Influência dos Hipnóticos no bloqueio neuromuscular produzido pelo cisatracúrio: emprego da aceleromiografia / Influence of hypnotics on cisatracurium-induced neuromuscular block: use of acceleromyograhpy / Influencia de los hipnóticos en el bloqueo neuromuscular producido por el cisatracurio: uso de la aceleromiografía

JUSTIFICATIVA E OBJETIVOS: Os efeitos farmacodinâmicos dos bloqueadores neuromusculares (BNM) podem ser influenciados por diferentes drogas, entre elas os hipnóticos. O objetivo deste estudo foi avaliar a influência do propofol e do etomidato sobre o bloqueio neuromuscular produzido pelo cisatracúrio. MÉTODO: Foram incluídos 60 pacientes, ASA I e II, submetidos a cirurgias eletivas sob anestesia geral, distribuídos aleatoriamente em dois grupos de acordo com o hipnótico empregado: GI (propofol) e GII (etomidato). As pacientes receberam midazolam (0,1 mg.kg-1) por via muscular como medicação pré-anestésica, a indução foi com propofol (2,5 mg.kg-1) ou etomidato (0,3 mg.kg-1) precedido de fentanil (250 µg) e seguido de cisatracúrio (0,1 mg.kg-1). Os pacientes foram ventilados com oxigênio a 100% até a obtenção de redução de 95% ou mais na amplitude da resposta do adutor do polegar, quando foi feita a laringoscopia e a intubação traqueal. A função neuromuscular foi monitorizada com aceleromiografia. Avaliaram-se o início de ação do cisatracúrio, as condições de intubação traqueal e as repercussões hemodinâmicas. RESULTADOS: Os tempos médios e os desvios padrão para o início de ação do cisatracúrio foram: GI (86,6 ± 14,3") e GII (116,9 ± 11,6"), com diferença significativa (p < 0,0001). As condições de intubação traqueal foram aceitáveis em 100% dos pacientes do GI e em 53,3% no GII (p < 0,0001). CONCLUSÕES: A instalação do bloqueio neuromuscular com o cisatracúrio foi mais rápida e as condições de intubação traqueal foram melhores nos pacientes que receberam propofol em relação ao grupo que recebeu etomidato, sem repercussões hemodinâmicas.

BACKGROUND AND OBJECTIVE: Different drugs, including hypnotics, may influence the pharmacodynamic effects of neuromuscular blockers (NMB). The aim of this study was to evaluate the influence of propofol and etomidate on cisatracurium-induced neuromuscular blockade. METHOD: We included 60 patients, ASA I and II, undergoing elective surgery under general anesthesia in the study and randomly allocated them into two groups, according to their hypnotic drug: GI (propofol) and GII (etomidate). Patients received intramuscular (IM) midazolam (0.1 mg.kg-1) as premedication and we performed induction with propofol (2.5 mg.kg-1) or etomidate (0.3 mg.kg-1), preceded by fentanyl (250 mg) and followed by cisatracurium (0.1 mg.kg-1). The patients were ventilated with 100% oxygen until obtaining a reduction of 95% or more in the adductor pollicis response amplitude, with subsequent laryngoscopy and tracheal intubation. Neuromuscular function was monitored by acceleromyograhpy. We evaluated the onset of action of cisatracurium, tracheal intubation conditions, and hemodynamic repercussions. RESULTS: The mean time and standard deviations of cisatracurium onset were: GI (86.6 ± 14.3 s) and GII (116.9 ± 11.6 s), with a significant difference (p < 0, 0001). Intubation conditions were acceptable in 100% of GI and 53.3% of GII patients (p < 0.0001). CONCLUSION: Induction of neuromuscular blockade with cisatracurium was faster, with better intubation conditions in patients receiving propofol compared to those receiving etomidate, without hemodynamic repercussions.

JUSTIFICATIVA Y OBJETIVOS: Los efectos farmacodinámicos de los bloqueantes neuromusculares (BNM) pueden estar influenciados por diferentes fármacos, entre ellos los hipnóticos. El objetivo de este estudio, fue evaluar la influencia del propofol y del etomidato sobre el bloqueo neuromuscular producido por el cisatracurio. MÉTODO: Se incluyeron en el estudio 60 pacientes, con ASA I y II, sometidos a cirugías electivas bajo anestesia general, distribuidos aleatoriamente en dos grupos de acuerdo con el hipnótico usado: GI (propofol) y GII (etomidato). Las pacientes recibieron midazolam (0,1 mg.kg-1) por vía muscular como medicación preanestésica, la inducción fue con propofol (2,5 mg.kg-1) o etomidato (0,3 mg.kg-1) precedido de fentanilo (250 µg) y seguido de cisatracurio (0,1 mg.kg-1). Los pacientes fueron ventilados con oxígeno al 100% hasta la obtención de la reducción de un 95% o más en la amplitud de la respuesta del aductor del pulgar cuando se hizo la laringoscopia y la intubación traqueal. La función neuromuscular fue monitorizada con aceleromiografía. Se evaluaron el inicio de acción del cisatracurio, las condiciones de intubación traqueal y las repercusiones hemodinámicas. RESULTADOS: Los tiempos promedios y las desviaciones estándar para el inicio de acción del cisatracurio fueron: GI (86,6 ± 14,3") y GII (116,9 ± 11,6"), con una diferencia significativa (p < 0,0001). Las condiciones de intubación traqueal fueron aceptables en un 100% de los pacientes del GI y en 53,3% en el GII (p < 0,0001). CONCLUSIONES: La instalación del bloqueo neuromuscular con el cisatracurio fue más rápida y las condiciones de intubación traqueal fueron mejores en los pacientes que recibieron propofol con relación al grupo que recibió etomidato, sin repercusiones hemodinámicas.

Comparison of the variability of the onset and recovery from neuromuscular blockade with cisatracurium versus rocuronium in elderly patients under total intravenous anesthesia

This study was designed to compare the variability of the onset and offset of the effect of two neuromuscular blocking drugs with different elimination pathways in adult and elderly patients during total intravenous anesthesia (TIVA). After Ethics Committee approval and patients’ informed consent, the drugs were compared in 40 adult and 40 elderly patients scheduled for elective surgery under TIVA with tracheal intubation who were randomized to receive a single bolus dose of 0.15 mg/kg cisatracurium or 0.9 mg/kg rocuronium. The time of onset of maximum depression, duration of action, and recovery index time were measured and recorded for each patient and variability is reported as means ± standard deviation. Time of onset was significantly shorter for rocuronium than cisatracurium for the adult and elderly groups (P = 0.000), but the variability of cisatracurium was significantly greater compared with rocuronium for the same age groups (93.25 vs 37.01 s in the adult group and 64.56 vs 33.75 s in the elderly group; P = 0.000). The duration of the effect in the elderly group receiving rocuronium was significantly longer than in the elderly group receiving cisatracurium, and the variability of the duration was significantly greater in the rocuronium group than in the cisatracurium group. Mean time of recovery was significantly longer for the elderly group receiving rocuronium than for the elderly group receiving cisatracurium (P = 0.022), and variability was also greater (P = 0.002). Both drugs favored good intubating conditions. In conclusion, cisatracurium showed less variability in these parameters than rocuronium, especially in the elderly, a fact that may be of particular clinical interest.

Comparing the effect of using atracourium and cis-atracourium as adjuvant agents to the local anesthetic substance on peribulbar-induced akinesia

Peribulbar anesthesia is widely applied in cataract surgeries. The aim of this study was comparing the effect of using Atracourium, cis-Atracourium, and placebo as adjuvant agents to the local anesthetic substance on peribulbar-induced akinesia in cataract surgeries. The study was double-blind randomized clinical trial, among the patients candidate for the cataract surgery who were hospitalized in ocular surgery ward in Farabi Hospital between 2006 and 2007. 90 patients were subcategorized into 3 groups randomly. Group I received a mixture [8 ml] containing equal parts of Marcaine 0.5%, Lidocaine 2% and Hyaluronidase 90 IU plus 0.5 ml normal saline; group II received the mixture [8 ml] plus 0.5 ml Atracourium 5 mg, and group III received the mixture [8 ml] plus 0.5 ml cis-Atracurium with the help of peribulbar blockage technique. The score of akinesia were evaluated in the 1st, 3rd, 5th, 10th minutes after administration of the medications. 10 minute after drug administration, 25 [92.6%] reached the total akinesia with Atracourium, 23 [85.2%] with cis-Atracourium, and 23 [85.2%] with the placebo [P>0.05]. Addition of low-dose Atracourium and cis-Atracourium to the anesthetic drug is recommended in order to accelerate the onset of akinesia resulted by the peribulbar block, and in order to enhance the quality of akinesia especially when Hyaloronidaze is not added

Tachyphylaxis to cisatracurium-Case reports and literature review

Nondepolarizing neuromuscular blocking agents [NNMBAs] are commonly used in the intensive care unit [ICU], mainly to facilitate mechanical ventilation in critically ill patients who are not responding to sedatives and analgesics alone. Tachyphylaxis, also referred to as resistance, may develop during long-term infusion of NNMBAs. Several case reports of tachyphylaxis to NNMBAs have been reported. Although the definite mechanisms of tachyphylaxis to NNMBAs are not clear, several pharmacodynamic and pharmacokinetic changes have been described with the development of resistance. Tachyphylaxis to NNMBAs is associated with adverse outcomes including inadequate ventilation, increased risk of dose-dependent side effects, and increased drug costs. Patients who develop tachyphylaxis to one NNMBA should be treated with another NNMBA if neuromuscular blockade [NMB] is still indicated. We report three cases of tachyphylaxis to cisatracurium in a surgical intensive care unit [SICU]: one in patient with acute respiratory distress syndrome [ARDS] and the other two with traumatic brain injury [TBI]

Efeito do propofol associado à efedrina no tempo de latência do cisatracúrio / Effect of propofol in combination with ephedrine upon the onset time of cisatracurium

OBJETIVOS: Este estudo teve por objetivo avaliar a eficácia da efedrina na prevenção dos efeitos hemodinâmicos induzidos pela associação do propofol e do remifentanil, assim como os efeitos sobre o tempo de latência do cisatracúrio. MÉTODOS: Sessenta pacientes com idade entre 18 e 52 anos, estado físico ASA I ou II, foram divididos em três grupos, aleatoriamente: G I - propofol 1 por cento; G II - propofol 1 por cento + efedrina 0,5 mg.ml-1 e G III - propofol 1 por cento + efedrina 1,0 mg.ml-1 (velocidade de infusão igual a 180 ml.h-1), até a perda da consciência. Administrou-se remifentanil (0,5 mg.kg-1.min-1) e cisatracúrio na dose de 0,15 mg.kg-1. Foram registrados os dados demográficos, os sinais vitais (PAS, PAM, PAD, FC e SpO2) e o tempo de latência do cisatracúrio. RESULTADOS: Os grupos foram homogêneos com relação aos dados demográficos. Houve diminuição estatisticamente significativa dos valores de PAS, PAM, PAD e FC, um e três minutos após a administração do propofol, porém sem significado clínico importante e sem diferença entre os grupos. As medianas para os tempos de latência do cisatracúrio foram: 178 s (G2 e G3) e 183 s (G1), mas sem diferença significante entre os grupos. CONCLUSÃO: Não houve diminuição clinicamente importante dos parâmetros hemodinâmicos avaliados nos grupos que receberam ou não a efedrina e o tempo de latência do cisatracúrio foi o mesmo para os diferentes grupos.

OBJECTIVE: The onset time of neuromuscular blocking drugs is partially determined by circulatory factors, including muscle blood flow and cardiac output. The aim of the present paper was to: 1) compare the haemodynamic effects of adding different doses of ephedrine to an induction dose of propofol and remifentanil. 2) onset time of cisatracurium. METHODS: Sixty patients were randomly allocated into three groups: G1 - 1 percent propofol; G2 - 1 percent propofol + 0.5 mg.ml-1 ephedrine and G3 - 1 percent propofol + 1.0 mg.ml-1 ephedrine. All patients received continuous infusion of remifentanil (0.5 mg.kg-1.min-1). The rate of propofol infusion was 180 ml.h-1 until loss of consciousness and a loading dose of cisatracurium (0.15 mg.kg-1) was then given. After induction of anesthesia, the ulnar nerve was stimulated supramaximally every 10s, and the evoked twitch response of the adductor pollicis was recorded by accelerometry. RESULTS: There was no statistical difference between groups with respect to age, weight, dose of propofol administered and onset time of cisatracurium (tables 1, 2). Heart rate, SpO2, systolic, diastolic and mean blood pressures were compared at 1 and 3 min post-induction. There were statistical differences in HR, SAP, DAP and MAP, without significant adverse clinical effects. CONCLUSIONS: There were no clinically important decreases in the hemodynamic parameters evaluated in the groups receiving ephedrine or not, and the onset time of cisatracurium was the same for all groups.

Cisatracurium in cardiac surgery - continuous infusion vs. bolus administration

The aim of this study was the comparison of infusion vs. intermittent bolus administration of cisatracurium [CA] following cardiac surgery with regard to total intraoperative dose and time of recovery from neuromuscular blockade. From June 2005 to April 2006 sixty ASA II-III patients who were undergoing coronary bypass graft and valve replacement surgery, were equally divided and randomized to receive either intermittent bolus [Group A, n = 30] or continuous infusion [Group B, n = 30] of CA in Madani Heart Center in the Tabriz [Iran]. Total intraoperative dose of CA and time to TOF ratio = 0.8 after operation were measured. Anesthesia technique in two groups was the same. All of the patients underwent cardiopulmonary bypass. Intensity of neuromuscular blockade maintained on one train-of-four [TOF] twitch response of adductor pollicis during operation. Mean received dose of CA was 32.8 +/- 20.6 micro/kg/hr in Group A and 89.7 +/- 39.4 micro/kg/hr in Group B [p = 0.003]. Total intraoperative dose of CA was 23.6 +/- 4.9 mg in Group A and 39.2 +/- 10.1 mg in Group B [p = 0.001]. Spontaneous recovery from neuromuscular blockade in ICU [TOF ratio = 0.8] was reached in 43.8 +/- 9.2 min in Group A, and 64.2 +/- 15.1 min in Group B [p = 0.0001]. Intubation time in ICU was not significantly different [Group A = 8.3 +/- 5.1 hrs vs. Group B = 10.2 +/- 6.2 hrs, p = 0.256]. These results support the intermittent bolus administration of cisatracurium in cardiac surgery following cardiopulmonary bypass

Comparative study of neuromuscular blocking and hemodynamic effects of rocuronium and cisatracurium under sevoflurane or total intravenous anesthesia

Neuromuscular blockers [NMB] are important adjuvant to general anesthesia, rocuronium bromide and cisatracurium besylate are considered relatively recently introduced non-depolarizing muscle relaxants. This study evaluates the enhancement of cisatracurium and rocuronium -induced neuromuscular block during anesthesia with 1.5 MAC sevoflurane or total i.v. anesthesia [TIVA], hemodynamic effects and side effects. 80 patients were randomly allocated into one of four equal groups to receive either rocuronium [under sevoflurane or propofol TIVA] or cisatracurium [under sevoflurane or propofol TIVA]. The NMB effects of rocuronium and cisatracurium were studied by constructing dose-effect curves. Acceleromyography [TOF-Guard] and train-of-four [TOF] stimulation of the ulnar nerve were used [2Hz every 15sec.]. Cisatracurium and rocuronium were administered in increments until depression of T[1]/T[0]>95% was reached. Hemodynamic effects of both muscle relaxants together with sevoflurane or propofol were assessed using thoracic bioimpedance. Depression of T[1]/T[0] was enhanced under sevoflurane compared to TIVA. ED[50] and ED[95] values of both drugs were significantly lower under sevoflurane more than TIVA. Recovery index 25-75% and time to a TOF ration of 0.70 were prolonged significantly by sevoflurane compared to TIVA. Hemodynamically, rocuronium and cisatracurium did not exert significant changes, but the interaction of the relaxants and the anesthetic agents resulted in statistically significant decline in some hemodynamic parameters at certain periods which are not clinically significant and required no medications. We conclude that the effects of rocuronium and cisatracurium are significantly enhanced during sevoflurane compared with propofol anesthesia and the recovery is slower

Intubating conditions and injection pain cisatracurium or rocuronium versus rocuronium cisatracurium combination

The present report evaluates the incidence of pain on intravenous injection and the condition oftracheal intubation at one minute following the administration of cisatracurium or rocuronium versus rocuronium-cisatracurium combination. We studied 60 patients, ASA 1, aged 18-60 years, undergoing elective surgical procedures. The patients were randomly assigned to 3 groups who received intravenously either 0.15 mg/kg cisatracurium [2ED[95]], 0,6 mg rocuronium [2ED[95]] or a combination of 0.075 mg/kg cisatracurium [ED[95]], plus 0.3 mg rocuronium [1ED[95]]. In the awake patients, the pain on injection of muscle relaxant was assessed on a four point scale [none, mild, moderate, severe]. Administration of the relaxant was followed by 1-2 mg/kg of lidocaine and 2 mg/kg propofol. Oro-tracheal intubation was performed 60 seconds following the administration of the relaxant. The intubating conditions were assessed and rated as excellent, good, fair or poor. The administration of 2ED[95] cisatracurium resulted in poor intubating conditions at 60s, without pain on injection. In contrast, the administration of 2ED[95] rocuronium resulted in excellent or good intubating conditions at 60s associated with high incidence of pain on injection in most of the patients. However, the combination of 1ED[95] cisatracurium with 1ED[95] rocuronium provided similar intubating conditions to the 2ED[95] rocuronium alone, associated with a significantly less pain on injection

Anestesia venosa total para laringectomia parcial em paciente na 28ª semana de gestação: relato de caso / Total intravenous anesthesia for partial laryngectomy in 28 weeks pregnant patient: case report

JUSTIFICATIVA E OBJETIVOS: Uma anestesia para paciente gestante constitui um desafio ao anestesiologista em virtude dos riscos para a mãe e para o feto. São muitas as complicações descritas pela literatura como malformações fetais, parto prematuro, instabilidade hemodinâmica materna e até morte fetal. O objetivo deste caso é mostrar uma paciente gestante de 28 semanas, submetida a laringectomia parcial sob anestesia geral venosa total com propofol, remifentanil e cisatracúrio. RELATO DO CASO: Paciente com 29 anos, 59 kg, primigesta de 28 semanas com diagnóstico prévio de carcinoma epidermóide próximo à corda vocal direita, sendo indicada laringectomia. A monitorização inicial constituiu-se de pressão arterial não-invasiva e invasiva, cardioscopia, oxicapnografia e cardiotocografia contínua realizada pela obstetra. Punção venosa no membro superior direito e membro superior esquerdo com cateter 16G e 18G, respectivamente. Foram administrados por via venosa midazolam (1 mg), cefazolina (1 g), metoclopramida (10 mg) e dipirona (1 g). A paciente recebeu oxigênio a 100 por cento sob máscara por 3 minutos e indução venosa foi feita com o uso de propofol em infusão na dose alvo de 3 æg.mL-1 e remifentanil contínuo (1 æg.kg-1 em bolus e 0,2 æg.kg-1.min-1 de manutenção). Como bloqueador neuromuscular, foi administrado cisatracúrio (13 mg) e procedeu-se a intubação traqueal com tubo 6,5 mm aramado com balonete. Foi mantida em plano anestésico com propofol e remifentanil em bomba, além de complementações de cisatracúrio. O feto permaneceu monitorizado continuamente com cardiotocografia realizada e analisada pela obstetra. Após o término da cirurgia foram desligadas as bombas infusoras de propofol e remifentanil, tendo a paciente despertado 10 minutos depois. Acordou sem dor e hemodinamicamente estável, sendo então encaminhada à sala de recuperação pós-anestésica. CONCLUSÕES: A anestesia venosa total com propofol e remifentanil proporcionou estabilidade hemodinâmica para a mãe e o feto, com um despertar precoce e suave.

A comparison of the efficacy of cisatracurium and atracurium in kidney transplantation operation.

Cisatracurium is a new intermediate-acting benzylisoquinolinium neuromuscular blocking agent that is one of the ten stereoisomers contained in atracurium besylate. Atracurium is known to be the muscle relaxant of choice in end stage renal disease patients. This study aimed to compare the efficacy of cisatracurium and atracurium in the aspect of intubation and maintenance dosages, hemodynamic response after intubation and cost effectiveness between the two agents in kidney transplant patients. MATERIAL AND METHOD: From August 2001 to July 2002, 46 end stage renal disease patients obtained kidney transplantation operation under general anesthesia with 50:50 N2O:O2, fentanyl, isoflurane anesthesia. Tracheal intubation and maintenance of muscle relaxant with each drug were administered in 23 of each group-atracurium as control (C) while cisatracurium was the study (S) group. RESULTS: There was no difference in the demographic data of the 2 groups--13 males/10 females in the S group and 11 males/12 females in the C group. Eighty-seven per cent in the S group underwent living-related kidney transplantation operation, with 55.56 per cent in the C group. Most of the donors were siblings, i.e. 42.11 per cent in the S group and 46.67 per cent in the C group. The mean dosage for intubation in the S group was 0.17 +/- 0.02 mg/kg and 1.25 +/- 0.49 microg/kg/min for maintenance. The mean dosage for intubation in the C group was 0.64 +/- 0.07 mg/kg and the mean maintenance dose was 5.38 +/- 0.83 microg/kg/min. In both groups there was no statistical difference in hemodynamic changes. One patient in the S group received calcium channel blocker to reduce blood pressure before induction of anesthesia, while 2 patients in the C group were given nifedipine 5 mg before induction. Although the cisatracurium cost was higher than atracurium, from the cost-minimization analysis, it turned out to be lower per case. CONCLUSION: This study demonstrated the efficacy of cisatracurium in hemodynamic stability and safety in kidney transplantation operations. In spite of the more costly price, cisatracurium is beneficial in some end stage renal disease (ESRD) patients with coronary artery disease who need very stable hemodynamics.

Pharmacological and clinical comparative study between atracurium and cisatracurium

Cistracurium besylate is an intermediate acting bis-benzylisoquinolinium neuromuscular blocking drug that is one of the steroisomers of atracurium. Phamacological and clinical studies were carried out in present work to assess some properties of cisatracurium in comparison with atracurium. The pharmacological part of this work included experiments on intact anaesthetized cats [to assess the effect on heart rate and blood pressure, and on isolated tissues to find out the effects of histamine. The clinical part of the study was carried out in 100 ASA I, II of adult patients and categorized into 5 groups, 20 patients in each group. Group I received 0.5 mg/kg atracurium, groups II, III, IV and V received cisatracurium in a doses of 0.1, 0.15, 0.2 and 0.4 mg/kg respectively. The groups has been assessed for intubation conditions, and haemodynamic stability by measuring [H.R.] and arterial [B.P.]. Plasma histamine levels were measured by Elysa technique. Experimental study showed that cisatracurium had no effect on blood pressure or heart rate of anaesthetized cat even in doses up to 4 mg/kg. In comparison, atracurium showed cardiovascular stability within therapeutic doses, but with the dose of 4 mg/kg severe hypotension was produced. Also, cisatracurium showed no effect on the isolated ileum of guinea pig and did not increase the contractile effect of histamine on the isolated guinea pig ileum. On the other hand, atracurium increased the effect of histamine on the ileum. The present clinical study showed that there was excellent to good intubation conditions after 2 minutes in 90% of patients who received 0.5 mg/kg atracurium versus 70% of patients who received the equipotent dose of cisatracurium 0.1 mg/kg. Increasing the dose of cisatracurium to 0.15 mg/kg produces excellent to good intubation conditions in 90% of patients after 2 minutes which increases to 98% of patients with increasing the dose of cisatracurium [0.2 mg/kg and 0.4 mg/kg]. There was no clinical evidence of histamine release in the groups receiving cisatracurium compared to 3 out of 20 patients who had cutaneous flushing following the administration of atracurium. The study showed significant increase in plasma histamine concentrations in atracurium group in comparison to cisatracurium group. Analysis of data obtained from the phamracological and clinical studies in this work demonstrated that cisatracurium provides excellent to good intubating conditions with apparent haemodynamic stability and no dose related changes in histamine concentration make cisatracurium a potentially useful muscle relaxant in clinical practice

Pharmacological and clinical comparative study between atracurium and cisatracurium

Cisatracuruim besylate is a new intermediate acting non depolarizing muscle relaxant. It is approximately three time more potent than atracurium as a neuromuscular blocking agent. The experimental study revealed that cisatracuruim produced dose dependent inhibition of muscle response to electrical stimulation of the sciatic nerve of anaesthetized cat, which was more potent than that produced by atracurium. Absence of contracture of frog's rectus abdominus after administration of both drugs indicate that depolarization could not be a mechanism of their paralyzing effect. Cisatracurium showed no effect on the blood pressure or heart rate of anaesthetized cat even in doses up to 4 mg / kg which is higher than the dose needed for neuromuscular blocking effect. In comparison, atracurium showed cardiovascular stability within the theraputic doses and even [6 x ED[95]] but with very high dose sever hypotension was produced both, cisatracurium and atracurium showed no effect on the myocardial contractility of isolated rabbite's heart. The comparative clinical study between atracurium and cisatracurium was done on 40 middle age adult patient ASA I and II undergoing elective surgery the patient classified into 2 groups [20 patient in each] group I received atracurium 0.5 mg / kg and Group II received cisatracurium 0.1 mg / kg. The onset time of cisatracurium was slightly longer than that for equipotent dose of atracurium [3.45 +/- 1.05] min versus [2.45 +/- 1.1] min respectively, the clinical effective duration of action, the recovery index and time of atracurium were similar to those of cisatracurium at equipotent dose. As regard to the cardiovascular system both cisatracurium and atracurium showed no significant changes in mean arterial blood pressure and heart rat at the equipotent dose. Cisatracurium is nondepolarizing muscle relaxant with intermediate duration of action, predictable recovery time and a constant pharmacodynamic profile which devoid of cardiovascular or histamin releasing effect and eliminated by non organ dependent hoffman elimination, so it is suitable drug to be introduced into clinical anaesthesia

Uso de bloqueadores neuromusculares em pacientes em miastenia gravis: relato de dois casos / Neuromuscular blockers in myasthenia gravis patients: report of two cases

Justificativa e objetivos - Existe uma grande diversidade na gravidade da Miastenia Gravis, assim como na dose e resposta aos bloqueadores neuromusculares (BNM). O objetivo deste relato é apresentar dois casos de bloqueio neuromuscular prologando com cisatracúrio e mivacúrio, em pacientes com Miastenia Gravis. Relatos dos Casos - Caso n§1 - Paciente masculino, 55 anos, 82 kg, com história de Miastenia Gravis submetido a timectomia por via transternal, sob anestesia geral com propofol, alfentanil, isoflurano e óxido nitroso. Para intubaçäo traqueal foi utilizado cisatracúrio (1,2mg). Após 3:45h de cirurgia, a reversäo com neostigmina foi considerada insatisfatória e o paciente teve que permanecer intubado por duas horas. Somente após este período a descurarizaçäo considerada satisfatória (T4/T1 em 0,9) e o paciente foi extubado. Caso n§2 - Paciente do sexo feminino, 42 anos, 59 kg, submetida à histerectomia por via vaginal sob anestesia combinada (peridural e geral). Foi feita monitorizaçäo da transmissäo neuromuscular antes da injeçäo de mivacúrio (0,2mg.kg-1) e notou-se intensa fadiga. Após 3:30h a relaçäo T4/T1 estava 0,15, havendo resposta a injeçäo de neostigmina (0,05µg.kg-1). Posteriormente foi diagnosticada Miastenia Gravis. Conclusöes - O uso de monitores de transmissäo neuromuscular, näo deve ficar restrito aos pacientes miastênicos, pois a diversidade das respostas aos BNM é comum nos pacientes normais

Farmacodinâmica do cisatracúrio no transplante renal / Pharmacodynamics of cisatracurium in renal transpantation

Objetivo: Determinar, em doentes portadores de insuficiência renal crônica, a farmacodinâmica do cisatracúrio durante o transplante renal. Métodos: Foram estudados 30 doentes divididos em dois grupos, 15 com funçao renal normal submetidos a cirurgia bucomaxilo-facial e 15 portadores de insuficiência renal crônica submetidos a transplante renal, submetidos a anestesia geral com etomidato, sufentanil e sevoflurano em concentraçoes inferiores a 1 por cento de fraçao expirada. Receberam dose venosa de 0,15 mg.kg-' de cisatracúrio na induçao e 0,05 mg.kg-' todas as vezes que Ti recuperava 25 por cento. A funçao neuromuscular foi monitorizada de forma contínua no membro superior pelo monitor TOF guard (Dinamark), utilizando o padrao de estimulaçao TOF (train-of-four ou sequência de quatro estímulos), através da estimulaçao supramáxima do nervo ulnar. Resultados: Os resultados referentes à farmacodinâmica do cisatracúrio mostram que o início de açao, a duraçao clínica e o índice de recuperaçao foram semelhantes entre os grupos. Os tempos para a relaçao T4/T1 atingir 0,7 e 0,9 a partir do último 25 por cento de Ti apresentaram diferença estatisticamente significante entre os grupos, com os maiores valores no grupo renal. Conclusao: Dos parâmetros farmacodinâmicos estudados, apenas a recuperaçao tardia prolongada nos doentes portadores de insuficiência renal crônica submetidos a transplante renal