Reversal of rapacuronium block during propofol versus sevoflurane anesthesia

We studied the antagonism of rapacuronium with edrophonium-atropine during propofol- or sevoflurane- based anesthesia in 60 healthy outpatients. After the induction of anesthesia with standardized doses of propofol and fentanyl, rapacuronium 1.5 mg/kg was administered to facilitate tracheal intubation. Patients were randomized to receive either a propofol infusion (100 microg. kg(-1). min(-1)) or sevoflurane (1.0%, end-tidal) in combination with nitrous oxide 66% for maintenance of anesthesia. Neuromuscular block was monitored by using electromyography at the wrist and reversed with edrophonium 1.0 mg/kg and atropine 0.015 mg/kg when the first twitch (T(1)) response of the train-of-four (TOF) stimulation recovered to 25% of the baseline value. The clinical duration of action (i.e., time to 25% T(1) recovery) was similar during both propofol (13.1 +/- 3.6 min) and sevoflu-rane (13.7 +/- 4.4 min) anesthesia. The time from 25% T(1) recovery to TOF ratio of 0.8 was also similar with propofol (3.4 +/- 2.1 min) and sevoflurane (5.9 +/- 8.7 min) (P > 0.05). Although none of the patients in the propofol group required more than 9 min to achieve a TOF ratio of 0. 8, two patients receiving sevoflurane required 31 min and 37 min. Adequate antagonism of rapacuronium block with edrophonium can be achieved within 10 min during propofol anesthesia. However, more prolonged recovery may occur in the presence of sevoflurane. Implications: We studied the reversal of rapacuronium-induced block with edrophonium and found that the residual rapacuronium block can be readily antagonized during propofol-based anesthesia. However, reversal of rapacuronium appears to be less predictable during sevoflurane-based anesthesia.     

Tactile assessment for the reversibility of rocuronium-induced neuromuscular blockade during propofol or sevoflurane anesthesia

We sought to determine whether tactile train-of-four (TOF) count can predict the efficacy of neostigmine administration for rocuronium-induced blockade during propofol or sevoflurane anesthesia, and to follow subsequent recovery until the TOF ratio reached 0.9. One-hundred-sixty patients, divided into eight equal groups, were randomly allocated to maintenance of anesthesia with propofol or sevoflurane. The tactile response of the adductor pollicis to TOF stimulation was evaluated on one arm, and the mechanomyographic response was recorded on the other. Neuromuscular block was induced with rocuronium 0.6 mg/kg and maintained with rocuronium to 15% of the control first twitch in TOF. Neostigmine 0.07 mg/kg was administered on reappearance of the first (Group I), second (Group II), third (Group III), or fourth (Group IV) tactile TOF response in each anesthesia. At this time, sevoflurane or the propofol dosage was reduced in each group (n = 20 in each group). The times from administration of neostigmine until the TOF ratio recovered to 0.7, 0.8, and 0.9 were recorded. The times [median (range)] to TOF ratio = 0.9 were 8.6 (4.7-18.9), 7.5 (3.4-9.8), 5.4 (1.6-8.6), and 4.7 (1.3-7.2) min in Groups I-IV during propofol anesthesia, respectively, and 28.6 (8.8-75.8), 22.6 (8.3-57.4), 15.6 (7.3-43.9), and 9.7 (5.1-26.4) min in corresponding groups during sevoflurane anesthesia, respectively (P < 0.0001). We recommend more than 2 TOF responses with propofol anesthesia and 4 TOF responses with sevoflurane anesthesia for adequate reversal within 10 and 15 min, respectively. The more tactile TOF responses present at the time of reversal achieved greater adequate recovery; however, tactile TOF responses are not a completely reliable predictor within a reasonable time period.     

Early and late reversal of rocuronium and vecuronium with neostigmine in adults and children.

We investigated the influence of the timing of neostigmine administration on recovery from rocuronium or vecuronium neuromuscular blockade. Eighty adults and 80 children were randomized to receive 0.45 mg/kg rocuronium or 0.075 mg/kg vecuronium during propofol/fentanyl/N2O anesthesia. Neuromuscular blockade was monitored by train-of-four (TOF) stimulation and adductor pollicis electromyography. Further randomization was made to control (no neostigmine) or reversal with 0.07 mg/kg neostigmine/0.01 mg/kg glycopyrrolate given 5 min after relaxant, or first twitch (T1) recovery of 1%, 10%, or 25%. Another eight adults and eight children received 1.5 mg/kg succinylcholine. At each age, spontaneous recovery of T1 and TOF was similar after rocuronium and vecuronium administration but was more rapid in children (P < 0.05). Spontaneous recovery to TOF0.7 after rocuronium and vecuronium administration in adults was 45.7 +/- 11.5 min and 52.5 +/- 15.6 min; in children, it was 28.8 +/- 7.8 min and 34.6 +/- 9.0 min. Neostigmine accelerated recovery in all reversal groups (P < 0.05) by approximately 40%, but the times from relaxant administration to TOF0.7 were similar and independent of the timing of neostigmine administration. Recovery to T1 90% after succinylcholine was similar in adults (9.4 +/- 5.0 min) and children (8.4 +/- 1.1 min) and was shorter than recovery to TOF0.7 in any reversal group after rocuronium or vecuronium administration. Recovery from rocuronium and vecuronium blockade after neostigmine administration was more rapid in children than in adults. Return of neuromuscular function after reversal was not influenced by the timing of neostigmine administration. These results suggest that reversal of intense rocuronium or vecuronium neuromuscular blockade need not be delayed until return of appreciable neuromuscular function has been demonstrated. Implications: These results suggest that reversal of intense rocuronium or vecuronium neuromuscular blockade need not be delayed until return of appreciable neuromuscular function has been demonstrated. Although spontaneous and neostigmine-assisted recovery is more rapid in children than in adults, in neither is return of function as rapid as after succinylcholine administration.     

性别因素对七氟醚增强顺阿曲库铵或罗库溴铵肌松效应的影响

目的 探讨性别因素对七氟醚增强顺阿曲库铵或罗库溴铵肌松效应的影响.方法 择期全麻手术患者240例,年龄20～60岁,ASA分级Ⅰ或Ⅱ级,BMI 20～30 kg/m2,随机分为2组(n=120):顺阿曲库铵组和罗库溴铵组,各组按性别和麻醉药再分4个亚组(n=30):女性异丙酚组、男性异丙酚组、女性七氟醚组和男性七氟醚组.各异丙酚组靶控输注异丙酚,血浆靶浓度2～6 μg/ml,各七氟醚组吸入七氟醚,于靶控输注或待呼气末七氟醚浓度稳定于1.71%5 min后,静脉注射顺阿曲库铵0.15 mg/kg或罗库溴铵0.6 mg/kg.记录肌松起效时间、肌松作用峰值时间、T1 25%恢复时间和TOFR25%恢复时间.结果 与异丙酚麻醉比较,女性患者七氟醚麻醉时,罗库溴铵TOFR 25%恢复时间延长,顺阿曲库铵肌松作用峰值时间、T1 25%恢复时间和TOFR 25%恢复时间延长,男性患者七氟醚麻醉时,罗库溴铵起效时间缩短,肌松作用峰值时间、T1 25%恢复时间和TOFR 25%恢复时间延长,顺阿曲库铵肌松作用峰值时间、T1 25%恢复时间和TOFR 25%恢复时间延长(P＜0.05或0.01);七氟醚麻醉时与男性患者比较,女性患者罗库溴铵T1 25%恢复时间和TOFR 25%恢复时间缩短,顺阿曲库铵起效时间缩短(P＜0.05或0.01).结论 七氟醚对罗库溴铵肌松的增强作用存在性别差异,男性强于女性;对顺阿曲库铵肌松的增强作用无明显性别差异.     

The comparative effect of single dose mivacurium during sevoflurane or propofol anesthesia in children

BACKGROUND: We aimed to randomly compare intubating conditions, recovery characteristics and neuromuscular effects of single dose of mivacurium (0.2 mg.kg(-1)) during sevoflurane vs. propofol anesthesia in 60 healthy children, undergoing inguinal surgery. METHODS: All children were randomly allocated to receive 2 mg.kg(-1) propofol iv or sevoflurane 8% inspired concentration for induction of anesthesia. Anaesthesia was maintained with 66% nitrous oxide in oxygen and 100-120 microg.kg(-1) propofol or sevoflurane approximately 2-3% inspired concentration with controlled ventilation. The ulnar nerve was stimulated at the wrist by a train-of four (TOF) stimulus every 20 s and neuromuscular function was measured at the adductor pollicis. When the response to TOF was stable, 0.2 mg.kg(-1) mivacurium was given. The trachea was intubated successfully at the first attempt in all patients. RESULTS: Onset time following a single dose of mivacurium was shorter in the sevoflurane group (2.99 min), than in the propofol group (4.42 min). The times to 25, 50, 75, and 90% recovery were significantly longer in the sevoflurane group (13.1, 15.7, 18.6, and 21.2 min, respectively) than in the propofol group (11.4, 13.2, 14.4, and 17.2 min respectively). TOF ratios of 50, 70, and 90% were significantly occurred later in sevoflurane group than propofol group. CONCLUSIONS: Our results indicate that when compared with propofol group, the sevoflurane group had an accelerated onset and a delayed recovery of neuromuscular block induced by mivacurium in children.     

Low doses of rocuronium during remifentanil-propofol-based anesthesia in children: comparison of intubating conditions

BACKGROUND : In this prospective double-blind study, intubation conditions were compared at 90 s following two different low doses of rocuronium during remifentanil and propofol anesthesia in children undergoing ambulatory procedures. METHODS : Forty-four children (ASA I-II, aged 3-12 years) undergoing day case ENT surgery were premedicated with midazolam 0.5 mg x kg(-1). Following atropine 10 microg x kg(-1), remifentanil infusion 0.5 microg x kg(-1) x min(-1) was started. After 60 s, anesthesia was induced with propofol 2.5 mg x kg(-1). Immediately after a bolus dose of propofol, the children received rocuronium doses of 0.15 mg x kg(-1) (group I, n = 22) or 0.3 mg x kg(-1) (group II, n = 22) in a randomized manner, after which an infusion of propofol 6 mg x kg(-1) h(-1) was added to the infusion of remifentanil 0.5 microg x kg(-1) min(-1) for maintenance of anesthesia. Intubating conditions were evaluated 90 s after rocuronium administration applying the Copenhagen Scoring System which included components of laryngoscopy, vocal cord movement and reaction to intubation. Hemodynamic values were recorded at predetermined time intervals. RESULTS : Excellent, good and poor intubation conditions were 18.2, 40.9 and 40.9% in group I and 40.9, 54.5 and 4.5% in group II. Clinically acceptable intubating conditions (excellent and good) were significantly higher in group II (95.5%) than in group I (59.1%) (P = 0.004). Mean values of heart rate and blood pressure did not differ significantly between groups. No children required any intervention for hemodynamic instability and/or muscle rigidity. CONCLUSIONS : The results suggest that 0.3 mg x kg(-1) of rocuronium may be a better low dose than 0.15 mg x kg(-1) of rocuronium for clinically acceptable intubating conditions in pediatric ambulatory surgery during remifentanil-propofol-based anesthesia at the doses used in the study.     

Use of sugammadex in a patient with narrow angle glaucoma

An 86-year-old woman was scheduled to receive fourth reconstructive surgery for femoral bone fracture under general anesthesia. She had been suspected with narrow angle glaucoma due to headache and bloodshot eyes during gastroscopy. During transfer to our hospital, she fell down and suffered from the right femoral neck fracture. The patient underwent femoral head replacement under spinal anesthesia. Later, she received surgeries twice uneventfully under spinal anesthesia; removal and re-implantation of the femoral bone head due to infection of the implanted head. Six months later, she fell down again and femoral bone was fractured during rehabilitation. Anesthesia was induced with propofol followed by rocuronium 0.9 mg x kg(-1) i.v. Anesthesia was maintained with propofol and remifentanil, and rocuronium was administered to maintain PTC of 10 or less. The surgery was completed in 150 minutes. At the end of surgery, a laryngeal mask was inserted and the tracheal tube was removed. TOF ratio recovered to 80% 8 minutes after sugammadex 2 mg kg(-1) i.v., and increased to 100% 3 minutes after additional 1 mg x kg(-1). Intraocular pressure stayed below 20 mmHg during the intervention. We could achieve full reversal of neuromuscular blockade and suppress increase in intraocular pressure with use of sugammadex.     

Neostigmine antagonism of rocuronium block during anesthesia with sevoflurance, isoflurane or propofol

PURPOSE: To examine the influence of continuing administration of sevoflurane or isoflurane during reversal of rocuronium induced neuromuscular block with neostigmine. METHODS: One hundred and twenty patients, divided into three equal groups, were randomly allocated to maintenance of anesthesia with sevoflurane, isoflurane or propofol. Neuromuscular block was induced with rocuronium and monitored using train-of-four (TOF) stimulation of the ulnar nerve and recording the force of contraction of the adductor pollicis muscle. Neostigmine was administered when the first response in TOF had recovered to 25%. At this time the volatile agent administration was stopped or propofol dosage reduced in half the patients in each group (n = 20 in each group). The times to attain TOF ratio of 0.8, and the number of patients attaining this end point within 15 min were recorded. RESULTS: The times (mean +/- SD) to recovery of the TOF ratio to 0.8 were 12.0 +/- 5.5 and 6.8 +/- 2.3 min in the sevoflurane continued and sevoflurane stopped groups, 9.0 +/- 8.3 and 5.5 +/- 3.0 min in the isoflurane continued and isoflurane stopped groups, and 5.2 +/- 2.8 and 4.7 +/- 1.5 min in the propofol continued and propofol stopped groups (P < 0.5-01). Only 9 and 15 patients in the sevoflurane and isoflurane continued groups respectively had attained a TOF ratio of 0.8 within 15 min (P < 0.001 for sevoflurane). CONCLUSIONS: The continued administration of sevoflurane, and to a smaller extent isoflurane, results in delay in attaining adequate antagonism of rocuronium induced neuromuscular block.     

Remifentanil and propofol without muscle relaxants or with different doses of rocuronium for tracheal intubation in outpatient anaesthesia

BACKGROUND: The use of muscle relaxants in outpatient anaesthesia is controversial; some authors recommend an induction regimen including propofol and opioids without muscle relaxants. This study evaluated the requirements for rocuronium after remifentanil/propofol. METHODS: We examined in four groups of ASA I-II patients (n= 30 for each) the intubating conditions three minutes after induction of anaesthesia with remifentanil 0.5 microg kg(-1) min(-1), propofol 2 mg kg(-1) without muscle relaxants or with different doses of rocuronium (0.6 mg kg(-1), 0.45 mg kg(-1), 0.3 mg kg(-1)) applying the criteria proposed by the Copenhagen Consensus Conference. In the second part of the study the time course of neuromuscular block was determined by electromyography using train-of-four (TOF) stimulation. To this end, another 60 ASA I-II patients were randomly assigned to receive remifentanil 0.5 microg kg(-1) min(-1), propofol 2 mg kg(-1) and either rocuronium 0.6 mg kg(-1), 0.45 mg kg(-1), 0.3 mg kg(-1), or 0.3 mg kg(-1) followed by neostigmine 40 microg kg(-1) and atropine 20 microg kg(-1) at a T1 recovery of 10% (n=15 for each). RESULTS: Intubating conditions were good or excellent in 30 patients after rocuronium 0.6 mg kg(-1) and in 18 patients when rocuronium was omitted (P<0.01). After 0.45 mg kg(-1) and 0.3 mg kg(-1) rocuronium the numbers were 29 and 30 patients, respectively. Reducing rocuronium from 0.6 mg kg(-1) to 0.45 mg kg(-1) or 0.3 mg kg(-1) increased the onset time from 136 (35) s to 199 (34) s and 249 (52) s (mean (SD)), (P<0.01); the clinical duration decreased from 38 (10) min to 24 (8) min and 16 (5) min, respectively (P<0.01); and the duration to a TOF-ratio of 0.8 decreased from 60 (11) min to 45 (9) min and 34 (7) min (P<0.01). After rocuronium 0.3 mg kg(-1) this time interval further decreased to 22 (3) min when neostigmine was given at a T1 of 10% (P<0.01 compared with spontaneous recovery after rocuronium 0.3 mg kg(-1)). CONCLUSION: After remifentanil/propofol intubation conditions were poor in 40% of patients without muscle relaxants; adding reduced doses of rocuronium to this regimen improved the intubation conditions significantly. In addition, reducing the initial dose of rocuronium markedly shortened its time course of action.     

Propofol anesthesia enhances the pressor response to intravenous ephedrine

The induction of anesthesia with propofol is often associated with a decrease in arterial blood pressure (BP). Although vasopressors are sometimes required to reverse the propofol-induced hypotension, little is known about the effect of propofol on these drugs. We studied the effects of propofol and sevoflurane on pressor response to i.v. ephedrine. Thirty adult patients were randomly assigned to one of two groups. In the Propofol group (n = 15), patients received propofol 2.5 mg/kg i.v. for induction followed by 100 microg x kg(-1) x min(-1) i.v. for maintenance. In the Sevoflurane group (n = 15), anesthesia was induced with sevoflurane 3%-4% in oxygen and maintained with sevoflurane 2% in oxygen. All patients in both groups received ephedrine 0.1 mg/kg i.v. before and after the anesthetic induction. Ephedrine increased the heart rate significantly (P < 0.05) in awake patients in both study groups. In contrast, there was no increase in heart rate after the ephedrine administration under propofol or sevoflurane anesthesia. In awake patients, transient increases in mean BP were observed after i.v. ephedrine in both groups. In the Propofol group, 2 min after the administration of ephedrine, mean BP increased 16% +/- 10% under anesthesia but increased only 4% +/- 6% when the same patients were awake. The magnitudes of the pressor responses to ephedrine during propofol anesthesia were significantly greater (P < 0.05) than during the awake state. However, ephedrine 0.1 mg/kg i.v. showed no significant increases in BP during sevoflurane anesthesia. We conclude that propofol, not sevoflurane, anesthesia augments the pressor responses to i.v. ephedrine. IMPLICATIONS: The effect of anesthetics on vasopressor-mediated cardiovascular effects is poorly understood. We evaluated the pressor response to ephedrine during propofol or sevoflurane anesthesia. Our study suggests that anesthesia-induced hypotension may be easier to reverse with ephedrine during propofol anesthesia than during sevoflurane anesthesia.     

七氟烷对糖尿病和非糖尿病患者罗库溴铵肌松效应影响的比较

目的 比较七氟烷对糖尿病和非糖尿病患者罗库溴铵肌松效应的影响.方法 择期腹部手术患者60例,年龄45～64岁,ASAⅡ级,其中Ⅱ型糖尿病患者30例,随机分为2组(n=15):异丙酚组(PD组)和七氟烷组(SD组);非糖尿病患者30例,随机分为2组(n=15):异丙酚组(PN组)和七氟烷组(SN组).静脉注射咪达唑仑、异丙酚和芬太尼行麻醉诱导后启动肌松监测,PD组和PN组静脉注射罗库溴铵0.6 mg/kg后气管插管,静脉输注异丙酚维持麻醉;SD组和SN组1%地卡因充分表面麻醉后气管插管.吸入七氟烷(呼气末浓度1.71%)10 min后静脉注射罗库溴铵0.6 mg/kg,吸入七氟烷(呼气末浓度1.71%)维持麻醉.记录肌松起效时间、维持时间和恢复指数.于静脉注射罗库溴铵后10、20、30、40、50、60、70、80、90、100、110、120 min时记录T1/T0比值及TOF比值(T4T1比值).结果 PN组与PD组、SN组与SD组、PD组与SD组间罗库溴铵起效时间、维持时间比较差异无统计学意义(P>0.05).与SN组和PD组比较,SD组恢复指数延长(P<0.05).静脉注射罗库溴铵后60～120 min,SD组T1/T0比值和TOF比值较PD组降低(P<0.05);静脉注射罗库溴铵后80～120 min,SD组TOF比值较SN组降低(P<0.05).结论 与非糖尿病患者相比,七氟烷对糖尿病患者罗库溴铵肌松效应的强化作用进一步增强.     

Spontaneous recovery profile of rapacuronium during desflurane, sevoflurane, or propofol anesthesia for outpatient laparoscopy

We evaluated the spontaneous recovery characteristics of rapacuronium during desflurane-, sevoflurane-, or propofol-based anesthesia in 51 consenting women undergoing laparoscopic tubal ligation procedures. After the induction of the anesthesia with standardized doses of propofol and fentanyl, 1.5 mg/kg IV rapacuronium was administered to facilitate tracheal intubation. Patients were randomized to receive either 1 minimum alveolar anesthetic concentration of desflurane, 1 minimum alveolar concentration of sevoflurane, or 100 microg. kg(-1). min(-1) propofol infusion in combination with 66% nitrous oxide in oxygen for maintenance of anesthesia. Neuromuscular blockade was monitored at the wrist by using electromyography. The degree of maximum blockade and the times for first twitch recovery (T(1)) to 5%, 25%, 50%, 75%, and 90%, as well as the recovery index, were similar in all three anesthetic groups. However, recovery times for the train-of-four ratio to achieve 0.7 and 0.8 were significantly longer with desflurane (44.4 +/- 18.9 and 53.5 +/- 22.4 min) and sevoflurane (44.8 +/- 15.1 and 53.2 +/- 15.8 min) compared with propofol (31.8 +/- 5.3 and 36.5 +/- 6.5 min). Eight patients (16%) required a maintenance dose of 0.5 mg/kg rapacuronium and reversal of rapacuronium residual block occurred in three (6%) patients. We conclude that spontaneous recovery after an intubating dose of 1.5 mg/kg rapacuronium was significantly prolonged by both desflurane and sevoflurane compared with propofol-based anesthesia. Routine monitoring of neuromuscular activity is recommended even when a single bolus dose of rapacuronium is administered during ambulatory anesthesia. IMPLICATIONS: When administered for laparoscopic surgery, the duration of action of an intubating dose of rapacuronium was prolonged 40%-50% by desflurane and sevoflurane, respectively, (versus propofol). Monitoring recovery of neuromuscular blockade produced by rapacuronium is particularly important when desflurane or sevoflurane is administered to ensure that an adequate recovery (train-of-four > or = 0.8) is achieved by the end of anesthesia.     

七氟烷对罗库溴铵、维库溴铵及阿曲库铵临床药效的影响

目的 以丙泊酚为对照,观察1.3 MAC的七氟烷对罗库溴铵、维库溴铵及阿曲库铵临床药效的影响.方法 选择60例择期腹部手术的病人随机分为6组,每组10人.七氟烷罗库溴铵组(sR组)、七氟烷维库溴铵组(SV组)及七氟烷阿曲库铵组(SA组)分别吸入1.3 MAC的七氟烷及静注芬太尼维持麻醉,丙泊酚罗库溴铵组(CR组)、丙泊酚维库溴铵组(CV组)及丙泊酚阿曲库铵组(CA组)以丙泊酚6 mg·kg-1·h-1～8 mg·kg～·h-1及芬太尼维持麻醉.监测起效时间、最大抑制程度、作用时间、维持速率、恢复时间、恢复指数.结果 七氟烷组与相应的对照组在最大抑制程度、恢复指数方面的无统计学差异,起效时间、作用时间、维持速率、恢复时间有统计学差异.结论 七氟烷能明显延长罗库溴铵、维库溴铵以及阿曲库铵的作用时间和恢复时间并减少其起效时间、维持剂量,但对最大抑制程度和恢复指数则无明显影响.     

The use of rocuronium in a patient with Becker muscular dystrophy

We report a case of thoracoscopic pulmonary resection for pneumothorax in a patient with Becker muscular dystrophy The sensitivity of nondepolarizing muscle relaxant in a patient with muscle dystrophy is reportedly higher than in a patient without muscle disease, and the duration of the effect is known to be prolonged. In a 26-year-old man (height 160 cm, weight 39 kg) with Becker muscular dystrophy, general anesthesia was induced with target controlled infusion of propofol (3.0 microg x ml(-1)) and 0.4 microg x kg(-1) of min(-1) of remifentanil. A small amount of rocuronium was also administered additionally until TOF ratio reached to 0%. Total amount of rocuronium was 20 mg (0.5 mg x kg(-1)) for intubation with a double-lumen tracheal tube. The duration of surgery was 68 min. We confirmed 84% recovery of TOF ratio 90 min after injection of rocuronium, and extubated the patient without reversal of rocuronium. We found that the maximum concentration in the plasma or effective site (Cp/Ce) of rocuronium was reached at the time of intubation.     

Onset and duration of action of rocuronium--from tracheal intubation, through intense block to complete recovery

BACKGROUND: The primary objective of this study was to establish the relation between the post tetanic count (PTC) and the time to reappearance of the first response (T1) in train-of-four (TOF) nerve stimulation following rocuronium 0.6 mg/kg, 0.9 mg/kg, and 1.2 mg/kg. The secondary objective was to evaluate the intubation conditions after 1 min. METHODS: One hundred and eight patients were randomised to one of three doses of rocuronium: 0.6, 0.9 or 1.2 mg/kg. Tracheal intubation was performed at 60 s by a blinded investigator. During propofol, fentanyl, midazolam anaesthesia the neuromuscular block was monitored by mechanography using TOF stimulation every 12 s. At 6 min intervals, a tetanic stimulation (50 Hz) was applied for 5 s preceded and followed by a 30 s period of 1 Hz stimulation until the reappearance of T1. RESULTS: There was a significant difference in recovery following the high dose and the two lower doses. The relation between time (min) to reappearance of T1 (t) and PTC can be expressed as follows: t(0.6 and 0.9 mg/kg)(min)=18.8-6.46 PTC and t(1.2 mg/kg)(min)=26.1-9.12 PCT. T1 was seen at a mean PTC level of 8 or 9 in all three groups. The intubation conditions were graded as excellent or good in all patients except in two patients following the 0.6 mg/kg dose of rocuronium. CONCLUSION: The PTC method can be used to predict the time to first response to TOF nerve stimulation during intense rocuronium induced neuromuscular blockade. The relation between PTC and the time to T1 was prolonged after 1.2 mg/kg compared with 0.6 mg/kg and 0.9 mg/kg. No further improvement in intubation conditions at 60 s was evident by increasing the rocuronium dose from 0.9 mg/kg to 1.2 mg/kg.     

Rocuronium duration of action under sevoflurane, desflurane or propofol anaesthesia

BACKGROUND AND OBJECTIVE: We conducted a prospective randomized study to evaluate whether the duration of action of a single bolus dose of rocuronium is influenced by maintenance of anaesthesia with sevoflurane, desflurane or propofol infusion. METHODS: Fifty-seven ASA I-II patients undergoing elective abdominal surgery were enrolled in this study. Anaesthesia was induced with thiopental 3-5 mg kg(-1) or propofol 2.5 mg kg(-1) and fentanyl 5 microg kg(-1) and tracheal intubation was facilitated with rocuronium 0.9 mg kg(-1). Thereafter patients were randomly allocated to three different groups to receive sevoflurane, desflurane or propofol for maintenance of anaesthesia. Recovery of neuromuscular function was monitored by single twitch stimulation of the ulnar nerve and by recording the adductor pollicis response using accelerometry. Intergroup recovery times to 5% of control value of single twitch were analysed using analysis of variance with Bonferroni correction. RESULTS: The mean (95% confidence interval) recovery time to 5% of control value of single twitch during desflurane anaesthesia was 90.18 (86.11-94.25) min. Significantly shorter recovery times were observed during sevoflurane or propofol anaesthesia, 58.86 (54.73-62.99) min and 51.11 (45.47-56.74) min, respectively (P < 0.001). There were also significant differences in the recovery time between groups receiving desflurane vs. sevoflurane (P < 0.001) and desflurane vs. propofol (P < 0.001). CONCLUSIONS: Desflurane anaesthesia significantly prolongs the duration of action of rocuronium at 0.9 mg kg(-1) single bolus dose, compared to sevoflurane or propofol anaesthesia maintenance regimens.     

Effect of epidurally administered bupivacaine on atracurium-induced neuromuscular blockade

The effect of epidurally administered bupivacaine on duration, intensity and reversal characteristics of atracurium-induced neuromuscular blockade was studied in 30 healthy patients anaesthetized with thiopentone, fentanyl, midazolam and nitrous oxide. Fifteen patients received, in addition, epidural anaesthesia with bupivacaine. The remaining patients served as controls. The ulnar nerve was stimulated at the wrist and the evoked twitch response from the adductor pollicis was measured with a force displacement transducer. Neuromuscular blockade was induced with atracurium 0.5 mg i.v. and maintained with repeated doses of atracurium 0.15 mg/kg whenever the twitch height had recovered to 15% of the initial twitch height. After operation, the neuromuscular blockade was reversed with neostigmine when the twitch height had recovered to 15%. In the epidural group the clinical duration of neuromuscular blockade, time until first response to train-of-four (TOF) and reversal time were all significantly prolonged (P less than 0.05). Post-tetanic count (PTC) after 20 min was also significantly lower in the epidural group (P less than 0.05). It is therefore concluded that epidurally administered bupivacaine prolongs atracurium-induced neuromuscular blockade. The clinical implication of the modest prolongation is, however, limited.     

Reversal of rocuronium-induced neuromuscular block with the novel drug sugammadex is equally effective under maintenance anesthesia with propofol or sevoflurane

In this study we investigated whether the novel reversal drug, sugammadex, is equally effective at reversing rocuronium-induced neuromuscular block (NMB) in patients under propofol or sevoflurane maintenance anesthesia. After receiving propofol for induction, patients were randomized to propofol (n = 21) or sevoflurane (n = 21). Rocuronium 0.6 mg/kg was administered for tracheal intubation. NMB was monitored using acceleromyography. At reappearance of the second twitch of the train-of-four ratio, sugammadex 2.0 mg/kg was administered by IV bolus. The primary end-point was time from start of sugammadex administration to recovery of train-of-four ratio to 0.9. Mean recovery time was 1.8 min after both propofol and sevoflurane anesthesia. The 95% confidence interval for the difference in recovery time between the 2 groups (-0.5 to +0.4 min) was well within the predefined equivalence interval (-1 to +1 min), indicating that recovery from NMB was unaffected by maintenance anesthesia. Thirteen patients (propofol n = 4; sevoflurane n = 9) experienced adverse events; these were treatment-related in 4 patients (propofol n = 3; sevoflurane n = 1). There were no treatment-related serious adverse events and no discontinuations or deaths. No residual paralysis occurred. The safety profile of sugammadex was somewhat more favorable under propofol than under sevoflurane anesthesia.     

High concentration sevoflurane induction of anesthesia accelerates onset of vecuronium neuromuscular blockade

PURPOSE: To investigate neuromuscular block using accelography after administration of vecuronium under sevoflurane 8% induction and maintenance with sevoflurane 2% in adults. METHODS: Patients were allocated to three groups: (1) group I: anesthesia was induced and maintained with propofol and fentanyl (n= 15), (2) group II: anesthesia was induced with propofol and maintained with N2O(66%)-O2-sevoflurane 2% (n = 15), (3) group III: anesthesia was induced with sevoflurane 8% using a vital capacity inhalation induction and maintained with N2O(66%)-O2-sevoflurane 2% (n = 15). 0.1 mg x kg(-1) vecuronium was used for paralysis three minutes after anesthetic induction and reversed using intravenous 0.04 mg x kg(-1) neostigmine with 0.02 mg kg atropine when the train-of-four (TOF) ratio returned to 25%. RESULTS: The onset time from initial administration of vecuronium to maximal block in the group III was shorter than that in the groups I and II (139 +/- 35, 193 +/- 35 and 188 +/- 47s, respectively: P < 0.05). The clinical duration from maximal block to 25% recovery of TOF ratio in group II and III was longer than that in the group I (47 +/- 15, 48 +/- 14 and 36 +/- 10 min, respectively: P < 0.05). The reversal times from administration of neostigmine to 75% of TOF ratio in groups II and III were longer than that in the group I (196 +/- 53, 208 +/- 64 and 136 +/- 28s, respectively: P < 0.05). CONCLUSIONS: Vital capacity inhalation induction of anesthesia with sevoflurane accelerates onset and prolongs duration of vecuronium neuromuscular block compared with propofol-fentanyl anesthesia.     

Maintenance and recovery characteristics after sevoflurane or propofol during ambulatory surgery in children with epidural blockade

PURPOSE: To compare the maintenance and recovery characteristics after sevoflurane with those after propofol in children with epidural blockade. METHODS: Fifty unpremedicated, children ASA I-II, 2-8 yr of age, scheduled for elective urological surgery as outpatients, were randomly allocated to receive either: 1) sevoflurane for induction and maintenance of anaesthesia or 2) propofol for induction (2-3 mg.kg-1 i.v.) and for maintenance (5-10 mg.kg-1.hr-1 i.v.). All children received N2O 70% in oxygen before induction and throughout the anaesthetic, rocuronium for neuromuscular blockade and a lumbar or caudal epidural block before incision. Heart rate (HR), systolic blood pressure (SBP), recovery times and all side effects during maintenance and recovery were recorded by a blinded observer. Adverse events during the first 24 hr were also recorded. RESULTS: Mean HR increased 5-10% after induction in both groups reaching a maximum by five minutes. Heart rate returned to baseline by skin incision in the sevoflurane group and by 10 min after induction in the propofol group. During maintenance, HR decreased by 10-20% below baseline values by 20 min in the propofol group only, where it remained for the remainder of the anaesthetic. Similarly, SBP increased by 10% after induction of anaesthesia in both groups, but returned to baseline by 10 min. Light anaesthesia occurred in four (16%) children, all in the propofol group. Emergence and recovery indices were similar in the two groups. DISCUSSION: Sevoflurane and propofol exhibit similar maintenance and recovery profiles when combined with epidural analgesia in children undergoing ambulatory surgery.