Full text of DOI:10.1007/BF03020529

CARDIOTHORACIC ANESTHESIA, RESPIRATION AND AIRWAY
287
Perioperative use of transesophageal echocardiog-
raphy by anesthesiologists: impact in noncardiac
surgery and in the intensive care unit
[L’utilisation périopératoire de l’échocardiographie transœsophagienne par les anesthésio-
logistes : les répercussions en chirurgie non cardiaque et à l’unité des soins intensifs]
André Y. Denault MD FRCPC,* Pierre Couture MD FRCPC,* Sylvie McKenty MD FRCPC,† Daniel Boudreault MD FRCPC,†
François Plante MD FRCPC,† Roger Perron RRT,† Denis Babin MSc,* Jean Buithieu MD FRCPC
‡
Background: The American Society of Anesthesiologists (ASA) has
published practice guidelines for the use of perioperative trans-
esophageal echocardiography (TEE) but the role and impact of TEE
performed by anesthesiologists outside the cardiac operating room
(OR) is still poorly explored. We report our experience in the use
of TEE in the noncardiac OR, the recovery room and in the inten-
sive care unit (ICU) in a university hospital, and analyze the impact
of TEE on clinical decision making.
Contexte : L’American Society of Anesthesiologists (ASA) a publié les
lignes directrices pour l’utilisation périopératoire de l’échocardiographie
transœsophagienne (ETO), mais le rôle et l’impact de l’ETO réalisée
par les anesthésiologistes à l’extérieur de la salle d’opération (SO) sont
encore peu connus. Nous présentons notre expérience de l’usage de
l’ETO dans une SO non cardiaque, dans la salle de réveil et à l’unité
des soins intensifs (USI) d’un hôpital universitaire. Aussi, nous
analysons l’impact de l’ETO sur la prise de décision en clinique.
Methods: Two hundred fourteen patients were included and TEE
indications were classified prospectively according to the ASA
guidelines. The examinations and data sheets were reviewed by
two anesthesiologists with advanced training in TEE. For each
examination, it was noted if TEE altered the management accord-
ing to five groups: 1) changing medical therapy; 2) changing surgical
therapy; 3) confirmation of a diagnosis; 4) positioning of an intravas-
cular device; and 5) TEE used as a substitute to a pulmonary artery
catheter.
Méthode : Deux cent quatorze sujets ont participé à l’étude et les
indications d’ETO ont été classifiées prospectivement selon les lignes
directrices de l’ASA. Les examens et les fiches techniques ont été
passées en revue par deux anesthésiologistes de formation avancée en
ETO. Pour chaque examen, on a noté si l’ETO modifiait le traitement
en regard de cinq groupes : 1) modification de la thérapie médicale 2)
modification de la thérapie chirurgicale 3) confirmation du diagnostic
4) installation d’une sonde intravasculaire 5) usage de l’ETO comme
substitut d’un cathéter artériel pulmonaire.
Results: Eighty-nine (37%), 67 (31%) and 58 (27%) patients had
category I, II and III indications. The impact was more significant in
category I where TEE altered therapy 60% of the time compared
with 31% and 21% for categories II and III (P < 0.001). The most
frequent reason for changing management was a modification in
medical therapy in 53 instances (45%).
Résultats : Quatre-vingt-neuf (37 %), 67 (31 %) et 58 (27 %)
patients présentaient des indications de catégorie I, II et III. L’ETO a
eu un impact plus significatif pour la catégorie I où elle modifiait la
thérapie dans 60 % des cas comparativement à 31 % et à 21 %
pour les catégories II et III (P < 0,001). C’est la modification de la
thérapie médicale qui apparaît comme la raison principale de change -
ment du traitement avec 53 cas (45 %).
Conclusion: Our results confirm a greater impact of TEE per-
formed by anesthesiologists on clinical management for category I
compared to category II and III indications in the noncardiac OR
surgical setting and in the ICU.
Conclusion : Nos résultats confirment une plus grande répercussion
de l’ETO réalisé par les anesthésiologistes sur le traitement clinique
pour les indications de catégorie I comparées à celles de catégories II
et III dans le contexte chirurgical d’une SO non cardiaque et de l’USI.
From the Department of Anesthesiology, Montreal Heart Institute;* and the Departments of Anesthesiology† and Medicine,‡ Centre
Hospitalier de l’Université de Montreal (CHUM), Hôpital Notre-Dame, Montreal, Quebec, Canada.
Address correspondence to: Dr. André Y. Denault, Department of Anesthesiology, Montreal Heart Institute, 5000 Bélanger Street East,
Montreal, Quebec H1T 1C8, Canada. Phone: 514-376-3330, ext. 3732; Fax: 514-376-8784; E-mail: denault@videotron.ca
Accepted for publication October 26, 2001.
Revision accepted November 16, 2001.
CAN J ANESTH 2002 / 49: 3 / pp 287–293

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CANADIAN JOURNAL OF ANESTHESIA
N 1996 guidelines for the use of perioperative
transesophageal echocardiography (TEE) were
published from a consensus conference by the
American Society of Anesthesiologists and the
examined when the multiplane probe was used. Color
Doppler interrogation of the mitral, aortic and tricus-
pid valve was also performed routinely. A cardiologist
trained in echocardiography (J.B.) was requested if
necessary for more specific examinations such as the
evaluation of unexpected severe valvular dysfunction.
At the time of examination, it was noted if TEE
changed the course of the current therapy or manage-
ment. This was further classified into five groups: 1)
TEE findings altered medical therapy, for instance, by
adding an inotrope or volume expansion; 2) TEE lead
to an unplanned surgical intervention; 3) TEE con-
firmed or invalidated a diagnosis which could have
lead to a surgical intervention; 4) TEE was useful in
positioning intravascular devices; 5) TEE was used as
a substitute to a pulmonary artery catheter (PAC).
Nine of our anesthesiologists have basic training in
TEE and two have advanced training with National
Board Certification (A.D., P.C.). However, all TEE
examinations and data sheets were supervised and
reviewed by those with advanced training. Our inter-
observer variability in the evaluation of cardiac func-
tion has been published.6–8
A consensus had to be reached between the two
TEE reviewers (A.D., P.C.) for an examination to be
accepted as altering medical therapy, otherwise it was
rejected. It was rejected if no explanation was provid-
ed or no consensus reached. TEE modified a surgical
intervention only if the surgeon stated, at the time of
examination, that without TEE, he would not have
performed or modified his intervention. Some exami-
nations may have been included in more than one sub-
category, for instance if TEE confirmed the
unsuspected presence of a patent foramen ovale dur-
ing spinal neurosurgery (category III) and modified
the surgical approach [lateral decubitus instead of
supine position (category I)].
I
American College of Cardiology.1 It appears from
these guidelines that the impact of TEE will occur
mostly during cardiac surgery. However, there is a
growing interest in the use of TEE by the anesthesiol-
ogist in the noncardiac surgical setting2,3 and in the
intensive care unit (ICU).4 The impact of TEE and
the noncardiac procedures which are most likely to
benefit from this monitoring technique are not well
defined. In addition, the role of ASA guidelines for
TEE has not been validated in a large number of
patients in which TEE was performed in the noncar-
diac surgical setting.
Since the introduction of TEE in our practice in
1990 at Notre-Dame Hospital, we previously report-
ed our experience in cardiac surgery5 but the role and
impact of TEE performed solely by anesthesiologists
outside of the cardiac operating theater is still poorly
explored. We now are reporting our experience in the
use of perioperative TEE in the noncardiac operating
room (OR), the recovery room and in the ICU to
determine the relative impact of category-based TEE
indications.
Methods
Following approval by our Ethics Committee, all TEE
examinations performed by anesthesiologists from
October 1993 to February 1997 (41 months) were
collected and classified in a database. Category I, II
and III indications were defined according to the ASA
guidelines on perioperative TEE.1 A category I is a
condition in which the use of TEE is supported by the
strongest evidence or expert opinion, a category II is
associated with weaker evidence and a category III has
little current scientific or expert support. TEE exami-
nations were performed in the OR, the recovery room
and the surgical ICU (SICU). Those performed in the
cardiac OR were excluded. Our SICU is a mixed ICU
mainly occupied by postoperative general surgery,
neurosurgery and cardiac surgery patients.
TEE examinations were done using a multiplane 5-
MHz transducer (Sonos 1500, Hewlett-Packard,
Andover, MA, USA) or a uniplane probe (Sonoline
CF, Siemens, Pleasanton, CA, USA) and included
two-dimensional imaging of the aorta, a mid-
esophageal four-chamber and a short-axis transgastric
view. The latter view was used for continuous moni-
toring during the procedure. A mid-esophageal two-
chamber and a long axis transgastric view of the left
ventricle and left ventricular outflow tract were also
Statistical analysis
Chi-square analysis was used to compare the impact of
TEE according to the category and group indications.
Analysis of variance was used to compare age of the
patients between the different groups. Statistical
analysis was done using the Statview 4.1 program
(Abacus Inc, Berkely, CA, USA). P < 0.05 was con-
sidered significant.
Results
From a total of 1,065 TEE exams, 214 (20%) consec-
utive examinations were classified as noncardiac
surgery and reviewed. From these, 155 (72%) were
performed during noncardiac surgery, four (2%) in the
recovery room and 55 (26%) in the SICU. Eighty-

Denault et al.: TEE I N NONCARDIAC A N D ICU
289
TABLE I Population characteristics and TEE exams
ASA-SCA Category
I
II
III
Total number of patients (%)
Age (mean)
n = 214
57
131/83
n = 86
89 (41)
57
53/36
53
60%
61
67 (31)
58
43/24
21
31%
60
58 (27)
57
35/23
12
21%
52
*†
*†
Sex (male/female)
Patients with modified therapy after TEE
Percentage per category
Age (mean)
60
Sex (male/female)
49/37
128
32/21
36
28%
58
11/10
46
36%
61
6/6
46
36%
59
Patients without modified therapy after TEE
Percentage per category
Age (mean)
*†
60
Sex (male/female)
Site of examinations
81/47
n = 155
n = 4
19/17
44
3
33/13
57
1
29/17
54
OR
RR
SICU
OR
n = 55
n = 43
42
20
9
13
4
10
*†
*†
Number of patients with modified therapy
per site
RR
SICU
n = 3
n = 40
n = 118
2
31
59
1
7
44
2
15
*†
†‡
Total number of modifications
ASA/SCA = American Society of Anesthesiologists/Society of Cardiovascular Anesthesiologists; TEE = transesophageal echocardiography;
OR = operating room; RR = recovery room; SICU = surgical intensive care unit; Rx = therapy. *P < 0.05 for category I vs II; †P < 0.05
for category I vs III; ‡P < 0.05 for category II vs III.
TABLE II Summary of surgical modifications related to the use of TEE
Modifications
Total number
Hemodynamic instability in the intensive care unit
Tamponade leading to mediastinal exploration
Mitral regurgitation and myocardial ischemia after gynecological
surgery leading to mitral valve replacement and coronary revascularisation
Vascular surgery
8
1
Aortic dissection associated with pericardial effusion leading to a
femoral bypass before surgery
2
Absence of aortic dissection
2
1
Unsuspected atrial thrombus and severe mitral stenosis leading
to thrombectomy and mitral valve replacement
Lung transplantation
Right ventricular dysfunction leading to cardiopulmonary bypass
Air emboli leading to revision of vascular anastomosis
Neurosurgery
2
1
Detection of a patent foramen ovale before ramisectomy leading
to surgical positional change
2
Total
19
TEE = transesophageal echocardiography.
nine patients (37%) had category I indications, 67
patients (31%) had category II indications and 58
patients (27%) were considered category III (Table I).
Category I (n = 89 patients) were the most common
indications for the use of TEE compared to category
II (P = 0.027) and III (P = 0.0046).
TEE changed management in 86 patients (40%) with
a total of 118 modifications. From these 86 patients, 43
were in the OR, three in the recovery room and 40 in
the ICU. Patients with changes in management were
more often in category I (60%) vs II (31%) or III (21%;
P
< 0.001). No difference in age and sex was observed in
those three categories and also in those with or without
modified therapy.
In the OR, 20 patients (46%) with modified therapy
were of category I and this was more frequent than in cat-
egory II (
P = 0.02) and III (P = 0.004). In the SICU, 31
(77%) patients with modified therapy were category I.

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CANADIAN JOURNAL OF ANESTHESIA
TABLE III Summary of studies on the impact of TEE in noncardiac surgery and in the ICU
Author
Reference
n
Location
Population
Overall
Medical
Surgical
impact
therapy
intervention
24%
Oh
Pearson
Font
13
14
10
11
17
18
15
19
20
12
21
22
23
51
62
112
83
60
32
78
77
111
113
48
61
127
ICU
ICU
ICU
ICU
SICU
ICU
ICU ER
ICU
ICU
ICU
OR
Mixed
Mixed
Mixed
Mixed
Cardiac
Mixed
Mixed
Mixed
Mixed
Mixed
Lung transplant
Mixed
Hemodynamically
unstable
44%
8%
Foster
22%
22%
28%
50%
48%
36%
33%
19%
3%
Reichert
Puybasset
Hwang
Khoury
Vignon
Chenzbraun
Gorcsan
Heidenreich
Sohn
18%
29%
9%
16%
25%
19%
21%
19%
28%
ICU
ICU
28%
52%
Cicek
24
25
26
16
27
4
119
108
62
121
61
OR and ICU Cardiac
18%
10%
Poelaert
Suriani
Alam
Slama
McLean
Kolev
ICU
OR
ICU
ICU
ICU
OR
No post-CABG
Liver transplant
Mixed
Noncardiac
Mixed
Mixed cardiac
and noncardiac
Mixed cardiac
and noncardiac
Noncardiac
44%
11%
32%
20%
26%
30%
18%
8%
11%
53
224
3
Brandt
Suriani
9
2
66
OR
OR
80%
63%
23%
15%
123
n = number of examinations; OR = operating room; ICU = intensive care unit; ER = emergency room; CABG = coronary artery bypass
graft.
Figure 1 illustrates the distribution of modifica-
tions. In 53 instances (45%) the modification in man-
agement was secondary to a change in medical
therapy. Twenty-one modifications in 19 patients
(18%) led to unplanned surgical reinterventions based
on TEE findings which are detailed in Table II.
Confirming or invalidating of a diagnosis was found to
change management in 35 instances (30%). The use of
TEE or as a substitute to a PAC or for positioning
intravascular devices was found to be useful in nine
instances (8%).
When TEE changed therapy, unplanned surgical
reinterventions (10% vs 13%) as a result of TEE were
as common in category I as II but a more significant
impact was found for altering medical therapy (36% vs
21%) in category I than II (P < 0.001) and I vs III
(36% vs 12%; P < 0.001; Figure 2).
Discussion
In this study using the ASA guidelines, we observed
that TEE performed by anesthesiologists can have an
impact of the clinical management of patients under-
going noncardiac surgical procedures, in the recovery
room and in the ICU. This was apparent mostly in
category I indications. The impact of TEE in the non-
cardiac setting was even more important than that we
had observed in cardiac surgery.5 These findings
extend the role of TEE outside the cardiac surgical
arena. This study represents a large anesthesiologists’
experience in the use of TEE in the noncardiac surgi-
cal and in the ICU setting using the ASA guidelines.1
While TEE is most likely to be useful in category I for
altering medical therapy, we did not observe any dif-
ference between categories I and II for surgical man-
agement. This could be explained by our sample size
and also because, in the ASA guidelines, few situations
in the noncardiac surgical setting (apart from hemo-
dynamic instability) are associated with a category I
indication. We also observed an impact of TEE in cat-
egory III indications in 12 patients (21%). This was
associated with the use of TEE as a monitoring tool in
General, vascular and thoracic surgery represented
83% of our use of TEE in the noncardiac surgical set-
ting. Therapy was more commonly modified in gener-
al surgery compared with vascular (P = 0.014) and
thoracic (P = 0.043).

Denault et al.: TEE I N NONCARDIAC A N D ICU
291
were rated as major, minor, limited and no impact. A
major impact was defined as treatment of a life-threat-
ening event, changing surgical technique or anesthetic
management or leading to further evaluation in the
postoperative period. Overall, the authors observed an
81% impact and a major impact was found in 15% of
their patients. This is higher than our overall impact of
41% but similar to the major impact of 19% (medical
and surgical) observed when considering only our non-
cardiac patients in the OR (n = 155). In agreement
with Suriani’s conclusions, we also found that the
major advantage of TEE was its rapid diagnostic capa-
bility during the period of hemodynamic instability.
Other studies included noncardiac patients moni-
tored with TEE in the OR. Brandt described the use
of intraoperative TEE in patients undergoing cardiac
(n = 46) and noncardiac surgery (n = 20).9 The indi-
cations in noncardiac surgery were mainly hemody-
namic instability in 50%. In four of these noncardiac
patients undergoing vascular surgery, TEE altered the
operative procedure. Kolev studied the influence of
TEE on intraoperative decision making using the ASA
guidelines.3 This European study included 224
patients, undergoing cardiac and noncardiac surgery,
from nine participating centres. Our results are in
agreement with their observations, resulting in a 30%
change in overall management, with a greater impact
in category I than category II.
Number of modifications
Number of modification
FIGURE 1 Distribution of the total number of modifications
which are detailed according to category I through III indications
for TEE.
Studies published in the ICU support our findings
(Table III). The clinical experience of several authors
demonstrates that TEE in the ICU picks up unexpect-
ed clinical findings in 25% to 59% of patients and has a
direct influence on the therapeutic decisions in 8% to
24% of cases.10–16 However, anesthesiologists trained in
TEE were not reported as those performing the
echocardiographic examination in most of these studies.
Limitations
FIGURE 2 Medical and surgical impact according to indication
category. (*P < 0.001 for medical therapy in category I vs II and I
vs III; n = number).
The greater impact of TEE in noncardiac surgery com-
pared to cardiac surgery can be explained by the non-
routine use of TEE in these patients. Consequently, a
bias could be introduced as patients are selected because
they are more likely to benefit from TEE. Using routine
TEE for noncardiac surgery would have yielded a lower
impact but this does not represent our practice. In the
noncardiac surgery setting, we use TEE mostly in cate-
gory I indications, and this supports that the use of TEE
in this context has a significant impact. Similarly, the role
of TEE in the ICU is clearly established during critical
situations. We did not exclude postoperative cardiac
surgery patients because of our mixed ICU population.
However, this could have reduced the overall surgical
impact in the ICU. We strongly believe that TEE has the
the OR and in the ICU. This group represents situa-
tions in which the role of TEE is being explored and,
consequently, were classified as category III.
The only similar noncardiac study in which anesthe-
siologists performed TEE in the OR was reported by
Suriani and coworkers2 in which the role of TEE was
explored in 123 noncardiac surgery patients. They
were classified as consultative if performed by a consul-
tant or non-consultative when performed by the
attending anesthesiologists. The consequences of TEE

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CANADIAN JOURNAL OF ANESTHESIA
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potential to become an essential tool for noncardiac
anesthesiologists in unstable patients undergoing non-
cardiac surgery and in the ICU because of its rapid diag-
nostic capabilities. This advantage of the TEE has to be
weighed against the cost and size of the equipment and
the expertise required at the bedside for continuous
monitoring. At present, this type of monitoring is avail-
able mostly in the cardiac operating suites of large cen-
tres. Certification by the National Board of
Echocardiography is now available for perioperative TEE
and may become mandatory for anesthesiologists eager
to make use of this diagnostic and monitoring modality.
In summary, TEE performed by anesthesiologists
can have a significant impact in the non-cardiac surgi-
cal theater, in the recovery room and the ICU. TEE
utilization has a greater impact for category I than cat-
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mainly in modifications of medical therapy.
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12 Chenzbraun A, Pinto FJ, Schnittger I. Transesophageal
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Acknowledgements
This study was supported by the “Plan de Pratiques
des anesthésiologistes de l’Hôpital Notre-Dame du
CHUM et de l’Institut de Cardiologie de Montréal, the
“Bourse Sheridan de la Société canadienne d’anesthési-
ologie” and the “Fondation d’anesthésiologie du
Québec de l’Association des anesthésistes du Québec”.
We thank Luce Bégin for secretarial support.
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