Download Fentanyl-etomidate anesthesia for cardioversion

European Heart Journal (1982) 3, 155-158
Fentanyl-etomidate anesthesia for cardioversion
F. HAGEMEIJER, R. VAN MECHELEN AND D. W . T H . SMALBRAAK
Departments of Cardiology and A nesthesiology, Sint Franciscus Gasthuis, Rotterdam, The Netherlands
KEY WORDS: Anesthesia, cardioversion, etomidate, fentanyl, naloxone.
Cardioversion consists of a transthoracic electrical anesthesia occurs in patients who are on maindischarge triggered by the QRS complex of the tenance doses of benzodiazepines, which nowadays
electrocardiogram and is intended to depolarize all is quite common. We became increasingly discardiac cells simultaneously in patients with supra- satisfied with the effectiveness of diazepam
ventricular or ventricular tachyarrhythmias, in anesthesia: administered in 5 mg increments intraorder to allow resumption of a regular sinus venously at 4-5 min intervals, it took easily up to 1
rhythml'l. Repeated discharges with increasing hour to achieve apparently good anesthesia.
energy content are frequently required during Waking up between cardioversion discharges was
titrated energy cardioversion before the arrhythmia common; in 10 patients undergoing cardioversion
is terminated and sinus rhythm resumes!1 • 21. Such a after diazepam (mean dose 57-5 mg), only three
patients had complete amnesia, two remembered
procedure obviously requires anesthesia.
Most drugs used in anesthesia may produce the cardioversion procedure slightly, and five had
depression of the respiratory center and, therefore, vivid and traumatic recollections of the electrical
the need for an anesthetist is apparent. This discharges. On the following day six patients still
constitutes no problem when an elective cardio- remembered painful shocks.
OrkoM observed that diazepam failed to induce
version is performed for chronic atrial fibrillation.
However, tachyarrhythmias may cause life- amnesia in 37% of patients, a situation quite
threatening heart failure or anginal pain, and in this unacceptable in elective cardioversion. Coe^l
emergency situation an anesthetist is not always reported similar problems. We considered diazeavailable in the Coronary Care Unit. Cardiologists pam anesthesia no longer suitable for cardiohave, therefore, used diazepam anesthesia, which version and decided to investigate which type of
causes no respiratory depression when admin- anesthesia could safely be used in emergency
istered slowly. It also produces amnesia, which situations by a cardiologist working alone with his
prevents recollection of the cardioversion pro- nursing staff. Our criteria were the following: the
procedure must be safe, without respiratory
Unfortunately, marked resistance to diazepam depression necessitating intubation and mechanical
ventilation; anesthesia must be effective, with total
amnesia of the electrical discharges; the procedure
Received for publication 30 May 1981; and in revised form 11
should take little time and not require lengthy
August 1981.
medical or nursing supervision. For these reasons
Requests for reprints to: F. Hagemeijer, MD, Sint Franciscus
we decided to use fentanyl and etomidatel6"8', a
Gasthuis, Kleiweg 500,3045 PM Rotterdam, The Netherlands.
OI95-668X/82/O2OI55+04 $02.00/0
© 1982 The European Society of Cardiology
Downloaded from http://eurheartj.oxfordjournals.org/ by guest on September 18, 2016
The effectiveness and safety of anesthesia with fentanyl and etomidate were evaluated in 44
patients undergoing elective cardioversion. No drop in blood pressure was observed; endotracheal
intubation was never necessary, and ambu bag assisted ventilation was needed in only five patients.
Anesthesia was induced within 7 min in all patients with a mean dose of09 mg of fentanyl and 15-4 mg of
etomidate. After cardioversion, naloxone 0-2 mg intravenously was used to antagonize fentanyl; patients
were fully awake on average 9 min after the last cardioversion discharge. Complete amnesia was observed
in all patients, both I hour after cardioversion and the next morning.
For cardioversion, fentanyl-etomidate is as safe, more effective and less time-consuming than
diazepam.
156 F. Hagemeijer, R. Van Mechelen and D. W.Th. Smalbraak
Table I Anesthesia for cardioversion
Time (min)
0
1
2
3
Afterwards
Drug
Comments
Dose
Atropine
Fentanyl
0-25 mg
OlOmg
Etomidate
Cardioversion
Naloxone
(Prethcamide)
0-20 mg/kg
Young, heavy: 0-15 mg
Old, lean: 005 mg
After 10 min give 010 mg/kg if needed
020 mg
(225 mg)
If respiration remains shallow
Material and methods
This study involved 44 patients undergoing
elective cardioversion. All procedures were carried
out in the Coronary Care Unit. Oxygen, suction, an
intubation set, and drugs were immediately available; a cardiologist, an anesthetist and a cardiac
nurse were present at all times during the investigation of the safety of the procedure.
ANESTHESIA (TABLE 1)
Each patient received consecutively the following
drugs, injected intravenously at 1 min intervals:
atropine 0-25 mg, fentanyl 0-05-0-15 mgW, and
etomidate02 mg/kg.
Pure oxygen (101/min) was administered by
mask from the time of the injection of fentanyl until
the patient had recovered consciousness. Assisted
ventilation with an ambu bag was carried out if
spontaneous breathing was too shallow according
to the clinical judgement of the attending physician.
After the final cardioversion discharge the
patient received naloxone 0-2 mgl'l intravenously.
Patient surveillance by the cardiologist and the
cardiac nurse was continued until the patient was
awake.
ASSESSMENT OF THE EFFECTIVENESS OF ANESTHESIA
For each procedure we measured the time needed
to recover consciousness after the last cardioversion
discharge. Effectiveness of anesthesia was evaluated
1 h after the last electrical discharge and the
following morning by asking the patient what he
remembered of the cardioversion procedure.
Memories were graded as vivid, slight, or absent.
Safety of the anesthetic procedure was ascertained
by measuring vital signs at regular time intervals
Table 2 Clinical characteristics
Age
Male/female
Indication
Atrial fibrillation
Atrial flutter
Supraventricular tachycardia
Ventricular tachycardia
32-84 years
30/14
35 79%
5 13%
2 4%
2 4%
throughout anesthesia; particular attention was
paid to blood pressure and spontaneous breathing.
Results
This study involved 30 men and 14 women from
32 to 84 years old, 12 patients were from 61 to 70
years old, and 16 were over 71. Atrial fibrillation
was the indication for cardioversion in 35 patients;
five patients had sustained an acute myocardial
infarction less than 48 h previously; nine patients
had chronic obstructive lung disease. None
required emergency cardioversion (Table 2).
The dosage of fentanyl ranged from 0'05 to
020 mg for young, heavy patients (mean: 0'9 mg).
The total dosage of etomidate ranged from 4 to
40 mg (mean: 154 mg). The low dose of 4 mg was
given to a patient in cardiogenic shock and atrial
fibrillation. The dose of 40 mg was administered in
divided doses during an episode of protracted
titrated cardioversion during which repeated doses
of disopyramide were given because of resistant
atrial fibrillation; repeated increments of etomidate
were needed. Anesthesia was achieved in 3-7 min
(mean: 4-6 min); with intravenous naloxone
patients were fully awake from 3 to 25 min (mean:
9 min) after the last electrical discharge (except the
patient in cardiogenic shock, who presented with
mental obtundation even before fentanyl-etomidate
anesthesia). No significant drop in blood pressure
Downloaded from http://eurheartj.oxfordjournals.org/ by guest on September 18, 2016
combination commonly used in our hospital for
minor surgical procedures.
Fentanyl-etomidate anesthesia 157
Downloaded from http://eurheartj.oxfordjournals.org/ by guest on September 18, 2016
was observed, even in the patient in cardiogenic were observed. None of the patients remembered
shock. No patient required endotracheal intu- the cardioversion procedure upon awaking, and
bation; five patients had slight respiratory 1 hour later this amnesia was confirmed. In
depression responding adequately to assisted venti- addition, despite the various drugs administered at
lation with an ambu bag (two of these patients had 1 min intervals, the entire cardioversion procedure
k chronic obstructive lung disease). After naloxone, was markedly less time-consuming when fentanylbreathing was adequate in 42 patients (two patients etomidate was used than with classical diazepam
each received 225 mg of the respiratory center anesthesia.
stimulant, prethcamide, with good results). No
Alternatives other than diazepam are available
patient had any recollection whatsoever of the for anesthesia: methohexital sodium (25-50 mg)
cardioversion procedure, either after 1 h or the next has been recommended by CoeM, who has never
morning.
encountered any respiratory depression necessitating intubation. We fear that in emergencies a
slight overdose of a short-acting barbiturate may
r Discussion
produce respiratory depression which is not reverAt first glance, anesthesia with fentanyl and sible with naloxone and requires endotracheal
etomidate seems cumbersome, because so many intubation. In addition, barbiturates have marked
drugs were administered consecutively. The cardiovascular effects through myocardial depresi. rationale for this medication sequence is the sion and vasodilatation. Although a barbiturate is
perfectly safe in the hands of a competent anesthefollowing.
Atropine was given for three reasons. Drying up tist who is familiar with the drug, it could be
of oropharyngeal secretions provides for easier very dangerous when administered by a cardiologist
endotracheal intubation, should this be necessary. in training to a patient with an acute myocardial
Fentanyl sometimes produces marked bradycardia, infarction and left ventricular failure.
and this may be disadvantageous in very sick
In our opinion, short-term anesthesia should be
cardiac patients. Finally, suppression of vagal carried out by an anesthetist; in emergency situtone may facilitate resumption of a sinus ations when no anesthetist is available, a cardiomechanism after overdrive suppression of the sinus logist in training may induce effective and safe
node by the tachyarrhythmial|Ol In supraven- anesthesia for cardioversion with fentanyl and
tricular tachyarrhythmias, however, atropine may etomidate, with little risk of respiratory depression.
improve atrioventricular conduction and increase As a matter of precaution, oxygen and suction
the ventricular rate; this drawback is of minor should be immediately available on the premises
importance because cardioversion discharges are where cardioversion is to be performed.
^ given only minutes later, and because an excessive
improvement of atrioventricular conduction can be
counteracted quite rapidly by the intravenous References
[1] Lown B. Electrical reversion of cardiac arrhythmias.
administration of verapamiH"].
Br Heart J 1967; 29:469-89.
Fentanyl is a synthetic opiate derivative well
[2] Hagemeijer F, Van Houwe E. Titrated energy cardioversion of patients on digitalis. Br Heart J 1975; 37:
known in the Coronary Care Unit, and given
t
1303-7.
L mainly to prevent two side-effects of etomidate:
' namely, pain at the site of injection due to the [3] Somers K, Gunstone RF, Patel AK, D'Arbela PG.
intravenous diazepam for direct current cardiosolvent, propylene glycol, and twitching of skeletal
version. BrMedJ 1971; 4: 13-5.
6 8
muscles! " !.
[4] Orko R. Anaesthesia for cardioversion: a comparison
of diazepam, thiopentone and propanidid. Br J
Naloxone administered at the end of the proAnaesth 1976; 48:257-62.
cedure antagonizes the effect of fentanyll'l and
EH. Anesthesia for elective cardioversion. N Engl
allows the patient to wake up rapidly from short- [5] Coe
JMed 1978; 299: 262.
i acting etomidate anesthesia.
[6] Van Hamme MJ, Ghoneim MM, Ambre JJ.
Pharmacokinetics of etomidate, a new intravenous
Anesthesia with fentanyl and etomidate proved
anesthetic. Anesthesiology 1978; 49:274-7.
very safe. Slight respiratory depression was most
probably caused by fentanyl rather than by [7] Korttila K, Tammisto T, Aromaa U. Comparison of
etomidate in combination with fentanyl or diazepam,
etomidate and only required ambu bag assisted
with thiopentone as an induction agent for general
ventilation. Endotracheal intubation was never
anaesthesia. BrJ Anaesth 1979; 51: 1151-7.
needed and no serious hemodynamic side-effects [8] Horrigan RW, Moyers JR, Johnson BH, ei al.
158 F. Hagemeijer, R. Van Mechelen and D. W. Th. Smalbraak
Etomidate vs. thiopental with and without fentanyl
— A comparative study of awakening in man.
Anesthesiology 1980; 52:362-^.
[9] Drummond GB, Davie IT, Scott DB. Naloxone: dosedependent antagonism of respiratory depression by
fentanyl in anaesthetized patients. Br J Anaesth 1977;
49:151^.
[10] Vassalle M. The relationship among cardiac pacemakers. Overdrive suppression. Circ Res 1977; 41:
269-77.
[11] Hagemeijer F. Verapamil in the management of
supraventricular tachyarrhythmias occurring after a
recent myocardial infarction. Circulation 1978; 57:
751-5.
Downloaded from http://eurheartj.oxfordjournals.org/ by guest on September 18, 2016