Intubating Conditions Under Non-Depolarizing Muscle Relaxants – A Comparative Study

Introduction: In conditions like significant burns,traumatic injuries or an abdominal infection succinylcholineadministration could be hazardous as it is associatedwith dangerous hyperkalemia. Vecuronium, atracuriumand Pancuronium not only are the alternatives but alsooffer skeletal muscle relaxation at shortest intervals postintubation. We assessed the intubating conditions achievedand the hemodynamic effects of pancuronium, vecuronium,and atracurium among patients undergoing routine surgicalprocedures requiring general anaesthesia.Material and methods: A prospective randomized trial wascarried out among 60 participants aged 15-56, who were inthe good physical condition and belonged to ASA I or ASAII categories.study was conducted at Civil Hospital, AizawlMizoram. The patients were randomly allocated to 3 groups oftwenty each viz, Group A, Group B and Group C. Followinginduction of anaesthesia Inj. Pancuronium bromide 0.1 mg/kg.was given to Group A; Inj. Vecuronium 0.1 mg/kg to GroupB. and Inj. Atracurium 0.6 mg/kg to Group C. Pulse rate andblood pressure were recorded immediately and time intervalafter intubation.Results: The apnoea time was longest in group A (57±7seconds) followed by group C (50±14 seconds) and groupB (49±8 seconds). The mean pulse rate, however, variedsignificantly post-intubation across the three groups. Theintergroup comparison showed a significantly higher rise ofthe mean arterial pressure in group A compared with group Bat all corresponding tie intervals in the post intubation period.Conclusion: Though all the three skeletal muscle relaxantsprovided adequate intubating conditions, Vecuronium offeredthe shortest intubation time while the Pancuronium took thelongest time.

​Compare Onset Time Of Cisatracurium For Tracheal Intubation With And Without Priming Dose Of Rocuronium

Background: Priming is one of those techniques in which a small dose of non-depolarizing muscle relaxants is administeredfollowed by a large intubating dose. Cisatracurium is the newly introduced drug with Hoffman elimination. The problem with itsuse is delayed onset of action. The present study was conducted to compare the onset of cisatracurium for tracheal intubationwith and without priming dose of rocuronium.Materials and Methods: A total of 60 American Society of Anesthesiologist physical Status Ι and ΙΙ patients undergoing surgeryunder general anesthesia were included in the study. Patients were divided into two groups of 30 each. Patients in Group Rreceived priming dose of rocuronium 0.06 mg/kg before intubating dose of cisatracurium (0.14 mg/kg). Group C patients didnot get any priming, only normal saline was given before intubating dose of cisatracurium (0.15 mg/kg).Results: Time gap between administration of the cisatracurium and complete loss of T1 was recorded as intubation time.The intubation time was significantly less in Group R, i.e., 130 ± 11.02 s as compared to Group C, i.e., 230.33 ± 12.82 s. Theintubating conditions were similar in both the groups. The hemodynamic changes were statistically insignificant. The time to25% recovery of the T1 response is defined as the clinically effective duration of neuromuscular block. The rate of recovery isdescribed by the recovery index, which is defined as the time from 25% to 75% T1 recovery.Conclusion: Priming with rocuronium decreased the onset time without increasing the clinical duration of action or recovery index.

Factors that affect the onset of action of non-depolarizing neuromuscular blocking agents / 대한마취과학회지

Neuromuscular blockade plays an important role in the safe management of patient airways, surgical field improvement, and respiratory care. Rapid-sequence induction of anesthesia is indispensable to emergency surgery and obstetric anesthesia, and its purpose is to obtain a stable airway, adequate depth of anesthesia, and appropriate respiration within a short period of time without causing irritation or damage to the patient. There has been a continued search for new neuromuscular blocking drugs (NMBDs) with a rapid onset of action. Factors that affect the onset time include the potency of the NMBDs, the rate of NMBDs reaching the effect site, the onset time by dose control, metabolism and elimination of NMBDs, buffered diffusion to the effect site, nicotinic acetylcholine receptor subunit affinity, drugs that affect acetylcholine (ACh) production and release at the neuromuscular junction, drugs that inhibit plasma cholinesterase, presynaptic receptors responsible for ACh release at the neuromuscular junction, anesthetics or drugs that affect muscle contractility, site and methods for monitoring neuromuscular function, individual variability, and coexisting disease. NMBDs with rapid onset without major adverse events are expected in the next few years, and the development of lower potency NMBDs will continue. Anesthesiologists should be aware of the use of NMBDs in the management of anesthesia. The choice of NMBD and determination of the appropriate dosage to modulate neuromuscular blockade characteristics such as onset time and duration of neuromuscular blockade should be considered along with factors that affect the effects of the NMBDs. In this review, we discuss the factors that affect the onset time of NMBDs.

Streptozotocin Diabetes Attenuates the Effects of Nondepolarizing Neuromuscular Relaxants on Rat Muscles

The hypothesis of this study was that diabetes-induced desensitization of rat soleus (SOL) and extensor digitorum longus (EDL) to non-depolarizing muscle relaxants (NDMRs) depends on the stage of diabetes and on the kind of NDMRs. We tested the different magnitude of resistance to vecuronium, cisatracurium, and rocuronium at different stages of streptozotocin (STZ)-induced diabetes by the EDL sciatic nerve-muscle preparations, and the SOL sciatic nerve-muscle preparations from rats after 4 and 16 weeks of STZ treatment. The concentration-twitch tension curves were significantly shifted from those of the control group to the right in the diabetic groups. Concentration giving 50% of maximal inhibition (IC50) was larger in the diabetic groups for all the NDMRs. For rocuronium and cisatracurium in both SOL and EDL, IC50 was significantly larger in diabetic 16 weeks group than those in the diabetic 4 weeks group. For SOL/EDL, the IC50 ratios were significantly largest in the diabetic 16 weeks group, second largest in the diabetic 4 weeks group, and smallest for the control group. Diabetes-induced desensitization to NDMRs depended on the stage of diabetes and on the different kind of muscles observed while was independent on different kind of NDMRs. The resistance to NDMRs was stronger in the later stage of diabetes (16 versus 4 weeks after STZ treatment). Additionally, when monitoring in SOL, diabetes attenuated the actions of neuromuscular blockade more intensely than that in EDL. Nonetheless, the hyposensitivity to NDMRs in diabetes was not relevant for the kind of NDMRs.

The study of proper depth of muscle relaxant in posterior fossa surgery under total intravenous anesthesia / 临床麻醉学杂志

Objective To investigate the proper depth of muscle relaxant without affecting elec-trophysiological monitoring in patients undergoing posterior fossa surgery under total intravenous an-esthesia (TIVA).Methods Forty patients selected for posterior fossa surgery were randomly divided into two groups A and B.Group A:no muscle relaxants were administered after anesthesia induction until the EMG was completed.Group B:muscle relaxants maintained in range of TOF 2%-25% dur-ing electrophysiological monitor.TIVA were used to all patients and BIS was maintained in range of 40-60.Two electrophysiological data were applied during the electrophysiological monitoring:sponta-neity EMG and evoked EMG.EMG amplitude was recorded at different TOF value.Operation time and the dosages of propofol,sufentanil,rocuronium bromide were recorded.Also,the SBP,DBP,HR at perioperational period and facial nerve function before surgery,one week and six months after sur-gery were recorded.Results The electrophysiological monitoring completed successfully in all pa-tients.The total amount of propofol in group A significantly increased than those in group B(P <0.05).Three patients in group A had body movement during the operation.Four cases in group B couldn??t perform electrophysiological monitor when the TOF had three signals.There were no differ-ence between the two groups in SBP,DBP,HR and facial nerve function.Conclusion Maintaining TOF value in range of 2%-25% under non-depolarizing muscle relaxant during CPA surgery doesn??t affect intraoperative nerve electrophysiological monitor and prevent body movement,total dose of sed-ative anesthetics is also decresed.

Azasteroids as Promising Neuromuscular Blockers: A Review.

Neuromuscular blockers are used during surgery with anesthesia to cause relaxation of muscles and control muscle movements. The purpose of this review is to focus on the synthesis and pharmacological activity of the neuromuscular blockers, to compare the main differences between the available polarizing and nondepolarizing neuromuscular blockers. Continuous improvement of knowledge about neuromuscular blockers in respect to synthesis, their pharmacology, adverse effects, and toxic effects were unanswered questions about neuromuscular junction and neuromuscular blockade in children is essential for the correct use of these drugs. In this review article, structure-activity relationships within polarizing and nondepolarizing neuromuscular blockers have been reviewed.

Efeitos hemodinâmicos do atracúrio e do cisatracúrio e o uso de difenidramina e cimetidina / Hemodynamic effects of atracurium and cisatracurium and the use of diphenhydramine and cimetidine / Efectos hemodinámicos del atracurio y del cisatracurio y el uso de la difenidramina y la cimetidina

Justificativa e objetivos: Haja visto que atracúrio pode causar hipotensão arterial no homem, investigaram-se os efeitos hemodinâmicos promovidos pelo atracúrio e pelo cisatracúrio e a proteção hemodinâmica conferida pela difenidramina e cimetidina em ratos. Método: 1) Ratos Wistar anestesiados com pentobarbital sódico e preparados de acordo com Brown e col. para avaliar doses de atracúrio e cisatracúrio para redução de T4/T1 da sequência de quatro estímulos maior ou igual a 95 por cento. 2) Avaliação das alterações hemodinâmicas de atracúrio e cisatracúrio por injeção venosa, medindo-se a pressão arterial sistêmica da artéria carótida e eletrocardiograma de ratos. 3) Observação de proteção hemodinâmica pelo tratamento prévio com difenidramina (2 mg.kg-1) e/ou cimetidina (4 mg.kg-1) por injeção venosa. Análise estatística: teste t de Student, ANOVA. Resultados: O atracúrio e o cisatracúrio não modificaram a pressão arterial média (PAM) nas doses de 1 mg.kg-1 e 0,25 mg.kg-1, respectivamente. Doses de 4 mg.kg-1 promoveram diminuição da PAM de 62,8 ± 4,5 por cento do controle para o atracúrio, e de 82,5 ± 2,3 por cento do controle para o cisatracúrio. Com difenidramina e cimetidina, a pressão sistólica diminuiu 95,4 ± 2,5 por cento do controle. Com cimetidina, pressão diastólica diminuiu 82,7 ± 8,4 por cento do controle. O efeito conjunto sobre as pressões sistólica e diastólica refletiu-se nos valores observados da PAM. Conclusões: A difenidramina e a cimetidina, isoladamente, não impediram a diminuição da pressão arterial média induzida pelo atracúrio. No entanto, associação destes dois fármacos foi eficaz na prevenção dos efeitos hemodinâmicos induzidos pelo atracúrio. O cisatracúrio nas doses do experimento não promoveu diminuição da pressão arterial que justificasse as medidas preventivas aplicadas nos grupos onde se utilizou o atracúrio.

Background and objectives: Since atracurium can cause hypotension in humans, the hemodynamic effects of atracurium and cisatracurium as well as the hemodynamic protection of diphenhydramine and cimetidine were investigated in rats. Methods: 1) Wistar rats were anesthetized with sodium pentobarbital and prepared according to Brown et al. to evaluate different doses of atracurium and cisatracurium in the reduction of T4/T1 equal or greater than 95 percent. 2) Assessment of the hemodynamic changes caused by the intravenous administration of atracurium and cisatracurium by monitoring the blood pressure in the carotid artery and the electrocardiogram of rats. 3) Observation of the hemodynamic protection of prior treatment with the intravenous administration of diphenhydramine (2 mg.kg-1) and/or cimetidine (4 mg.kg-1). Statistical analysis: Student t test and ANOVA. Results: Doses of 1 mg.kg-1 and 0.25 mg.kg-1 of atracurium and cisatracurium respectively did not change the mean arterial pressure (MAP). Doses of 4 mg.kg-1 of atracurium and cisatracurium decreased MAP to 62.8 ± 4.5 percent and 82.5 ± 2.3 percent respectively when compared to control levels. When the rats were pre-treated with diphenhydramine and cimetidine, diastolic pressure was reduced to 95.4 percent ± 2.5 percent. With cimetidine, diastolic pressure was reduced to 82.7 ± 8.4 percent when compared to the control group. The effects on systolic and diastolic blood pressure were reflected in the levels of MAP. Conclusions: The isolated administration of diphenhydramine and cimetidine did not prevent the reduction in mean arterial pressure induced by atracurium. However, the association of both drugs was able to prevent the hemodynamic effects of atracurium. The doses of cisatracurium used in this study did not cause a reduction in blood pressure significant enough to justify the use of the preventive measures used in the atracurium groups.

Justificativa y objetivos: Habida cuenta de que el atracurio puede causar hipotensión arterial en el hombre, se investigaron los efectos hemodinámicos promovidos por el atracurio y por el cisatracurio, y la protección hemodinámica dada por la difenidramina y la cimetidina en ratones. Método: 1) Ratones Wistar anestesiados con pentobarbital sódico y preparados de acuerdo con Brown y col. para evaluar las dosis de atracurio y cisatracurio para la reducción de T4/T1 de la secuencia de cuatro estímulos mayor o igual al 95 por ciento. 2) Evaluación de las alteraciones hemodinámicas del atracurio y el cisatracurio por inyección venosa, midiendo la presión arterial sistémica de la arteria carótida y electrocardiograma de ratones. 3) Observación de la protección hemodinámica por el tratamiento previo con difenidramina (2 mg.kg-1) y/o cimetidina (4 mg.kg-1) por inyección venosa. Análisis estadístico: test t de Student, ANOVA. Resultados: El atracurio y el cisatracurio no modificaron la presión arterial promedio (PAP) en las dosis de 1 mg.kg-1 y 0,25 mg.kg-1, respectivamente. Las dosis de 4 mg.kg-1 disminuyeron la PAP de 62,8 ± 4,5 por ciento del control para el atracurio, y de 82,5 ± 2,3 por ciento del control para el cisatracurio. Con la difenidramina y la cimetidina, la presión sistólica se redujo a 95,4 ± 2,5 por ciento del control. Con la cimetidina, la presión diastólica disminuyó 82,7 ± 8,4 por ciento del control. El efecto con-junto sobre las presiones sistólica y diastólica se reflejó en los valores observados de la PAP. Conclusiones: La difenidramina y la cimetidina, aisladamente, no impidieron la disminución de la presión arterial promedio inducida por el atracurio. Sin embargo, la asociación de esos de los fármacos fue eficaz en la prevención de los efectos hemodinámicos inducidos por el atracurio. El cisatracurio, en las dosis del experimento, no promovió una disminución de la presión arterial que justificase las medidas preventivas...

Influência de anestésicos locais sobre o bloqueio neuromuscular produzido pelo rocurônio: ação da lidocaína e da mistura enantiomérica em excesso de 50 por cento de bupivacaína na junção neuromuscular / Influencia de anestésicos locales sobre el bloqueo neuromuscular producido por el rocuronio: acción de la lidocaína y de la mezcla enantiomérica en exceso de 50 por ciento de bupivacaína en la junción neuromuscular / Influence of local anesthetics on the neuromuscular blockade produced by rocuronium: effects of lidocaine and 50 percent enantiomeric excess bupivacaine on the neuromuscular junction

Justificativa e objetivos: Os efeitos dos anestésicos locais (AL) na transmissão neuromuscular e sua influência no bloqueio neuromuscular produzido por bloqueadores neuromusculares competitivos são ainda alvo de pouca investigação. O objetivo do estudo foi avaliar in vitro os efeitos da lidocaína e da mistura enantiomérica em excesso de 50 por cento de bupivacaína (S75-R25) no bloqueio neuromuscular...

Background and objetives: The effects of local anesthetics (LA) on neuromuscular transmission and their influence on the neuromuscular blockade produced by competitive neuromuscular blockers have not been fully investigated. The objective of this study was to evaluate, in vitro, the effects of lidocaine and 50 percent enantiomeric excess bupivacaine (S75-R25) on the neuromuscular blockade produced by rocuronium...

Justificativa y objetivos: Los efectos de los anestésicos locales (AL), en la transmisión neuromuscular y su influencia en el bloqueo neuromuscular producido por bloqueadores neuromusculares competitivos, todavía no se ha investigado lo suficiente. El objetivo del estudio, fue evaluar in vitro los efectos de la lidocaína y de la mezcla enantiomérica en exceso de 50 por ciento de bupivacaína (S75-R25) en el bloqueo neuromuscular...

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...

In vitro and in vivo neuromuscular effects of atracurium and rocuronium in rats treated with carbamazepine for seven days / Efeitos neuromusculares in vitro e in vivo do atracúrio e do rocurônio em ratos submetidos a tratamento de sete dias com carbamazepina / Efectos neuromusculares in vitro e in vivo del atracurio y del rocuronio en ratones sometidos a tratamiento de siete días con carbamazepina

JUSTIFICATIVA E OBJETIVOS: Trata-se de um estudo experimental que investigou in vitro e in vivo o bloqueio neuromuscular produzido pelo rocurônio e atracúrio em ratos tratados com carbamazepina e determinou as concentrações de citocromo P450 e b5 redutase em microssomos hepáticos. MÉTODO: Ratos foram tratados por sete dias com carbamazepina (CBZ) - 40 mg.kg-1 pelo método de gavagem e sacrificados no oitavo dia sob anestesia com uretana. As preparações in vitro e in vivo foram montadas de acordo com as técnicas de Bulbring e de Leeuwin e Wolters, respectivamente. As concentrações e doses utilizadas dos bloqueadores nas preparações in vitro e in vivo foram, respectivamente, 20 µg.mL-1 e 0,5 mg.kg-1 para atracúrio (ATC); 4 µg.mL-1 e 0,6 mg.kg-1 para rocurônio (ROC). Cada protocolo teve um n = 5 e as respostas foram observadas por 60 minutos. Os efeitos do ATC e ROC foram avaliados nas preparações de ratos tratados (Cbz t) e comparados com os observados nas de ratos não-tratados (CBZst). As concentrações de citocromo P450 e b5 redutase foram determinadas em microssomos isolados de fígados de ratos tratados (CBZt) e comparadas com as obtidas em ratos não tratados (CBZst). RESULTADOS: A carbamazepina não alterou a amplitude das respostas musculares; in vitro e in vivo, não houve diferença entre o bloqueio neuromuscular produzido pelo atracúrio nas preparações CBZt versus CBZst; o bloqueio neuromuscular produzido pelo rocurônio nas preparações CBZt foi potencializado in vitro. A carbamazepina não alterou as concentrações de citocromo P450 e b5. CONCLUSÕES: O tratamento por sete dias com carbamazepina não influenciou no bloqueio produzido pelo atracúrio, e alterou in vitro os efeitos do rocurônio. O tempo de tratamento não foi suficiente para causar indução enzimática e diminuir a sensibilidade ao rocurônio.

BACKGROUND AND OBJECTIVES: This experimental study investigated the in vitro and in vivo neuromuscular blockade of rocuronium and atracurium in rats treated with carbamazepine and determined the concentration of cytochrome P450 and b5 reductase in hepatic microsomes. METHODS: Rats were treated with carbamazepine (CBZ) - 40 mg.kg-1 by gavage and sacrificed on the eighth day under anesthesia with urethane. In vitro and in vivo preparations followed the techniques of Bulbring and Leeuwin and Wolters, respectively. Concentrations and doses of the neuromuscular blockers used in in vitro and in vivo preparations were, respectively, 20 µg.mL-1 and 0.5 mg.kg-1 for atracurium (ATC); and 4 µg.kg-1 and 0.6 mg.kg-1 for rocuronium (ROC). Each protocol had an n = 5 and the response was observed for 60 minutes. The effects of ATC and ROC were evaluated in the preparations of rats treated with carbamazepine (CBZt) and compared to those of non-treated rats (CBZst). The concentration of cytochrome P450 and b5 reductase were determined in hepatic chromosomes of rats treated with carbamazepine (CBZt) and non-treated rats (CBZst). RESULTS: Carbamazepine did not change the amplitude of neuromuscular response; differences in the neuromuscular blockade produced by atracurium in CBZ1 preparations were not observed, in vitro or in vivo, when compared with CBZst; the neuromuscular blockade produced by rocuronium in CBZt preparations was potentiated in vitro. Carbamazepine did not change the concentrations of cytochrome P450 and b5. CONCLUSIONS: Seven-day treatment with carbamazepine did not change the neuromuscular blockade produce by atracurium, but altered the in vitro effects of rocuronium. The duration of the treatment was not enough to cause enzymatic induction and decrease the sensitivity to rocuronium.

JUSTIFICATIVA Y OBJETIVOS: Se trata de un estudio experimental que investigó in vitro e in vivo el bloqueo neuromuscular producido por el rocuronio y atracurio en ratones tratados con carbamazepina y determinó las concentraciones de citocromo P450 y b5 reductasis en microsomas hepáticos. MÉTODO: Ratones fueron tratados por siete días con carbamazepina (CBZ) - 40 mg.kg-1 a través de una sonda y sacrificados al octavo día bajo anestesia con uretana. Las preparaciones in vitro e in vivo fueron montadas de acuerdo con las técnicas de Bulbring y de Leeuwin y Wolters, respectivamente. Las concentraciones y dosis utilizadas de los bloqueadores en las preparaciones in vitro e in vivo fueron, respectivamente, 20 µg.mL-1 y 0,5 mg.kg-1 para atracurio (ATC); 4 µg.mL-1 y 0,6 mg.kg-1 para rocuronio (ROC). Cada protocolo tuvo un n = 5 y las respuestas fueron observadas por 60 minutos. Los efectos del ATC y ROC fueron evaluados en las preparaciones de ratones tratados (Cbz t) y comparados a los observados en los de ratones no tratados (CBZst). Las concentraciones de citocromo P450 y b5 reductasis fueron determinadas en microsomas aislados de hígados de ratones tratados (CBZt) y comparadas con las obtenidas en ratones no tratados (CBZst) RESULTADOS: La carbamazepina no alteró la amplitud de las respuestas musculares; in vitro y in vivo, no hubo diferencia entre el bloqueo neuromuscular producido por el atracurio en las preparaciones CBZt versus CBZst; el bloqueo neuromuscular producido por el Rocuronio en las preparaciones CBZt fue potenciado in vitro. La carbamazepina no alteró las concentraciones de citocromo P450 y b5. CONCLUSIONES: El tratamiento por siete días con carbamazepina, no influenció en el bloqueo producido por el atracurio, y alteró in vitro los efectos del rocuronio. El tiempo de tratamiento no fue suficiente para causar la inducción enzimática y disminuir la sensibilidad al rocuronio.

The Effects of Non - depolarizing Neuromuscular Blockers on the Succinylcholine Induced Muscle Fasciculation , Postoperative Musle Pain and Relaxation / 대한마취과학회지

To study the effects of small amounts of non-depolarizing neuromuscular blockers on the muscle fasciculation, postoperative muscle pains and relaxation time by succinylcholine, three groups of patients were pretreated with vecuronium (0.01 mg/kg), pancuronium (0.015 mg/kg) and gallamine (0, 2 mg/kg) 3 minutes before succinylcholine injection, respectively and compared their results with control group-saline pretreated group. The results are as follows; 1) Intensity of muscle fasciculation deereased significantly in all groups with non-depolarizing neuromuscular blockers, and frequency had the fewest in pancuronium pretreated group than the others. 2) Intensity of postoperative muscle pains decreased significantly in groups pretreated with pancuronium and gallamine, and frequency had the fewest in gallamine pretreated group than the others. 3) Pretreatment with non-depolarzing neuromuscular blocker had no effects on the onset time of muscle relaxation of succinylcholine but recovery of muscle relaxation by succinylchoine was more rapidly occured than control group. Above results, it will be suggest that gallamine and pancuronium can be used more effectively to prevent muscle fasciculation and postoperative muscle pain without influence on succinylcholine-induced muscle relaxation.