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A method of rapid-sequence induction using high-dose narcotics with vecuronium or vecuronium and pancuronium in patients with coronary artery disease
A Method of Rapid-Sequence Induction Using High-Dose Narcotics With Vecuronium or Vecuronium and Pancuronium in Patients With Coronary Artery Disease Mitsuru
Nakatsuka,
MD, Paul Franks, MD, and Richard L. Keenan,
A method of rapid-sequence induction was studied in 18 patients undergoing coronary artery bypass grafting (CABG) to assess the adequacy of relaxation for endotracheal intubation without resulting in major changes in heart rate (HRj. Ten patients received vercuronium, 0.2 mg/kg (VI; and eight patients received vecuronium, 0.1 mg/kg, and pancuronium, 0.1 mg/kg (V + PI. All patients then received fentanyl, 50 to 70 pgfkg. or sufentanil. 5 to 7 pglkg. followed 80 seconds later by intubation. Patients were assessed for ulnar and mandibular nerve response to train-of-four (TOF) and tetanic (T) stimulation at 80 seconds: presence or absence of coughing or bucking; degree of vocal cord relaxation (1 = none, 2 = some, 3 = complete relaxation); ability to intubate at 80 seconds; and changes in HR. At the time of intubation, 17 patients had four twitches to TOF and a positive response to T stimulation of the ulnar nerve, while all 18 patients had zero or one twitch to TOF and only four had a positive response
T
HE NEED for inducing general anesthesia in patients with cardiac disease who have a full stomach is not uncommon. Cardiac side effects often make the drugs commonly used for a rapid-sequence induction, such as thiopental and succinylcholine, undesirable in these patients. Fentanyl and sufentanil, with their lack of myqcardial depressant effects, and vecuronium, with no known cardiac effects, have been welcome additions in cardiac anesthesia. These drugs, though, have some problems of their own. When given rapidly and/or in large doses, the narcotics can cause chest wall rigidity and a decrease in heart rate.’ Vecuronium had been thought to have too slow an onset time to be used for rapid-sequence induction; however, recent data have shown that the onset time of vecuronium can be appropriately shortened by using larger doses.* On the other hand, an increased heart rate, as might result from inadequate anesthesia at the time of intubation, or peri-induction hypoxia or hypercarbia are also undesirable in patients with coronary artery disease. Thompson et al suggested that an increased heart rate during the per&induction period is associated with myocardial ischemia,3 and Slogoff and Keats showed that perioperative ischemia is associated with perioperative myocardial infarction.4
MD
to T stimulation of the mandibular nerve (P < COO1 for T and TOF, ulnar Y mandibular). Coughing and bucking were not observed in any patient. Vocal cord position was “3” in 14 patients and “2” in four patients. All patients were intubated without difficulty. The mean change in HR was -4.1 beats/min for patients receiving V and +18.4 beats/min for those receiving V + P (P c: .002 for change in HRI, with two V + P patients developing tachycardia. It is concluded that the onset of neuromuscular blockade is more rapid in the distribution of the mandibular nerve than at the ulnar nerve; mandibular nerve stimulation is a better predictor of adequate intubating conditions; good intubating conditions can be attained with either V or V + P; and, rapid-sequence induction with V is safe from a cardiac standpoint as measured by changes in HR. but the addition of pancuronium is unnecessary. @ 1988 by Grune & Stratton, Inc.
A method of rapid-sequence induction was studied using high-dose narcotics and nondepolarizing muscle relaxants to assess the adequacy of relaxation for endotracheal intubation and the degree of cardiac stability as measured by minimal changes in heart rate (HR). METHODS
Eighteen patients undergoing coronary artery bypass grafting (CABG) served as subjects in this study. The study was approved by the Committee on the Conduct of Human Research and informed consent was obtained. Ten patients received preoxygenation with 100% O2 for three minutes, then vercuronium, 0.2 mg/kg (V), intravenously (IV), followed immediately by fentanyl, 50 to 70 wg/kg, IV, or sufentanil, 5 to 7 pg/kg, IV, followed 60 seconds later by endotracheal intubation. Eight patients received preoxygenation with 100% 0, for three minutes, then vecuronium, 0.1 mg/kg, and pancuronium, 0.1 mg/kg (V + P), IV, followed immediately by fentanyl, 50 to 70 pg/kg, or sufentanil, 5 to 7 rg/kg, IV, followed 60 seconds later by endotracheal intubation.
From the Department of Anesthesiology, Medical College of Virginia, and McGuire Veterans Administration Medical Center, Richmond, VA. Address reprint requests to Mitsuru Nakatsuka, MD, Department of Anesthesiology, MCV Station-Box 695, Richmond, VA 23298. 0 1988 by Grune & Stratton, Inc. 0888-6296/88f0202-0009$03.00/0
Journal of CardiothoracicAnesthesia, Vol 2, No 2 (April), 1988: pp 177-l 8 1
177
NAKATSUKA,
178
Patients were assessed for their response to trainof-four (TOF) and tetanic (T) stimulation of the ulnar and mandibular nerves at 60 seconds; whether coughing or bucking were present; the degree of vocal cord relaxation at the time of intubation judged by the intubator on a scale of 1 to 3 complete relaxation); and whether (l=none,2-some,3intubation was possible. In addition, the preinduction HR, whether the HR increased or decreased with induction, and maximal or minimal HR were noted. Ulnar nerve stimulation was performed by placing electrodes over the ventral medial aspect of the elbow and the ventral surface of the wrist with notation made of the presence or absence of contraction of the adductor policis brevis. Mandibular nerve stimulation was performed by placing standard electrocardiogram electrodes in proximity to the condyle and the angle of the mandible and noting the presence or absence of contraction of the masseter muscle resulting in mouth closure. The TOF stimulation used was 2 Hz for two seconds, and the tetanic stimulation was 50 Hz for five seconds. Using the TOF, the number of twitches was counted, and a positive response was defined as more than one twitch, while for T, the presence of a contraction was defined as a positive response. Comparisons of nerve stimulation results and vocal cord relaxation of the patients receiving V or V + P, TOF and T responses of the ulnar nerve to the manibular nerve, and the nerve stimulation response to degree of vocal cord relaxation were performed using Fisher’s exact test. Comparisons of preinduction HR. postinduction HR, and changes in HR of the V group to the V + P group were performed using an analysis of variance. RESULTS
Demographic data were essentially the same for both the V and V + P groups (Table 1). The average ages for the V and V + P groups were 64.2 years and 58.8 years, respectively. The left ventricular ejection fraction averaged 59.6% for the V group and 60.7% for the V + P group. The incidence of a past history of a myocardial infarction was nine of ten patients for the V group and six of eight patients for the V + P group. Table 1. Demographic
Data
V
No. of patients (n) Sex (M/F) Ages (yr) Weight (kg) Preoperative scopolamine in)
v+p
10
8
812 64.2 & 3.4*
7/l 58.8 k 7.3’
75.8
91.3
& 4.0* 9
f 7.7* 6
History of myocardial infarction (n) LVEF (%)
9 59.6
+ 3.5,
6 60.7
8
6
Beta-adrenergic blocker (n)
7
8
*Mean + SD.
The ulnar nerve TOF exhibited four twitches in 17 of 18 patients (9/10 V, 8/8 V + P), and there was a positive response to T in 17 of 18 patients (9/10 V, 8/8 V + P) at 60 seconds after relaxant administration. However, the mandibular nerve TOF exhibited either zero or one twitch in all patients, and only four of 18 patients (2/10 V, 2/8 V + P) had a positive response to mandibular nerve T. No significant difference existed between the V patients and the V + P patients for either TOF or T stimulation. However, the differences between TOF and T stimulation of the ulnar nerve compared to the mandibular nerve were both significant (P < .OOOlfor both). Coughing and bucking were not observed in any patient. Vocal cord relaxation was judged to be “3” in 14 patients, “2” in four patients, and “1” in no patients. All patients were intubated without difficulty. There was no statistically significant correlation between muscle relaxants(s) and degree of vocal cord relaxation or between response to nerve stimulation and degree of vocal cord relaxation. Four of ten patients in the V group developed an increase in HR and six had a decrease. No V patient had a clinically significant decrease in HR, and no patient developed a new bradycardia. One V patient with a bradycardia preinduction experienced a further decrease in HR from 55 to 50 beats/min. Mean preinduction HR for the V group was 76.2 beats/min, mean postinduction HR was 72.1 beats/min, and the mean change was -4.1 beats/min. All eight V + P patients experienced an increase in HR. Two patients developed a potentially hazardous tachycardia, one patient’s HR increasing from 75 to 100 beats/min and the other from 75 to 120 beats/min. Mean preinduction HR for the V + P group was 59.1 beats/min, mean postinduction HR was 75.4 beats/min, and mean change was 16.3 beats/min. The differences in pre- and postinduction HR between the V and V + P groups were not statistically significant; however, the difference in change in HR was (P < .002). All results are summarized in Table 2.
+ 10.6*
Ca channel blocker (n)
Abbreviation: LVEF, left ventricular ejection fraction.
FRANKS, AND KEENAN
DISCUSSION
It is estimated that about ten million people have ischemic heart disease in the United States
RAPID-SEQUENCE
INDUCTION
179
IN CARDIAC SURGERY
Table 2.
Relaxation
and Heart Rate Changes Muscle
Relaxant v+p
V Patient
1
2
Ulnar nerve at
TOF
+
60s Mandibular nerve
T TDF
++ _
T
-+
at 60s Coughing or bucking
3
4
5
6
7
8
9
10
11
12
13
14
+
+
+
+
+
+
-
+
+
+
+
+
_
+ _
++++-++++++ _ _ _
_
-+--_-_+_-_
_
_
_
_
_
_
_
15
16
17
16
+
+
+
+
+
_
+ _
+ _
++ _
_
_
_
-+
---------------
Vocal cord relaxation
23
332333233223
2
333
HR preinduction
56
55
100
80
80
07
75
75
65
87
45
60
57
56
75
75
60
45
HR postinduction
59
50
80
90
70
82
76
65
67
82
64
65
58
70
120
100
62
64
and, among them, approximately four million people have one or more myocardial infarctions. Since one million to two million patients with ischemic heart disease undergo surgery each year, many cardiac patients may require emergency cardiac or noncardiac surgery for a variety of reasons in spite of full stomachs. The goal of the present study was to investigate the means of safely inducing general anesthesia in these patients while protecting them against aspiration and avoiding cardiac compromise. Sufentanil has a slightly faster onset of action than fentanyl, but it was found that both drugs were effective in combination with the muscle relaxants in preparing for intubation at 60 seconds. Fentanyl and sufentanil are devoid of myocardial depressant effects; however, particularly at high doses or when administered quickly, they can result in a potentially hazardous decrease in HR or possibly even short periods of asystole.‘*s~6However, in the 18 patients studied, no problematic decreases in HR occurred regardless of the muscle relaxant(s) used. Premedication with scopolamine in 15 of the patients might have attenuated the HR decrease from the narcotics or vecuronium since glycopyrrolate has been shown to be effective with vecuronium.7 Vecuronium is an attractive drug for use in patients with coronary artery disease because it has minimal cardiac side effects.8 Although the onset of neuromuscular blockade with vecuronium is relatively rapid, it has been felt to be too long for rapid-sequence inductions. However, two techniques have recently been developed to shorten the neuromuscular blockade onset time with vecuronium. The first technique involves
the priming principlegvlO;because of the variability in response to this technique it was not selected for this study. The authors were concerned that some patients might be underdosed, ie, not entirely relaxed at intubation, while other patients might be overdosed with the priming dose, experiencing muscle weakness, respiratory difficulty, and potentially adverse cardiac effects as a result of the anxiety this would provoke. In a recent study by Zahl and Ellison using the priming principle for rapid-sequence induction in patients undergoing cardiac surgery, two of 24 patients experienced respiratory difficulty after the priming dose associated with an increase in HR and blood pressure.” Recently, Casson and Jones demonstrated that by increasing the dose of vecuronium using multiples of the EDg5 (0.05 mg/kg), the time to onset of neuromuscular blockade could be significantly shortened.2 Specifically, by using a dose of 0.2 mg/kg the time to 95% depression of T1 was 95 seconds. Using 0.4 mg/kg this time was 87 seconds. Subsequently, Lennon et al successfully intubated ASA class I and II patients at 60 seconds using 0.25 mg/kg of vecuronium.‘2 Agoston et al suggested that vecuronium produced complete relaxation of the vocal cords when the hand muscles were about 50% paralyzed,13 and Norman et al also reported that vercuronium produced respiratory paralysis before hand muscle paralysis.14 Furthermore, Chauvin et al explained that the more rapid onset of paralysis of the respiratory muscles with vecuronium may provide relatively good intubating conditions soon after the injection of vecuronium, despite the persistence of peripheral residual muscle tone.15 Based on these studies, it was felt
NAKATSUKA,
180
that intubation at 60 seconds when using 0.2 mg/kg of vecuronium or 0.1 mg/kg of vecuronium plus 0.1 mg/kg of pancuronium might be feasible. Intubation at 60 seconds was preferred to 90 seconds because of the rapid rate of oxygen desaturation that can occur in patients with a poor cardiac output, and a rapid-sequence induction for cardiac patients with a full stomach should be fast. The data demonstrate that in all patients adequate intubating conditions were obtained at 60 seconds. Part of the reluctance to attempt rapid intubation with vecuronium or vecuronium and pancuronium might stem from misleading data from ulnar nerve stimulation. The techniques of TOF and T stimulation of the ulnar nerve, in comparison to stimulation of other nerves as a means of assessing preparedness for intubation, have not been well studied. TOF and T stimulation of the mandibular branch of the trigeminal nerve were evaluated because of the convenience of administering the stimulus as well as observing the response at the head of the operating table, and because blood supply to muscle groups supplied by this nerve overlaps with blood supply to the muscles controlling the vocal cords and larynx. It was found that not only was the onset of neuromuscular blockade, as assessed by TOF and T stimulation, more rapid in the mandibular nerve distribution compared to the ulnar nerve, but also that mandibular nerve stimulation is a better predictor of adequate intubating conditions. Thomson et al have shown an association between an increased HR on induction and myocardial ischemia,3 and Slogoff and Keats have shown an association between perioperative ischemia and postoperative myocardial infarction.4 Patients can develop ischemia without an increase in HR, particularly those on beta-adren-
FRANKS, AND KEENAN
ergic blocking drugs. Newer methods for assessing ischemia exist including pulmonary artery pressure changes, thallium scans,16 and changes in the slope of the left ventricular end-systolic pressure/volume curve.17 In the present study, HR increased in four patients in the V group, but the increases were small. In the V + P group, all patients experienced an increase in HR. The two patients who developed a significant tachycardia had increases in HR of 33% and 60%. Heart rate decreases in the V group to the point of presenting a problem were not experienced. This finding is in variance with the experience of some other investigators. Gravlee et al found that the need to treat hypotension and/or bradycardia occurred in 13 of 46 patients induced with narcotics and vecuronium.” Intubation at ten minutes in their patients, compared to one minute in the present study, may have been responsible for this difference. Thus, with the reported method the addition of pancuronium to attenuate these decreases is not necessary, since it may have been at least partially responsible for the HR increase in the V + P groups. Recently, other investigators have also experienced adverse results with the use of pancuronium in patients with heart disease, both with standard and rapid-sequence inductions.11*‘9*20 In summary, this study demonstrates that a method of rapid-sequence induction using highdose narcotics and vecuronium is safe and feasible for patients with ischemic heart disease. However, addition of pancuronium is not desirable since it may cause a significant increase in heart rate. This method can be applied to induce anesthesia for patients with ischemic heart disease and a full stomach while maintaining cardiac stability.
REFERENCES 1. Bovill JG, Sebel PS, Stanley TH: Opioid analgesits in anesthesia: with special reference to their use in cardiovascular anesthesia. Anesthesiology 61:731-755, 1984 2. Casson WR, Jones RM: Vecuronium-induced neuromuscular blockade. The effect of increasing dose on speed of onset. Anesthesia 41:354-357, 1986 3. Thompson IR, Mutch WAC, Cullingan JD: Failure of intravenous nitroglycerin to prevent intraoperative myocardial ischemia during fentanyl-pancuronium anesthesia. Anesthesiology, 61:385-393, 1984 4. Slogoff S, Keats AS: Does perioperative myocar-
dial &hernia lead to postoperative myocardial infarction? Anesthesiology 61:107-l 14, 1985 5. Starr NJ, Dhun HS, Estafanous FG: Bradycardia and asystole following the rapid administration of sufentanil with vecuronium. Anesthesiology, 64521-523, 1986 6. Sebel PS, Bovill JG: Opioid analgesics in cardiac anesthesia, in Kaplan JA (ed): Cardiac Anesthesia (ed 2). Philadelphia, Grune & Stratton, 1987, pp 67-125 7. Cozanitis DA, Poutt OJ, Rosenberg PH: Vecuronium-induced bradycardia. A comparison with pancuronium
RAPID-SEQUENCE INDUCTION IN CARDIAC SURGERY
with and without glycopyrrolate premeditation. Anesthesiology 65:A117, 1986 8. Scott RPF, Savarese JJ: New muscle relaxants and the cardiovascular system, in Kaplan JA (ed): Cardiac Anesthesia (ed 2). Philadelphia, Grune & Stratton, 1987, pp 151-179 9. Schwarz S, Bias W, Lackner F, et al: Rapid tracheal intubation with vecuronium: the priming principle. Anesthesiology 62:388-391, 1985 10. Miller RD: The priming principle. Anesthesiology 62:381-382, 1985 11. Zahl K, Ellison N: Rapid induction and intubation with pancuronium or vecuronium and sufentanil for cardiac surgery. Anesthesiology 65:A519, 1986 12. Lennon DO, Olson RA, Gronert GA: Atracurium and vecuronium for rapid-sequence endotracheal intubation. Anesthesiology 64:510-513, 1986 13. Agoston S, Salt P, Newton D, et al: The neuromuscular blocking action of Org NC 45, a new pancuronium derivative, in anaesthetic patients. Br J Anaesth 52:535, 1980 14. Norman J, Read D, duBoupay M: Hand and respiratory paralysis by Org NC 45 in man. Br J Anaesth 52:956, 1980
181
15. Chauvin M, Lebrault C, Dovaldestin P: The neuromuscular blocking effect of vecuronium on the human diaphragm. Anesth Analg 66: 117-l 22, 1987 16. Kleinman B, Henkin RE, Glisson SN, et al: Qualitative evaluation of coronary flow during anesthesia induction using thallium-201 perfusion scans. Anesthesiology 64:157-164, 1986 17. Iskandrian AS, Heo J: Left ventricular pressure/ volume relationship in coronary heart disease. Am Heart J 112:375-381, 1986 18. Gravlee CP, Ramsey FM, Roy RC, et al: Pancuronium is hemodynamically superior to vecuronium for narcotic/relaxant induction. Anesthesiology 65:A46, 1986 19. Paulissian R, Mahdi M, Joseph N, et al: Hemodynamic responses to pancuronium and vecuronium during high-dose fentanyl anesthesia for coronary artery bypass grafting. Anesthesiology 65:A523, 1986 (abstr) 20. Estafanous FG, Williams G, Sethna D, et al: Effects of preoperative Ca channel blockers, beta-blockers, and pancuronium or vecuronium on hemodynamics of induction of anesthesia in patients with coronary disease receiving sufentanil anesthesia. Anesthesiology 65:A524, 1986 (abstr)
Nakatsuka,
MD, Paul Franks, MD, and Richard L. Keenan,
A method of rapid-sequence induction was studied in 18 patients undergoing coronary artery bypass grafting (CABG) to assess the adequacy of relaxation for endotracheal intubation without resulting in major changes in heart rate (HRj. Ten patients received vercuronium, 0.2 mg/kg (VI; and eight patients received vecuronium, 0.1 mg/kg, and pancuronium, 0.1 mg/kg (V + PI. All patients then received fentanyl, 50 to 70 pgfkg. or sufentanil. 5 to 7 pglkg. followed 80 seconds later by intubation. Patients were assessed for ulnar and mandibular nerve response to train-of-four (TOF) and tetanic (T) stimulation at 80 seconds: presence or absence of coughing or bucking; degree of vocal cord relaxation (1 = none, 2 = some, 3 = complete relaxation); ability to intubate at 80 seconds; and changes in HR. At the time of intubation, 17 patients had four twitches to TOF and a positive response to T stimulation of the ulnar nerve, while all 18 patients had zero or one twitch to TOF and only four had a positive response
T
HE NEED for inducing general anesthesia in patients with cardiac disease who have a full stomach is not uncommon. Cardiac side effects often make the drugs commonly used for a rapid-sequence induction, such as thiopental and succinylcholine, undesirable in these patients. Fentanyl and sufentanil, with their lack of myqcardial depressant effects, and vecuronium, with no known cardiac effects, have been welcome additions in cardiac anesthesia. These drugs, though, have some problems of their own. When given rapidly and/or in large doses, the narcotics can cause chest wall rigidity and a decrease in heart rate.’ Vecuronium had been thought to have too slow an onset time to be used for rapid-sequence induction; however, recent data have shown that the onset time of vecuronium can be appropriately shortened by using larger doses.* On the other hand, an increased heart rate, as might result from inadequate anesthesia at the time of intubation, or peri-induction hypoxia or hypercarbia are also undesirable in patients with coronary artery disease. Thompson et al suggested that an increased heart rate during the per&induction period is associated with myocardial ischemia,3 and Slogoff and Keats showed that perioperative ischemia is associated with perioperative myocardial infarction.4
MD
to T stimulation of the mandibular nerve (P < COO1 for T and TOF, ulnar Y mandibular). Coughing and bucking were not observed in any patient. Vocal cord position was “3” in 14 patients and “2” in four patients. All patients were intubated without difficulty. The mean change in HR was -4.1 beats/min for patients receiving V and +18.4 beats/min for those receiving V + P (P c: .002 for change in HRI, with two V + P patients developing tachycardia. It is concluded that the onset of neuromuscular blockade is more rapid in the distribution of the mandibular nerve than at the ulnar nerve; mandibular nerve stimulation is a better predictor of adequate intubating conditions; good intubating conditions can be attained with either V or V + P; and, rapid-sequence induction with V is safe from a cardiac standpoint as measured by changes in HR. but the addition of pancuronium is unnecessary. @ 1988 by Grune & Stratton, Inc.
A method of rapid-sequence induction was studied using high-dose narcotics and nondepolarizing muscle relaxants to assess the adequacy of relaxation for endotracheal intubation and the degree of cardiac stability as measured by minimal changes in heart rate (HR). METHODS
Eighteen patients undergoing coronary artery bypass grafting (CABG) served as subjects in this study. The study was approved by the Committee on the Conduct of Human Research and informed consent was obtained. Ten patients received preoxygenation with 100% O2 for three minutes, then vercuronium, 0.2 mg/kg (V), intravenously (IV), followed immediately by fentanyl, 50 to 70 wg/kg, IV, or sufentanil, 5 to 7 pg/kg, IV, followed 60 seconds later by endotracheal intubation. Eight patients received preoxygenation with 100% 0, for three minutes, then vecuronium, 0.1 mg/kg, and pancuronium, 0.1 mg/kg (V + P), IV, followed immediately by fentanyl, 50 to 70 pg/kg, or sufentanil, 5 to 7 rg/kg, IV, followed 60 seconds later by endotracheal intubation.
From the Department of Anesthesiology, Medical College of Virginia, and McGuire Veterans Administration Medical Center, Richmond, VA. Address reprint requests to Mitsuru Nakatsuka, MD, Department of Anesthesiology, MCV Station-Box 695, Richmond, VA 23298. 0 1988 by Grune & Stratton, Inc. 0888-6296/88f0202-0009$03.00/0
Journal of CardiothoracicAnesthesia, Vol 2, No 2 (April), 1988: pp 177-l 8 1
177
NAKATSUKA,
178
Patients were assessed for their response to trainof-four (TOF) and tetanic (T) stimulation of the ulnar and mandibular nerves at 60 seconds; whether coughing or bucking were present; the degree of vocal cord relaxation at the time of intubation judged by the intubator on a scale of 1 to 3 complete relaxation); and whether (l=none,2-some,3intubation was possible. In addition, the preinduction HR, whether the HR increased or decreased with induction, and maximal or minimal HR were noted. Ulnar nerve stimulation was performed by placing electrodes over the ventral medial aspect of the elbow and the ventral surface of the wrist with notation made of the presence or absence of contraction of the adductor policis brevis. Mandibular nerve stimulation was performed by placing standard electrocardiogram electrodes in proximity to the condyle and the angle of the mandible and noting the presence or absence of contraction of the masseter muscle resulting in mouth closure. The TOF stimulation used was 2 Hz for two seconds, and the tetanic stimulation was 50 Hz for five seconds. Using the TOF, the number of twitches was counted, and a positive response was defined as more than one twitch, while for T, the presence of a contraction was defined as a positive response. Comparisons of nerve stimulation results and vocal cord relaxation of the patients receiving V or V + P, TOF and T responses of the ulnar nerve to the manibular nerve, and the nerve stimulation response to degree of vocal cord relaxation were performed using Fisher’s exact test. Comparisons of preinduction HR. postinduction HR, and changes in HR of the V group to the V + P group were performed using an analysis of variance. RESULTS
Demographic data were essentially the same for both the V and V + P groups (Table 1). The average ages for the V and V + P groups were 64.2 years and 58.8 years, respectively. The left ventricular ejection fraction averaged 59.6% for the V group and 60.7% for the V + P group. The incidence of a past history of a myocardial infarction was nine of ten patients for the V group and six of eight patients for the V + P group. Table 1. Demographic
Data
V
No. of patients (n) Sex (M/F) Ages (yr) Weight (kg) Preoperative scopolamine in)
v+p
10
8
812 64.2 & 3.4*
7/l 58.8 k 7.3’
75.8
91.3
& 4.0* 9
f 7.7* 6
History of myocardial infarction (n) LVEF (%)
9 59.6
+ 3.5,
6 60.7
8
6
Beta-adrenergic blocker (n)
7
8
*Mean + SD.
The ulnar nerve TOF exhibited four twitches in 17 of 18 patients (9/10 V, 8/8 V + P), and there was a positive response to T in 17 of 18 patients (9/10 V, 8/8 V + P) at 60 seconds after relaxant administration. However, the mandibular nerve TOF exhibited either zero or one twitch in all patients, and only four of 18 patients (2/10 V, 2/8 V + P) had a positive response to mandibular nerve T. No significant difference existed between the V patients and the V + P patients for either TOF or T stimulation. However, the differences between TOF and T stimulation of the ulnar nerve compared to the mandibular nerve were both significant (P < .OOOlfor both). Coughing and bucking were not observed in any patient. Vocal cord relaxation was judged to be “3” in 14 patients, “2” in four patients, and “1” in no patients. All patients were intubated without difficulty. There was no statistically significant correlation between muscle relaxants(s) and degree of vocal cord relaxation or between response to nerve stimulation and degree of vocal cord relaxation. Four of ten patients in the V group developed an increase in HR and six had a decrease. No V patient had a clinically significant decrease in HR, and no patient developed a new bradycardia. One V patient with a bradycardia preinduction experienced a further decrease in HR from 55 to 50 beats/min. Mean preinduction HR for the V group was 76.2 beats/min, mean postinduction HR was 72.1 beats/min, and the mean change was -4.1 beats/min. All eight V + P patients experienced an increase in HR. Two patients developed a potentially hazardous tachycardia, one patient’s HR increasing from 75 to 100 beats/min and the other from 75 to 120 beats/min. Mean preinduction HR for the V + P group was 59.1 beats/min, mean postinduction HR was 75.4 beats/min, and mean change was 16.3 beats/min. The differences in pre- and postinduction HR between the V and V + P groups were not statistically significant; however, the difference in change in HR was (P < .002). All results are summarized in Table 2.
+ 10.6*
Ca channel blocker (n)
Abbreviation: LVEF, left ventricular ejection fraction.
FRANKS, AND KEENAN
DISCUSSION
It is estimated that about ten million people have ischemic heart disease in the United States
RAPID-SEQUENCE
INDUCTION
179
IN CARDIAC SURGERY
Table 2.
Relaxation
and Heart Rate Changes Muscle
Relaxant v+p
V Patient
1
2
Ulnar nerve at
TOF
+
60s Mandibular nerve
T TDF
++ _
T
-+
at 60s Coughing or bucking
3
4
5
6
7
8
9
10
11
12
13
14
+
+
+
+
+
+
-
+
+
+
+
+
_
+ _
++++-++++++ _ _ _
_
-+--_-_+_-_
_
_
_
_
_
_
_
15
16
17
16
+
+
+
+
+
_
+ _
+ _
++ _
_
_
_
-+
---------------
Vocal cord relaxation
23
332333233223
2
333
HR preinduction
56
55
100
80
80
07
75
75
65
87
45
60
57
56
75
75
60
45
HR postinduction
59
50
80
90
70
82
76
65
67
82
64
65
58
70
120
100
62
64
and, among them, approximately four million people have one or more myocardial infarctions. Since one million to two million patients with ischemic heart disease undergo surgery each year, many cardiac patients may require emergency cardiac or noncardiac surgery for a variety of reasons in spite of full stomachs. The goal of the present study was to investigate the means of safely inducing general anesthesia in these patients while protecting them against aspiration and avoiding cardiac compromise. Sufentanil has a slightly faster onset of action than fentanyl, but it was found that both drugs were effective in combination with the muscle relaxants in preparing for intubation at 60 seconds. Fentanyl and sufentanil are devoid of myocardial depressant effects; however, particularly at high doses or when administered quickly, they can result in a potentially hazardous decrease in HR or possibly even short periods of asystole.‘*s~6However, in the 18 patients studied, no problematic decreases in HR occurred regardless of the muscle relaxant(s) used. Premedication with scopolamine in 15 of the patients might have attenuated the HR decrease from the narcotics or vecuronium since glycopyrrolate has been shown to be effective with vecuronium.7 Vecuronium is an attractive drug for use in patients with coronary artery disease because it has minimal cardiac side effects.8 Although the onset of neuromuscular blockade with vecuronium is relatively rapid, it has been felt to be too long for rapid-sequence inductions. However, two techniques have recently been developed to shorten the neuromuscular blockade onset time with vecuronium. The first technique involves
the priming principlegvlO;because of the variability in response to this technique it was not selected for this study. The authors were concerned that some patients might be underdosed, ie, not entirely relaxed at intubation, while other patients might be overdosed with the priming dose, experiencing muscle weakness, respiratory difficulty, and potentially adverse cardiac effects as a result of the anxiety this would provoke. In a recent study by Zahl and Ellison using the priming principle for rapid-sequence induction in patients undergoing cardiac surgery, two of 24 patients experienced respiratory difficulty after the priming dose associated with an increase in HR and blood pressure.” Recently, Casson and Jones demonstrated that by increasing the dose of vecuronium using multiples of the EDg5 (0.05 mg/kg), the time to onset of neuromuscular blockade could be significantly shortened.2 Specifically, by using a dose of 0.2 mg/kg the time to 95% depression of T1 was 95 seconds. Using 0.4 mg/kg this time was 87 seconds. Subsequently, Lennon et al successfully intubated ASA class I and II patients at 60 seconds using 0.25 mg/kg of vecuronium.‘2 Agoston et al suggested that vecuronium produced complete relaxation of the vocal cords when the hand muscles were about 50% paralyzed,13 and Norman et al also reported that vercuronium produced respiratory paralysis before hand muscle paralysis.14 Furthermore, Chauvin et al explained that the more rapid onset of paralysis of the respiratory muscles with vecuronium may provide relatively good intubating conditions soon after the injection of vecuronium, despite the persistence of peripheral residual muscle tone.15 Based on these studies, it was felt
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that intubation at 60 seconds when using 0.2 mg/kg of vecuronium or 0.1 mg/kg of vecuronium plus 0.1 mg/kg of pancuronium might be feasible. Intubation at 60 seconds was preferred to 90 seconds because of the rapid rate of oxygen desaturation that can occur in patients with a poor cardiac output, and a rapid-sequence induction for cardiac patients with a full stomach should be fast. The data demonstrate that in all patients adequate intubating conditions were obtained at 60 seconds. Part of the reluctance to attempt rapid intubation with vecuronium or vecuronium and pancuronium might stem from misleading data from ulnar nerve stimulation. The techniques of TOF and T stimulation of the ulnar nerve, in comparison to stimulation of other nerves as a means of assessing preparedness for intubation, have not been well studied. TOF and T stimulation of the mandibular branch of the trigeminal nerve were evaluated because of the convenience of administering the stimulus as well as observing the response at the head of the operating table, and because blood supply to muscle groups supplied by this nerve overlaps with blood supply to the muscles controlling the vocal cords and larynx. It was found that not only was the onset of neuromuscular blockade, as assessed by TOF and T stimulation, more rapid in the mandibular nerve distribution compared to the ulnar nerve, but also that mandibular nerve stimulation is a better predictor of adequate intubating conditions. Thomson et al have shown an association between an increased HR on induction and myocardial ischemia,3 and Slogoff and Keats have shown an association between perioperative ischemia and postoperative myocardial infarction.4 Patients can develop ischemia without an increase in HR, particularly those on beta-adren-
FRANKS, AND KEENAN
ergic blocking drugs. Newer methods for assessing ischemia exist including pulmonary artery pressure changes, thallium scans,16 and changes in the slope of the left ventricular end-systolic pressure/volume curve.17 In the present study, HR increased in four patients in the V group, but the increases were small. In the V + P group, all patients experienced an increase in HR. The two patients who developed a significant tachycardia had increases in HR of 33% and 60%. Heart rate decreases in the V group to the point of presenting a problem were not experienced. This finding is in variance with the experience of some other investigators. Gravlee et al found that the need to treat hypotension and/or bradycardia occurred in 13 of 46 patients induced with narcotics and vecuronium.” Intubation at ten minutes in their patients, compared to one minute in the present study, may have been responsible for this difference. Thus, with the reported method the addition of pancuronium to attenuate these decreases is not necessary, since it may have been at least partially responsible for the HR increase in the V + P groups. Recently, other investigators have also experienced adverse results with the use of pancuronium in patients with heart disease, both with standard and rapid-sequence inductions.11*‘9*20 In summary, this study demonstrates that a method of rapid-sequence induction using highdose narcotics and vecuronium is safe and feasible for patients with ischemic heart disease. However, addition of pancuronium is not desirable since it may cause a significant increase in heart rate. This method can be applied to induce anesthesia for patients with ischemic heart disease and a full stomach while maintaining cardiac stability.
REFERENCES 1. Bovill JG, Sebel PS, Stanley TH: Opioid analgesits in anesthesia: with special reference to their use in cardiovascular anesthesia. Anesthesiology 61:731-755, 1984 2. Casson WR, Jones RM: Vecuronium-induced neuromuscular blockade. The effect of increasing dose on speed of onset. Anesthesia 41:354-357, 1986 3. Thompson IR, Mutch WAC, Cullingan JD: Failure of intravenous nitroglycerin to prevent intraoperative myocardial ischemia during fentanyl-pancuronium anesthesia. Anesthesiology, 61:385-393, 1984 4. Slogoff S, Keats AS: Does perioperative myocar-
dial &hernia lead to postoperative myocardial infarction? Anesthesiology 61:107-l 14, 1985 5. Starr NJ, Dhun HS, Estafanous FG: Bradycardia and asystole following the rapid administration of sufentanil with vecuronium. Anesthesiology, 64521-523, 1986 6. Sebel PS, Bovill JG: Opioid analgesics in cardiac anesthesia, in Kaplan JA (ed): Cardiac Anesthesia (ed 2). Philadelphia, Grune & Stratton, 1987, pp 67-125 7. Cozanitis DA, Poutt OJ, Rosenberg PH: Vecuronium-induced bradycardia. A comparison with pancuronium
RAPID-SEQUENCE INDUCTION IN CARDIAC SURGERY
with and without glycopyrrolate premeditation. Anesthesiology 65:A117, 1986 8. Scott RPF, Savarese JJ: New muscle relaxants and the cardiovascular system, in Kaplan JA (ed): Cardiac Anesthesia (ed 2). Philadelphia, Grune & Stratton, 1987, pp 151-179 9. Schwarz S, Bias W, Lackner F, et al: Rapid tracheal intubation with vecuronium: the priming principle. Anesthesiology 62:388-391, 1985 10. Miller RD: The priming principle. Anesthesiology 62:381-382, 1985 11. Zahl K, Ellison N: Rapid induction and intubation with pancuronium or vecuronium and sufentanil for cardiac surgery. Anesthesiology 65:A519, 1986 12. Lennon DO, Olson RA, Gronert GA: Atracurium and vecuronium for rapid-sequence endotracheal intubation. Anesthesiology 64:510-513, 1986 13. Agoston S, Salt P, Newton D, et al: The neuromuscular blocking action of Org NC 45, a new pancuronium derivative, in anaesthetic patients. Br J Anaesth 52:535, 1980 14. Norman J, Read D, duBoupay M: Hand and respiratory paralysis by Org NC 45 in man. Br J Anaesth 52:956, 1980
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15. Chauvin M, Lebrault C, Dovaldestin P: The neuromuscular blocking effect of vecuronium on the human diaphragm. Anesth Analg 66: 117-l 22, 1987 16. Kleinman B, Henkin RE, Glisson SN, et al: Qualitative evaluation of coronary flow during anesthesia induction using thallium-201 perfusion scans. Anesthesiology 64:157-164, 1986 17. Iskandrian AS, Heo J: Left ventricular pressure/ volume relationship in coronary heart disease. Am Heart J 112:375-381, 1986 18. Gravlee CP, Ramsey FM, Roy RC, et al: Pancuronium is hemodynamically superior to vecuronium for narcotic/relaxant induction. Anesthesiology 65:A46, 1986 19. Paulissian R, Mahdi M, Joseph N, et al: Hemodynamic responses to pancuronium and vecuronium during high-dose fentanyl anesthesia for coronary artery bypass grafting. Anesthesiology 65:A523, 1986 (abstr) 20. Estafanous FG, Williams G, Sethna D, et al: Effects of preoperative Ca channel blockers, beta-blockers, and pancuronium or vecuronium on hemodynamics of induction of anesthesia in patients with coronary disease receiving sufentanil anesthesia. Anesthesiology 65:A524, 1986 (abstr)