PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Rocuronium”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1994

Quantifying the interaction of rocuronium (Org 9426) with etomidate, fentanyl, midazolam, propofol, thiopental, and isoflurane using closed-loop feedback control of rocuronium infusion.

The present study was designed to evaluate the interactions of rocuronium with etomidate, fentanyl, midazolam, propofol, thiopental, and isoflurane using closed-loop feedback control of infusion of rocuronium. Sixty patients were randomly assigned to one of six sequences where anesthesia was maintained with etomidate, fentanyl, midazolam, propofol, or thiopental and nitrous oxide, or with isoflurane and nitrous oxide. The possible interaction of rocuronium with the anesthetics was quantified by determining the asymptotic steady-state rate of infusion (Iss) of rocuronium necessary to produce a constant 90% neuromuscular block. This was accomplished by applying nonlinear curve fitting to data on the cumulative dose requirement during the initial 90-min period after bolus administration of rocuronium. Patient characteristics and controller performance, i.e., the ability of the controller to maintain the neuromuscular block constant at the set-point, did not differ significantly between the groups. Iss values calculated per lean body mass were 0.64 +/- 0.22, 0.60 +/- 0.15, 0.61 +/- 0.21, 0.67 +/- 0.31, 0.63 +/- 0.15, and 0.39 +/- 0.17 mg.kg-1.h-1 in the etomidate, fentanyl, midazolam, propofol, thiopental, and isoflurane groups, respectively. The isoflurane group had a lower steady-state rate of infusion of rocuronium than the other five groups (P < 0.05). Compared to intravenous anesthetics, etomidate, fentanyl, midazolam, propofol, or thiopental, isoflurane reduced the infusion requirement of rocuronium by 35%-40%.

Adult↗
PubMed1997

[The interaction between rocuronium and smoking. The effect of smoking on neuromuscular transmission after rocuronium].

UNLABELLED: Recent studies have shown different results concerning the effects of smoking on neuromuscular blocking agents. Some reports indicate that smokers need higher doses of vecuronium, but are more sensitive to atracurium. The aim of this study was to evaluate the effects of smoking on onset and recovery time after a single 0.6 mg/kg intubating dose of rocuronium an analog of vecuronium. METHODS: Following institutional approval and informed consent, 20 smokers (> 10 cigarettes/day) and 20 nonsmokers were included in the study. Following oxazepam premedication and induction with fentanyl and thiopental, single-twitch stimulation of the ulnar nerve was performed every 10 s. Following stabilisation of control responses, patients received rocuronium 0.6 mg/kg for intubation. Anaesthesia was maintained with enflurane < or = 0.8 vol.% (end-tidal) and 65% nitrous oxide in oxygen. Onset time and recovery to 25% and 75% of the twitch control values were recorded. RESULTS: Onset and recovery times were not different between smokers and nonsmokers. CONCLUSIONS: The results of the present study suggest that chronic nicotine exposure does not change onset time or duration of rocuronium neuromuscular blockade. A previous study found a greater need for vecuronium in smokers and discussed stimulation of the neuromuscular junction and enhanced biotransformation due to the enzyme-inducing properties of nicotine. The differences in our results could be partly due to a longer period of refraining from smoking in our patients, leading to very low nicotine blood concentrations without the proposed receptor-stimulating effect. Another cause for different behaviour of the two analogs could be different elimination pathways. Recent investigations suggest that rocuronium may not be eliminated principally by the liver. Therefore, enhanced nicotine-induced biotransformation, as suggested for vecuronium, would not occur with rocuronium.

Adult↗
PubMed1997

Thiopental-rocuronium versus ketamine-rocuronium for rapid-sequence intubation in parturients undergoing cesarean section.

We investigated the neuromuscular effects and conditions of tracheal intubation after administration of rocuronium in 40 parturients undergoing elective cesarean section. After preoxygenation, anesthesia was induced in 20 patients by thiopental 4 mg/kg and, in the other 20 patients, by ketamine 1.5 mg/kg. Rocuronium 0.6 mg/kg was then administered, and neuromuscular transmission was assessed using electromyographic response to train-of-four stimulation of the ulnar nerve at the wrist every 10 s. The time to T1/control ratio of 50% neuromuscular block (NMB) as well as the time to maximum NMB (onset time) were compared in the two groups. The time to 50% block was 45 +/- 10 s in the thiopental group and 42 +/- 14 s in the ketamine group, while the onset time was 105 +/- 35 s in the thiopental group and 101 +/- 35 s in the ketamine group. Neither the time to 50% NMB nor the onset time were significantly different between the two groups. Tracheal intubation at 50% NMB was easily performed in all patients in the ketamine-rocuronium group but was difficult in 75% of the thiopental-rocuronium group. We concluded that ketamine 1.5 mg/kg followed by rocuronium 0.6 mg/kg may be suitable for rapid-sequence induction of anesthesia in parturients undergoing cesarean section.

Adult↗
PubMed1994

Quantitation of the interaction of rocuronium bromide with etomidate, fentanyl, midazolam, propofol, thiopentone, and isoflurane using closed-loop feedback control of infusion of rocuronium.

Sixty patients were randomly assigned to one of six groups (n = 10 in each case) in which anaesthesia was induced and maintained with etomidate, fentanyl, midazolam, propofol or with thiopentone and N2O, or isoflurane and N2O. After obtaining control measurements, rocuronium 0.6 mg kg-1 was given for intubation followed by an infusion, controlled by closed-loop feedback at 90% block. The steady-state rates of infusion were (in the same order) 0.64 +/- 0.22, 0.60 +/- 0.15, 0.61 +/- 0.21, 0.67 +/- 0.31, 0.63 +/- 0.15 and 0.39 +/- 0.17 mg kg-1 h-1 (Mean +/- SD). The intravenous agents did not interact with recuronium to any clinically significant degree. Isoflurane reduced the requirements by 35-40%.

Androstanols↗
PubMed1994

Neuromuscular effects of rocuronium bromide and mivacurium chloride administered alone and in combination.

BACKGROUND: Rocuronium is a new nondepolarizing neuromuscular blocking agent with a rapid onset but with intermediate duration of action. Mivacurium, on the other hand, is a new short-acting nondepolarizing neuromuscular relaxant, but of slower onset of action. The current study was undertaken to characterize the interaction between rocuronium and mivacurium. METHODS: In the first study, the dose-response relations of rocuronium, mivacurium, and their combination were studied in ASA physical status 1 or 2 patients during thiopental-fentanyl-N2O anesthesia. One hundred ten patients, randomly assigned to 1 of 11 groups of 10 patients each, received mivacurium 30, 50, or 70 micrograms.kg-1; rocuronium 100, 200, 250, or 300 micrograms.kg-1; or an equieffective combination of both drugs (1 ED50 rocuronium + 1 ED50 mivacurium; 1/2 ED50 rocuronium + 1/2 ED50 mivacurium; 1/4 ED50 rocuronium + 1/4 ED50 mivacurium; or 1/8 ED50 rocuronium + 1/8 ED50 mivacurium, where ED50 is the dose producing 50% depression of the first twitch height). In the second study, 50 patients, ASA physical status 1 or 2, anesthetized with thiopental-fentanyl-N2O, were randomly allocated to 5 groups of 10 patients each to receive one of the following neuromuscular blocking drugs or drug combination: rocuronium 600 micrograms.kg-1 (group 1), mivacurium 150 micrograms.kg-1 (group 2) rocuronium 150 micrograms.kg-1 + mivacurium 37.5 micrograms.kg-1 (group 3), rocuronium 300 micrograms.kg-1 + mivacurium 75 micrograms.kg-1 ((group 4), or rocuronium 600 micrograms.kg-1 + mivacurium 150 micrograms.kg-1 (group 5). RESULTS: The calculated ED50 values and their 95% confidence intervals were 125 (122-129) and 37 (36-38) micrograms.kg-1 for the rocuronium and mivacurium groups, respectively. The interaction between rocuronium and mivacurium was found to be synergistic. The measured ED50 of the mixture was only 62% of the predicted value assuming a purely additive interaction. In the second study, rocuronium 600 micrograms.kg-1 group and group 3 had similar onset times (99 [74-123] and 114 [100-128] s, respectively), which were significantly shorter than that observed in the mivacurium 150 micrograms.kg-1 group (178 [149-206] s). Onset times in groups 4 and 5 were significantly shorter than that in each of the other study groups (69 [63-76] and 73 [65-80] s, respectively). Clinical duration of action (recovery of T1 to 25% of baseline twitch height) was significantly greater in group 5 (55 [51-60] min) than with all other doses and agents, and briefest (P < 0.01) with mivacurium 150 micrograms.kg-1 (14.5 [12.6-16.5] min) and group 3 (14.7 [13.4-16] min). CONCLUSIONS: The interaction between rocuronium and mivacurium was found to be synergistic.

Adult↗
PubMed1997

Comparison of suxamethonium and different combinations of rocuronium and mivacurium for rapid tracheal intubation in children.

The use of suxamethonium in children is associated with undesirable side effects. The synergistic effect of a rocuronium-mivacurium combination can be considered as an acceptable alternative to suxamethonium in clinical practice. The calculated ED50 of the rocuronium-mivacurium mixture was only 62% of the predicted value assuming a purely additive interaction. The use of this combination has not been evaluated in children. In this two-part study, we assessed the intubating conditions and pharmacodynamics of suxamethonium, rocuronium, mivacurium or a rocuronium-mivacurium combinations in children. We studied 120 ASA I children of both sexes, aged 3-10 yr. Children were premedicated with trimeprazine 2 mg kg-1 orally, and received fentanyl 2 micrograms kg-1 and propofol 2 mg kg-1 for induction of anaesthesia. They were allocated randomly to receive one of the following drugs or drug combinations: suxamethonium 1.0 mg kg-1, mivacurium 0.2 mg kg-1, rocuronium 0.6 or 0.9 mg kg-1, mivacurium 0.1 mg kg-1 with rocuronium 0.3 mg kg-1 or mivacurium 0.15 mg kg-1 with rocuronium 0.45 mg kg-1. In part 1, 60 s after administration of the neuromuscular blocking drug or drug combination, tracheal intubation was performed in 60 children by mimicking rapid sequence induction, and intubating conditions were evaluated by a blinded investigator according to a standard score. In part 2, neuromuscular monitoring was established before administration of neuromuscular blocking agent(s) and the time from injection of drug or drug combination until complete ablation of T1 (onset) and recovery of T1 to 25% (duration) were recorded in another 60 children. The frequency of distribution of excellent or good intubating conditions in the higher dose of rocuronium and the combination groups were similar to those in the suxamethonium group, but significantly different (P < 0.05) from those in the mivacurium group. Mean onset time was faster in the suxamethonium (55.1 (SD 11.4) s), rocuronium 0.9 mg kg-1 (70.5 (37.7) s), mivacurium 0.1 mg kg-1 with rocuronium 0.3 mg kg-1 (67 (35.9) s) and mivacurium 0.15 mg kg-1 with rocuronium 0.45 mg kg-1 (55 (26.7) s) groups compared with the mivacurium 0.2 mg kg-1 (116 (26.8) s) and rocuronium 0.6 mg kg-1 (97.9 (29) s) groups. This study demonstrated that the combination of rocuronium 0.45 mg kg-1 and mivacurium 0.15 mg kg-1 could possibly be considered as an acceptable alternative to suxamethonium when rapid sequence induction of anaesthesia is indicated in children because it provides uniform excellent intubating conditions and complete neuromuscular block in < 60 s.

Androstanols↗
PubMed1996

Rocuronium priming of atracurium-induced neuromuscular blockade: the use of short priming intervals.

STUDY OBJECTIVE: To evaluate the effects of priming doses of rocuronium on the duration of priming interval and on the outcome of priming sequence using rocuronium-atracurium combination. DESIGN: Three phase, randomized, controlled study. SETTING: Inpatient anesthesia in a university hospital. PATIENTS: 144 ASA physical status I and II patients, 19 to 57 years of age, weighing 50 to 90 kg, and undergoing low-risk elective surgery. INTERVENTIONS: Phase I, two equal groups (n = 12) of adult patients anesthetized with propofol, fentanyl, and nitrous oxide (N2O), received a priming dose of rocuronium 0.1 mg/kg or vecuronium 0.015 mg/kg. Phase II included six equal groups (n = 12): Groups 1, 2, and 3 received a priming dose of rocuronium 0.1 mg/kg and atracurium 0.42 mg/kg for intubation. The priming intervals were, respectively, 1, 1.5, or 2 minutes in Groups 1, 2, and 3. Groups 4, 5, and 6 received, respectively, a bolus dose of rocuronium 0.6 mg/kg, atracurium 0.5 mg/kg, or succinylcholine 1 mg/kg. Intubation was performed at maximum block. Phase III included four equal groups (n = 12). A priming dose of rocuronium 0.1 mg/kg (Group 1) or a placebo (Groups 2, 3, and 4) was given to awake patients. Anesthesia was induced during the one-minute priming interval. Intubating doses of atracurium 0.42 mg/kg, rocuronium 0.6 mg/kg, atracurium 0.5 mg/kg, or succinylcholine 1 mg/kg were given to Groups 1, 2, 3, and 4, respectively. Intubation was attempted 1 minute after intubating doses were administered. MEASUREMENTS AND MAIN RESULTS: Adductor pollicis response to train-of-four stimulation was recorded mechanically in Phases I and II only. The priming interval after rocuronium 0.1 mg/kg was in the range of 1 to 2 minutes. Priming doses of rocuronium resulted in significant acceleration in the onset time of intubating doses of atracurium, irrespective of the duration of the priming interval. The onset times [mean (SD)] following rocuronium-atracurium sequence in Groups 1, 2, and 3 were, respectively, 67 (17), 73 (14), and 66 (18) seconds and were comparable with the onset of bolus doses of rocuronium and succinylcholine. In Phase II, good to excellent intubating conditions were obtained in 41% to 58% of patients included in Groups 1 through 5. Excellent to good intubating conditions were obtained in all patients (100%) who received succinylcholine. In Phase III, good to excellent intubating conditions were obtained in 91% of patients who received recuronium-atracurium sequence. Symptoms of muscle weakness were not reported. CONCLUSIONS: Priming doses of recuroniums 0.1 mg/kg reduce the priming interval to 1 minute, allow early induction of anesthesia, eliminate patient discomfort, and accelerate the onset time of altracurium with intubating conditions comparable with succinylcholine and rocuronium.

Adult↗
PubMed1996

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↗
PubMed1993

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↗
PubMed1994

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↗
PubMedDate not supplied

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↗
PubMed1998

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↗
PubMed1997

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↗
PubMed1997

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↗
PubMed1997

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↗
PubMed1994

Pharmacokinetics and pharmacodynamics of rocuronium in patients with cirrhosis.

BACKGROUND: Rocuronium, like other steroidal nondepolarizing muscle relaxants, may in part be eliminated by the liver. To determine the influence of liver disease on its neuromuscular blocking effect, we studied the pharmacokinetics and pharmacodynamics of rocuronium in patients with cirrhosis. METHODS: Eighteen patients undergoing elective surgery, 10 with cirrhosis and 8 with normal liver function, were studied. Anesthesia was induced with intravenous thiopental 5-7 mg.kg-1 and maintained with 60% nitrous oxide in oxygen and repeated doses of fentanyl 2 micrograms.kg-1. The force of thumb adduction in response to supramaximal ulnar nerve stimulation was monitored and recorded. An intravenous bolus of rocuronium 0.6 mg.kg-1 was administered and venous blood sampled at frequent intervals for 6 h. Plasma concentrations of rocuronium was measured by high-pressure liquid chromatography. Data were fitted to both a pharmacokinetic and a pharmacodynamic model by using a two-compartment open model and an effect compartment model. Data were analyzed by least-squares regression. RESULTS: The onset of neuromuscular blockade was longer (P < 0.01) in patients with cirrhosis (158 +/- 56 s) than in normal patients (108 +/- 33 s). Recovery of the thumb twitch to 75 and 90% of its control value was 77 +/- 25 and 88 +/- 29 min in cirrhotic patients versus 57 +/- 11 and 64 +/- 13 min, respectively, in normal patients (P < 0.05). The central volume of distribution of rocuronium was 104 +/- 21 in cirrhotic patients and 78 +/- 24 ml.kg-1 in normal patients (P < 0.05). No significant difference in elimination kinetics was observed between the two groups. The elimination half-life was 87.5 +/- 17.5 min in normal patients and 96.0 +/- 36.8 min in cirrhotic patients (difference not significant). This increased onset time was linearly correlated to the increased central volume of distribution of rocuronium in cirrhosis. CONCLUSION: Rocuronium onset time is longer in cirrhotic patients than in those with normal liver function; this can be explained by an increase in the volume in which rocuronium initially distributes. Although elimination kinetics are unchanged in patients with cirrhosis, rocuronium recovery time is prolonged in cirrhotic patients.

Androstanols↗
PubMed1995

Pharmacokinetics of rocuronium in children aged 4-11 years.

BACKGROUND: Rocuronium is a new nondepolarizing muscle relaxant with a rapid onset and intermediate duration of action. Although the pharmacokinetics of rocuronium have been determined in adults and the elderly, similar data are lacking in children. Accordingly, rocuronium's pharmacokinetics were determined in children aged 4-11 yr. METHODS: Rocuronium (600 micrograms/kg) was administered to 20 children aged 4-11 yr anesthetized with nitrous oxide and < or = 1% halothane, and four plasma samples were obtained over 4 h to determine rocuronium concentrations. The pharmacokinetics of rocuronium were determined using two sparse-sampling population approaches, mixed-effects modeling, and naive pooled data analysis. RESULTS: With mixed-effects modeling, weight-normalized plasma clearance varied with weight (P < 0.01), being 79.4 ml.min-1 + 3.13 ml.kg-1.min-1. Neither weight-normalized distributional clearance (2.67 ml.kg-1.min-1), weight-normalized central compartment volume (106 ml/kg), nor weight-normalized volume of distribution at steady-state (224 ml/kg) varied with weight, height, or age. Similar results were obtained with the naive pooled data approach. CONCLUSIONS: Maturational changes were observed in rocuronium's weight-normalized clearance but not in its weight-normalized distributional clearance or volume of distribution. Assuming that the duration of rocuronium's neuromuscular effects is influenced by its pharmacokinetics, repeated administration or continuous infusion of rocuronium should result in larger dose requirements and more rapid recovery in younger, compared to older, children.

Age Factors↗
PubMed1997

Bioavailability of intramuscular rocuronium in infants and children.

BACKGROUND: Intramuscular rocuronium, in doses of 1,000 microg/kg in infants and 1,800 microg/kg in children, produces complete twitch depression in 5-6 min. To determine the rate and extent of absorption of rocuronium after intramuscular administration, blood was sampled at various intervals after rocuronium administration by both intramuscular and intravenous routes to determine plasma concentrations (Cp) of rocuronium. METHODS: Twenty-nine pediatric patients ages 3 months to 5 yr were anesthetized with N2O and halothane. The trachea was intubated, ventilation was controlled, and adductor pollicis twitch tension was measured. When anesthetic conditions were stable, rocuronium (1,000 microg/kg for infants and 1,800 microg/kg for children) was injected either intramuscularly (in the deltoid muscle) or intravenously. Four venous plasma samples were obtained from each child 2-240 min after rocuronium administration. A mixed-effects population pharmacokinetic analysis was applied to these values to determine bioavailability, absorption rate constant, and time to peak Cp with intramuscular administration. RESULTS: With intramuscular administration, rocuronium's bioavailability averaged 82.6% and its absorption rate constant was 0.105 min(-1). Simulation indicated that Cp peaked 13 min after rocuronium was given intramuscularly, and that 30 min after intramuscular administration, less than 4% of the administered dose remained to be absorbed from the intramuscular depot. CONCLUSIONS: After rocuronium is administered into the deltoid muscle, plasma concentrations peak at 13 min, and approximately 80% of the administered drug is absorbed systemically.

Androstanols↗