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Comparison of rocuronium and mivacurium to succinylcholine during outpatient laparoscopic surgery.

Tracheal intubating conditions and neuromuscular effects of succinylcholine, rocuronium, and mivacurium were studied in 100 healthy women undergoing outpatient laparoscopic surgery. After a standardized fentanyl-thiopental induction, tracheal intubation was facilitated with succinylcholine 1 mg/kg in Groups I (n = 23) and II (n = 25), rocuronium 0.6 mg/kg in Group III (n = 27), or mivacurium 0.2 mg/kg in Group IV (n = 25). If clinically indicated, bolus doses of rocuronium 5-10 mg (Groups I and III) or mivacurium 2-4 mg (Groups II and IV) were administered during the maintenance period. Anesthesia was maintained with desflurane and nitrous oxide 60% in oxygen. At the end of the surgery, residual neuromuscular block was reversed with edrophonium 0.5 mg/kg and atropine 10 micrograms/kg, if needed. The neuromuscular function was assessed using electromyography with a train-of-four mode of stimulation every 10 s at the wrist. Intubating conditions 90 s after succinylcholine and rocuronium were significantly better than after mivacurium. The onset time (from the end of injection until 95% suppression of the first twitch [T1]) for succinylcholine (63 +/- 21 s and 62 +/- 17 s in Groups I and II, respectively) were significantly shorter than for rocuronium (158 +/- 76 s) or mivacurium (210 +/- 93 s). Moreover, the onset times for rocuronium were significantly shorter than mivacurium. The recovery times (of T1 to 25% of the control value) were significantly shorter with succinylcholine and mivacurium than rocuronium. Significantly fewer patients needed reversal of residual neuromuscular blockade after mivacurium compared to rocuronium. One patient in Group I and six patients in Group IV displayed erythema on the upper body. Postoperative myalgia were experienced by 16% of the patients in Groups I and II compared to none in Groups III and IV. There was on difference in the incidence of postoperative nausea and vomiting among the four groups. In conclusion, rocuronium appears to be an acceptable alternative to succinylcholine for tracheal intubation. However, rocuronium's longer duration of action increases the need for reversal drugs. When rapid tracheal intubation is unnecessary, mivacurium is also an acceptable alternative to succinylcholine and is associated with a more rapid spontaneous recovery than rocuronium.

Adult↗

Comparison of rocuronium, succinylcholine, and vecuronium for rapid-sequence induction of anesthesia in adult patients.

BACKGROUND: Succinylcholine has been the agent of choice when clinical conditions require emergency airway protection during a rapid-sequence induction of anesthesia. Rocuronium, a new nondepolarizing muscle relaxant with a brief onset of action, but devoid of the adverse reactions associated with succinylcholine, may be an alternative to succinylcholine. To test this hypothesis, the authors compared rocuronium with succinylcholine and vecuronium for rapid-sequence induction of anesthesia. METHODS: Fifty patients, ASA 1-3, were randomly designated to receive one of three intravenous doses of rocuronium (0.6, 0.9, and 1.2 mg/kg), vecuronium (0.1 mg/kg), or succinylcholine (1.0 mg/kg). Patients were premedicated with midazolam and fentanyl, and received 2-7 mg/kg thiopental for induction of anesthesia. Sixty seconds after receiving a muscle relaxant, intubation of the trachea was attempted by a clinician who was blinded to the muscle relaxant administered. Neuromuscular monitoring was established before administration of the muscle relaxant. The time from injection of muscle relaxant until complete ablation of T1 (onset) and recovery of T1 to 25% (duration) were recorded. Tracheal intubating conditions were evaluated, and the presence or absence of fasciculations was noted. RESULTS: Onset times for patients receiving 0.9 mg/kg (75 +/- 28 s) and 1.2 mg/kg rocuronium (55 +/- 14 s), and succinylcholine (50 +/- 17 s) were similar. Onset times for the groups given 0.6 mg/kg rocuronium (89 +/- 33 s) and vecuronium (144 +/- 39 s) were significantly longer. Clinical duration of action was longest with 1.2 mg/kg rocuronium, similar with 0.6 and 0.9 mg/kg rocuronium, and vecuronium, and least with succinylcholine. CONCLUSIONS: There is a dose-dependent decrease in onset time with rocuronium. The onset times for the two larger doses of rocuronium were similar to that for succinylcholine, but clinical duration of action with rocuronium was significantly longer. The brief onset time achieved with rocuronium indicates that administration of 0.9-1.2 mg/kg is an acceptable alternative to succinylcholine for rapid-sequence induction of anesthesia.

Adolescent↗

Different priming techniques, including mivacurium, accelerate the onset of rocuronium.

Different priming sequences of equipotent doses of rocuronium and mivacurium on the onset of maximum neuromuscular block and intubating conditions were compared with those obtained after succinylcholine. During thiopentone-fentanylnitrous oxide anaesthesia, 70 patients were randomly assigned into seven groups. Group I received mivacurium 0.15 mg.kg-1 as a single bolus dose. Group II received a priming dose of mivacurium 0.015 mg.kg-1 followed three minutes later by mivacurium 0.135 mg.kg-1. Group III received rocuronium 0.6 mg.kg-1 as a single bolus dose, and Group IV received an initial dose of rocuronium 0.06 mg.kg-1 followed by rocuronium 0.54 mg.kg-1. Group V received a priming dose of mivacurium 0.015 mg.kg-1 followed by rocuronium 0.54 mg.kg-1. Group VI received an initial dose of rocuronium 0.06 mg.kg-1 followed by mivacurium 0.135 mg.kg-1. Group VII received succinylcholine 1.0 mg.kg-1. Groups I, III, and VII received a placebo injection before the administration of the neuromuscular blocking drug. Additional thiopentone 2 mg.kg-1 iv was given 30 sec before intubation. Onset times (mean (95% confidence interval)) after priming a rocuronium block with either rocuronium (73 (57-90) sec) or mivacurium (58 (47-69) sec) were similar to those after succinylcholine (54 (40-68) sec), and were shorter (P < 0.01) than that observed in other groups. Intubating conditions were not different between the groups. The duration of neuromuscular block was shortest with succinylcholine. It is concluded that priming a rocuronium block with either mivacurium or rocuronium resulted in a neuromuscular block comparable to that of succinylcholine in both the onset of action and intubating conditions.

Adult↗

Clinical pharmacology of rocuronium (Org 9426): study of the time course of action, dose requirement, reversibility, and pharmacokinetics.

STUDY OBJECTIVE: To evaluate the time course of action, dose requirement, reversibility, and pharmacokinetics of rocuronium (Org 9426) under 3 anesthetic techniques (nitrous oxide-fentanyl supplemented with propofol, halothane, or isoflurane). DESIGN: Prospective, randomized study. SETTING: Operating suite at a university hospital. PATIENTS: 36 ASA physical status I-III patients aged 18 to 65 years who were scheduled for elective surgery. INTERVENTIONS: The time course of action of an intubation dose of rocuronium 600 micrograms/kg was investigated in 36 patients. In 18 of these patients, the maintenance dose requirement of rocuronium and reversibility by neostigmine were evaluated. In the remaining 18 patients, the pharmacokinetics of rocuronium after the intubating dose were studied. Neuromuscular transmission was monitored by mechanomyography. Venous blood samples and urine were analyzed by high-performance liquid chromatography. MEASUREMENTS AND MAIN RESULTS: With the exception of a longer clinical duration of rocuronium-induced neuromuscular block in the isoflurane group compared with the propofol group (p = 0.03), time course of action variables were similar in the 3 groups. In patients receiving maintenance doses of rocuronium, the dose requirement until reversal was 636 +/- 191 micrograms/kg/hr, 496 +/- 107 micrograms/kg/hr, and 384 +/- 127 micrograms/kg/hr for the propofol, halothane, and isoflurane groups, respectively (p = 0.02 for the isoflurane group vs. the propofol group). With respect to the reversal of a rocuronium-induced neuromuscular block, there were no differences in the percentage recovery or rate of recovery among the 3 groups. Pharmacokinetic analysis showed no significant differences for rocuronium during the 3 anesthetic techniques. CONCLUSION: Isoflurane potentiates the rocuronium-induced neuromuscular block, resulting in a longer clinical duration and lower maintenance dose requirement. This difference is not explained by differences in pharmacokinetics but is probably due to increased sensitivity of the neuromuscular junction to rocuronium during isoflurane anesthesia.

Adolescent↗

The intubating laryngeal mask airway: rocuronium improves endotracheal intubating conditions and success rate.

STUDY OBJECTIVE: To assess intubating conditions without neuromuscular blocking drugs, to determine the relation between the dose of rocuronium and the probability of achieving excellent or at least good (good or excellent) intubating conditions with the intubating laryngeal mask airway (ILMA), and finally, to determine the relationship between rocuronium use and the success rate of endotracheal intubation. DESIGN: Prospective, randomized, double-blinded, placebo-controlled study. SETTING: University-affiliated medical center. PATIENTS: Sixty American Society of Anesthesiologists physical status I and II patients undergoing elective surgery. INTERVENTIONS: Anesthesia was induced with propofol 2.5 mg/kg and fentanyl 1 microg/kg. One minute after loss of consciousness, patients received rocuronium 0.2 mg/kg or saline. In the rocuronium group, if intubating conditions were scored as poor, rocuronium dose in the next patient was increased by 0.05 mg/kg. If intubating conditions were scored as good, no change was made, but if conditions were scored as excellent, the dose was decreased by 0.05 mg/kg. One minute after rocuronium or saline administration, an ILMA was used to intubate the trachea. If intubation was unsuccessful, a second attempt was made using the ILMA. MEASUREMENTS: We recorded intubating conditions and the success rate of tracheal intubation. MAIN RESULTS: Without rocuronium, the probability of achieving at least good intubating conditions with the ILMA was 30%. A rocuronium dose of 0.2 mg/kg resulted in a probability of 80% to achieve at least good intubating conditions. Rocuronium significantly increased the success rate of the second intubation attempt. CONCLUSION: To achieve good or excellent intubating conditions with the ILMA, a rocuronium dose lower than the standard intubating dose of 0.6 mg/kg can be used. Neuromuscular blockade increases the success rate of intubation if a second attempt is necessary.

Adult↗

Rocuronium plasma concentrations during three phases of liver transplantation: relationship with early postoperative graft liver function.

BACKGROUND: Previous studies have suggested that neuromuscular blocking agents might be used to assess liver function during liver transplantation. This study examines changes in rocuronium plasma concentration during liver transplantation, to assess graft function. METHODS: A constant-rate infusion of rocuronium was administered to 17 adult patients undergoing liver transplantation. Blood samples were taken at 30-min intervals throughout the procedure, which was divided into three phases: paleo-, an-, and neohepatic. Assay of plasma concentrations of rocuronium was by a gas chromatographic-mass spectrometry technique. Postoperative liver function was followed for up to five days by measuring plasma aminotransferases. RESULTS: In 14 of the 15 patients who survived the transplantation procedure, there was a 7-50% decrease in rocuronium concentration during the neohepatic phase compared with the anhepatic phase. In contrast, rocuronium concentrations increased in the two patients who died after surgery, one as a result of primary non-function and one from massive bleeding. In one patient who survived there was no change in rocuronium concentration. The increase in plasma rocuronium concentration during the neohepatic phase in the two patients who died was consistent with high levels of plasma aminotransferases. CONCLUSIONS: Comparison of changes in plasma rocuronium concentration during the neohepatic phase with early postoperative liver function tests suggests the potential use of rocuronium as a pharmacokinetic probe for predicting liver function during liver transplantation. Further study of rocuronium's potential as an intraoperative pharmacodynamic probe of liver function by measuring neuromuscular paralysis is suggested.

Adult↗

A comparison of the intubation conditions between mivacurium and rocuronium during balanced anesthesia.

BACKGROUND: Comparisons of the intubation conditions with mivacurium and rocuronium from previous reports are confounded by the use of varied induction regimens. The authors compared intubation conditions of mivacurium, rocuronium, and a placebo at 90 s and their recovery profiles during anesthesia with nitrous oxide, oxygen, and propofol. METHODS: After induction with midazolam, fentanyl, and propofol in a randomized blinded study, 100 patients received one of the following treatments: 0.25 mg/kg mivacurium in divided doses (0.15 mg/kg followed by 0.1 mg/kg 30 s later); 0.45, 0.6, 0.9, or 1.2 mg/kg rocuronium; or placebo. Evoked thumb adduction was measured throughout. Intubation was attempted 90 s after the initial dose of mivacurium and other treatment doses by a "blinded" physician. Intubating conditions were graded as excellent, good, poor, or not possible. Spontaneous recovery was studied until a 25% initial twitch height was reached. Mean arterial blood pressure and heart rate changes between groups were determined before induction through 6 min after administration of the study drugs. RESULTS: There were no important changes or intergroup differences in mean arterial blood pressure and heart rate. Intubation conditions were good or excellent for both mivacurium and rocuronium at the 0.9 mg/kg dose (93%) and at the 1.2 mg/kg dose (100%). Rocuronium at the 0.6 mg/kg dose was excellent in 27% of patients, whereas rocuronium at the 0.45 mg/kg dose had the least number of excellent conditions and the most poor or not possible assessments. Patients given placebo could not be intubated. Times to maximum blockade for 0.9 and 1.2 mg/kg rocuronium were the shortest. The times to 25% recovery for 0.6 mg/kg rocuronium (mean +/- SD = 27 +/- 8.6 min), 0.9 mg/kg (43.1 +/- 10.8), and 1.2 mg/kg (62.3 +/- 17.4 min) were significantly longer than were those for mivacurium (17.4 +/- 6.2 min). CONCLUSIONS: Mivacurium in a 0.25 mg/kg divided dose and rocuronium at 0.9 mg/kg and 1.2 mg/kg provide good or excellent intubation conditions at 90 s in most patients. Rocuronium was faster in onset at the higher doses (0.9 and 1.2 mg/kg) but had more prolonged recovery times to 25% single twitch height.

Adult↗

The haemodynamic effects of rocuronium and vecuronium are different under balanced anaesthesia.

BACKGROUND: Rocuronium has been reported to have minimal haemodynamic effects. However, this conclusion has been drawn primarily from investigations conducted under narcotic-based anaesthesia. This study was designed to evaluate the cardiovascular effects of rocuronium under isoflurane/N2O/fentanyl anaesthesia and to compare rocuronium's haemodynamic effects to those of vecuronium and pancuronium. METHODS: Anaesthesia was induced with fentanyl 2 micrograms/kg, thiopentone 4 mg/kg, and suxamethonium 0.5 mg/kg in 75 ASA I or II patients. After tracheal intubation, anaesthesia was maintained with isoflurane 0.5% and N2O 50% in oxygen. Five min after intubation (baseline), patients randomly received either vecuronium 100 micrograms/kg, rocuronium 600 micrograms/kg, rocuronium 900 micrograms/kg, rocuronium 1200 micrograms/kg, or pancuronium 140 micrograms/kg. One min after administration of muscle relaxant, mean arterial pressure (MAP) and heart rate (HR) were recorded and were subsequently measured at 1-min intervals for the next 4 min. RESULTS: HR decreased significantly (P < 0.05) at all times compared to baseline in patients receiving vecuronium. HR significantly (P < 0.05) increased in those receiving rocuronium 1200 micrograms/kg or pancuronium. Patients who received vecuronium had a significant (P < 0.05) decrease in MAP at all times compared to baseline. Comparing results between groups, patients who received rocuronium or pancuronium had significantly (P < 0.05) higher MAP compared to those administered vecuronium. CONCLUSION: The haemodynamic effects of rocuronium and vecuronium are different under balanced anaesthesia. Rocuronium may attenuate the fall in MAP that often occurs under balanced anaesthesia without surgical stimulation.

Adolescent↗

The use of low-dose rocuronium to facilitate laryngeal mask airway insertion.

In this two-phase study, the efficacy of low-dose rocuronium to facilitate laryngeal mask airway (LMA) insertion was evaluated. First, the onset time of 100, 150 and 300 micrograms.kg-1 rocuronium was determined using mechanomyography in three groups of patients (n = 10 in each) anaesthetized with propofol-fentanyl-nitrous oxide. In the second part, 100, 150 or 300 micrograms.kg-1 rocuronium or placebo was administered randomly to four groups of patients (n = 50 in each) in a double-blind manner. Following this, anaesthesia was induced with propofol 2.5 mg.kg-1. Patients in the group of 300 micrograms.kg-1 rocuronium or placebo received propofol after 1.5 min. Patients in the group of 100 or 150 micrograms.kg-1 rocuronium received propofol after 3 min. The LMA was inserted 90 sec later. Immediately before the induction of anaesthesia, patients were questioned about the symptoms of neuromuscular block. In phase 1, onset times were 180 sec (SD 41), 191 sec (59) and 89 sec (34), respectively. In phase 2, insertion of the LMA was graded as easy in 90.6% of patients receiving rocuronium, compared with 42% of patients who had only propofol (P < 0.05). Rocuronium improved the overall ease of LMA insertion. LMA insertion was graded easy in 80% of patients who received 100 micrograms.kg-1 rocuronium. The incidence of unpleasant effects was greatest with 300 micrograms.kg-1 rocuronium. The optimal dose needed to facilitate LMA insertion with minimal unpleasant effects appeared to be 100 micrograms.kg-1 rocuronium.

Adult↗

Comparison of neuromuscular action of rocuronium, a new steroidal non-depolarizing agent, with vecuronium.

BACKGROUND: Rocuronium is a new nondepolarizing muscle relaxant. It features a rapid onset and lack of histamine release: It has an intermediate onset of action as vecuronium. The purpose of this study was to compare the neuromuscular action and condition of intubation after a bolus dose of rocuronium or vecuronium (2 x ED90). We also compared the duration of relaxation after intubation and maintenance doses of each drug. METHODS: Sixty male or female patients, age 18-65, scheduled for elective surgery under general anesthesia were divided randomly into two groups (rocuronium and vecuronium group). All patients were ASA class I-II and pre-operative laboratory data were normal. Anesthesia was performed with fentanyl, isoflurane and O2. Rocuronium 0.6 mg/kg (2 x ED90) or vecuronium 0.1 mg/kg (2 x ED90) was given during induction of anesthesia. The response of adductor pollicis was measured with acceleromyography. Neuromuscular block was maintained by bolus injection of rocuronium 0.15 mg/kg or vecuronium 0.025 mg/kg when T1 reached 25% of control. Onset time, duration, recovery indices, intubation condition and T4/T1 ratio to 70% were recorded. Side effects were recorded during the study. RESULTS: The onset time was significantly longer in vecuronium group than that of rocuronium group (102.8 +/- 26.9 s vs. 54.9 +/- 10.9 s, p < 0.05). The clinical durations of action were respectively 44.2 +/- 13.2 min in rocuronium group and 42.5 +/- 9.1 min in vecuronium group (T1 to 25%). The duration of the maintenance were respectively 28.8 +/- 9.5 min in rocuronium group and 26.1 +/- 6.8 min in vecuronium group (T1 to 25%). No adverse effect occurred with either drug. The intubation condition was similar in both groups. CONCLUSIONS: We conclude that rocuronium provides a more rapid onset of action than that of vecuronium. Rocuronium is an intermediate-acting muscle relaxant as vecuronium with good to excellent intubation condition. It may be an useful alternative to vecuronium for rapid tracheal intubation.

Adolescent↗

Neuromuscular efficacy and histamine-release hemodynamic changes produced by rocuronium versus atracurium: a comparative study.

BACKGROUND: Rocuronium and atracurium are muscle relaxants used for short-and intermediate-duration surgical procedures. This study compares rocuronium and atracurium with regard to neuromuscular efficacy, hemodynamic changes, and their effects on plasma histamine concentration. MATERIALS AND METHODS: Sixty adult patients scheduled for general surgical operations lasting less than 120 minutes were clinically randomized to receive either 0.6mg/kg rocuronium (group-1, n=30) or 0.5mg/kg atracurium (group-2, n=30). Twitch response to a course of four electrical stimulations, baseline heart rate, and mean blood pressure were monitored, as well as histamine levels through venous blood samples. RESULTS: The onset time of neuromuscular block was 54+/-22 seconds in the rocuronium group, vs. 94+/-26 seconds in atracurium group (p=0.001). The clinical duration of the intubating dose was 34+/-6.9 minutes in the rocuronium group, vs. 45+/-7.1 minutes in atracurium group (p<0.001). Tracheas were intubated in less than 90 seconds from the time of the injection of the muscle relaxant in only 20 of the 30 patients in the atracurium group, but in all 30 patients in the rocuronium group (p=0.005). Atracurium, but not rocuronium, produced significant reduction of mean arterial blood pressure and increased heart rate at all times. Atracurium resulted in a significant increase in plasma histamine concentrations at one and three minutes of 232% and 149% (as percentage changes from control values, p<0.01). This corresponded significantly with the decrease in mean arterial blood pressure and the increase in heart rate (p<0.01). Rocuronium did not result in significant changes in plasma histamine concentrations. Further, 62+/-10% of the patients in the atracurium group, and none of rocuronium group, had clinical signs of histamine release. CONCLUSION: Rocuronium provides more suitable conditions for rapid tracheal intubation than atracurium, is associated with a shorter clinical duration, has less effect on mean arterial blood pressure and heart rate, and has less histamine releasing potency when compared to atracurium.

Journal Article↗

Rocuronium versus succinylcholine-atracurium for tracheal intubation and maintenance relaxation during propofol anesthesia.

STUDY OBJECTIVES: To compare the onset and offset time (clinical duration), and intubating conditions obtained with rocuronium bromide 0.6 mg/kg and succinylcholine 1.0 mg/kg after induction with propofol and fentanyl; and to compare rocuronium with atracurium for maintenance during propofol anesthesia. DESIGN: Prospective, open-label, parallel group comparative, randomized study. SETTING: Operating rooms of a university hospital. PATIENTS: 30 ASA physical status I and II adult patients scheduled for elective surgeries with general anesthesia. INTERVENTIONS: Patients premedicated with midazolam 2 mg were anesthetized with fentanyl 2 microg/kg followed by propofol 2.5 mg/kg and muscle relaxants. Group 1 (n = 15) received succinylcholine 1.5 mg/kg and Group 2 (n = 16) received rocuronium bromide 0.6 mg/kg. Intubation was performed 60 seconds after the administration of muscle relaxant. Patients in Group 1 received atracurium and patients in Group 2 received rocuronium for maintenance if required. MEASUREMENTS: The ease of intubation was scored using a scale of 1 to 4. Onset and offset time monitored with evoked twitch response of the adductor pollicis were recorded. MAIN RESULTS: Intubation was successful in all patients and there was no difference in scores between the two groups. Although onset time was shorter with succinylcholine than with rocuronium, neuromuscular blockade was successfully antagonized in both groups, and the recovery profile was not different between the two groups. CONCLUSIONS: Rocuronium bromide at a dose of 0.6 mg/kg, when used with propofol and fentanyl for induction, provides intubating conditions similar to succinylcholine 1.0 mg/kg at 1 minute. The actual onset time and offset time, however, are significantly longer with rocuronium. There was no difference between atracurium and rocuronium as a maintenance drug. Rocuronium is suitable for surgical procedures greater than 30 minutes, eliminating the need for an additional relaxant to succinylcholine.

Adolescent↗

Rocuronium infusion requirements and plasma concentrations at constant levels of neuromuscular paralysis during three phases of liver transplantation.

STUDY OBJECTIVE: To develop a rapid online test of graft liver function during liver transplantation. DESIGN: Prospective, observational study. SETTING: University hospital transplant unit. PATIENTS: 17 adult patients with end-stage liver disease who underwent liver transplantation surgery. INTERVENTIONS: Rocuronium infusion dose requirements and plasma concentrations to maintain constant levels of neuromuscular paralysis during three phases of liver transplantation and their relationship with early postoperative liver function tests were studied. MEASUREMENTS: Infusion dose requirements of rocuronium, assay of rocuronium plasma concentrations using gas chromatography-mass spectrometry, and intensity of neuromuscular blockade were measured. MAIN RESULTS: A 24% decrease in rocuronium infusion requirements was observed during the an-hepatic phase. Rocuronium requirement during the neohepatic phase was increased only modestly or remained unchanged in 14 of the 16 patients who had normal graft function in the immediate postoperative period. Rocuronium plasma concentrations for maintaining constant levels of paralysis were significantly lower during the neohepatic phase than during the paleohepatic and anhepatic phases, indicating that there is likely to be a change in pharmacodynamics during this phase. Significant reduction in rocuronium infusion requirements during the neohepatic phase was observed in the only patient who had poor graft function in the early postoperative stage, suggesting that the reduced infusion requirement to maintain a constant neuromuscular paralysis may be related to the functional state of the graft liver after reperfusion. CONCLUSIONS: A significant reduction in rocuronium infusion requirement during the neohepatic phase may be suggestive of impaired organ function after reperfusion of the graft liver. Rocuronium may serve as a potential online indicator of graft liver function during liver transplantation by measurement of its infusion requirements during transplantation.

Adolescent↗

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.

Androstanols↗

Probability of acceptable intubation conditions with low dose rocuronium during light sevoflurane anaesthesia in children.

BACKGROUND: To define the rocuronium doses which would provide 50%, 90%, and 95% probability of 'acceptable' intubation conditions during light sevoflurane anaesthesia, we studied 60 children aged 2-7 years in a prospective, randomised, assessor blinded study. METHODS: After mask ventilation with 1 MAC sevoflurane/N2O for 17+/-1 (x+/-SD) min we administered rocuronium (either 0.15, 0.22, 0.3, 0.5, or 1.0 mg. kg(-1)) or placebo, and quantified the evoked force of the adductor pollicis muscle. Intubation conditions were assessed before and 2 min after injection of the test drug. RESULTS: Intubation conditions were improved significantly with rocuronium and scored 'acceptable' in 70%, 90%, and 100% of the children after injection of rocuronium 0.15, 0.22, and 0.3 mg x kg(-1), respectively. In parallel, twitch tension decreased to 53% (6-100), 26% (11-100), and 11% (0-19) of baseline (median (range)). Recovery of train-of-four ratio to 0.8 was achieved 13 (7-19), 16 (8-28), and 27 (23-44) min after injection of the respective rocuronium doses. Higher rocuronium doses did not further improve intubation conditions but only prolonged time of neuromuscular recovery. Logistic regression analysis revealed that rocuronium 0.11 (CI 0.05-0.16), 0.21 (0.14-0.28), and 0.25 (0.15-0.34) mg x kg(-1) provides a 50%, 90%, and 95% probability of 'acceptable' intubation conditions in children during 1 MAC sevoflurane/N2O anaesthesia, respectively. Furthermore, we calculated that force depression of adductor pollicis muscle to 81% (CI 72-90), 58% (42-74), and 50% (29-71) of baseline is associated with 50%, 90%, and 95% probability of 'acceptable' intubation conditions. CONCLUSIONS: Submaximal depression of muscle force with low dose rocuronium improves intubation conditions in children during light sevoflurane anaesthesia while allowing rapid recovery of neuromuscular function. However, when using low dose rocuronium neuromuscular monitoring may be helpful to detect children with inadequate response to the relaxant so as to avoid an unsuccessful intubation attempt.

Androstanols↗

Urinary, biliary and faecal excretion of rocuronium in humans.

The excretion of rocuronium and its potential metabolites was studied in 38 anaesthetized patients, ASA I-III and 21-69 yr old. Rocuronium bromide was administered as an i.v. bolus dose of 0.3 or 0.9 mg kg-1. In Part A of the study, the excretion into urine and bile, and the liver content were studied. Plasma kinetics (n = 19) were similar to those reported previously. Urinary recovery within 48 h after administration was 26 (8)% (mean (SD)) (n = 8) of the dose. In bile obtained from T-drains, the recovery within 48 h was 7 (6)% (n = 11). The rocuronium concentration in bile declined bi-exponentially, with half-lives of 2.3 (0.7) and 16 (11) h respectively (n = 6). In three patients from whom stoma fluid was collected, the amount of rocuronium recovered ranged from 0.04 to 12.0% of the dose. In liver tissue obtained from four patients undergoing hemihepatectomy, the estimated amount of rocuronium at 2-5 h after administration ranged between 6.3 and 13.2% (n = 4). In the second part of the study (Part B), urine and faeces were collected over 4-8 days and the recovery was 27 (13)% and 31 (23)% of the dose respectively (n = 10). In most samples, irrespective of the type of biological material, only small amounts of the metabolite 17-desacetyl-rocuronium was found. The results demonstrate that rocuronium is taken up by the liver and excreted into bile in high concentrations. The faecal and urinary excretion of unchanged rocuronium are the major routes of rocuronium elimination.

Adult↗

Time course of action of sugammadex (Org 25969) on rocuronium-induced block in the Rhesus monkey, using a simple model of equilibration of complex formation.

BACKGROUND: Reversal of neuromuscular block can be accomplished by chemical encapsulation of rocuronium by sugammadex (Org 25969), a synthetic gamma-cyclodextrin derivative. The present study determined the time course of the reversal action of sugammadex on rocuronium-induced block in the anaesthetized Rhesus monkey using train-of-four stimulation. METHODS: A bolus injection of rocuronium 100 microg kg(-1) (about 1xED(90)) was given to determine the degree of neuromuscular block reached by this dose. After complete spontaneous recovery, a rapid bolus injection of sugammadex, 1 mg kg(-1), was given and at different time intervals (15, 30 or 60 min, in three different experiments) the effect of another rocuronium bolus injection of 100 microg kg(-1) was determined. RESULTS: Injection of the first dose of rocuronium resulted in a mean neuromuscular block (depression of first twitch) of 93 (SEM=1.6)%. Fifteen minutes after injection of sugammadex the same rocuronium dose resulted in 17% (SEM=5.6) block. After 30 and 60 min these maximum blocks amounted to 49% (SEM=7.6) and 79% (SEM=4.2), respectively. The estimated half-life of sugammadex in Rhesus monkey is 30 (SEM=4.9) min. CONCLUSIONS: The half-life of sugammadex (Org 25969), a new fast and efficient reversal agent for rocuronium-induced block, is relatively short in the Rhesus monkey, implying the possibility to perform neuromuscular block by rocuronium shortly after reversal of a prior block. In translation to the human situation differences in rocuronium sensitivity and kinetics should be taken into account.

Androstanols↗

Dose-response and time course of effect of rocuronium in male and female anesthetized patients.

UNLABELLED: To determine differences from dose-response and time-course of rocuronium between male and female patients, 60 adult patients (30 male and 30 female), ASA grade I, aged 17-52 yr, undergoing elective plastic surgery were studied. Anesthesia was maintained with 60% nitrous oxide in oxygen, thiopental, and incremental doses of fentanyl as required. Neuromuscular function was assessed mechanomyographically with train-of-four (TOF) stimulation at the wrist every 12 s, and the percentage depression of the T1 response was used as the study variable. The dose-response relationship of rocuronium was determined by a cumulative dose-response technique. The results showed that the dose-response curve of rocuronium in the men was shifted to the right, indicating a decrease in the sensitivity to rocuronium-induced neuromuscular block versus the women. The 50%, 90%, and 95% effective doses of rocuronium were 178.4 +/- 53.7, 358.7 +/- 101.3, and 386.2 +/- 113.4 microg/kg, respectively, in male patients, and 128.8 +/- 42.5, 252.8 +/- 51.7, and 274.4 +/- 59.4 microg/kg in female patients. After an intravenous administration of total dose of 400 microg/kg rocuronium, neuromuscular block was significantly longer in the men than in the women. The duration of peak effect, clinical duration, and total duration were 6.5 +/- 3.0, 12.5 +/- 4.9, and 33.6 +/- 8.7 min, respectively, in male patients, and 11.8 +/- 2.7, 18.5 +/- 5.3, and 46.8 +/- 9.6 min in female patients. We conclude that women were approximately 30% more sensitive to rocuronium compared with men. IMPLICATIONS: The authors found that women were 30% more sensitive to rocuronium than men. This suggests that the routine dose of rocuronium should be reduced in women compared with men.

Adolescent↗