. With appropri-
ate measures, the emphysema disap-
peared within several hours, so we deci-
ded to define this as an annoying, but
minor, complication because there were
no residual problems for the patient.
Difficulties in introducing the cannula
were encountered twice and were rela-
ted to the transition from obturator to
cannula-tip. As discussed, the diameter of
a Shiley-cannula is relatively large, ma-
king introduction sometimes difficult,
but not impossible. Puncture of the
tracheal tube is a well known problem,
which is diagnosed easily by rotating and
Blunt dissection. This is not always
necessary. However, the use of the
Crile’s forceps was in many cases clin-
ically important. We always perform
blunt dissection in the midline, avoiding
blood vessels lying more laterally. Iden-
tification of the trachea, by digital
palpation, was a lot easier, so the
puncture was easier and the time of
compromised ventilation was therefore
shorter than before the use of the Crile’s
forceps. Many other authors using the
multiple dilators technique, and even
Ciagla in his original paper, advocate
the use of some blunt dissection and so
do several authors using the Blue Rhino
technique [7–10].
We appreciate the good wishes of
Drs Morgan and Roberts, but we want
to stress that the meticulous way we
prospectively registered our peri-opera-
tive complications makes our survey
difficult to compare with registrations
not done in the context of research.
P. Morgan
R.G. Roberts
University Hospital of Wales,
Cardiff CF14 4XW, UK
References
1 Dulguerov P, Gysin C, Perneger TV,
Chevrolet JC. Percutaneous or surgical
tracheostomy: a meta-analysis. Critical
Care Medicine 1999; 27: 1617–25.
2 Massick DD, Yao S, Powell DM, et al.
Bedside tracheostomy in the intensive
care unit: a prospective randomized trial
comparing open surgical tracheostomy
with endoscopically guided percutane-
ous dilational tracheotomy. Laryngoscope
2001; 111: 494–500.
B. G. Fikkers
J. M. M. Verwiel
3 Bowen CP, Whitney LR, Truwit JD,
Durbin CG, Moore MM. Comparison
of safety and cost of percutaneous ver-
sus surgical tracheostomy. American
Surgeon 2001; 67: 54–60.
F. J. A. van den Hoogen
University Medical Center Nijmegen,
6500 HB Nijmegen, The Netherlands
E-mail: b.fikkers@ic.umcn.nl
4 Beiderlinden M, Karl Walz M, Sander
A, Groeben H, Peters Complications of
bronchoscopically guided percutaneous
dilational tracheostomy: beyond the
References
1 van Heerbeek N, Fikkers BG, van den
Hoogen FJ. False passage during
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287

Correspondence Anaesthesia, 2003, 58, pages 280–300
.....................................................................................................................................................................................................................
percutaneous tracheostomy using the
Guide Wire Dilating Forceps. Inter-
national Journal of Surgical Investigation
2001; 3: 469–72.
2 Trottier SJ, Hazard PB, Sakabu SA
et al. Posterior tracheal wall perfor-
ation during percutaneous dilational
tracheostomy: an investigation into its
mechanism and prevention. Chest
1999; 115: 1383–9.
3 Mostert MJ, Stuart H. Subcutaneous
emphysema caused by a fenestrated
tracheostomy tube. Anaesthesia 2001;
56: 191–2.
4 L’her E, Goetghebeur D, Boumedi-
enne A, Renault A, Boles JM. Use
of the Blue Rhino tracheostomy set
for emergency airway management.
Intensive Care Medicine 2001; 27: 322.
5 Dob DP, McLure HA, Soni N. Failed
intubation and emergency percutane-
ous tracheostomy. Anaesthesia 1998;
53: 72–4.
Figure 5
6 McLure HA, Dob DP, Mannan MM,
Soni N. A laboratory comparison of
two techniques of emergency percu-
taneous tracheostomy. Anaesthesia
syringes, taps, extension tubing and the first line vasopressor for obstetric
intravenous cannulae can result in loss regional anaesthesia.
1997; 52: 1199–201.
7 Ciaglia P, Firsching R, Syniec C.
of anaesthetic agent. Pooling of propo-
Recent evidence supports the use of
Elective percutaneous dilatational
tracheostomy. A new simple bedside
procedure; preliminary report. Chest
1985; 87: 715–19.
fol and clear opiate solutions on the alpha adreno-receptor agonists as an
syringe driver and sheets is not always alternative, or in addition, to ephedrine
obvious. We present a simple, low-cost for the treatment or prevention of
device for detecting leakage in a TIVA hypotension during spinal anaesthesia
8 Bewsher MS, Adams AM, Clarke
CW, McConachie I, Kelly DR.
Evaluation of a new percutaneous
dilatational tracheostomy set
system.
for elective Caesarean section [1–4]. We
A coloured paper towel, as routinely are concerned, however, about the risks
used in the anaesthetic room, is folded of changing practice en masse towards
and placed under system connections at the use of potent agents that may be
the syringe and at the patient cannula relatively unfamiliar to many anaesthet-
(Fig. 5). Fluid leaking onto the paper ists. We suggest the following measures
towel results in a dramatic darkening of to minimise the risk:
the coloured paper, which is appreci-
able at a glance and from a distance. basis rather than an individual basis.
This simple device adds to patient safety
at negligible cost.
apparatus. Anaesthesia 2001; 56:
859–64.
9 Johnson JL, Cheatham ML, Sagraves
SG, Block EF, Nelson LD. Percuta-
neous dilational tracheostomy: a
comparison of single- versus multiple-
dilator techniques. Critical Care Medi-
cine 2001; 29: 1251–4.
Policy change should be on a unit
Units should have a clear, written
policy for the dilution and administration
of their chosen vasopressor. We append
our local regimen as an example.
For phenylephrine, there may be
advantages in arranging for the hospital
pharmacy to supply premixed solutions.
In addition, we wish to draw atten-
tion to the existence of different for-
mulations of phenylephrine. An initial
order for the supply of phenylephrine to
10 Scott MJ, Leigh J. Percutaneous
tracheostomy in three morbidly obese
patients using the ÕBlue RhinoÕ tech-
nique. Anaesthesia 2000; 55: 917–19.
A. J. Matthews
E. Rawlings
Derriford Hospital,
Plymouth L6 8DH, UK
A simple leak detection device
for TIVA
Phenylephrine in obstetric
regional anaesthesia
Leakage from total intravenous anaes- We wish to raise awareness of poten- the delivery suite from the hospital
thesia (TIVA) devices is a potential
cause of inadequate anaesthesia and
pharmacy at one of our units led to
the supply of ampoules containing
awareness. Loose connections between use of phenylephrine from ephedrine as 50 mg of phenylephrine in 5 ml.
tially serious drug administration errors
that may occur when changing to the
288
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Anaesthesia, 2003, 58, pages 280–300
.....................................................................................................................................................................................................................
Correspondence
Clearly this represented a hazard, and Apparatus/preparation
others should be aware of this.
NB treating relative bradycardia
Use a ÔGraseby 3400 anaesthesia pumpÕ. (heart rate 50–60 beat.min)1) with
Draw 30 ml of the diluted phenyl- glycopyrronium when the SBP is nor-
ephrine solution (100 lg.ml)1) into a mal, or increased, can lead to moder-
V. E. Bythell
Royal Victoria Infirmary,
Newcastle-upon Tyne,
E1 4LP, UK
50-ml luer lock syringe.
Before attaching to the patient, prime
a fine bore infusion line using the bolus delivery.
facility on the syringe driver.
Connect the infusion line and the i.v.
ate ⁄ severe hypertension.
Discontinue infusion
following
E-mail: vbythell@aol.com
P. Mowbray
Problems performing a sciatic
nerve block in an amputee
fluid line, via a Y-connector, to an i.v.
cannula. Use an anti reflux valve to
prevent reflux of vasopressor into the
i.v. giving set. Ensure that the i.v. fluid
infusion runs continuously during the
phenylephrine infusion to flush the
dead space in the Y-connector. Alter-
natively use a dedicated i.v. cannula for
the phenylephrine infusion.
University Hospital of North Tees,
Stockton TS19 8PE, UK
We would like to highlight an interest-
ing clinical conundrum that we faced
recently. An 81-year-old-male diabetic
patient had undergone a below knee
amputation for a gangrenous right foot
under spinal anaesthesia. He presented
on the emergency list one week later for
an above knee amputation of the same
limb due to infection. This time he was
toxaemic and uncooperative. It was
decided that a ÔlightÕ general anaesthetic
with a combined femoral and sciatic
block would be the best technique in
this circumstance, giving good intra-
operative and postoperative analgesia.
Anaesthesia was induced with mida-
zolam, fentanyl and propofol. A laryn-
geal mask airway was inserted and
anaesthesia maintained with oxygen,
air and sevoflurane. Under aseptic con-
ditions the femoral nerve was located
using a 20G short bevelled polar needle
with a nerve locator set at 1Hz with a
current of 0.4 mA. Following a negat-
ive aspiration test, the block was insti-
tuted using 20 ml of bupivacaine
0.375%. However, when the sciatic
block was attempted via the lithotomy
approach, we realised that we would
not be able to elicit contractions of the
foot. After careful consideration, 20 ml
bupivacaine 0.375% was injected in the
groove between biceps femoris and
semitendinous muscles at the midpoint
between the greater trochanter and the
ischial tuberosity at a depth of 6 cm as
described by Raj et al. [1]. Surgery
proceeded uneventfully and the patient
emerged from anaesthesia pain free.
Whilst we are aware of the contro-
versies of putting regional blocks in
patients who are anaesthetised [2,3],
even had the sciatic block been per-
formed awake, we could not have relied
on the patient to describe paraesthesia
over the sciatic distribution. We would
D. W. Cooper
James Cooke University Hospital,
Middlesborough TS4 3BW, UK
References
1 Cooper DW, Carpenter M, Mowbray
P, Desira WR, Ryall DM, Kokri MS.
Fetal and maternal effects of phenyl-
ephrine and ephedrine during spinal
anaesthesia for caesarean delivery.
Anesthesiology, in press.
Infusion protocol
Baseline maternal systolic blood pres-
sure (SBP) should be measured before
coming to theatre. NB the SBP meas-
ured in the anaesthetic room immedi-
ately prior to spinal anaesthesia is often
10–20% greater than true baseline.
Immediately following intrathecal
injection of local anaesthetic:
2 Lee A, Ngan Kee WD, Gin T. A quan-
titative, systematic review of randomized
controlled trials of ephedrine versus
phenylephrine for the management of
hypotension during spinal anesthesia for
cesarean delivery. Anesthesia and Anal-
gesia 2002; 94: 920–6.
Start the phenylephrine infusion at
20 ml.h)1 (33 lg.min)1).
Measure SBP every minute.
3 Mercier FJ, Riley ET, Frederickson WL,
Roger-Christoph S, Benhamou D,
Cohen SE. Phenylephrine added to
prophylactic ephedrine infusion during
spinal anesthesia for elective cesarean
section. Anesthesiology 2001; 95: 668–74.
4 Ngan Kee WD, Lau TK, Khaw KS,
Lee BB. Comparison of metaraminol
and ephedrine infusions for maintaining
arterial pressure during spinal anesthesia
for elective cesarean section. Anesthesi-
ology 2001; 95: 307–13.
Measure heart rate continuously.
Aim to keep systolic arterial pressure
at baseline.
Alter infusion rate by doubling or
halving (range 2.5–40 ml.h)1).
If the SBP decreases below baseline,
double the set infusion rate (maximum
rate 40 ml.h)1). If SBP continues to
decrease give 1 ml boluses as required
from the syringe driver.
Maternal hypotension (SBP < 75% of
baseline) not responding to the max-
imum infusion rate of 40 ml.h)1 and
1 ml boluses: give 3 mg boluses of eph-
edrine and ⁄ or put the patient in the full
left lateral position. Treat any associated
Appendix
Protocol for phenylephrine
(100 lg.ml)1) infusion during spinal bradycardia with glycopyrronium.
If the SBP increases above baseline,
IMPORTANT: Dilution of Phenyl- keep halving the infusion rate, and stop
anaesthesia for Caesarean section
ephrine to 100 lg.ml)1
Add 10 mg of phenylephrine (1 ml
:
the infusion if < 2.5 ml.h)1 is required.
Maternal hypertension (SBP > 125%
of 10 mg.ml)1 solution) to a 100-ml of baseline): stop the infusion and restart
bag of normal saline.
it at half the rate once it has fallen below
this threshold.
If heart rate < 60 bpm and the patient
is hypotensive, or if heart rate < 45
bpm: give glycopyrronium 200 lg i.v.
Clearly label as phenylephrine
100 lg.ml)1, date, sign and add red
phenylephrine sticker.
Exclude patients with PIH.
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289

Correspondence Anaesthesia, 2003, 58, pages 280–300
.....................................................................................................................................................................................................................
D. Sood
welcome any comments or suggestions
on this case.
the RLMA when in situ. In this device,
the tracheal connector stops the RLMA
from spinning on the stylet and yet
leaves it easy to withdraw once posi-
tioned in the patient.
Whilst interesting to learn of a
broadly similar solution to this problem,
it is suggested that the need to inflate a
cuff (to prevent the outer tube rotating)
as an alternative to the simpler East
Grinstead design, is perhaps an over-
complication and, in use, more time
consuming.
M. Rupinder Singh
A. Grewal
C. Lok
S. Saini
P. Kirk
I. Singh
North Manchester General Hospital,
Manchester M8 5RB, UK
D.M.C. & Hospital,
Ludhiana-141001,
Punjab, India
References
E-mail: drgurdeep@yahoo.com
1 Raj PP, Parks RI, Watson TD, Jenkins
MT. A new single position supine
approach to sciatic-femoral nerve
block. Anesthesia and Analgesia 1975;
54: 489–93.
Stylet for reinforced laryngeal
mask airway
I read with interest the recent corres-
pondence ÔStylet for reinforced laryn-
geal mask airwayÕ (Shimoda
Yoshitake. Anaesthesia 2002; 57: 1140–
1). We have been using similar intro-
ducers for some nine years for safe and
P. Andrews
2 Bromage PR. Masked Mischief.
Regional Anesthesia 1996; 21 (6S): 62–3.
3 Aitkenhead AR. The pattern of litiga-
tion against anaesthetists. British Journal
of Anaesthesia 1994; 73: 10–21.
Queen Victoria Hospital,
East Grinstead, RH19 3DZ, UK
E-mail: paul.andrews@qvh.nhs.uk
&
simple insertion of the reinforced laryn- Measurement of oxygen
geal mask airway (RLMA) without the consumption during low-flow
need to guide it by hand inside the anaesthesia
mouth. Our original device (Fig. 6)
Volume and colour coding
for syringes
A recent paper (Leonard et al. Anaesthesia
2002; 57: 654–8), evaluated elaborate
cheal connector with cold acrylic glue, techniques for the estimation of oxygen
and an uncuffed paediatric red rubber consumption, but it does seem rather
perverse to use invasive measurement of
cardiac output and the reverse Fick
A second version was devised shortly method to do so. Also your recent
incorporated a metal intubating stylet
fixed into a Portex female plastic tra-
We read with interest the article:
ÔStandardised colour coding for syringe
drug labels: a national survey’ (Christe
& Hill. Anaesthesia 2002; 57: 773–98)
and thought of reporting our hospital
policy regarding syringe labels.
tracheal tube was railroaded over the
stylet to ensure a Ôsnug fitÕ.
In our hospital, hand-written white
syringe drug labels are used but only
on volume-coded syringes of specific
capacity. For an adult patient, it is a
convention to load the drugs in appro-
priate volume-coded syringe, label and
keep them on the anaesthesia machine
as follows:
correspondent (Shankar. Anaesthesia
2002; 57: 1136) does not need to do
straightforward to use, particularly all those sums to estimate the oxygen
after (Fig. 7) that dispensed with the red
rubber tube as it was found to be more
consumption of his patients. If he sticks
to his first principle of adding enough
oxygen to keep a closed circuit full, then
it follows that the patient’s requirements
will always be met. But if the bellows are
at the top of the ventilator ÔbottleÕ, he
will not know how much gas is being
dumped from the circuit into the scav-
enging system. All that is required is for
the bellows to be below the top of the
bottle and for enough oxygen to be
supplied to keep it at a constant level at
the end of each expiration. The oxygen
added is then equal to the patient’s
consumption, assuming nitrous oxide is
not being used.
when removing the introducer from
Induction agents
Neuromuscular
blockers
20 ml
Depolariser
Non-depolariser
Narcotics
Anticholinesterase
+ Anticholinergic
Others
2 ml
5 ml
1 ml
10 ml
Figure 6
3 ml (labelled
and kept on side
trolley)
We fully agree with the authors that
syringe labels should have an interna-
tional colour coding, but along with it
we strongly recommend that the syrin-
ges should also be volume coded of
specific capacity for specific drugs so
that only looking at the volume of the
syringe immediately tells the anaesthet-
ist the class of drug it contains.
In any case, Dr Shankar’s sums are a
little suspect. He first asserts that
the oxygen consumption is limited by
the amount of oxygen flowing into the
system, and that the patient cannot take
up more oxygen than is given to him.
This may be true when the oxygen in
the circuit is running out, but oxygen
consumption is dependent on the
Figure 7
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Anaesthesia, 2003, 58, pages 280–300
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Correspondence
metabolic rate, not on the oxygen intracuff pressure of the laryngeal tube about anaesthetic practice for cardio-
supply. Even if the oxygen supply is (LT) 30 min after its insertion, rightly version. A questionnaire was sent to
turned off, oxygen continues to be expressing their concerns of mucosal consultant anaesthetists at 150 randomly
consumed at the same rate and all that damage that may occur [1,2]. With these selected hospitals throughout the UK.
happens to begin with is that the concerns in mind and after approval Questions were designed to establish
volume in the circuit decreases. If the from our ethics committee, and consent basic data about the site and timing of
oxygen concentration in a 6-l circuit is from the patients, we conducted a study the procedure and the personnel, drugs
33%, then it contains 2 l of oxygen. At a in which 40 ASA grade I and II patients, and equipment available.
consumption of 250 ml.min)1
,
this undergoing elective surgery had their
Of the questionnaires sent, 107
would be halved after 4 min, and the airways maintained with a LT size 4 (71.3%) were returned. The results
oxygen concentration would then be (0.3 mm cuff ). We assessed the rise in showed that 86% of cardioversions
20% (1 l in a total of 5 l).
He then omits to say where the progression of surgery.
machine is sampling gas. Most machines After induction of anaesthesia and thetist provided anaesthesia in 79.5% of
intracuff pressure of the LT with the were performed either in theatre or a
critical care area. A consultant anaes-
measuring Ôinspired-expiredÕ oxygen muscle relaxation, a size 4 LT was cases whilst less than 5% were admin-
levels sample from the patient end of inserted. The cuff of the LT in group A istered by an SHO. This can be
the circle, so the oxygen measured is (n ¼ 20) was inflated with air to a compared to the 46% and 18.5% of
end-expired, not mixed-expired. This 60-cm H2O pressure using a mano- cardioversions performed by consultant
means that his calculation of inspired- meter, while in group B (n ¼ 20), the physicians and SHO’s, respectively.
expired oxygen difference needs to be cuff was inflated with Entonox to a Anaesthesia for cardioversion was pro-
multiplied by the alveolar, not the total pressure of 60 cm H2O. Anaesthesia vided by on-call staff in 53% of cases
minute volume, to derive oxygen con- was maintained with halothane in En- whilst 40% were done during a specif-
sumption. He is over-estimating the tonox. The intra cuff pressure was ically allocated session. Ninety-eight
oxygen consumption considerably. The monitored using
best place to measure mixed-expired gas 10 min interval for a period of 30 min. during normal working hours and
concentrations is from the expiratory We found that in group A, the mean skilled anaesthetic assistance was avail-
a monometer at percent of cardioversions were done
limb of the circle, as far away from the (sd) rise in intracuff pressure was able for 86% of cases. Recent electro-
patient as possible, just before the gases 12 (3) cm H2O while in group B the lyte and coagulation results were
go into the soda-lime canister. The rise was 4 (2) cm H2O. Our results available in 79% and 69% of cases,
mixed-expired oxygen concentration confirm the earlier study of Giatini et al. respectively. Adequate emergency air-
measured is usually 2–3% higher than and possibly provide a cheap and easy way equipment, suction and drugs
end-expired, due to ÔenrichmentÕ with method to solve the problem of nitrous were available for 90% of cardio-
dead-space gas (containing inspired oxide diffusion into the LT cuff.
oxygen concentrations). The inspired-
S. A. Khan
versions, whilst full monitoring was
available in 85%, and an anaesthetic
machine was used in 69% of cases.
Propofol was the anaesthetic agent of
choice in 90% of hospitals whilst 9%
used etomidate; 43% of departments
used short-acting opiates to provide
analgesia during cardioversion. A writ-
ten protocol for anaesthesia for cardio-
version existed in 14% of anaesthetic
departments, but only 7% actively
audited their results.
The Royal College of Anaesthetists
has published recommendations regard-
ing the safe conduct of anaesthesia for
cardioversion [1]. Concerns have been
expressed that cardioversion is often
performed out of hours, in remote sites,
by inexperienced anaesthetists, with
suboptimal assistance and equipment
[2]. The results of our survey show
that, in general, the standards of equip-
ment and staffing are high with the vast
majority of cardioversions being per-
formed by consultant anaesthetists in an
expired difference is thus only about
M. M. H. Siddiqi
2–3%, and multiplying it by the total
R. M. Khan
minute volume will give a fair estimate
J.N. Medical College Hospital,
of oxygen consumption. It is also poss-
A.M.U. Aligarh, India
ible to measure mixed-expired carbon
E-mail: drshariqalikhan@hotmail.com
dioxide concentration here, and using
end-tidal carbon dioxide and the Bohr
equation, to derive dead-space and
alveolar ventilation. You have to be
References
1 Asai T, Kawachi S. Pressure exerted by
cuff of laryngeal tube on the orophar-
very keen on doing sums, however, to
ynx. Anaesthesia 2001; 56: 912.
favour this method.
2 Nguyen Tu H, Saidi N, Lieutaund T,
D. M. Jackson
Bensaid S, Menival V, Duvaldestin P.
Swindon, SW6 6PB, UK
Nitrous oxide increases tracheal cuff
E-mail: dmjackson@doctors.org.uk
pressure and the incidence of tracheal
lesions in anesthetized patients.
Anesthesia and Analgesia 1999; 89:
Diffusion of nitrous oxide into
the cuff of the laryngeal tube
187–90.
We read with great interest the recent Anaesthesia for cardioversion
correspondence (Giatini et al. Anaesthe-
sia 2002; 57: 506) in which the authors We conducted a postal survey of ana-
reported a rise of 15 cm H2O in the esthetic departments which enquired
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291

Correspondence Anaesthesia, 2003, 58, pages 280–300
.....................................................................................................................................................................................................................
appropriate setting during normal
working hours. However, few depart-
ments have written protocols for, or
actively audit the results of cardio-
version.
attempt was unsuccessful so a second
attempt was carried out using the same
space. Despite difficulties, the epidural
space was eventually located using
approximately 10 ml of air. The cath-
eter was then advanced about 4 cm into
the epidural space. Neither cerebrospi-
nal fluid nor blood could be aspirated
from the epidural catheter. Following a
test dose of 2 ml of lidocaine 2% with
1 : 200 000 epinephrine, a bolus of
20 ml of a mixture bupivacaine 0.1%
and fentanyl 2 lg.ml)1 was injected
into the catheter. This was followed
S. James
I. J. Broome
Falkirk & District General Hospital,
Falkirk, UK
E-mail: ian.broome@fvah.scot.nhs.uk
References
Figure 9 The size 3 bulb can be occluded
by the patients tongue.
1 Whitaker D. Anaesthesia for Cardiover-
sion– Anaesthesia Outside Theatres. 9.6 –
The Royal College of Anaesthetists
2000.
by a continuous infusion at 10 ml.h)1
.
After 20 min, pain relief was unsatisfac-
tory despite withdrawal of the catheter
by 1 cm and repeated bolus doses of
10 ml bupivacaine 0.25%.
unique problem to the fibre-light bulb
system with the potential for patient
harm.
2 Stoneham MD. Anaesthesia for Cardio-
version. Anaesthesia 1996; 51: 565–70.
The epidural catheter was therefore
re-sited for the third time at the L1–2
space using 3 ml of air from a 10-ml air
filled syringe to detect loss of resistance.
Good analgesia was achieved with this
attempt providing a sensory level of
block up to T7. Normal delivery
occurred 6 h later. Following this, the
epidural catheter was removed prior to
discharge to the postnatal ward.
The following day, the patient com-
plained of numbness in her right
buttock and foot. Neurological exam-
ination revealed multiple areas of altered
sensation over the right buttock and
lateral aspect of the right calf corres-
ponding to dermatomes L4 ⁄ 5. There
was no motor weakness with intact
deep tendon reflexes. Perineal sensa-
tions were present with a normal rectal
sphincter tone. Computed tomograph
(CT) scans showed a low absorption
image consistent with the presence of
gas in the epidural space. EMG revealed
no conduction disturbance.
On day 4, sensations started to return
on the lateral aspect of the patient’s right
leg and there was complete neurological
recovery over the right buttock and
thigh within the proceeding 5 days.
We consider that the air injected
into the epidural space may have been
responsible for the neurological symp-
toms experienced by the patient. The
return of sensation after 4 days suggests
that air pockets in the epidural space
take a few days to absorb into the
blood stream. There was no other
R. J. Price
D. Russell
Let there be light
M. A. Garrioch
Southern General Hospital,
Glasgow G51 4TF, UK
E-mail: rjp@doctors.org.uk
Fibre-light laryngoscope blades can be
dismantled and the bulbs sterilised and
re-used. We report a critical incident
arising from incorrect assembly.
Prior to an emergency intubation, a
laryngoscope was tested and a bright
light was seen from the tip of the blade.
On inserting the laryngoscope into the
patients mouth, no light was apparent.
Direct laryngoscopy was therefore not
possible.
On further inspection of the laryng-
oscope, a size 4 MacIntosh blade had
been assembled with a size 3 fibre-light
bulb. The size three bulb does not
extend sufficiently through the flange of
the blade (Figs 8 and 9). Consequently,
the patient’s tongue occluded the light
source. We believe that this represents a
Air in the epidural space leading
to a neurological deficit
We report a case of transient neurolog-
ical impairment following the use of air
to detect loss of resistance during
placement of an epidural catheter for
labour analgesia.
A 29-year-old Asian female, prima-
gravida presented to the delivery suite
in labour at 39 weeks gestation having
had an uneventful antenatal period. Her
uterine contractions were of moderate
intensity, palpable every 4 min, with a
foetal heart rate of 140 beat.min)1
without any decelerations. Pelvic
examination revealed an effaced cervix,
2–3 cm dilated, with a cephalic presen-
tation at minus 2 station. Intramuscular
pethidine was used for relief of labour
pain after artificial rupture of the mem-
branes. After the start of an oxytocin
infusion, the patient requested epidural
analgesia.
Following a full explanation of the
risks and benefits, the epidural was
attempted with the patient in the sitting
position using a 16G Tuohy needle at
the L3–4 space and an air-filled syringe
to detect the loss of resistance. The first
Figure 8 Above: a Mac 4 blade with a
size 3 fibre-light bulb: it does not extend
through the flange. Below: correctly
assembled.
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Anaesthesia, 2003, 58, pages 280–300
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Correspondence
apparent cause for this neurological severe headache for the mother as we down to 120 beat.min)1 and systolic
deficit. This iatrogenic problem could found out.
have been potentially avoided by using Our patient was
blood pressure 110 mmHg. A 12-lead
27-year-old- ECG was recorded, which showed a
a
saline instead of air to detect loss of mother, a doctor, who required opera- normal sinus rhythm with no ST
resistance. tive delivery for failure to progress. An depression. The headache persisted
Various neurological deficits caused epidural was placed at the L 3–4 level and lasted over 2 h. She made a full
by air in the epidural space have been during labour, which was topped up for recovery and serum troponin I levels
reported including acute nerve root the Caesarean section. The block was taken 12 h later proved to be normal.
compression [1], chronic radiculopathy effective up to the T4 dermatome level.
Headaches are reported adverse
[2] and cauda equina syndrome [3]. Shortly after, the systolic blood press- effects of ephedrine, metaraminol and
There is therefore a risk of inflicting a ure dropped from 105 mmHg to atropine. These are usually brief and of
neurological deficit following the use of 70 mmHg, and as she complained of mild to moderate intensity. Our patient
air to detect the epidural space, which nausea, a 6-mg bolus of ephedrine was experienced such an intense headache
can potentially lead to protracted inves- administered. Over the next 10 min, and for over 2 h that we had to consider
tigations to exclude any neural damage further boluses of ephedrine totalling to pre eclampsia in our differential diag-
and a prolonged hospital stay. This sort 24 mg was given to restore the blood noses. The question remains: should we
of complication might be occurring pressure. In the meantime, surgery had have intervened as we did? We were
more frequently than is reported and it commenced and a healthy male infant concerned as the ECG progressively
is our firm belief that air should no was delivered. A syntocinon-bolus of changed from sinus rhythm to Ôsignifi-
longer be used during epidural catheter 5 units was administered and an infu- cantÕ ST depression, then to bradycardia
placement. However, anaesthetists who sion of 20 units in 500 ml of saline with ST depression and through to a
continue the practice of injecting air for commenced. About 30 min into the junctional rhythm. Throughout these
the identification of the epidural space operation, the ECG trace showed changes, the mother remained symp-
should be aware of this and associated marked ST depression (2 mm) but the tomless despite the hypotension. There
complications.
mother did not complain of any symp- is at least one study that showed that ST
toms. The heart rate was around 75–80 segment changes are not necessarily
beat.min)1 and the systolic blood pres- innocuous [3]. Syntocinon has been
sure 85 mmHg. The syntocinon infu- implicated as one of the causes [4].
sion was discontinued and metaraminol However, in view of the presence of a
0.25 mg administered. It was at this dysrrhythmia and hypotension, we felt
stage that the ECG changed from sinus it appropriate to intervene. Would
Krishnam
A. Mallick
Leeds General Infirmary,
Leeds, LS1 3EX, UK
References
rhythm with ST segment depression glycopyronium have been
a better
1 Kennedy TM, Ullman D, Harte FA,
Saberski LR, Greenhouse B. Lumbar
root compression secondary to epidural
air. Anesthesia and Analgesia 1998; 67:
1184–6.
to junctional rhythm with a rate of alternative? Was this a case of treating
55 beat.min)1. The mother remained the patient and not the ECG? We
symptomless, even as the systolic pres- would like to know what others might
sure dropped to 75 mmHg. Surgery do if confronted with a similar situation.
was stopped temporarily to rule out a We feel that if faced with the same
vagal reflex to handling of the uterus, problem again we would be compel-
but it did not restore the rhythm. A led to intervene, but probably use
bolus of atropine 0.3 mg was given to glycopyronium.
2 Miguel R, Morse S, Murtagh R. Epi-
dural air associated with multiradicular
syndrome. Anesthesia and Analgesia
1991; 73: 92–4.
correct the dysrrhythmia, but within a
K. Ramachandran
3 Nay PG, Milaszkiewicz R, Jothiling-
ham S. Extradural air as a cause of
paraplegia following lumbar analgesia.
Anaesthesia 1993; 48: 402–4.
minute following the injection, she
Srirangadarshan
complained of a severe headache, so
V. Kapoor
severe that she became acutely dis-
North Manchester General Hospital,
tressed. The heart rate increased to
Manchester, M8 5RB, UK
150 beat.min)1 and the systolic blood
Treating ECG changes during
Caesarean section: is it worth
the headache?
pressure to 160 mmHg. Fentanyl
100 lg and midazolam 2 mg was given
References
1 Mathew JP, Fliesher LA, Rinehouse JA
to ease the pain and reduce the anxiety,
et al. ST segment depression during
but the headache remained. Surgery
labour and delivery. Anesthesiology,
ECG changes are not uncommon was allowed to proceed as further
during Caesarean section [1,2]. In the increments of fentanyl (25 lg) were
vast majority, these changes are inno- given to ease the intensity of her
cuous and do not require any inter- headache. The mother was transferred
vention. The most disconcerting are to the recovery room an hour after the
ST segment depression. However, start of the operation where she was
intervening can literally result in a fully monitored. The heart rate was
1992; 77: 635–41.
2 Palmer CM, Norris MC, Giudici MC
et al. Incidence of electrocardiographic
changes during Caesarean delivery
under regional anaesthesia. Anesthesia
and Analgesia 1990; 70: 36–43.
Ó 2003 Blackwell Publishing Ltd
293

Correspondence Anaesthesia, 2003, 58, pages 280–300
.....................................................................................................................................................................................................................
3 Moran C, Ni Bhuinneain M, Geary M
et al. Myocardial ischaemia in normal
patients undergoing elective Caesarean
section: a peripartum assessment.
influenced by the effect of pollution on raising the question as to whether
staff or other health implications. A nitrous oxide should still be readily
small number of trainees (5%) felt that it available on the anaesthetic machine?
would be acceptable to make nitrous
K. A. Henderson
Anaesthesia 2001; 56: 1051–8.
oxide unavailable, 32% felt that it
N. Raj
4 Spence A. Oxytocin during Caesarean
section. Anaesthesia 2002; 57: 710–11.
should be available on request and
J. E. Hall
62% felt that it should remain freely
University Hospital of Wales,
available. Thus, 38% felt that there
Cardiff, CF14 4XW, UK
should be some restriction in nitrous
E-mail: hallje@cf.ac.uk
oxide availability, whereas only 20% of
The use of nitrous oxide
in anaesthetic practice: a second
questionnaire survey
consultants felt there should be some
restriction in its use.
Concealed airway complication
Half the trainees (50%) stated that all during LeFort I osteotomy
their anaesthetic machines had the pro-
vision of medical air, 48% said that some We would like to report an unusual but
machines have medical air and 2% that potentially serious airway complication
none had provision. As to when med- of Lefort I osteotomy. A 34-year-old-
ical air is used, 68% stated frequently, female, weighing 80 kg, presented for
Following our questionnaire survey
among consultant anaesthetists (Hend-
erson et al. Anaesthesia 2002; 57: 1155–
8), it was felt that a further survey
should be carried out among junior
anaesthetists to ascertain their views on
the use of nitrous oxide in anaesthetic
practice.
30% occasionally and 2% never.
LeFort I osteotomy for the correction of
When asked about their use of total class III malocclusion. The pre-opera-
intravenous anaesthesia (TIVA), 57% tive physical examination and the rout-
stated that over the last 3 years their ine blood tests were normal. She was
use of TIVA has increased. When TIVA anaesthetised with propofol, remifenta-
is used, 80% supplement with oxy- nil infusion, rocuronium, and sevoflu-
gen ⁄ air and 20% with oxygen ⁄ nitrous rane in oxygen and air. The trachea was
Whilst we achieved a 75% response
rate amongst consultants, we only had a
42% response rate amongst the trainee
grades. This may reflect either the
increased mobility of trainees so that
fewer of the questionnaires were
received, or that the trainee population
are less interested in the topic of this
questionnaire. However, a total number
of 206 questionnaires were returned,
which is not an insubstantial number.
Of the valid questionnaires, 52% were
male, 41% female and 7% did not state.
Thus the sample had a much greater
proportion of female anaesthetists than
the original consultant questionnaire.
The minimum number of years in
clinical anaesthesia was 3 months; the
maximum was 28 years, with a mean of
4.96 years.
oxide.
easily intubated with a preformed nasal
Generally the responses indicated that tracheal tube (Portex 6.5 mm internal
the majority of trainees who took part diameter) via her left naris. The surgical
felt that nitrous oxide pollution in procedure was completed in 2 h and the
operating theatres was not a problem. intra-operative anaesthetic management
A total of 18% have decreased their use was uneventful. Ventilatory parameters
as a result of health and pollution including peak airway pressure, expired
concerns; however, 14% considered minute volume and end-tidal carbon
nitrous oxide to be a problem but had dioxide were continuously monitored
not altered their practice.
throughout the procedure. On comple-
Further analysis was carried out on tion of the operation and after attaining
the female responses to determine whe- spontaneous breathing and regaining
ther there was a greater concern for consciousness, the trachea was extubated.
health and pollution issues among this At the time of extubation a cut was
group. A total of 26% stated that this was noticed on the lateral aspect of the
the case, whereas 14% of the male tracheal tube (Fig. 10), which was
responders felt there was a problem. 45 mm away from the black mark. It
Generally the responses followed that
of the consultant body, with 81% stating
that they used nitrous oxide frequently
and 19% occasionally. Over the last
3 years, 42% said that their use had
stayed the same, with 55% stating it
had decreased and 3% saying it had
increased. An overwhelming majority
(96%) stated that they avoided using
nitrous oxide for certain operations, 4%
stated they wouldn’t avoid using nitrous
oxide.
A
minority of females (18%) had was an oblique cut in the longitudinal
changed their practice as a result of plane of the tracheal tube and it meas-
health and pollution issues and 13% felt ured 12 mm in length.
that it was a problem but had not
changed their practice.
On closer examination of the cut
edges (Fig. 11), it was confirmed that
Despite the poorer response rate from the pneumatic saw that was used on the
the trainee grades to this questionnaire, maxilla had made the cut on the tube.
the absolute number of responses was The cut involved the full thickness of
not negligible and there appears to be a the wall of the tracheal tube. It had very
greater concern about the effects of narrowly missed the pilot tube hence
health and pollution generated from the cuff was intact. Surprisingly and
nitrous oxide amongst this group. A fortunately, this cut did not produce a
higher percentage of trainees than con- gas leak. Also, no changes either in the
sultants (38% vs 20%) would like to see peak airway pressure or in the expired
a restriction on the use of nitrous, again minute volume were noted during the
Most trainees (74%) did not feel that
pollution from nitrous oxide was a
problem, but 79% did not feel that
their use of nitrous oxide had been
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Correspondence
by inserting a smaller uncuffed tracheal
tube through the lumen of the original
tube may help to ventilate the patient
[2]. The Cook airway exchange cath-
eter would also be a useful tool for
changing the tracheal tube. Hought
et al. have described the use of a metallic
tube protector to avoid accidental dam-
age to the nasal tracheal tube [5].
In conclusion, during the maxillary
osteotomy and similar orthognathic
surgical procedures, one should be very
vigilant for the immediate recognition
of any damage to the nasal tracheal tube.
An alternative plan for managing the
airway and appropriate equipments
should be readily available.
M. Adke
C. Mendonca
Figure 10
University Hospitals of Coventry and
Warwickshire,
Coventry CV2 2DX, UK
E-mail: mendoc@doctors.org.uk
References
1 Valentine DJ, Kaban LB. Unusual
nasoendotracheal tube damage during
Le Fort I osteotomy. Case report.
International Journal of Oral Maxillofacial
Surgery 1992; 21: 333–4.
2 Peskin RM, Sachs SA. Intraoperative
management of a partially severed
endotracheal tube during orthognathic
surgery. Anesthesia Progress, 1986; 33:
247–51.
3 Hosseini Bidgoli SJ, Dumont L, Mattys
M, Mardirosoff C, Damaseaxu P. A
serious anaesthetic complication of a
Lefort I Osteotomy. European Journal of
Anaesthesiology 1999; 16: 201–3.
4 Fagraeus L, Angelillo JC, Dolan EA.
Figure 11
A serious anesthetic hazard during
Orthognathic Surgery. Anesthesia and
Analgesia 1980; 59: 150–3.
procedure.
1.5 l.min)1 was used during the main- tube is vulnerable to the surgical instru-
tenance phase of anaesthesia. ments. There are few reports of inad-
A
fresh gas flow of these surgical steps, the nasal tracheal
5 Hought R, Zallen RD, Nathan R. Use
of a metallic tube protector during
maxillary osteotomy. Journal of Oral
Surgery 1978; 36: 977.
Our aim of reporting this case is to vertent severing of the nasal tracheal
increase awareness of a possible serious tube during maxillary osteotomy [1–4].
airway complication during maxillary Several options for managing the airway
osteotomy. The nature of the surgical have been described. Packing around
procedure and the intermaxillary fix- the tracheal tube may seal the air leak in
ation at the end of the procedure certain situations [1], whereas on some
requires nasotracheal intubation. The occasions, there may be a need to
surgical procedure involves mobilisation change the tracheal tube during the
of the maxilla from the lateral nasal wall, middle of the surgical procedure [4].
nasal spine and the nasal septum. During Bypassing the tear in the tracheal tube
Not NICE advice
In September 2002, the National Insti-
tute for Clinical Excellence (NICE)
published a document entitled: Guid-
ance on the use of ultrasound locat-
ing devices for placing central venous
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Correspondence Anaesthesia, 2003, 58, pages 280–300
.....................................................................................................................................................................................................................
Sevoflurane conscious sedation
for MRI scanning
catheters [1], which recommended that one, do one, teach oneÕ approach that
two-dimensional (2-D) imaging ultra- forms the usual teaching of the land-
sound guidance should be the preferred mark technique will always fare poorly
method for elective internal jugular vein in terms of outcome when compared to
catheterisation in adults and children. an ultrasound guided technique that
One could make any number of criti- involves a 2–3 h initial training session.
While undergoing conservative treat-
ment for a gastrointestinal complaint as
an inpatient, a 48-year-old-lady devel-
oped symptoms suggestive of a cauda
equina syndrome. An urgent magnetic
resonance imaging (MRI) scan was
arranged, and while in the MRI suite,
the patient expressed concerns about
going into the scan room. The ortho-
paedic SHO administered diazepam
20 mg. This had minimal effect and
the patient still felt unable to cooperate.
Therefore the anaesthetic team was
asked for support. In the patient’s past
history, an endoscopic retrograde cho-
langiopancreatography (ERCP) had to
be postponed and later to be performed
under sedation as the patient suffered
from a fear from enclosed spaces. Her
BMI was 41 kg.m)2 and she had a full
meal less than 6 h ago.
cisms of this document: for instance,
Finally, significant legal implications
references for the 20 randomised con- may result from this pronouncement.
trolled trials on which the guidelines Guidelines are not law, but conduct that
was founded are not quoted, there departs from accepted practice may lead
appears to have been a general lack of to liability in negligence [3], in this
consultation with anaesthetists (who site instance both for the doctor (for failing
the majority of central lines in hospi- to use ultrasound guidance) and vicar-
tals), there is an apparent lack of clinical iously for the hospital (for failing to
experience of central line insertion of provide the equipment ⁄ enforce the
36 ⁄ 41 of the appraisal committee mem- code of practice). It would be for the
bers, data that did not support the court to decide, however, whether
proposed guidelines has been suppressed non-compliance with the guidelines
(paragraph 4.1.6), none of the trials was an unreasonable departure from
reviewed involved elective non-cardiac accepted practice. Interestingly, the
surgical patients, and clinically irrelevant court could be asked to consider whe-
endpoints were used (does it really ther the guidelines are reasonable or
matter that 2-D ultrasound guidance rational in the first instance.
quickens central venous catheterisation
by 69s?).
Until the logistical and medicolegal
ramifications of these guidelines are
We offered a trial of conscious
sedation to the patient, explained the
technique to her and showed her the
facemask to be used. Following reas-
surance, the patient felt able to enter
the scan room and was asked to hold
the facemask as close to her face as she
could possibly manage. She was given
50% nitrous oxide in oxygen and
sevoflurane 0.5% to breathe. Verbal
contact was maintained with the
patient throughout the procedure, and
the patient’s heart rate and oxygen
saturation were monitored continu-
ously. Furthermore, she was given an
alarm button that she could press
should she experience any form of
distress and which would lead to the
procedure being stopped and the
patient being taken out of the scanner.
The procedure was completed without
problems, and the patient was pleased
with this form of treatment. As the
investigation confirmed a cauda equina
syndrome, an emergency operation was
arranged.
Several important points need to be resolved, it would seem prudent for
made about this guidance. Firstly, there anaesthetists to inform patients that the
is an issue of cost [2]. Lacking evidence new guidelines exist but that equipment
of cost effectiveness from the trials and expertise are not yet available,
reviewed, NICE based their analysis whilst continuing to inform the patient
on a theoretical model, using a set of about the risks and consequences of
unjustified assumptions. Amongst other central line insertion via the landmark
variables, their analysis suggested that method.
cost savings were made because the
S. M. White
ultrasound method Ôavoided 90 arterial
St.Thomas’ Hospital,
punctures for every 1000 patients trea-
London, SE1 7EH, UK
tedÕ. My logbook tells me that in 7 years
E-mail: igasbest@hotmail.com
of anaesthesia, I have punctured the
carotid artery five times during 1095
otherwise successful attempts at central
line placement (all involving a 19G
locator needle; two of the five cases
related to misinterpretation of a 2-D
ultrasound image), which tends to indi-
cate that the cost effectiveness model
used may not be terribly accurate. In
addition, the initial equipment expen-
diture for hospitals would be significant
(at our hospital, 15 machines costing at
least £6500 each – Site RiteTM II).
Second, there is an issue of training. I
References
1 National Institute for Clinical Excel-
lence. Technology Appraisal. Guid-
ance – No. 49. Guidance on the Use of
Ultrasound Locating Devices for Placing
Central Venous Catheters. http://
www.nice.org.uk/pdf/Ultra
sound_49_GUIDANCE.pdf.
2 NICE. Technology Appraisal. Guidance
No. 49 on the Use of Ultrasound Locating
Devices for Placing Central Venous Cathe-
ters – Comments from the Royal College.
About a year later, the patient was
admitted to our hospital again for an
elective operation to be anaesthetised by
one of the authors. On this occasion,
she reconfirmed that the conscious
sedation had been much appreciated
by her, and that her neurological
of Anaesthetists. http://www.rcoa.
would suggest that, if my own experi-
ence is anything to go by, the reason for
ac.uk/newsflash/newsflash.asp?
FLA_ID=46.
a significantly higher complication rate
using the landmark method is that
operators have never been trained
properly in its performance – the Ôsee
3 Dugdale AM, Stanton KM. Professional
Negligence –, 3rd edn. Butterworths,
London 1998, Para. 15, 23.
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Correspondence
Table 2 The public’s view of the reasons
for premedication.
To premed or not to premed
symptoms had improved dramatically
following the operation.
National Anaesthesia Day is our oppor-
tunity as a profession to make contact
with the public and provide them with a
better understanding of what exactly it is
that we do. Equally, it is also a valuable
time to explore the public’s perceptions
and views on various aspects of our day-
to-day practices. During the last National
Anaesthesia Day, we conducted a survey
at the Oxford Radcliffe Hospitals to look
at people’s experiences and understand-
ing of the use of premedication.
Members of the general public who
viewed the National Anaesthesia day
displays were asked to complete a
4-point questionnaire about premedi-
cation. The questions asked included.
When you have an anaesthetic for an
operation do you expect to be given a
premed before you go to the operating
theatre? What do you think premeds are
given for? Have you ever been given a
premed before an operation and wished
you had not? Have you ever had an
operation without being given a pre-
med when you wished one had been
prescribed?
We had 92 responses to our ques-
tionnaire. These were completed by a
cross section of the public including
patients, outpatients, visiting relatives
and friends and members of staff (non-
theatre staff). The majority (68%) indi-
cated that they expected to be given a
premed before an operation; 20% were
undecided and only 12% did not expect
to have a premed. The public were
asked to indicate from a list of options
the possible reasons for having a pre-
med. The responses to this question are
provided in Table 2. Of those people
who had previously had an operation,
only 13% who were given a premed
wished they had not been; while 18% of
those who had been to theatre without
being prescribed a premed indicated
Sevoflurane conscious sedation as
described by Lahoud et al. [1] has
become an established part of anxiety
management in community dentistry.
The technique described by Lahoud
et al. employs the use of nitrous oxide
40% in oxygen, supplemented by sevo-
flurane 0.1–0.3%, administered through
a nasal mask. Lahoud et al. report a
success rate of over 90% for effective
treatment of anxiety during dental pro-
cedures, which is a major improvement
of the results that can be achieved with
nitrous oxide in oxygen alone (40%
failure rate). The advantage of inhala-
tional sedation over intravenous seda-
tion is its ease of controlling the depth
of sedation as gases are quickly exhaled
again, whereas metabolism of intraven-
ous drugs takes considerably longer.
We are not aware of the routine use
of conscious sedation in the MRI
setting. For this patient, the technique
allowed us to alleviate her fears and
enabled her to cooperate with the
procedure, and avoided general anaes-
thesia in a patient with a full stomach.
A slightly higher concentration of sevo-
flurane was chosen for our patient, to
compensate for the dilution of anaes-
thetic gases as the patient felt unable to
hold the mask directly onto her face.
Reason
Number (%)
To make you sleepy
59 (64%)
62 (67%)
16 (17%)
18 (20%)
20 (22%)
6 (7%)
To stop you feeling anxious
To settle your stomach
To give you pain relief
To stop you feeling sick
To reduce the swelling
caused by the operation
To control your blood pressure 18 (20%)
To control the amount
of saliva you make
None of the above
Don’t know
26 (28%)
0 (0%)
7 (8%)
likely that they will have some opinions
about its use. This brief survey indicates
that this is the case and that there is an
expectation on the part of the public
and hence patients for premedication to
be given. We should therefore include a
full discussion about premedication with
all patients, whether it is our intention
to prescribe it or not. Our survey
showed that most patients knew that
anxiolysis and sedation are key reasons
for prescribing premedication but far
fewer were aware of the other, often
more frequent reasons for giving pre-
medication. It is important that patients
are made aware of the nature of the
premedication that has been prescribed
for them so that they are not disappoin-
ted by the lack of sedation experienced
following premed of, for example,
ranitidine and metoclopramide. Whe-
ther to prescribe or not to prescribe a
premed depends on the individual
patient, anaesthetist, medical and surgi-
cal factors; however, it is worth re-
membering that patients have their own
expectations and views on the subject.
Sevoflurane
conscious
sedation
proved to be a valuable alternative to a
general anaesthetic in this case, especially
as intravenous sedation had already failed.
The patient was comfortable, maintained
her own airway and retained verbal
contact with the treating team at all times.
Scavenging remains a problem, espe-
cially if a patient is not able to tolerate a
tight fitting mask. Further studies are
needed to evaluate the possible use of
conscious sedation for elective MRI
procedures on a regular basis.
K. C. Hames
John Radcliffe Hospital,
Oxford, OX3 9DU, UK
S. Ju¨rgens
that they would like to have had one. Midwifes putting the pressure
There are a wide variety of indications on…?
for various drugs to be given prior to
Queen’s Medical Centre,
Nottingham, NG7 2UH, UK
induction of anaesthesia and the com- We read with interest the article relating
mencement of surgery. Premedication to application of cricoid pressure using a
is frequently the part of the anaesthetic part task trainer (Owen et al. Anaesthesia
procedure that people will experience 2002; 57: 1098–101). We recently
and remember as they wait on the ward undertook a similar audit in our depart-
for their operation; therefore, it seems ment. The original idea was born after a
Reference
1 Lahoud GYG, Averly PA, Hanlon MR.
Sevoflurane inhalation conscious seda-
tion for children having dental treat-
ment. Anaesthesia 2001; 56: 476–80.
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Correspondence Anaesthesia, 2003, 58, pages 280–300
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midwife was noted to have said to one Infrequent group range 12–40 N, med- no signs of any vegetations or mural
of the specialist registrars (SpRs), in a ian 30 N, mean 29 N and mode 40 N. thrombi.
rather indignant fashion, Ôwe can do We conclude that there is no difference
Pre-operatively he appeared to be in
cricoid too, you know!Õ whilst the said in the effectiveness of cricoid applied by total heart block [Figs 12 and 13] but had
SpR was awaiting the arrival of the frequent or non-frequent users, especi- no symptoms of syncope. His exercise
operating
department practitioner ally when the original training tech- tolerance had decreased to walking
(ODP) for an emergency Caesarean niques were perhaps inadequate. So approximately 20 yards. He was a poor
section. This lead us to wonder whether what should our answer have been to historian and was generally argumenta-
there was any difference in the accuracy the midwife in question, when maybe tive anddisinterested inourexplanations.
of cricoid pressure applied by frequent she could have performed as accurate We initially postponed his surgery to
and non-frequent users. cricoid pressure as some of our trained await a cardiology opinion, requesting
We surveyed 52 members of the staff? Another thought, perhaps, is that a pre-operative pacemaker (preferably
theatre staff including all members of midwives could be trained to apply permanent). He was diagnosed as being
the anaesthetic medical staff, all ODPs, cricoid pressure, which would leave in atrial fibrillation and having a left
recovery staff and some intensive care the ODP with hands free to assist with bundle branch block and left axis devi-
staff. The survey consisted of a ques- any potential airway problem (that idea ation. He was asymptomatic and
tionnaire relating to length of time since ought to put the pressure on!…).
training, any training specific to cricoid
assessed as being low risk, and therefore
not needing a pacing wire; however,
after further debate, the cardiologists
placed a temporary pacing wire for the
operation. It was hoped to remove this
postoperatively.
C. Mearns
pressure, frequency of application of
J. Elliott
cricoid, knowledge of correct forces and
East Surrey Hospital,
any complications. We then assessed
Redhill RH1 5RH, UK
accuracy of cricoid pressure using the
50 ml air-filled syringe technique men-
tioned by Ashurst et al. [1] and Flucker
et al. [2]. After an initial attempt, the
operators were shown the distance of
the syringe that they had to move the
plunger in order to apply a 30-N force.
Our results were similar to Owen’s
group in as much as the pretraining
R, Ruth M. The 50 millilitre syringe as
range of results was wide, with a range
8–60 N, median 30 N, mean 29 N, and
mode 40 N. After training, there was a
vast improvement, with the range being
20–40 N, median 30 N, mean 30 N and
mode 30 N. We then compared those
who performed cricoid regularly, i.e.
more frequently than once a month, to
those who performed it seldom or
never. Training in cricoid pressure had
been received in 54% of our group,
mainly theatre ODPs, who were the
group who performed cricoid fre-
quently. The original training had been
in the form of verbal instruction in 33%,
a mixture of verbal instruction and
hands on patient experience in 47%,
whereas only one person had received
any training on a mannequin or mech-
anical device. All training had been
given during original ODP training,
which varied from 1 year to 18 years
previously. The results between the 2
groups showed that there was no differ-
ence in the accuracy of cricoid pressure
applied. Frequent group range 8–60 N,
median, mean and mode all 40 N.
We anaesthetised him and paced his
heart at a rate of 70 beat.min-1 and he
remained cardiovascularly stable. Mon-
itoring included invasive blood pressure
monitoring to assess beat-to-beat arter-
ial blood pressure.
References
1 Ashurst N, Rout CC, Rocke DA,
Gouws E. Use of a mechanical simu-
lator for training in applying cricoid
pressure. British Journal of Anaesthesia
1996; 77: 468–72.
He was paralysed, intubated and
ventilated and the operation seemed to
be proceeding without a problem; we
even sent for the next patient. We
demonstrated four twitches on the
nerve stimulator and added reversal of
neostigmine 2.5 mg and glycopyro-
nium 500 lg for good measure, and
awaited the usual spontaneous respira-
tions to return. His tidal volumes
appeared to be adequate and he was
extubated. The patient responded more
slowly than normal and appeared to be
finding it increasingly difficult to breath.
He was resedated and we assisted his
ventilation.
On reapplying the nerve stimulator,
we found four strong and equal twitches
with no fade and a sustained muscle
contraction on tetanic stimulus.
The penny then dropped as we
reflected on his characteristic frontal
baldness, the ptosis and the decreased
mental fortitude that is often present
with myotonic dystrophy (synonym:
Steinert muscular dystrophy).
2 Flucker CJ, Hart E, Weisz M, Griffiths
an inexpensive training aid in the
application of cricoid pressure. European
Journal of Anaesthesiology 2000; 17:
443–7.
Why so slow?
We would like to report an interesting
case of bradycardia.
A 52-year-old-gentleman presented
for bilateral excision of hidradenitis
suppuritiva. His previous admission
had been for the treatment of a ÔblackÕ
toe secondary to an embolus. He was
not on warfarin at the time as his down
and out lifestyle was deemed not con-
ducive to anticoagulation.
He initially declined to have a trans-
thoracic echocardiogram but was con-
vinced to undergo the procedure last
year. The result hinted at a mild
increase in the intraventricular septum
but good left and right ventricular
function. Although the left atrial
appendage was not visible, there was
Although the prevalence is about
3–5 in 100 000, it never the less is
with us. It is inherited as an autosomal
298
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Anaesthesia, 2003, 58, pages 280–300
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Correspondence
Figure 12
Figure 13
dominant trait with the gene respon- the conducting system resulting in first examining the facial or distal limb
sible residing on the long arm of degree heart block, bundle branch muscles [4].
chromosome 19 [4]. Unlike other block and widening of the QRS
Aldridge in Aberdeen [3] looked at
myotonic syndromes, it is a multisys- complex with sudden death associated the characteristics in 16 patients
temic disorder with most patients with third degree heart block [4]. (Table 3), and also found a 52% com-
presenting between the ages of 15 Myotonia is demonstrable on EMG, plication rate in previously diagnosed
and 35 years old. Cardiac abnormalit- but myotonic discharges are less abun- cases and a 35% complication rate in
ies are usual and most commonly dant than in non-dystrophic myoto- undiagnosed cases. We are not advising
there is a progressive deterioration of nias. They are best demonstrated by that we investigate all the these
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299

Correspondence Anaesthesia, 2003, 58, pages 280–300
.....................................................................................................................................................................................................................
Table 3
Our patient is no longer suffering
from his previous malodorous condition
and is enjoying life with his new
pacemaker.
Symptoms and associated findings
Male %
Female %
Family history elicited
Ptosis
Facial weakness
Neck weakness
Dysarthria
Distal muscle weakness wasting
Abnormal gait ⁄ Foot drop
Decrease or absent reflexes
Symptomatic myotonia
Balding
Testicular atrophy
Female infertility ⁄ endometriosis
Low IQ
89
78
89
66
55
100
55
66
78
78
55
75
75
62
100
75
87
25
37
75
12
G. Morton
J. Bowes
Morriston Hospital,
Swansea, UK
References
1 Butt AD. Anaesthetic Hazards in
undiagnosed myotonia dystrophica. A
case report. South African Medical Journal
1984; 66: 538–40.
25
12
50
0
25
12
37
44
44
11
11
0
Cataract
2 Asada M, Suzuki H, Sumitoma M.
Anesthetic management for cardio-
verter defibrillator implantation in a
patient with preoperatively undiag-
nosed myotonic dystrophy. Masui 2001;
50: 1136–8.
Associated diabetes
Family history of diabetes
Thyroid abnormality
ECG abnormality
33
3 Aldridge LM. Anaesthetic problems in
Myotonic Dystrophy. British Journal of
Anaesthesia 1985; 57: 1119–30.
4 Russell SH, Hirsch NP. Anaesthesia
and myotonia. British Journal of Anaes-
thesia 1994; 72: 210–16.
symptoms as we are convinced that after attempt to explain why a sign is present.
checking for testicular atrophy, the The questions to be asked are why the
patient will be wondering about the ECG was so slow, and more import-
holistic role of the anaesthetist as a peri- antly why was our diagnosis so slow?
operative physician!
The retrospectoscope is a powerful
The intra-operative diagnosis is not instrument and when we were debating
unique and occurs internationally [1,2]. the merits of a pacemaker pre-opera-
We should always attempt to think tively, we should have been looking for
laterally and look for family history and the cause.
5 Marsh DF, Scott RC. Anaesthesia in
myotonic dystrophy. British Journal of
Anaesthesia 1994; 73: 124.
300
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