Large bolus dose vs. continuous infusion of cisatracurium during hypothermic cardiopulmonary bypass surgery

BACKGROUND AND OBJECTIVE: We investigated whether a high bolus dose of cisatracurium (8x ED95) given at induction can provide muscle relaxation for the major part of a cardiac procedure with hypothermic cardiopulmonary bypass, avoid important postoperative residual curarization and cause no waste of product. METHODS: Twenty patients were randomly assigned either to Group 1 (n = 10) or Group 2 (n = 10). Those in Group 1 were given cisatracurium in a high bolus dose (0.4 mg kg(-1)). Those in Group 2 received cisatracurium 0.1 mg kg(-1) at induction followed after 30 min by a continuous infusion of cisatracurium. As an escape medication in case of patient movement, a bolus dose of cisatracurium 0.03 mg kg(-1) was given. RESULTS: In Group 1 (large cisatracurium bolus dose), the clinical duration of effect (until T1/T0 = 25%) was 110 min. Six of 10 patients in Group 1 required additional boluses of cisatracurium intraoperatively. Four of these six had received an additional bolus near the end of surgery and had a train-of-four (TOF) ratio = 0 at the end. The other four patients in Group 1 had a final TOF ratio >0.9. In Group 2 (continuous cisatracurium infusion), only two patients had a TOF ratio >0.9 at the end of surgery, no patient moved and none received additional boluses. The total amount of cisatracurium used in the bolus and infusion Groups was 34.5 +/- 7.8 and 21.3 +/- 5.7 mg, respectively (P = 0.0004). CONCLUSIONS: For continued neuromuscular block during hypothermic cardiac surgery, a high bolus dose of cisatracurium appears to be safe, although it is not an alternative to a continuous infusion, as its neuromuscular blockade does not cover the intraoperative period and a high incidence of movements occurs. In the patients who received a high bolus dose of cisatracurium, postoperative residual curarization appeared after additional boluses had been given. The consumption of cisatracurium by high bolus was significantly greater than with continuous infusion.     

顺式阿曲库铵不同用药方式对老年全凭静脉麻醉肌松作用的影响

目的 探讨顺式阿曲库铵不同用药方式对老年患者全凭静脉麻醉肌松作用的影响.方法 60例掸期在全麻下行普外科手术的老年患者,ASA I～Ⅱ级.年龄7l～87岁,随机分为A组(η=20)和B组(η=40),其中B组再随机分为B1组(η=20)和B2组(η=20).肌松诱导:A组单次予顺式阿曲库铵0.2 mg·kg-1静注;B...     

Cisatracurium-induced neuromuscular blockade is affected by chronic phenytoin or carbamazepine treatment in neurosurgical patients

The effect of chronic anticonvulsant therapy (CAT) on the maintenance and recovery profiles of cisatracurium-induced neuromuscular blockade has not been adequately studied. In this study, we compared the pharmacokinetics and pharmacodynamics of cisatracurium after a prolonged infusion in patients with or without CAT. Thirty patients undergoing intracranial surgery were enrolled in the study: 15 patients under CAT (carbamazepine and phenytoin, Group A) and 15 controls receiving no anticonvulsant therapy (Group C). Anesthesia was standardized and both groups received a bolus of cisatracurium followed by an infusion to maintain a 95% twitch depression. A steady-state was obtained and the infusion was kept constant for 2 additional hours. Neuromuscular blockade was then allowed to spontaneously recover. Blood samples were taken for measurement of cisatracurium plasma concentration during the steady-state period (Cp(ss)95) and at various times during recovery. Demographic and intraoperative data were similar. CAT resulted in faster 25% and 75% recovery of the first twitch. The rate of infusion of cisatracurium needed to maintain a 95% twitch depression at steady-state was 44% faster in Group A (P < 0.001). The clearance of cisatracurium was significantly faster in Group A when compared with Group C (7.12 +/- 1.87 versus 5.72 +/- 0.70 L . kg(-1) . min(-1), P = 0.01). The Cp(ss)95 was also significantly larger in Group A (191 +/- 45 versus 159 +/- 36 ng/mL, P = 0.04). In addition, patients receiving CAT had a 20% increase in the clearance of cisatracurium that, in turn, resulted in a faster recovery of neuromuscular blockade after an infusion of the drug. Also, patients under CAT had a 20% increase in their Cp(ss)95, indicating an increased resistance to the effect of cisatracurium.     

Accelerated reversal of atracurium blockade with divided doses of neostigmine

The hypothesis that administration of neostigmine in divided doses might accelerate the antagonism of neuromuscular blockade was investigated. Neostigmine 0.05 mg X kg-1 was administered either in a single bolus dose (Group I, n = 16) or in an initial dose of 0.01 mg X kg-1 followed three minutes later by 0.04 mg X kg-1 (Group II, n = 16) for antagonism of atracurium-induced blockade. Reversal was attempted at 10 per cent spontaneous recovery of twitch height. The mean time (+/- SD) from the first injection of the drug until the train-of-four (TOF) ratio value had reached 0.75 was significantly shorter in Group II (p less than 0.05) than in Group I (391.8 +/- 83.3 and 468.6 +/- 150.3 seconds respectively). The rate of TOF ratio recovery was 2.5 times faster after neostigmine administration in divided doses. It is concluded that administration of neostigmine in divided doses, as described in this study, produced a significantly faster reversal of residual atracurium-induced neuromuscular blockade as compared to a single bolus administration.     

Postoperative residual curarization with cisatracurium and rocuronium infusions

BACKGROUND AND OBJECTIVE: Monitoring of neuromuscular blockade still often relies on clinical judgement. Moreover, there are substantial national differences in the use of agents to 'reverse' their effects. We investigated the recovery characteristics and incidence of postoperative residual curarization after cisatracurium and rocuronium infusions for long duration interventions without systematic antagonism. METHODS: In 30 patients undergoing major surgery, we measured infusion dose requirements for rocuronium and cisatracurium during propofol anaesthesia. Infusions were discontinued at the beginning of surgical closure; spontaneous recovery of neuromuscular function was awaited in both groups. Neostigmine (50 microg kg(-1)) was administered only when a patient started to wake without a train-of-four ratio (TOF) of 0.9. RESULTS: In the cisatracurium and rocuronium groups, four (27%) and one (7%) patients, respectively, had a TOF ratio > or = 0.9 at the end of surgery. The TOF ratio in each group at that time was 51 +/- 32% for cisatracurium and 47 +/- 31% for rocuronium (P = 0.78). Six patients (40%) in the cisatracurium group and seven (47%) in the rocuronium group required neostigmine. The TOF ratio at the time of reversal was 63 +/- 7% for cisatracurium and 40 +/- 19% for rocuronium (P = 0.01). The time interval between the end of surgery and a TOF ratio of 0.9 was 10 +/- 9 min for cisatracurium and 18 +/- 13 min for rocuronium (P = n.s.). CONCLUSIONS: Patients receiving a cisatracurium or rocuronium infusion have a high incidence of postoperative residual curarization when the block is not antagonized. When 'reversal' is not attempted, cisatracurium seems to be safer than rocuronium.     

Muscle relaxation does not influence venous oxygen saturation during cardiopulmonary bypass

STUDY OBJECTIVE: To examine whether the omission of neuromuscular blocking drugs during cardiopulmonary bypass (CPB) is associated with increased anesthetic requirements, higher frequency of intraoperative movements, and lower venous oxygen saturation (SvO(2)). DESIGN: Prospective, randomized study. SETTING: Large community hospital. PATIENTS: 30 ASA physical status III and IV patients scheduled for cardiac surgery. INTERVENTIONS: Patients were randomized to one of two groups: group 1 (n = 15) received a 3xED(95) bolus dose of cisatracurium at induction and thereafter no more neuromuscular blocking drug; group 2 (n = 15) received a continuous infusion of cisatracurium during the entire procedure. INTERVENTIONS: Both groups received a standardized anesthetic with bispectral index-guided propofol target-controlled infusion and a remifentanil infusion steered by hemodynamic changes. Venous oxygen saturation was continuously determined during CPB. MEASUREMENTS AND MAIN RESULTS: Propofol consumption was 5.4 +/- 1.7 and 4.4 +/- 1.0 mg/(kg/h) in groups 1 and 2, respectively (P = 0.07). Remifentanil consumption was 0.15 +/- 0.05 and 0.17 +/- 0.05 mug/(kg/min) in groups 1 and 2, respectively (P = 0.19). In groups 1 and 2, no patient recalled any intraoperative phenomena; none moved or had diaphragmatic contractions. During CPB, SvO(2) was 81.3 +/- 3.2% (76%-85%) in group 1 and 80.6 +/- 3.1% (73%-85%) in group 2 (P = 0.53). CONCLUSIONS: Omitting the continuous administration of neuromuscular blocking drugs during CPB did not increase anesthetic requirements. No intraoperative movements occurred, nor was there decreased SvO(2).     

Pharmacodynamic interactions between cisatracurium and rocuronium

The onset and duration of maintenance doses of neuromuscular blocking drugs may be influenced by the original neuromuscular blocking drug used. We assessed the effect of the interaction between steroidal and benzo-isoquinolinium compounds on the clinical duration of maintenance doses of cisatracurium. Sixty adult patients undergoing anesthesia with isoflurane, nitrous oxide, and oxygen were randomized to receive the following: Group I = rocuronium 0.6 mg/kg followed by cisatracurium 0.03 mg/kg when the first twitch in the train-of-four (TOF) recovered to 25%, Group II = cisatracurium 0.15 mg/kg followed by cisatracurium 0.03 mg/kg, and Group III = rocuronium 0.6 mg/kg followed by rocuronium 0.15 mg/kg. Neuromuscular blockade was monitored using acceleromyography (TOF-Guard, Boxtel, The Netherlands). The clinical duration (mean +/- SD) of the first 2 maintenance doses was 41 +/- 10, 31 +/- 7++, and 25 +/- 8++ min, and 39 +/- 11, 30 +/- 6+, 29 +/- 9* min in Groups I-III, respectively (*P < 0.05, +P < 0.01, ++P < 0.001; Group I versus II and III). Thus, the clinical duration of the first two maintenance doses of cisatracurium was prolonged when administered after rocuronium. IMPLICATIONS: We assessed the clinical effect of administering cisatracurium after an intubating dose of rocuronium in 60 patients undergoing isoflurane/nitrous oxide and oxygen anesthesia. The clinical duration of the first two maintenance doses of cisatracurium administered after rocuronium was significantly prolonged. This supports the contention that combinations of structurally dissimilar neuromuscular blocking drugs result in a synergistic effect.     

Is muscle relaxant necessary for cardiac surgery?

The need for continuous and complete paralysis during the entire cardiac surgery has not yet been investigated and is still controversial. In a series of 87 patients undergoing cardiac surgery with normothermic cardiopulmonary bypass, we studied the delay of recovery, incidence of residual paralysis, unwanted patient movement, and difficult surgical conditions after a single dose of atracurium (0.5 mg/kg) or cisatracurium (0.15 mg/kg). Anesthesia was induced with etomidate and remifentanil followed by tracheal intubation. The delay to obtain a train-of-four ratio of >0.9 was longer with cisatracurium than with atracurium (86 +/- 18 versus 97 +/- 19 min). However, at the end of surgery, this ratio was >0.9 for all patients. The presence of unwanted patient movement, diaphragmatic contractions, and difficult surgical conditions were observed. Delay of extubation of the trachea was similar in both groups. We conclude that there is no need for continuous neuromuscular blockade during cardiac surgery. A single dose of either atracurium or cisatracurium is sufficient to provide efficient paralysis from the start of induction leading to quicker recovery from paralysis in fast-track cardiac surgery.     

Cisatracurium-induced neuromuscular blockade in anticonvulsant treated neurosurgical patients

Patients treated with the anticonvulsants phenytoin or carbamazepine are resistant to steroidal neuromuscular blocking agents. We studied the effect of cisatracurium on onset, duration, and speed of recovery from neuromuscular blockade (NMB) in acutely anticonvulsant treated patients ([< 2 weeks] [AA]), chronically anticonvulsant treated patients ([> 2 weeks] [CA]) and patients not on anticonvulsants ([controls] [C]). After Internal Review Board approval, 10 AA, 14 CA, and 14 C neurosurgical patients were studied. Anesthetic induction was midazolam, fentanyl, and thiopental, and maintenance was fentanyl and 0.5 MAC isoflurane in O2. The evoked compound electromyogram of the hypothenar eminence was monitored (TOF supramaximal stimulus at 2 Hz every 20 seconds). Baseline TOF was established, then cisatracurium (0.2 mg/kg) was administered IV. Onset (time to maximal paralysis), duration [time to recovery of first twitch (T1) to 25% of baseline] and speed of recovery (time of recovery from 10%-25% of baseline) were recorded. Data were analyzed using ANOVA. Onset (C = 4 +/- 2, AA = 3 +/- 1, CA = 3 +/- 1.5 minutes) and duration (C = 69 +/- 13, AA = 64 +/- 19, CA = 59 +/- 19 minutes) were not different among the groups (P > .7). Speed of recovery was significantly faster in both AA (6 +/- 2 minutes) and CA (6 +/- 3 minutes) than in C (12 +/- 9 minutes) patients (P < .05). (Data = mean +/- SD). Onset and duration of cisatracurium-induced neuromuscular relaxation was not affected by acute or chronic anticonvulsant treatment, but speed of recovery was significantly faster. Frequent NMB monitoring is necessary to detect the greater speed of recovery in anticonvulsant-treated patients during cisatracurium muscle relaxation.     

The relationship of posttetanic count and train-of-four responses during recovery from intense cisatracurium-induced neuromuscular blockade

Posttetanic count (PTC) has been used to quantify intense degrees of nondepolarizing neuromuscular blockade. Our objective in the present investigation was to discern whether PTC correlates with recovery from intense cisatracurium-induced neuromuscular blockade under both inhaled and IV anesthesia. In 60 patients, anesthesia was induced with propofol 2 mg/kg and fentanyl 1.5 micro g/kg IV. Recovery from intense neuromuscular blockade induced by cisatracurium (0.15 mg/kg) was studied in 2 groups. Group 1 (n = 30) had anesthesia maintained with propofol 100-200 micro g x kg(-1) x min(-1) and 60% N(2)O in O(2), whereas Group 2 (n = 30) had anesthesia maintained with isoflurane (end-tidal concentration 0.8%) and 60% N(2)O in O(2). Neuromuscular functions were monitored using acceleromyography. Cycles of posttetanic stimulation were repeated every 6 min with train-of-four (TOF) stimulation in between. Measurement included times to posttetanic responses and to the first response to TOF stimulation (T(1)), as well as the correlation between PTC and T(1). In Group 1, the mean times to PTC(1) and T(1) were 35.6 +/- 7.5 and 46.9 +/- 6.5 min, respectively. Corresponding times in Group 2 were 39.5 +/- 6.8 and 56.7 +/- 5.4 min, respectively. There was a good time correlation, r = 0.919 for propofol (Group 1) and r = 0.779 for isoflurane (Group 2), between PTC and T(1) recovery in both groups. The PTC when T(1) appeared ranged between 8 and 9 in Group 1 and 8 and 14 in Group 2. Conforming to original observations with other neuromuscular blocking drugs, there is a correlation between PTC and TOF recovery from intense cisatracurium-induced neuromuscular blockade allowing better monitoring of this intense degree of blockade during both IV (propofol) and isoflurane anesthesia. IMPLICATIONS: Monitoring posttetanic count during intense neuromuscular blockade allows the clinician to estimate the intensity of the blockade and estimate recovery time. The relationship between posttetanic count and train-of-four recovery from intense cisatracurium-induced neuromuscular blockade was documented under both IV and inhaled anesthesia.     

Is the diagnosis of significant residual neuromuscular blockade improved by using double-burst nerve stimulation?

This study evaluated the use of double-burst stimulation (DBS) in the diagnosis of significant post-operative residual neuromuscular blockade. Ninety patients were allocated to three equal groups. In Group A the degree of residual neuromuscular blockade was assessed by clinical criteria (CC) only; in Group B by CC and manual evaluation of the response to train-of-four (TOF) nerve stimulation; and in Group C by CC, manual evaluation of the response to TOF, and DBS stimulation. Immediately after arrival in the recovery room mechanical twitch was recorded using TOF stimulation. The mean (+/- SD) TOF ratios were 0.53 +/- 0.19 in Group A, 0.67 +/- 0.11 in Group B and 0.81 +/- 0.08 in Group C. The incidence of a TOF ratio of less than 0.7 was 83.3% in Group A, 56.7% in Group B and 6.7% in Group C. It is concluded that the use of DBS enabled the anaesthetist to recognize significant residual block and thus reduced the incidence of post-operative residual neuromuscular blockade.     

Primingtechnik mit Cisatracurium

OBJECTIVE: Priming can significantly shorten the onset of nondepolarizing neuromuscular blocking agents (NNBA) measured at the adductor pollicis muscle (APM). In spite of the known risks, priming is very popular especially in cases where NNBAs with a long onset time are used. However, there are no data regarding the onset of action for a priming technique measured at the laryngeal muscles although these muscles are of great importance for conditions of intubation and patient safety. The aim of this study was to compare a bolus application and a priming technique with respect to the laryngeal onset time and peak effect. PATIENT AND METHODS: After approval of the local ethics committee and written informed consent, 36 patients undergoing elective thyroid surgery were enrolled in the study. Anesthesia was induced and maintained with a target controlled infusion of propofol (target concentration 2.7-6.0 microg/ml) and infusion of remifentanil (0.25-0.75 microg/kgbw/min). After loss of consciousness, a tube with a surface electrode was placed into the trachea without the application of any neuromuscular blocking agent. Neuromuscular monitoring consisted of evoked electromyography (EMG) of the laryngeal adductor muscles via the surface electrode and evoked acceleromyography (TOF Guard) of the right adductor pollicis muscle (APM). After transcutaneous stimulation of the recurrent laryngeal nerve and ulnar nerve, either 0.9% NaCl followed by 0.1 mg/kgbw cisatracurium after 3 min (bolus group, n=12), a priming dose of 0.01 mg/kgbw cisatracurium followed by 0.09 mg/kgbw 3 min later (low dose priming group, n=12) or a priming dose of 0.015 mg/kgbw cisatracurium followed by cisatracurium 0.085 mg/kgbw 3 min later (high dose priming group, n=12) were injected. Lag time, onset time and peak effect of NMB were recorded and compared between the groups. RESULTS: Demographic data, lag time and peak effect were comparable between the three groups. Onset time at the laryngeal muscles was significantly shorter in the high dose priming group (80+/-17 s), when compared to the low dose priming group (128+/-23 s) and bolus group (142+/-29 s). Onset time at the APM was also significantly shorter in the high dose priming group (154+/-35 s), when compared with the bolus group (226+/-76 s). The recovery of the neuromuscular function measured at the APM showed no differences between the groups. CONCLUSION: Our results show that only high dose priming of cisatracurium can significantly shorten the laryngeal onset time. However, clinical routine use is not recommended due to possible side-effects.     

Preservation of myocardial ATP during cardioplegia: comparison of techniques

Preservation of myocardial ATP enhances the heart's ability to resume normal function following aortic crossclamping (AXC). Preservation of this high energy substrate during 4 cardioplegia delivery techniques was evaluated and compared with changes occurring during 4 hours of continuous coronary perfusion. Dogs (31) were placed on cardiopulmonary bypass and transmural left ventricular biopsies obtained for control ATP measurements. Animals were then divided into five groups: Group I (n = 6): 4 hrs. of continuous coronary perfusion (CCP); Group II (n = 6): 3 hrs. continuous AXC, multidose blood cardioplegia (MBC); Group III (n = 6): 3 hrs. continuous AXC, multidose crystalloid cardioplegia (MCC); Group IV (n = 6): 2 hrs. intermittent AXC, single dose BC (SBC); Group V (n = 7): 2 hrs. continuous AXC, continuous perfusion BC (CBC). In each group, where applicable, myocardial biopsies were taken at 30 minute intervals during AXC, before and after cardioplegia injection, and 30 minutes following final unclamping and rewarming. Hearts in Group II (MBC) and V (CBC) showed greatest preservation of ATP stores (increases 1.1 +/- 1.2%, increases 1.8 +/- 0.9% respectively; p greater than .05) ATP levels rose as high as 23 +/- 2% (p less than .005) above control immediately following cardioplegia injection in Group II (MBC). Group IV showed poorest preservation of ATP (decreases 26 +/- 5%, p less than .01) with levels falling as much as 37 +/- 10% (p less than .01) during the period of AXC. Hearts in Group I (CCP) demonstrated a 15.6 +/- 7.5% decrease in ATP from control (p less than .05). Group III (MCC) also showed a steady decline in ATP declining 18 +/- 3% (p less than .005) from control. These data indicate that multidose blood and continuous-blood cardioplegia techniques will maintain normal myocardial ATP stores throughout the period of AXC. These groups actually show a slight rise in ATP as compared to 4 hrs. of continuous coronary perfusion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Influence of neostigmine on the course of neuromuscular blockade with rocuronium or cisatracurium: a randomized, double-blind trial

OBJECTIVES: To compare the time-course of neuromuscular blockade with rocuronium or cisatracurium during intravenous anesthesia, in terms of both the time to spontaneous recovery or time to reversal after administration of neostigmine. MATERIAL AND METHODS: Patients classified as ASA 1-2 were randomized to receive blinded administration of a single injection of twice the 95% effective dose of rocuronium or cisatracurium for general anesthesia, and then neostigmine plus atropine at recovery of the first train-of-4 (TOF) twitch at 5% or 25%, or normal saline solution as placebo at recovery of the first TOF twitch at 25%. The neuromuscular blockade was monitored by acceleromyography. Intergroup comparisons were carried out by Student t test and analysis of variance. RESULTS: Sixty patients were enrolled. Mean (SD) time to onset was faster with rocuronium at (1.04 [0.32] minutes) compared with cisatracurium at (2.58 [0.81] minutes) and duration was shorter: time to the first twich at 5% was 30 (6.4) minutes with rocuronium and 38.1 (9.7) minutes with cisatracurium. The total duration of blockade (time to the 80% TOF ratio) was also shorter with rocuronium when the neuromuscular blockade was reversed, but there were no differences in the time to block reversal when neostigmine was not used: 62 (18.9) minutes to recovery from the rocuronium blockade vs 66.96 (15.9) minutes to recover from a cisatracurium blockade. A high percentage of patients had less than an 80% TOF ratio at 60 and 90 minutes of administration of the neuromuscular blockerswhen reversal was not used (patients receiving rocuronium, 60% at 60 minutes, and 20% at 90 minutes; patients receiving cisatracurium, 80% at 60 minutes, and 40% at 90 minutes). CONCLUSION: Not antagonizing a rocuronium- or cisatracurium-induced neuromuscular blockade in surgical procedures lasting less than 90 minutes can lead to a high percentaje of residual blockade (TOF ratio <80%).     

腹腔镜手术中持续输注与间断静注顺式阿曲库铵维持深度肌松的药效学比较

目的探讨持续输注顺式阿曲库铵维持深度肌松在腹腔镜手术中的有效性和安全性。方法择期行腹腔镜辅助胃肠道肿瘤根治术患者60例,年龄18~65岁,随机分为A、B两组,每组30例。A组使用顺式阿曲库铵0.15 mg/kg诱导插管,并在强直刺激后计数(post tetanic count,PTC)恢复至≥3时以初始速率0.2mg·kg-1·h-1开始泵注,术中维持肌松深度在PTC≤2。B组使用顺式阿曲库铵0.15mg/kg诱导插管,并在每次PTC恢复至≥3时间断追加0.05mg/kg,术中维持肌松深度在PTC≤2。记录肌松药使用总量,肌松药使用时间(A组:诱导至泵注结束时间;B组:诱导到最后一次加药时间),手术时间,手术开始0、1、2h及关腹时肌松满意度(0~10分),恢复指数(T1从25%恢复至75%的时间),TOFr比值恢复至0.7、0.9的时间,以及压舌板试验完成情况,低氧血症、肺不张、肺炎等情况。结果与B组比较,A组平均肌松药使用量明显增加(P0.05);在手术开始0、1、2h时手术医师对肌松满意度A组明显高于B组(P0.05);恢复指数、TOFr比值恢复至0.7的时间和TOFr比值恢复至0.9的时间两组差异无统计学意义。拔管后A组出现低氧血症2例(7.1%),B组出现低氧血症1例(4.2%);不能完成压舌板试验A组3例(10.7%),B组4例(16.7%),两组差异均无统计学意义。术后均未出现肺不张、肺炎。结论持续输注顺式阿曲库铵用于腹腔镜手术维持深度肌松安全有效。相较于间断静注给药,持续输注肌松药使用量较大,肌松满意度高,虽然停药后恢复时间稍长,但对术后肌松残余无明显影响。     

七氟烷对顺式阿曲库铵和罗库溴铵肌松作用的影响

目的：比较七氟烷对顺式阿曲库铵和罗库溴铵肌松效应的影响。方法：择期手术患者240例,随机分为顺式阿曲库铵组（CIS120例）和罗库溴铵组（ROC120例）。两组患者再随机分为丙泊酚组（60例）和七氟烷组（60例）,均静脉注射咪达唑仑、芬太尼和丙泊酚行麻醉诱导,丙泊酚组靶控输注丙泊酚维持麻醉,设定血浆靶控浓度2～6μg/mL,输注丙泊酚5min后静脉注射顺式阿曲库铵0.15mg/kg或罗库溴铵0.6mg/kg;七氟烷组在呼气末七氟烷浓度稳定于1MAC5min后静脉注射顺式阿曲库铵0.15mg/kg或罗库溴铵0.6mg/kg。结果：CIS两组,起效时间差异无统计学意义（P〉0.05）;七氟烷组完全肌松时间、维持时间与丙泊酚组比较均显著延长（P〈0.01）。ROC两组,起效时间差异无统计学意义（P〉0.05）;七氟烷组完全肌松时间、维持时间与丙泊酚组比较均显著延长（P〈0.01）。结论：七氟烷对顺式阿曲库铵及罗库溴铵的肌松均有增效作用。     

Neuromuscular effects of cisatracurium in morbidly obese patients

Obesity is associated with significant changes in body composition and function that may alter the pharmacodynamics and pharmacokinetics of various drugs. In this study, we investigated the neuromuscular effects of cisatracurium in morbidly obese as compared to control group of normal body weight patients. In the morbidly obese group (n = 20), corrected weight was used to calculate the drug doses. In the control group (n = 20), the dose was calculated on ideal body weight (IBW). 0.15 mg/kg(-1) cisatracurium was administered as the neuromuscular blocker. Neuromuscular effects were recorded at T0 (onset time), T1 (appearance of first stimulus of TOF), T25 (25% recovery of T1) and T25-75 (time of T25 to T75, recovery time). T0 was determined as 177 +/- 23 s and 168 +/- 19 s in the morbidly obese, and control group, respectively. T25 was determined as 46 +/- 7 min and 56 +/- 8 min, in the morbidly obese and control group, respectively (p < 0.05). T25-75 was determined as 11 +/- 5 min and 14 +/- 6 min in the morbidly obese and control group, respectively (p < 0.05). Intubation conditions were determined as good in 13, excellent in 7 patients in the morbidly obese group, and as good in 4 and excellent in 16 patients in the control group (p < 0.05). As different neuromuscular effects of cisatracurium were detected, we conclude that ne uromuscular agents must be monitored in the morbidly obese patients.     

Die Wirkung unterschiedlicher Primingdosierungen auf die Pharmakodynamik von Cisatracurium

OBJECTIVE: The aim of the study was to evaluate the effect of two different priming regimen on the onset time of 100 micrograms/kg cisatracurium, when compared to bolus administration. METHODS: 51 patients were randomly assigned and received either a bolus of 100 micrograms/kg cisatracurium, or a priming dose of 10 micrograms/kg cisatracurium followed after 4 min by 90 micrograms/kg cisatracurium, or a priming dose of 15 micrograms/kg cisatracurium followed after 4 min by 85 micrograms/kg cisatracurium. The neuromuscular monitoring was performed using a mechanomyograph (Groningen II Monitor). Anaesthesia was induced with propofol and fentanyl and maintained by continuous infusion of propofol. RESULTS: The priming combination of 15 micrograms/kg cisatracurium followed after 4 min by 85 micrograms/kg cisatracurium produced a statistically significant reduction in the onset time (95% block) (180 +/- 60 s) and time to complete block (210 +/- 48 s), when compared to the bolus group (240 +/- 60 s and 288 +/- 66 s) (p < 0.05). CONCLUSION: Our data indicate that the "priming principle" is an appropriate technique to shorten the onset time of cisatracurium. To achieve a maximum effect the priming combination of 15 micrograms/kg cisatracurium followed after 4 min by 85 micrograms/kg cisatracurium is recommended.     

The benefits and new predictors of early extubation following coronary artery bypass grafting.

OBJECTIVE: This study researched cardiorespiratory effects and cost-effectiveness of early extubation in patients following coronary artery bypass grafting. METHODS: We retrospectively examined the character of 86 (38 preoperative, 12 intraoperative, 36 postoperative) variables in 78 patients after coronary artery bypass grafting (CABG) at our hospital. The patients were classified into three groups according to the time of extubation: Group A (less than 8 hours), Group B (8 to 24 hours) and Group C (24 hours or more). RESULTS: There were 43 patients in Group A (55%), 27 patients in Group B (35%), and 8 patients in Group C (10%). Univariate preoperative analysis revealed several differences between Groups A and B: 15 variables were found to reach statistical significance. Stepwise logistic regression analysis implicated decreased forced expiratory volume rate in the first second (FEV1.0%), postoperative cardiac index (CI) after admission to the intensive care unit (ICU) and usage of postoperative temporary pace-makers as predictors of late extubation. Also, there was a statistical significance in usage of diuretics within the first day (15.8+/-11.6 vs 28.8+/-22.6 mg; p = 0.044) and in the ICU days (3.6+/-0.8 vs 4.2+/-1.0; p = 0.004) between early and late extubation groups. CONCLUSIONS: Early extubation within 8 hours into the ICU stay was accomplished in 55% of the patients in this study. We speculate that the benefits of early extubation contain improvement of cardiac function, reduction in respiratory infection and complications, and cost saving as the result of diminished ICU admission. Also, we have shown that decreased FEV1.0%, decreased CI and the usage of a postoperative temporary pacemaker were independent predictors of prolonged intubation in our study.