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PANCURONIUM AND THE NEONATE
Br. J. Anaesth. (1975), 47, 75
PANCURONIUM AND THE NEONATE E. J. BENNETT, S. RAMAMURTHY, F. Y. DALAL AND M. R. SALEM SUMMARY
The newborn is increasingly subjected to major surgical procedures, and the anaesthetic techniques used commonly involve muscle relaxants. This study was performed to determine if pancuronium bromide is suitable for use in anaesthesia at this age, and to attempt to establish an index of dose and potency for this drug. METHOD
All the surgical procedures were upon the abdomen. Thus muscle relaxation and apnoea could be better judged and the patients' general condition was less complicated than in those with cardiac, thoracic, or neurosurgical conditions. Twenty-five patients were studied. All were under 28 days of age at the time of the procedure. Pancuronium was given in a strength of 100 ^g/ml. All neonates were premedicated with atropine 0.1 mg i.m., 1 hour before operation. On the operating table the patient was placed on a warm water mattress, maintained at a temperature of 40 °C. After ascertaining that the stomach had been decompressed and that secretions, if any, had been removed from the pharynx, an orotracheal tube was inserted while the infant was awake. A 50:50 mixture of nitrous oxide in oxygen was then given using the Rees variation of the Ayre's T-tube, with a total flow rate of 4 litre/min. The initial dose of pancuronium, 50 or 100 /ig, depending upon whether the infant weighed less or more than 2.27 kg, was injected intravenously. The time of onset, and the effect of this dose, were assessed. Full control of ventilation and adequate relaxation were used as the end-points. No attempt was made E. J. BENNETT, M.D., S. RAMAMUKTHY, M.D., Department
of Anesthesiology, University of Illinois Hospitals, 840 South Wood Street, Chicago, Illinois 60612; F. Y. DALAL, M.D., M. R. SALEM, M.D., Department of Anes-
thesiology, Loyola University Stritch School of Medicine, Maywood, Illinois 60153.
to assist or control ventilation until apnoea was observed. An Argyle "Medicut" cannula, 18 gauge, was placed percutaneously in the arm or the foot, and 5% dextrose in lactated Ringer's solution was infused at a rate of 8 ml/kg/hr. The duration of action of pancuronium was assessed as the interval from apnoea until there was a need for an incremental dose or until the block could be antagonized. Using a potency ratio, derived from the literature, of 5:1 for pancuronium compared with tubocurarine, the initial dose was 50 or 100 /ig, according to the weight. It was soon noticed, however, that almost all the smaller and the younger infants became apnoeic with this dose and required no further doses. The initial dose was then reduced to 25 or 50 ;ug respectively if the infant was less than 7 days old. In all the babies the block was reversed with a mixture of atropine 0.018 mg/kg and neostigmine 0.08 mg/kg given i.v. RESULTS AND DISCUSSION
The amounts of pancuronium necessary to produce the desired effects, in each patient, can be seen in figure 1. Table I lists the dose necessary for each newborn to establish the proper conditions. Figure 2 is a reproduction of the data of Bush and Stead (1962) for tubocurarine. Figure 3 shows the regression lines from figures 1 and 2 and it can be seen that the two slopes are significantly different. If potency is determined from these lines, the potency ratio of pancuronium is approximately 9 times that of tubocurarine at one day of age, and this ratio decreases progressively to a ratio of 6 : 1 at 28 days of age. At 7 days of age, the ratio is 8:1, and at 14 days of age, 7 : 1 . There is no doubt that the neonate is sensitive to pancuronium. The dose required for relaxation and apnoea at one day of age is 40 /ig/kg, a dose which in the presence of 50% nitrous oxide in
Downloaded from http://bja.oxfordjournals.org/ at University of Iowa Libraries/Serials Acquisitions on June 28, 2015
Pancuronium bromide was used safely as the muscle relaxant for neonatal anaesthesia. No untoward effects were seen and the neuromuscular block was successfully reversed in all patients. The potency ratio of pancuronium as compared with tubocurarine ranged from 9 : 1 at birth to 6 : 1 at one month of age.
BRITISH JOURNAL OF ANAESTHESIA
76 r =0.75843
dTC = 357.78 + 6 87x PC = 37.40 + 1.96 x
o 600500>
| 400-
o a. 00-
dTC-, ---—
80-
^ P C ^
200100-
14 20 Age in Days
40- ^
^
20-
2
28
8 14 20 Age in Days
28
FIG. 3. Comparison of regression lines of pancuronium and tubocurarine.
FIG. 1. Pancuronium bromide. TABLE I.
"
Dose of pancuronium (.fg/kg) and age (days).
the sensitivity to pancuronium becomes less; relaxation and apnoea were obtained only after 92 /ig/kg at 28 days of age. 1 36 14 70 A nerve stimulator was not used to test the 1 42 14 59 1 37 14 59 response of these neonates. If the effect of a muscle 1 33 14 59 relaxant is to be tested in the presence of minimal 1 50 15 66 2 33 21 62 anaesthesia, two factors need to be considered. 3 44 21 106 First, the effect of supramaximal stimulation upon 7 50 26 99 the neonate and his response (Churchill-Davidson 8 55 26 101 11 99 35 28 and Wise, 1963). Secondly, the observation that 12 106 28 99 there needs to be an occupancy ratio of 25-50% 14 37 28 59 for the peripheral muscles and 50-75% for the diaphragm for any effect of a non-depolarizing r =0.59580 block to be appreciated (Waud and Waud, 1972a,b). Since it was the clinical effects that were being observed, and as the neonate reacts to nerve • ^^^ 600stimulation in such a way that recordings are not 500practical, apnoea was used as the end-point. ^ 400In comparing the drug requirements with respect to age and weight, the potency of pancuronium is • §!.30O- • • 6-9 times that of tubocurarine. In none of our 200patients was there evidence that the block failed to reverse adequately. There was no evidence of iOOabnormal cardiovascular responses although these were not studied specifically. The time from injec8 14 28 20 tion of pancuronium to onset of paralysis was 30 Age in Days sec to 1 min depending upon the intensity of the FIG. 2. Tubocurarine (after Bush and Stead, 1962). effect. The duration of the block varied between Reprinted with permission of authors and Br. J. Anaesth. 50 and 90 min, from full apnoea until reversal oxygen would be unlikely to affect the ventilation could be accomplished or an increment was necesof an adult. This compares with the dose of 360 sary. Stead (1955) investigated the action of tubo^ig/kg for tubocurarine at this age (Bush and Stead, curarine in the newborn in a study of neonates 1962). There is also no doubt that as age increases, less than 48 hours old undergoing surgical proceAge
Dose
Age
Dose
Downloaded from http://bja.oxfordjournals.org/ at University of Iowa Libraries/Serials Acquisitions on June 28, 2015
60-
PANCURONIUM AND THE NEONATE
77
Downloaded from http://bja.oxfordjournals.org/ at University of Iowa Libraries/Serials Acquisitions on June 28, 2015
dures. He used the abolition of respiration as an dose. Throughout the procedure, if incremental endpoint. His conclusion was that the newborn doses are required, 1/5 to 1/6 of the dose required was exquisitely sensitive to tubocurarine and he to achieve the end-point is given. The maintenance likened the newborn neuromuscular junction to that anaesthetic is 50% nitrous oxide in oxygen with in myasthenia gravis. Bush and Stead (1962), controlled respiration. The duration that can be reporting on 215 babies in the first month of life, expected at this dose range is 75 ± 20 min. Predictarepeated this finding (fig. 2). bility of this effect has been reported by Deschene, However, Walts and Dillon (1969), reporting on Desrosiers and Bedard (1972) in adults. At the end another study with the newborn, doubted that this of the procedure, the residual effects of pancurowas so. If body weight was used, their results agreed nium are reversed with a mixture of atropine, 0.018 with the earlier study, but they suggested that using mg/kg, and neostigmine, 0.08 mg/kg, given intraanother parameter, such as surface area, the "myas- venously in all cases. thenia response" was not present. They studied 15 The cause of the sensitivity of the neonate to patients of whom only four were truly newborn, non-depolarizing drugs is not known. It may be and four were over the age of 28 days; five patients that a different parameter is required, such as extrahad pyloric stenosis, of whom three had a metabolic cellular fluid volume, or body surface area. It may acidosis. Churchill-Davidson and Wise (1964) also also be the result of differences in protein binding, reported that the neonatal neuromuscular response or an alteration in the response of the motor endwas not different from that of the adult. But their plate, or prejunctional receptors. However, for series contained only three patients aged 1, 2, and practical purposes, body weight remains the easiest 3 weeks respectively. Yamamoto, Baba and Shirat- measurement to make and apply in the operating suchi (1972) reported on the effects of pancuronium room. In the assessment of the newborn, conceptual in children. They noted that there were four age (the age from conception), would appear to be children under one month of age without comment- more important than actual age and will allow for ing upon any specific effects. The ages of these premature/postmature differences in response. Of four were not given. They used a dose of 80 /*g/kg course the use of potent anaesthetic drugs, such as and obtained a duration of action of 42 r"in halothane, ethrane and ether, alters the amounts of approximately. The results of the present study non-depolarizing relaxants that should be given. agree with those of Bush and Stead, that the newSome neonates were eliminated from the series born is sensitive to non-depolarizing muscle relax- where it was apparent that antibiotics had been ants, that this sensitivity diminishes with age to the administered for more than 5 days and increased extent that, at one month of age, the motor end- sensitivity was observed. Kanamycin and gentaplate has an almost normal response. This study mycin were the antibiotics which were associated shows that pancuronium is similar in its effects to with the most notable effects. tubocurarine. The potency ratio of pancuronium to CONCLUSION tubocurarine is 6:1 to 9 : 1 , at this dose level and for this age group. This potency ratio has been Pancuronium is effective as a muscle relaxant for suggested with adults receiving large doses, and the newborn and it appears that the newborn Lund and Stovner (1970) have shown that the response is "myasthenic" in type as it is with potency varies with the dose from 5:1 to 7.5:1. tubocurarine. This study would appear to indicate It is now our practice to administer pancuronium that the potency of pancuronium is at least 6-9 to the newborn in the following doses: times that of tubocurarine for the doses studied. 0-1 week 30 ^g/kg ACKNOWLEDGEMENT 1-2 weeks 60 /*g/kg The statistical analysis was performed by M. K. Patel, 2-4 weeks 90 /*g/kg M.SC. (Mathematics), M.SC. (Statistics), of the University This dose is reduced in prematurity, acidosis, hypo- of Illinois. thermia, or in other conditions in which the sensiREFERENCES tivity to pancuronium can reasonably be expected Bush, G. H., and Stead, A. L. (1962). The use of dto be increased, including antibiotics. tubocurarine in neonatal anaesthesia. Br. J. Anaesth., 34, 721. The clinical end-point, control of respiration and H. C , and Wise, R. P. (1963). muscle relaxation, is achieved by giving additional Churchill-Davidson, Neurotnuscular transmission in the newborn infant. amounts of pancuronium, 1/4 to 1/2 of this initial Anesthesiology, 24, 271.
BRITISH JOURNAL OF ANAESTHESIA
78
LE PANCURONIUM CHEZ LES NOUVEAUX-NES RESUME
Le bromure de pancuronium a 6t6 employ^ de maniere
sure comme medicament relichant pour l'anesthesie neonatale. Aucun effet fficheux n'a tti remarqu6 et l'anesthesie s'est trouvee effectivement inversee dans tous les patients. Le rapport d'efficacW du pancuronium par rapport a la d-tubocurarine allait de 9 a 1 a la naissance a 6 a 1 a l'age d'un mois. PANCURONIUM BEI NEUGEBORENEN ZUSAMMENFASSUNG
Pancuroniumbromid wurde ohne Gefahr als das Entspannungsmittel fur neonatale Anasthesie verwendet. Es kam zu keinen unerwunschten Nebenwirkungen, und die Anasthesie wurdein alien Patienten wirksam wieder aufgehoben. Das StarkeverhUltnis von Pancuronium im Vergleich zu d-Tubocurarin reichte von 9:1 bei der Geburt bis zu 6:1 im Alter von einem Monat. PANCURONIUM EN RECIEN NA CIDOS SUMARIO
Se emple6 satisfactoriamente bromuro de pancuronium como relejante para anestesia neonatal. No se observaron efectos desfavorables y la anestesia tuvo un efecto de reversion eficaz en todos los pacientes. La relaci6n de potencia del pancuronium comparado con d-tubocurarine vari6 entre 9:1 al nacimiento y 6:1 a la edad de un mes.
Downloaded from http://bja.oxfordjournals.org/ at University of Iowa Libraries/Serials Acquisitions on June 28, 2015
Churchill-Davidson, H. C , and Wise, R. P. (1964). The response of the newborn to muscle relaxants. Can. Anaesth. Soc. J., 11, 1. Deschene, J. P., Desrosiers, R., and Bedard, P. (1972). A clinical study of pancuronium—a new muscle relaxant for abdominal surgery. Can. Anaesth. Soc. J., 19, 412. Lund, I., and Stovner, J. (1970). Dose-response curves for tubocurarine, alcuronium, and pancuronium. Acta Anaesthesiol. Scand. [SuppL], 37, 238. Stead, A. L. (1955). The response of the newborn infant to muscle relaxants. Br. J. Anaesth., 27, 124. Walts, L. F., and Dillon, J. B. (1969). The response of newborns to succinylcholine and d-tubocurare. Anesthesiology, 31, 35. Waud, B. E., and Waud, D. R. (1972a). The relation between the response of "Train-of-four" stimulation and receptor occlusion during competitive neuromuscular block. Anesthesiology, 37, 413. (1972b). The margin of safety of neuromuscular transmission in the muscle of the diaphragm. Anesthesiology, 37, 417. Yamamoto, T., Baba, H., and Shiratsuchi, T. (1972). Clinical experience with pancuronium bromide in infants and children. Anesth. Analg. (Cleve.), 51, 919.
PANCURONIUM AND THE NEONATE E. J. BENNETT, S. RAMAMURTHY, F. Y. DALAL AND M. R. SALEM SUMMARY
The newborn is increasingly subjected to major surgical procedures, and the anaesthetic techniques used commonly involve muscle relaxants. This study was performed to determine if pancuronium bromide is suitable for use in anaesthesia at this age, and to attempt to establish an index of dose and potency for this drug. METHOD
All the surgical procedures were upon the abdomen. Thus muscle relaxation and apnoea could be better judged and the patients' general condition was less complicated than in those with cardiac, thoracic, or neurosurgical conditions. Twenty-five patients were studied. All were under 28 days of age at the time of the procedure. Pancuronium was given in a strength of 100 ^g/ml. All neonates were premedicated with atropine 0.1 mg i.m., 1 hour before operation. On the operating table the patient was placed on a warm water mattress, maintained at a temperature of 40 °C. After ascertaining that the stomach had been decompressed and that secretions, if any, had been removed from the pharynx, an orotracheal tube was inserted while the infant was awake. A 50:50 mixture of nitrous oxide in oxygen was then given using the Rees variation of the Ayre's T-tube, with a total flow rate of 4 litre/min. The initial dose of pancuronium, 50 or 100 /ig, depending upon whether the infant weighed less or more than 2.27 kg, was injected intravenously. The time of onset, and the effect of this dose, were assessed. Full control of ventilation and adequate relaxation were used as the end-points. No attempt was made E. J. BENNETT, M.D., S. RAMAMUKTHY, M.D., Department
of Anesthesiology, University of Illinois Hospitals, 840 South Wood Street, Chicago, Illinois 60612; F. Y. DALAL, M.D., M. R. SALEM, M.D., Department of Anes-
thesiology, Loyola University Stritch School of Medicine, Maywood, Illinois 60153.
to assist or control ventilation until apnoea was observed. An Argyle "Medicut" cannula, 18 gauge, was placed percutaneously in the arm or the foot, and 5% dextrose in lactated Ringer's solution was infused at a rate of 8 ml/kg/hr. The duration of action of pancuronium was assessed as the interval from apnoea until there was a need for an incremental dose or until the block could be antagonized. Using a potency ratio, derived from the literature, of 5:1 for pancuronium compared with tubocurarine, the initial dose was 50 or 100 /ig, according to the weight. It was soon noticed, however, that almost all the smaller and the younger infants became apnoeic with this dose and required no further doses. The initial dose was then reduced to 25 or 50 ;ug respectively if the infant was less than 7 days old. In all the babies the block was reversed with a mixture of atropine 0.018 mg/kg and neostigmine 0.08 mg/kg given i.v. RESULTS AND DISCUSSION
The amounts of pancuronium necessary to produce the desired effects, in each patient, can be seen in figure 1. Table I lists the dose necessary for each newborn to establish the proper conditions. Figure 2 is a reproduction of the data of Bush and Stead (1962) for tubocurarine. Figure 3 shows the regression lines from figures 1 and 2 and it can be seen that the two slopes are significantly different. If potency is determined from these lines, the potency ratio of pancuronium is approximately 9 times that of tubocurarine at one day of age, and this ratio decreases progressively to a ratio of 6 : 1 at 28 days of age. At 7 days of age, the ratio is 8:1, and at 14 days of age, 7 : 1 . There is no doubt that the neonate is sensitive to pancuronium. The dose required for relaxation and apnoea at one day of age is 40 /ig/kg, a dose which in the presence of 50% nitrous oxide in
Downloaded from http://bja.oxfordjournals.org/ at University of Iowa Libraries/Serials Acquisitions on June 28, 2015
Pancuronium bromide was used safely as the muscle relaxant for neonatal anaesthesia. No untoward effects were seen and the neuromuscular block was successfully reversed in all patients. The potency ratio of pancuronium as compared with tubocurarine ranged from 9 : 1 at birth to 6 : 1 at one month of age.
BRITISH JOURNAL OF ANAESTHESIA
76 r =0.75843
dTC = 357.78 + 6 87x PC = 37.40 + 1.96 x
o 600500>
| 400-
o a. 00-
dTC-, ---—
80-
^ P C ^
200100-
14 20 Age in Days
40- ^
^
20-
2
28
8 14 20 Age in Days
28
FIG. 3. Comparison of regression lines of pancuronium and tubocurarine.
FIG. 1. Pancuronium bromide. TABLE I.
"
Dose of pancuronium (.fg/kg) and age (days).
the sensitivity to pancuronium becomes less; relaxation and apnoea were obtained only after 92 /ig/kg at 28 days of age. 1 36 14 70 A nerve stimulator was not used to test the 1 42 14 59 1 37 14 59 response of these neonates. If the effect of a muscle 1 33 14 59 relaxant is to be tested in the presence of minimal 1 50 15 66 2 33 21 62 anaesthesia, two factors need to be considered. 3 44 21 106 First, the effect of supramaximal stimulation upon 7 50 26 99 the neonate and his response (Churchill-Davidson 8 55 26 101 11 99 35 28 and Wise, 1963). Secondly, the observation that 12 106 28 99 there needs to be an occupancy ratio of 25-50% 14 37 28 59 for the peripheral muscles and 50-75% for the diaphragm for any effect of a non-depolarizing r =0.59580 block to be appreciated (Waud and Waud, 1972a,b). Since it was the clinical effects that were being observed, and as the neonate reacts to nerve • ^^^ 600stimulation in such a way that recordings are not 500practical, apnoea was used as the end-point. ^ 400In comparing the drug requirements with respect to age and weight, the potency of pancuronium is • §!.30O- • • 6-9 times that of tubocurarine. In none of our 200patients was there evidence that the block failed to reverse adequately. There was no evidence of iOOabnormal cardiovascular responses although these were not studied specifically. The time from injec8 14 28 20 tion of pancuronium to onset of paralysis was 30 Age in Days sec to 1 min depending upon the intensity of the FIG. 2. Tubocurarine (after Bush and Stead, 1962). effect. The duration of the block varied between Reprinted with permission of authors and Br. J. Anaesth. 50 and 90 min, from full apnoea until reversal oxygen would be unlikely to affect the ventilation could be accomplished or an increment was necesof an adult. This compares with the dose of 360 sary. Stead (1955) investigated the action of tubo^ig/kg for tubocurarine at this age (Bush and Stead, curarine in the newborn in a study of neonates 1962). There is also no doubt that as age increases, less than 48 hours old undergoing surgical proceAge
Dose
Age
Dose
Downloaded from http://bja.oxfordjournals.org/ at University of Iowa Libraries/Serials Acquisitions on June 28, 2015
60-
PANCURONIUM AND THE NEONATE
77
Downloaded from http://bja.oxfordjournals.org/ at University of Iowa Libraries/Serials Acquisitions on June 28, 2015
dures. He used the abolition of respiration as an dose. Throughout the procedure, if incremental endpoint. His conclusion was that the newborn doses are required, 1/5 to 1/6 of the dose required was exquisitely sensitive to tubocurarine and he to achieve the end-point is given. The maintenance likened the newborn neuromuscular junction to that anaesthetic is 50% nitrous oxide in oxygen with in myasthenia gravis. Bush and Stead (1962), controlled respiration. The duration that can be reporting on 215 babies in the first month of life, expected at this dose range is 75 ± 20 min. Predictarepeated this finding (fig. 2). bility of this effect has been reported by Deschene, However, Walts and Dillon (1969), reporting on Desrosiers and Bedard (1972) in adults. At the end another study with the newborn, doubted that this of the procedure, the residual effects of pancurowas so. If body weight was used, their results agreed nium are reversed with a mixture of atropine, 0.018 with the earlier study, but they suggested that using mg/kg, and neostigmine, 0.08 mg/kg, given intraanother parameter, such as surface area, the "myas- venously in all cases. thenia response" was not present. They studied 15 The cause of the sensitivity of the neonate to patients of whom only four were truly newborn, non-depolarizing drugs is not known. It may be and four were over the age of 28 days; five patients that a different parameter is required, such as extrahad pyloric stenosis, of whom three had a metabolic cellular fluid volume, or body surface area. It may acidosis. Churchill-Davidson and Wise (1964) also also be the result of differences in protein binding, reported that the neonatal neuromuscular response or an alteration in the response of the motor endwas not different from that of the adult. But their plate, or prejunctional receptors. However, for series contained only three patients aged 1, 2, and practical purposes, body weight remains the easiest 3 weeks respectively. Yamamoto, Baba and Shirat- measurement to make and apply in the operating suchi (1972) reported on the effects of pancuronium room. In the assessment of the newborn, conceptual in children. They noted that there were four age (the age from conception), would appear to be children under one month of age without comment- more important than actual age and will allow for ing upon any specific effects. The ages of these premature/postmature differences in response. Of four were not given. They used a dose of 80 /*g/kg course the use of potent anaesthetic drugs, such as and obtained a duration of action of 42 r"in halothane, ethrane and ether, alters the amounts of approximately. The results of the present study non-depolarizing relaxants that should be given. agree with those of Bush and Stead, that the newSome neonates were eliminated from the series born is sensitive to non-depolarizing muscle relax- where it was apparent that antibiotics had been ants, that this sensitivity diminishes with age to the administered for more than 5 days and increased extent that, at one month of age, the motor end- sensitivity was observed. Kanamycin and gentaplate has an almost normal response. This study mycin were the antibiotics which were associated shows that pancuronium is similar in its effects to with the most notable effects. tubocurarine. The potency ratio of pancuronium to CONCLUSION tubocurarine is 6:1 to 9 : 1 , at this dose level and for this age group. This potency ratio has been Pancuronium is effective as a muscle relaxant for suggested with adults receiving large doses, and the newborn and it appears that the newborn Lund and Stovner (1970) have shown that the response is "myasthenic" in type as it is with potency varies with the dose from 5:1 to 7.5:1. tubocurarine. This study would appear to indicate It is now our practice to administer pancuronium that the potency of pancuronium is at least 6-9 to the newborn in the following doses: times that of tubocurarine for the doses studied. 0-1 week 30 ^g/kg ACKNOWLEDGEMENT 1-2 weeks 60 /*g/kg The statistical analysis was performed by M. K. Patel, 2-4 weeks 90 /*g/kg M.SC. (Mathematics), M.SC. (Statistics), of the University This dose is reduced in prematurity, acidosis, hypo- of Illinois. thermia, or in other conditions in which the sensiREFERENCES tivity to pancuronium can reasonably be expected Bush, G. H., and Stead, A. L. (1962). The use of dto be increased, including antibiotics. tubocurarine in neonatal anaesthesia. Br. J. Anaesth., 34, 721. The clinical end-point, control of respiration and H. C , and Wise, R. P. (1963). muscle relaxation, is achieved by giving additional Churchill-Davidson, Neurotnuscular transmission in the newborn infant. amounts of pancuronium, 1/4 to 1/2 of this initial Anesthesiology, 24, 271.
BRITISH JOURNAL OF ANAESTHESIA
78
LE PANCURONIUM CHEZ LES NOUVEAUX-NES RESUME
Le bromure de pancuronium a 6t6 employ^ de maniere
sure comme medicament relichant pour l'anesthesie neonatale. Aucun effet fficheux n'a tti remarqu6 et l'anesthesie s'est trouvee effectivement inversee dans tous les patients. Le rapport d'efficacW du pancuronium par rapport a la d-tubocurarine allait de 9 a 1 a la naissance a 6 a 1 a l'age d'un mois. PANCURONIUM BEI NEUGEBORENEN ZUSAMMENFASSUNG
Pancuroniumbromid wurde ohne Gefahr als das Entspannungsmittel fur neonatale Anasthesie verwendet. Es kam zu keinen unerwunschten Nebenwirkungen, und die Anasthesie wurdein alien Patienten wirksam wieder aufgehoben. Das StarkeverhUltnis von Pancuronium im Vergleich zu d-Tubocurarin reichte von 9:1 bei der Geburt bis zu 6:1 im Alter von einem Monat. PANCURONIUM EN RECIEN NA CIDOS SUMARIO
Se emple6 satisfactoriamente bromuro de pancuronium como relejante para anestesia neonatal. No se observaron efectos desfavorables y la anestesia tuvo un efecto de reversion eficaz en todos los pacientes. La relaci6n de potencia del pancuronium comparado con d-tubocurarine vari6 entre 9:1 al nacimiento y 6:1 a la edad de un mes.
Downloaded from http://bja.oxfordjournals.org/ at University of Iowa Libraries/Serials Acquisitions on June 28, 2015
Churchill-Davidson, H. C , and Wise, R. P. (1964). The response of the newborn to muscle relaxants. Can. Anaesth. Soc. J., 11, 1. Deschene, J. P., Desrosiers, R., and Bedard, P. (1972). A clinical study of pancuronium—a new muscle relaxant for abdominal surgery. Can. Anaesth. Soc. J., 19, 412. Lund, I., and Stovner, J. (1970). Dose-response curves for tubocurarine, alcuronium, and pancuronium. Acta Anaesthesiol. Scand. [SuppL], 37, 238. Stead, A. L. (1955). The response of the newborn infant to muscle relaxants. Br. J. Anaesth., 27, 124. Walts, L. F., and Dillon, J. B. (1969). The response of newborns to succinylcholine and d-tubocurare. Anesthesiology, 31, 35. Waud, B. E., and Waud, D. R. (1972a). The relation between the response of "Train-of-four" stimulation and receptor occlusion during competitive neuromuscular block. Anesthesiology, 37, 413. (1972b). The margin of safety of neuromuscular transmission in the muscle of the diaphragm. Anesthesiology, 37, 417. Yamamoto, T., Baba, H., and Shiratsuchi, T. (1972). Clinical experience with pancuronium bromide in infants and children. Anesth. Analg. (Cleve.), 51, 919.