Atropine is more efficient than ZM241385 to reduce a drastic level of fade caused by cisatracurium at 50 Hz / Atropina é mais eficiente que ZM241385 para reduzir o intenso nível de fadiga causada por cisatracurium a 50 Hz

The effects of atropine (non selective muscarinic antagonist) and ZM241385 (A2A receptors antagonist) in the cisatracurium-induced drastic (100%) level of fade at 50 Hz (10 s) (100% Fade) were compared in the phrenic nerve-diaphragm muscle preparations of rats indirectly stimulated at a physiological tetanic frequency (50 Hz). The lowest dose and the instant cisatracurium caused 100% Fade were investigated. Cisatracurium induced 100% Fade 15 min after being administered. Atropine reduced the cisatracurium-induced 100% Fade, but the administration of ZM241385 separately, or combined with atropine, did not cause any effect in the cisatracurium-induced 100% Fade. Data indicate that the simultaneous blockage of M1 and M2 muscarinic receptors on motor nerve terminal by atropine is more efficient than the blockage of presynaptic A2A receptors for a safer recovery of patients from neuromuscular blockade caused by cisatracurium.

Os efeitos de atropina e ZM241385 (antagonistas de receptores A2A) no drástico (100%) nível de fadiga (100% Fadiga) produzido pelo cisatracúrio a 50 Hz (10 s) foram comparativamente investigados em preparações nervo frênico músculo diafragma isolado de ratos indiretamente estimuladas com a frequência fisiológica tetanizante de 50 Hz. A menor dose e o instante no qual cisatracúrio causou 100% Fadiga foram pesquisados. O cisatracúrio induziu 100% Fadiga 15 min depois de ser administrado. A atropina reduziu a fadiga de 100% causada pelo cisatracúrio, mas ZM241385, ou a administração combinada de atropina com ZM241385, não causou qualquer efeito na 100% Fadiga produzida pelo cisatracúrio. Os dados indicam que o bloqueio simultâneo dos receptores muscarínicos M1 e M2 no terminal nervoso motor pela atropina é mais eficiente do que o bloqueio dos receptores pré-sinápticos A2A no auxilio da recuperação mais segura do bloqueio da transmissão neuromuscular causada por cisatracúrio.

Estudo comparativo entre uma e duas doses efetivas (DE95) de rocurônio para a intubação traqueal / A comparative study between one and two effective doses (ED95) of rocuronium for tracheal intubation

JUSTIFICATIVA E OBJETIVOS: Os bloqueadores neuromusculares (BNM) são fármacos utilizados para produzir relaxamento da musculatura esquelética e facilitar a intubação traqueal (IT). A literatura descreve como sendo necessárias duas doses efetivas (DE95) o ideal para a IT. O rocurônio é um BNM não-despolarizante do tipo esteróide, sintético e de duração intermediária. O objetivo desse estudo foi avaliar e comparar as condições de intubação traqueal (IT), utilizando uma e duas doses efetivas (DE95) do rocurônio, seguindo os critérios da Conferência de Consenso de Copenhague. MÉTODO: Foram avaliados 60 pacientes divididos aleatoriamente em dois grupos de 30, de ambos os sexos, idades entre 20 e 60 anos, estado físico ASA I e II, Mallampati 1 e 2, índice de massa corporal (IMC) < 35, submetidos a anestesia geral. No Grupo 1 (G1) foi administrado 0,3 mg.kg-1 (1 DE95) e no Grupo 2 (G2), 0,6 mg.kg-1 DE95 (2 DE95) de rocurônio. Os parâmetros para a avaliação da IT foram baseados nos critérios da Conferência de Consenso de Copenhague (Good Clinical Research Practice): laringoscopia, cordas vocais (posição e movimentação), reação à inserção do tubo e/ou a insuflação do balonete (movimento dos membros e tosse). RESULTADOS: Todas as intubações foram consideradas excelentes ou boas (aceitáveis), não havendo, portanto, nenhum caso em que não se logrou êxito ou que tenha sido classificado como ruim (inaceitável). Os resultados da análise estatística não foram significativos. Portanto, não houve diferença clínica significativa em nenhum dos parâmetros avaliados. CONCLUSÕES: O rocurônio tanto na dose de 0,3 mg.kg-1 quanto na de 0,6 mg.kg-1 DE95 proporcionou condições clinicamente aceitáveis de IT nos procedimentos eletivos.

BACKGROUND AND OBJECTIVES: Neuromuscular blockers (NMB) are used to induce relaxation of skeletal muscles and facilitate tracheal intubation (TI). According to the literature, two effective doses (ED95) of NMB are ideal for TI. Rocuronium is a steroid-type, synthetic, non-depolarizing neuromuscular blocker of medium duration. The objective of this study was to evaluate and compare the conditions of tracheal intubation with one and two effective doses (ED95) of rocuronium, following the criteria of the Copenhagen Consensus Conference. METHODS: Sixty patients of both genders, ages 20 to 60 years, physical status ASA I and II, Mallampati 1 and 2, body mass index (BMI) < 35, who underwent general anesthesia, randomly divided in two groups of 30 patients, were evaluated. Group 1 (G1) received 0.3 mg.kg-1 of rocuronium (1 ED95), and Group 2 (G2) received 0.6 mg.kg-1 (2 DE95). Parameters used to evaluate TI were based on the criteria of the Copenhagen Consensus Conference (Good Clinical Research Practice): laryngoscopy, vocal cords (position and movements), reaction to the insertion of the tube and/or filling of the cuff (movements of limbs and cough). RESULTS: All intubations were considered excellent or good (acceptable); therefore, there were no cases of failure or any intubation considered bad (unacceptable). The results of the statistical analysis were not significant. Consequently, we did not observe any clinically significant differences in the parameters evaluated. CONCLUSIONS: Both doses of rocuronium, 0.3 mg.kg-1 and 0.6 mg.kg-1 ED95, provided clinically satisfactory parameters of TI in elective procedures.

JUSTIFICATIVA Y OBJETIVOS: Los bloqueadores neuromusculares (BNM) son fármacos utilizados para producir el relajamiento de la musculatura esquelética y facilitar la intubación traqueal (IT). La literatura describe que son necesarias de los dosis efectivas (DE95) lo ideal para la IT. El rocuronio es un BNM no despolarizador del tipo esteroide, sintético y de duración intermedia. El objetivo de este estudio fue evaluar y comparar las condiciones de intubación traqueal (IT), utilizando una y de los dosis efectivas (DE95) del rocuronio, secundando los criterios de la Conferencia de Consenso de Copenhague. MÉTODO: Se estudiaron 60 pacientes divididos aleatoriamente en 2 grupos de 30, de ambos sexos, edades entre 20 y 60 años, estado físico ASA I y II, Mallampati 1 y 2, índice de masa corporal (IMC) < 35, sometidos a anestesia general. En el Grupo 1 (G1) se administró 0,3 mg.kg-1 (1 DE95) y en el Grupo 2 (G2) 0,6 mg.kg-1 DE95 (2 DE95) de rocuronio. Los parámetros para la evaluación de la IT fueron en base a los criterios de la Conferencia de Consenso de Copenhague (Good Clinical Research Practice): Laringoscopia, cuerdas vocales (posición y movimiento), reacción a la inserción del tubo y/o a la insuflación del globo (movimiento de los miembros y tos). RESULTADOS: Todas las intubaciones se consideraron excelentes o buenas boas (aceptables), y no hubo ningún caso en que no se logró el éxito o que no haya sido clasificado como malo (inaceptable). Los resultados del análisis estadístico no arrojaron nada de importante. Por tanto, no hubo diferencia clínica significativa en ninguno de los parámetros evaluados. CONCLUSIONES: El rocuronio tanto en la dosis de 0,3 mg.kg-1 como en la de 0,6 mg.kg-1 DE95 proporcionó condiciones clínicamente aceptables de IT en los procedimientos de elección.

The Usage Pattern of Neuromuscular Blocker at Intensive Care Unit / 대한구급학회지

BACKGROUND: The neuromuscular blocker is helpful to intubate the patients and reduce the amount of anesthetic agent. It also used at intensive care unit (ICU) to maintain airway patency, to achieve proper ventilatory care, etc. This survey is to determine the neuromuscular blocker usage patterns in ICU settings. METHODS: Three hundred general hospitals with ICU settings were chosen. We designed a 10 itemed questionnaire which has several subquestions with multiple choices and sent it to them. After three months, forty seven hospitals returned the questionnaire and we made careful analysis with it. RESULTS: The most frequent indication of neuromuscular blocker was to facilitate the mechanical ventilation (80.9%). Vecuronium was the most common neuromuscular blocker used (97.9%). Only 6.4% of them used peripheral nerve stimulator and the rest of them (89.4%) used clinical information to determine the degree of neuromuscular blocker. The respondents reported that recovery from muscle relaxation was needed on a periodic basis for regular neurological examinations (59.6%) in ICU settings. All respondents used the sedatives or narcotics with neuromuscular blocker and only 6.4% used reversal agents. CONCLUSIONS: Although the rate of reply was not much (15.7%), we could get the current usage pattern of neuromuscular blocker at ICU. We recommend using short to intermediate acting neuromuscular blocker than long acting agents. Continuous infusion with careful dosage titration by peripheral nerve stimulator would be helpful to achieve rapid recovery. Additional sedatives and narcotics are beneficial to reduce the amount of neuromuscular blocker and to make patients comfortable as well.

Comparative Study of Pharmacokinetics in the Onset and Offset of Mivacurium and Other Muscle Relaxants / 대한마취과학회지

BACKGROUND: The purpose of this study was to evaluate mivacurium in the pharmacokinetics of onset and offset. METHODS: In 127 adult patients of ASA physical status I or II without any factors involving the neuromuscular function under general anesthesia, onset time (lag and manifest time) and clinical duration were measured after bolus or divided doses of ED95 x 2 of succinylcholine (SCC), rocuronium (ROC), atracurium (ATR), mivacurium (MIV), pancuronium (PAN) or vecuronium (VEC). Recovery time was defined as the recovery index and total duration measured after subsequent ED95 of MIV at 25% recovery of control twitch height from neuromuscular block induced by ED95 x 2 of ATR, MIV, PAN or VEC. Plasma cholinesterase (PChE) levels were measured following PAN or ATR. RESULTS: Onset time was faster with SCC and ROC, the low potency drugs, than with ATR, MIV, PAN or VEC, the high potent drugs. Manifest time was shorter in low potency drugs but longer in high potency drugs than lag time after bolus or divided doses of muscle relaxants given. Divided doses of various drugs induced a shortened onset time, but the patterns of relationship between lag and manifest time associated with drug potency did not alter. The recovery times with administered MIV were slowest after PAN pretreatment, and fastest after MIV pretreatment. PChE levels decreased significantly from 3 min to over 180 min after PAN administeration but not ATR. CONCLUSIONS: The onset time of MIV was not improved due to high drug potency as other nondepolarizing neuromuscular blockers. However, in spite of high potency, the recovery time of MIV was faster than other drugs. This results may be depend upon PChE activity rather than drug potency. Additionally, the prolonged recovery of MIV was not only under the influence of low PChE activity but also other some factors such as: the first relaxants administered before MIV dominated the neuromuscular block so that the duration of MIV given subsequently changed to resemble that of the first. The longer elimination half-life of the underlying relaxant prolonged the effects of subsequentshorter acting MIV. Structural similarities or dis-similarities between the interacting MIV and other drugs may have effects more potent in dis-similarity than in similarity.

The Effects of Hypothermic Hemodilutional Cardiopulmonary Bypass on the Pseudocholinesterase Level / 대한마취과학회지

Pseudocholinesterase is known to be involved in the metabolism of succinylcholine, mivacurium, procaine, chloroprocaine, tetracaine, cocaine, heroin, and other drugs, although the physiologic function has not been well established. Prolonged neuromuscular block following administration of succinylcholine correlates with very low or genetically variant cholinesterase activity. The determination of pseudocholinesterase activity is of importance to the anesthetist in order to predict the susceptibility of the patient to the muscle relaxant, succinylcholine. The purpose of this study was to investigate the change of pseudocholinesterase level during cardiopulmonary bypass(CPB) for open heart surgery with hemodilution and hypothermia. Seven venous blood samples before induction of anesthesia(control), during CPB, and until the fifth postoperative day in 12 patients who underwent open heart surgery were taken. The pseudocholinesterase level was measured by Wako kit and JASCO UVIDEC 77 clinical spectrophotometer. The results were as follows ; 1) The control hematocrit was 40.32+/-6.21% and decreased to 23.72+/-1.86% immediately after the start of CPB(p<0.01) and to 22.42+/-1.93 % 30 minutes after the start of CPB(p<0.01). 2) The control pseudocholinesterase value of 1296.67+/-251.03 IU/L decreased to 915.67+/-228.16 IU/L immediately after the start of CPB(p<0.01), and to 727.83+/-197.58 IU/L 30 minutes after the start of CPB(p<0.01). 3) The mean values of pseudocholinesterase level immediately posteratively, on the first postoperative, and the third postoperative days were 1488.50+/-333.52 IU/L, 1913. 17+614.50 IU/L and 1620.92+/-458.82 IU/L, respectively, and those were significantly increased from the control value(p<0.05, p<0.01, and p<0.01, respectively). 4) The mean value of pseudocholinesterase level on the fifth postoperative day was 1392.25+/-271.69 IU/L, which was not significantly different from the control valule. 5) Transfused units of whole blood, packed red cells, and fresh frozen plasma were 2.8+/-1.4, 3.2 +/-1.0, 3.4+/-0.9, respectively.

The Effect of Intravenous Solu-cortef on Vecuronium Induced Muscle Twitch Height Rabbit / 대한마취과학회지

It is a widespread clinical practice to administer large doses of corticosteroids to patients in cases of shock and or neurosurgery; corticosteroids given intravenously have been proposed and used. Corticosteroids, when administered in this way during surgery have been implicated in intera- ctions with neuromuscular blocking agents. Therefore, the effects of Solu-cortef in the neuromuscular blockade produced by vecuronium were studied in vivo on the indirectly stimulated tibialis anterior muscles of the rabbits aneth- etized with urethane and pentothal sodium. Control group of rabbits was given intravenous boius of 0.1 mg/kg vecuronium to produce twitch depression and recovery as recorded by biophysiograph and measured at anterior tibialis muscle twitch in response to common peroneal nerve by double burst stimulation (DBS). First study group (S-l group) of rabbits was given intravenous bolus of 16 mg/kg Solu- cortef thirty minutes before, and then 0.1 mg/kg vecuronium intravenous bolus was given. Twitch depression and recovery was measured as control group. Seeond study group (S-2 group) of rabbits was given intravenous bolus of 0.1 mg/kg vecuronium during recovery phase, intravenous bolus of 16 mg/kg Solu-cortef was given at DBS ratio 0.5. Statistical analysis was confirmed by oneway ANOVA test,followed by Student- Newman-Keuls test. The results were as follows', 1) In control group,'recovery times to DRS ratio at 0.5 and 0.8 were 1,089.2+42.94 and 1,272.0 +'54.87 sec. 2) In first study group',axovery times to DBS ratio at 0.5 and 0.8 were 1,208.8>61.95 and 1,417.4+65.02 sec. It shows some what prolonged recovery time than control but statistically not significant. 3. In second study group;recovery times to DBS ratio at 0.5 was 1,218.4+/-61.16 sec. DBS ratio was deereased to 0.22 when intravenous bolus of Solu-cortef was given,thereafter DBS ratio was gradually increased Recovery times to DBS ratio at 0.5 and 0,8 were 1,444.0 and 1,633.8+/-65.02 sec. More prolonged recovery times were observed. It was statistically significant to compare with control and first study group (P<0,05). By the above results ; acute intravenous bolus Solu-cortef may affeet the vecuronium induced neuromuscular block in rabbits.

A Study on the Priming Effects of Nondepolarizing Neuromuscular Blockers / 대한마취과학회지

The authors studied the priming effects of the nondepolarizing neuromuscular blockers on the frequency of discomfort, intubation condition and the time interval between the administration of nondepolarizing neuromuscular blockers and endotracheal intubation. Thirty two patients were divided randomly into four groups: the patients administered vecuronium priming dose, 0.02mg/kg and intubating dose, 0.06mg/kg (Group I), vecuronium customary single dose, 0.1 mg/kg (Group II), pancuronium priming dose, 0.02 mg/kg and intubation dose, 0.06mg/kg (group III) and pancurnium customary single dose, 0.1 mg/kg (group IV). The results were as follows. 1) Seven patients complained discomfort after administration of priming dose in the priming groups. (Group I and III) 2) There was better intubating condition in the priming groups than the customary single dose groups. 3) The time intervals between the administration of intubating dose and the maximum depression of single twitch response were revealed 57.9+/-14.6 seconds, 115.5+/-27.2 seconds, 74.5+/-30.0 seconds and 101.4+/-13. 7 seconds in I, II, III and IV group respectively. The time interval in group I was significantly shorter than group II (p< 0.05). And the interval in group III was also significantly shorter than group IV (p<0.05). With the above results we conclude that the priming groups provide smooth and rapid intubation condition than the customary single dose group, in spite of small total intubating dose.

The Effects of Atropine and Glycopyrrolate mixed to Neostigmine on Heart Rate in Anesthetized Pediatric Patients / 대한마취과학회지

Fourty pediatric patients anesthetized with halothane-nitrous oxide-oxygen, who received pancronium for the maintenance of muscular relaxation, were divided into two groups. On anesthesia, in group l, atropine(20ug/kg) and neostigmin(40ug/kg), and in group ll, glycopyrrolate(10ug/kg) and neostigmine(40ug/kg) were injected transvenously. The changes in heart rate and arrythmis were then observed. The results were as follows: 1) The safety and effectiveness of both groups in antagonizing the muscarinic actions of neostigmine were demonstrated. 2) Glycopyrrolate produced a significantly smaller change in heart rate than atropine. 3) In both groups, arrhythmis could not be observed.