Efeitos neuromusculares e cardiovasculares do pipecurônio: estudo comparativo entre diferentes doses / Efectos neuromusculares y cardiovasculares del pipecuronio: estudio comparativo entre diferentes dosis / Neuromuscular and cardiovascular effects of pipecuronium: a comparative study between different dose

JUSTIFICATIVA E OBJETIVOS: O pipecurônio é um bloqueador neuromuscular não-despolarizante, com propriedades similares as do pancurônio, mas desprovido de efeitos cardiovasculares. Foram avaliados os efeitos neuromusculares, as condições de intubação traqueal e as repercussões hemodinâmicas de duas diferentes doses de pipecurônio. MÉTODO: Pacientes foram distribuídos em dois grupos de acordo com a dose de pipecurônio: Grupo I (0,04 mg.kg-1) e Grupo II (0,05 mg.kg-1). A medicação pré-anestésica consistiu em midazolam (0,1 mg.kg-1) por via muscular, 30 minutos antes da operação. A indução anestésica foi obtida com propofol (2,5 mg.kg-1) precedido de fentanil (5 µg.kg-1) e pipecurônio nas doses de 0,04 e 0,05 mg.kg-1 para os Grupos I e II, respectivamente. Os pacientes foram ventilados com O2 a 100 por cento sob máscara até a redução de 75 por cento da amplitude da resposta a estímulo isolado (1 Hz), quando foram realizadas a laringoscopia e intubação traqueal. O isoflurano (0,5 a 1 por cento) em mistura de O2 e N(2)0 a 50 por cento para a manutenção da anestesia, foi introduzido logo após a intubação traqueal. Os pacientes foram ventilados mecanicamente para manter P ET CO2 entre 32 e 36 mmHg. A farmacodinâmica do pipecurônio foi avaliada por aceleromiografia. RESULTADOS: Os tempos médios e desvios-padrão para o início de ação, duração clínica (T1(25 por cento)) e índice de recuperação (T1(25-75 por cento)) foram: Grupo I (122,10 ± 4,18 s, 49,63 ± 9,54 min e 48,21 ± 6,72 min) e Grupo II (95,78 ± 8,91 s, 64,84 ± 13,13 min e 48,52 ± 4,95 min). O início de ação, a duração clínica e as condições de intubação traqueal foram significativamente diferentes entre os grupos. CONCLUSÕES: O pipecurônio na dose 0,05 mg.kg-1 pode ser usado em procedimentos de longa duração, nos quais é desejável evitar alterações cardiocirculatórias.

BACKGROUND AND OBJECTIVES: Pipecuronium is a non-depolarizing neuromuscular blocker with similar properties to pancuronium, but without cardiovascular effects. Neuromuscular effects, conditions of tracheal intubation, and hemodynamic repercussions of two different doses of pipecuronium were evaluated. METHOD: Patients were divided into two groups according to the dose of pipecuronium: Group I (0.04 mg.kg-1) and Group II (0.05 mg.kg-1). Intramuscular midazolam (0.1 mg.kg-1) was administered 30 minutes before the surgery. Propofol (2.5 mg.kg-1), preceded by fentanyl (5 µg.kg-1) and pipecuronium (0.04 and 0.05 mg.kg-1 for Groups I and II, respectively), was administered for anesthetic induction. Patients were ventilated with 100 percent oxygen via a face mask until a 75 percent reduction in the amplitude of the response to an isolated stimulus (1 Hz) is achieved, at which time laryngoscopy and intubation were carried out. Anesthetic maintenance was achieved with isoflurane (0.5 to 1 percent) with a mixture of 50 percent O2 and N2O. Mechanical ventilation was used to maintain P ET CO2 between 32 and 36 mmHg. The pharmacodynamics of pipecuronium was evaluated by acceleromyography. RESULTS: Mean times and standard deviation for the onset of action, clinical duration (T1(25 percent)), and recovery index (T1(25-75 percent)) were: Group I (122.10 ± 4.18 sec, 49.63 ± 9.54 min, and 48.21 ± 6.72 min), and Group II (95.78 ± 8.91 sec, 64.84 ± 13.13 min, and 48.52 ± 4.95 min). Onset of action, clinical duration, and conditions of tracheal intubation were significantly different for both groups. CONCLUSIONS: Pipecuronium at a dose of 0.05 mg.kg-1 can be used in prolonged procedures in which cardiovascular changes should be avoided.

JUSTIFICATIVA Y OBJETIVOS: El pipecuronio es un bloqueador neuromuscular no despolarizador, con propiedades similares a las del pancuronio, pero desprovisto de efectos cardiovasculares. Se evaluaron los efectos neuromusculares, condiciones de intubación traqueal y las repercusiones hemodinámicas de de los diferentes dosis de pipecuronio. MÉTODO: Los pacientes fueron distribuidos en de los grupos de acuerdo a la dosis de pipecuronio: Grupo I (0,04 mg.kg-1) y Grupo II (0,05 mg.kg-1). La medicación preanestésica consistió en midazolam (0,1 mg.kg-1) por vía muscular, 30 minutos antes de la operación. La inducción anestésica se obtuvo con propofol (2,5 mg.kg-1) precedido del fentanil (5 µg.kg-1) y del pipecuronio en las dosis de 0,04 y 0,05 mg.kg-1 para los Grupos I y II, respectivamente. Los pacientes se ventilaron con O2 a 100 por ciento bajo máscara hasta la reducción de un 75 por ciento de la amplitud de la respuesta al estímulo aislado (1 Hz), cuando fueron realizadas la laringoscopía y la intubación traqueal. El isoflurano (0,5 a 1 por ciento) en mezcla de O2 y N(2)0 a un 50 por ciento para el mantenimiento de la anestesia, fue introducido a continuación de la intubación traqueal. Los pacientes fueron ventilados mecánicamente para mantener el P ET CO2 entre 32 y 36 mmHg. La farmacodinámica del pipecuronio se evaluó por aceleromiografía. RESULTADOS: Los tiempos promedios y desviaciones estándar para el inicio de acción, duración clínica (T1(25 por ciento)) e índice de recuperación (T1(25-75 por ciento)) fueron los siguientes: Grupo I (122,10 ± 4,18 seg, 49,63 ± 9,54 min y 48,21 ± 6,72 min) y Grupo II (95,78 ± 8,91 seg, 64,84 ± 13,13 min y 48,52 ± 4,95 min). El inicio de acción, la duración clínica y las condiciones de intubación traqueal fueron significativamente diferentes entre los grupos. CONCLUSIONES: El pipecuronio, en la dosis 0,05 mg.kg-1 puede ser usado en procedimientos de larga duración donde se desee evitar alteraciones ca...

Effects of cisatracurim on cardiovascular system and histamine release in comparison to atracurium and pipecuronium

The aim of this work was to evaluate the hemodynamic change profile and assessment of histamine release associated with cisatracurium administration in both young adults and elderly patients, both experimentally and clinically, in comparison with the parent drug, atracurium, and with a cardiovascular stable relaxant, pipecuronium. The clinical study was done on 120 patients who were assigned into two groups according to their age. Each group was further subdivided into three subgroups [n=20] who randomly received only one of the three neuromuscular blockers; pipecuronium, atracurium and cisatracurium. The hemodynamic changes over time were measured and manifestations of histamine release were assessed. The experimental study was done to study the effect of gradually increasing doses of pipecuronium, atracurium, and cisatracurium on isolated rabbit heart and the possible histamine release. In the clinical study, there were either clinically or statistically significant cardiovascular changes in the mean heart rate or in the mean values of systolic, diastolic and mean blood pressure following cisatracurium or pipecuronium in both age groups. In contrast, atracurium showed an elevation in the mean HR in one age group [young adults] and a reduction in the mean values of systolic, diastolic and mean blood pressure in the elderly group in comparison to the other groups. Histamine release signs shown with the atracurium-receiving patients were comparable and statistically significant from those of the nearly absent signs in the cisatracurium-receiving patients. In patients receiving pipecuronium, these signs were completely absent. In the experimental study, cisatracurium in a dose 32xED50 resulted in apparent increase in the correction of the ventricles. Atracurium in a lesser dose [16xED50] produced a similar effect. These responses were abolished completely after the injection of H-2 antagonist up to 64xED50 of pipecuronium failed to produce any change in ventricular contraction. In conclusion, cisatracurium in the clinically used doses appears to have much less or may be devoid of histamine release than atracurium and so it has a cardiovascular stability as pipe curonium

Neuromuscular blockade profile of pipec - uronium in patients with liver cirrhosis

This study aimed to evaluate the neuromuscular blockade profile of pipecuronium in 20 patients suffering from hepatic cirrhosis and divided equally into two groups [a control healthy group and hepatic group submitted to operations to relieve portal hypertension]. All patients were subjected to general anesthesia induced by thiopentone sodium 5 mg/kg, followed by pipecuronium 0.06 mg/kg to facilitate endotracheal intubation and maintained by N2O: O2 [2: 1] and halothane 0.5-1.0% with 0.01 mg/kg of pipecuronium as maintenance relaxation doses. Endotracheal intubation was successfully performed when TI ratio reached 10% and TOF ratio approximately reached 0% as traced by Datex relaxograph. The onset of action of pipecuronium, duration of clinical relaxation of bolus dose and total dose requirements were measured

Comparison of cardiovascular and neuromuscular properties of pancuronium, doxacurium and pipecuronium during induction of anesthesia for open heart surgery

This study compared hemodynamic and neuromuscular properties of pancuronium, doxacurium and pipecuronium during induction of anesthesia in 45 patients undergoing open valvular heart surgery. Anesthesia was induced with fentanyl 10 mg.kg-1 and thiopentone 23 mg.kg-1. Each patient received twice the ED95 of either pancuronium [0.15 mg.kg-1, n=15] or doxacurium [0.05 mg.kg-1, n=15] or pipecuronium [0.1 mg.kg-1 n=15]. Hemodynamic measurements were recorded before induction of anesthesia, before intubation, immediately after intubation and five minutes post-intubation. Pancuronium significantly increased heart rate and mean arterial blood pressure, but this decrease was not statistically significant and heart rate was nearly stable. On the other hand, there was minimal change in heart rate and mean arterial blood pressure with pipecuronium. Other hemodynamic parameters did not change. The time from muscle relaxant administration to 95% suppression of the first twitch of train of 4 stimuli was significantly longer for doxacurium than that for pancuronium and pipecuronium. Therefore, pipecuronium seems to be more satisfactory neuromuscular blocker than either pancuronium or doxacurium for induction of anesthesia for open heart surgery

Experimental study of the effects of pipecuronium, atracurium and pancuronium on cardiovascular system

The present work was undertaken to study the effects of pipecuronium, atracurium and pancuronium on isolated perfused rabbit heart, isolated rabbit atrium and on carotid arterial blood pressure as well as ECG changes with each drug administration. The results demonstrated that pipecuronium in a dose of 100 mug/kg b. wt. had no significant effect on heart rate and carotid arterial blood pressure of anesthetized cat. Atracurium [150 mug/kg b. wt.] produced 7.5% increase in basal heart rate and short lasting drop of arterial blood pressure lasting for approximately 1-1.5 min. followed by rapid recovery. Pancuronium [100 mug/kg b. wt.] increased heart rate by about 15.5% [p <0.05] and long lasting hypotension lasted for approximately 4-5 min. With gradual recovery to the pre-injection level. Pipecuronium and pancuronium produced no change in isometric contraction of rabbit atria in concentration range [5-20 mug/ml]. However, atracurium in concentrations of 30, 60, 120 mug/ml produced dose-dependent increase in contraction of rabbit atria without any effect on heart rate. When the chronotropic effects of three drugs were investigated using acetylcholine as an agonist on isolated perfused rabbit heart, it was found that pancuronium, but not pipecuronium and atracurium, produced a significant degree of antagonism to the bradycardia produced by acetylcholine. It was concluded that pipecuronium appears to be a suitable replacement for pancuronium for the production of muscular relaxation of relatively long duration in patients in whom elevation of heart rate has to be avoided. Also, the vagolytic effects of pancuronium are desirable, especially when counter acting the bradycardiac tendency of large doses of fentanyl. And that the transient hemodynamic effect of atracurium is probably of little clinical significance in the healthy patient

Cardiovascular effects of pipecuronium bromide, experimental and clinical study

Pipecuronium bromide, a new steroidal non-depolarizing blocking agent, has a duration of action similar to that of pancronium, but unlike pancronium appears to be devoid of cardiovascular effects. The purpose of this work is to study the effect of pipecuronium bromide on the cardiovascular system. This experimental study on anesthetized dogs showed that pipecuronium bromide within the therapeutic range caused no significant change in mean systemic blood pressure, heart rate, QRS complex, and ST segment of ECG record. Larger doses of the drug, however, resulted in mild bradycardia which was abolished by atropine. No appreciable change was observed in the force of myocardial contraction when pipecuronium bromide was perfused in the isolated rabbits heart. Using the noninvasive cardiodynamic data processing system, no significant change was found in the various cardiovascular parameters in 20 patients receiving pipecuronium bromide under nitrous oxide and halothane anesthesia. Pipecuronium bromide is thus recommended for the production of muscular relaxation for relatively long operations, when it is desirable to avoid changes in the cardiovascular system