Onset time and duration of action of rocuronium 0.6 mg/kg in patients above 80 years of age: A comparison with young adults

Onset time, duration of action, and intubating conditions after mivacurium in elderly and younger patients

BACKGROUND

The neuromuscular blocking agent mivacurium can be used during anesthesia to facilitate tracheal intubation. Data on onset time, duration of action, and effect on intubating conditions in patients 80 years and older are however limited. We hypothesized that onset time and duration of action of mivacurium would be longer in elderly patients than in younger adults.

METHODS

This prospective observational study included 35 elderly (≥80 years) and 35 younger (18-40 years) patients. Induction of anesthesia comprised fentanyl 1-3 μg kg-1 and propofol 1.5-2.5 mg kg-1 and propofol and remifentanil for maintenance. Acceleromyography was used for monitoring neuromuscular blockade. The primary outcome was onset time defined as time from injection of mivacurium 0.2 mg kg-1 to a train-of-four (TOF) count of zero. Other outcomes included duration of action (time to TOF ratio ≥0.9), intubating conditions using the Fuchs-Buder scale and the intubating difficulty scale (IDS), and occurrence of hoarseness and sore throat postoperatively.

RESULTS

No difference was found in onset time comparing elderly with younger patients; 219 s (SD 45) versus 203 s (SD 74) (difference: 16 s (95% CI: -45 to 14), p = .30). Duration of action was significantly longer in elderly patients compared with younger patients; 52 min (SD 17) versus 30 min (SD 8) (difference: 22 min [95% CI: 15 to 28], p < .001). No difference was found in the proportion of excellent intubating conditions (Fuchs-Buder); 31/35 (89%) versus 26/35 (74%) (p = .12) or IDS score (p = .13). A larger proportion of younger patients reported sore throat 24 h postoperatively; 34% versus 0%, p = .0002. No difference was found in hoarseness.

CONCLUSION

No difference in onset time of mivacurium 0.2 mg kg-1 was found comparing elderly and younger patients. However, elderly patients had significantly longer duration of action. No difference was found in intubating conditions.

Suspected Accidental Infiltration of Rocuronium During General Anesthesia Induction: A Case Report

There are few reports on rocuronium infiltration under general anesthesia. We report a case of suspected accidental rocuronium infiltration during anesthesia induction. A 25-year-old woman with autism spectrum disorder, intellectual disability, and epilepsy was scheduled for the extraction of 4 impacted third molars under general anesthesia. After induction with sevoflurane, an intravenous (IV) line was established in the left cephalic vein. Rocuronium was administered; however, subcutaneous swelling at the IV site was observed immediately. Spontaneous ventilations were maintained until additional rocuronium was administered via a new IV line. After heat pack application, the swelling disappeared 60 minutes after infiltration, and no tissue damage was observed. A strategy was developed to continue neuromuscular monitoring until recovery occurred. Acceleromyography was used, and the train-of-4 ratios at 99, 130, and 140 minutes after infiltration were 0.79, 0.91, and 1.0, respectively. Sugammadex was administered to prevent neuromuscular blockade recurrence. The patient was extubated once adequate return of muscle function and consciousness were observed. No neuromuscular block prolongation or recurrence were observed postoperatively. When rocuronium infiltration is suspected, it is important to eliminate swelling at the infiltration site and determine a management strategy based on neuromuscular monitoring.

Tracheal intubating conditions in elderly patients when train-of-four count is zero after rocuronium 0.6 or 0.9 mg/kg. A secondary analysis

PURPOSE

The neuromuscular blocking agent rocuronium can be administered to facilitate tracheal intubation. We hypothesized that rocuronium 0.9 mg/kg provided a larger proportion of patients with vocal cords in abducted position compared to rocuronium 0.6 mg/kg at train-of-four (TOF) 0.

METHODS

This secondary analysis was based on 52 elderly surgical patients of which 36 patients received rocuronium 0.6 mg/kg and 16 patients received rocuronium 0.9 mg/kg. Neuromuscular block was monitored with acceleromyography with TOF stimulation at the ulnar nerve. The primary outcome was the proportion of patients with vocal cords in abducted position at TOF 0. Secondary outcomes were intubating conditions evaluated by the Fuchs-Buder scale, the Intubating Difficulty Score (IDS), onset time, and duration of action of rocuronium.

RESULTS

At TOF 0, a significantly larger proportion of patients had vocal cords in abducted position in the rocuronium 0.9 mg/kg group (81%) compared with the rocuronium 0.6 mg/kg group (53%); difference (%) 28, 95% Cl 3-53, P = 0.05. Excellent intubating conditions (Fuchs-Buder) were more common in the rocuronium 0.9 mg/kg group (62.5%); difference (%) 32.5, 95% Cl 4-61), P = 0.03. No significant difference was found in IDS or onset time of rocuronium (difference 19 s, 95% Cl: -5-43). Duration of action was significantly longer (difference 29 min, 95% Cl: 10-47) in the 0.9 mg/kg group.

CONCLUSION

The proportion of patients with vocal cords in abducted position was significantly larger after rocuronium 0.9 mg/kg compared to rocuronium 0.6 mg/kg at TOF 0 monitored at the ulnar nerve.

Comparison of the onset and offset times of two available formulations of rocuronium bromide in an animal model

Rocuronium bromide is a neuromuscular blocker in widespread use in anaesthesia, emergency and intensive care. Reports of reduced efficacy of a new different formulation of rocuronium bromide were submitted to Medsafe, the New Zealand Medicines and Medical Devices Safety Authority, in 2020. Given the requirement for rapid and predictable paralysis for patient safety the efficacy of the two available formulations of rocuronium bromide was investigated in an animal model. After ethics committee approval, 19 rats were anaesthetised and paralysis, defined as loss of tibialis anterior flexion on direct electrical stimulation of the sciatic nerve, was assessed by mechanomyography in response to ED90 doses of rocuronium.Paralysis was observed at a median of 12 seconds for the new different formulation: A, Hameln Pharma (interquartile range (IQR) 6-106 seconds) and 28 seconds for formulation B: Pfizer (IQR 12-68 seconds) P = 0.48. Offset of paralysis was observed after 293 seconds for formulation A (IQR 250-372 seconds) and 241 seconds for formulation B (IQR 220-263 seconds). While the differences observed were substantial, they were not statistically significant. Moreover, the direction of observed difference was towards a shorter median onset and longer offset for the newer formulation, a finding in the opposite direction to the initial clinical concern.Relevance to the clinical situation is indeterminate given the study was stopped at low numbers for futility and limitations around the clinical applicability of animal pharmacokinetics and dynamics. Nevertheless our findings provide some reassurance that the newly available different formulation of this critical use medication does not exhibit a substantial increase in time to onset.

Comparison of onset time, duration of action, and intubating conditions after cisatracurium 0.15 mg/kg in young and elderly patients

Introduction

Tracheal intubation during anesthesia can be facilitated by the neuromuscular blocking agent cisatracurium. However, limited data exists about onset time, duration of action and effect on intubating conditions in elderly patients above 80 years of age. We hypothesized that elderly patients would present a longer onset time and duration of action compared to younger adults.

Methods

This prospective observational study included 31 young (18–40 years) and 29 elderly (≥ 80 years) patients. Patients were given fentanyl 2 μg/kg and propofol 1.5–2.5 mg/kg for induction of anesthesia and maintained with remifentanil and propofol. Monitoring of neuromuscular function was performed with acceleromyography. Primary outcome was onset time defined as time from injection of cisatracurium 0.15 mg/kg (based on ideal body weight) to a train-of-four (TOF) count of 0. Other outcomes included duration of action (time to TOF ratio ≥ 0.9), intubation conditions using the Fuchs-Buder scale and the Intubating Difficulty Scale (IDS), and occurrence of hoarseness and sore throat postoperatively.

Results

Elderly patients had significantly longer onset time compared with younger patients; 297 seconds (SD 120) vs. 199 seconds (SD 59) (difference: 98 seconds (95% CI: 49–147), P < 0.001)). Duration of action was also significantly longer in elderly patients compared with younger patients; 89 minutes (SD 17) vs. 77 minutes (SD 14) (difference: 12 minutes (95% CI: 2.5–20.5) P = 0.01)). No difference was found in the proportion of excellent intubating conditions (Fuchs-Buder); 19/29 (66%) vs 21/31 (68%) (P = 0.86) or IDS score (P = 0.74). A larger proportion of elderly patients reported hoarseness 24 hours postoperatively; 62% vs 34% P = 0.04.

Conclusion

In elderly patients cisatracurium 0.15 mg/kg had significantly longer onset time and duration of action compared with younger patients. No difference was found in intubating conditions at a TOF count of 0.

Trial registration

Clinicaltrials.gov (NCT04921735, date of registration 10 June 2021).

Rocuronium 0.3 mg/kg or 0.9 mg/kg comparing onset time, duration of action and intubating conditions in patients 80 years and older. A randomized study

BACKGROUND

Limited data exist about the optimal dose of rocuronium for intubation in elderly patients. We hypothesized that rocuronium 0.9 mg kg^-1 would lead to a shorter onset time than 0.3 mg kg^-1 in patients above 80 years.

METHODS

Thirty-four patients were randomized to either rocuronium 0.3 mg kg^-1 or 0.9 mg kg^-1 . The primary outcome was onset time defined as time to train-of-four (TOF) count of 0. Other outcomes included duration of action (time to TOF ratio > 0.9), proportion of excellent intubating conditions using the Fuchs-Buder scale and tracheal intubating conditions using the Intubating Difficulty Scale (IDS).

RESULTS

Rocuronium 0.9 mg kg^-1 resulted in shorter onset time compared to rocuronium 0.3 mg kg^-1 ; 108 sec (SD 40) vs. 228 sec (SD 140) (difference: 119 seconds (95% CI: 41-196), P=0.005)), respectively. However, in 66% of the patients receiving rocuronium 0.3 mg kg^-1 a TOF count of 0 was not obtained. Duration of action was longer after rocuronium 0.9 mg kg^-1 : 118 minutes (SD 43) vs. 46 minutes (SD 13) (difference: 72 minutes (95% CI: 49-95) P<0.0001)), and a greater proportion of excellent intubating conditions (Fuchs-Buder) was obtained; 11/16 (69%) vs 4/18 (22%) (P=0.006). No difference was found regarding IDS score.

CONCLUSION

Rocuronium 0.9 mg kg^-1 resulted in a shorter onset time compared to rocuronium 0.3 mg kg^-1 in patients above 80 years of age. In 66% of the patients receiving rocuronium 0.3 mg kg^-1 a TOF count of 0 was not obtained.

Influence of the amount of skeletal muscle mass on rocuronium-induced neuromuscular block

OBJECTIVE

To evaluate the effects of skeletal muscle mass on the rocuronium-induced neuromuscular block.

DESIGN

A prospective, double-blinded, observational study SETTING: A tertiary care university hospital POPULATION: One hundred one patients aged 18-65 years who were scheduled to undergo major surgery lasting more than 1 h under general anaesthesia.

METHODS

All participants underwent body composition analysis before anaesthesia and were allocated into two groups; the muscular and non-muscular group, according to skeletal muscle mass. During anaesthesia induction, rocuronium 1.0 mg kg^-1 of total body weight was injected followed by neuromuscular monitoring using train-of-four stimulation every 15 s.

MAIN OUTCOME MEASURES

The onset time of rocuronium included the elapsed time from the rocuronium injection until 95% depression of first twitch (T1) and the time to no response to TOF stimulation. The duration was evaluated as the elapsed time from the rocuronium injection to 25% recovery of the final T1 (T_DUR25), and the time to the reappearance of T1 (T_TOF1) and T4 (T_TOF4). These pharmacologic data were compared between two groups.

RESULTS

There was no significant difference in the onset time of rocuronium between the two groups. However, T_DUR25 (min) was significantly shorter in the muscular group than in the non-muscular group (p =  0.035 and p =  0.014 in males and females, respectively). T_TOF1 and T_TOF4 were also shorter in the muscular group than in the non-muscular group.

CONCLUSIONS

Total body weight-based dosing of rocuronium might prolong the neuromuscular relaxation effect in patients with a small amount of skeletal muscle.

Polymorphisms contribute to differences in the effect of rocuronium in Chinese patients

Rocuronium is widely utilized in clinical general anaesthesia, and individual differences in pharmacology and clearance have been observed. Two hundred thirty-six Chinese patients undergoing selective thyroid/breast mass resection were studied. Total intravenous anaesthesia was induced with a single dose of propofol (2 mg·kg^-1 ), sufentanil (0.5 μg·kg^-1 ), and rocuronium (0.6 mg·kg^-1 ) and maintained with propofol (3-5 mg·kg^-1 ·h^-1 ) and remifentanil (0.2-0.4 μg·kg^-1 ·min^-1 ). Intubation conditions and a train-of-four index of patients were utilized to assess the effects and duration of rocuronium. The data from 228 patients were analysed and reported. Genotypes NR1I2 rs2472677 C > T, NR1I2 rs6785049 G > A, SLCO1B1 rs4363657 T > C, SLCO1A2 rs4762699 T > C, and UGT1A1 rs4148323 G > A contributed to individual variation in rocuronium. Of the clinical variables tested, age, BMI, total dose of propofol, NR1I2 rs2472677, and SLCO1A2 rs4762699 correlated significantly (P < 0.05 for all) with the clinical duration or total clinical action time of rocuronium in a multiple linear regression model. No significant interactions were observed in intubation conditions. Genetic variations in NR1I2 rs2472677, NR1I2 rs6785049, SLCO1B1 rs4363657, SLCO1A2 rs4762699, and UGT1A1 rs4148323 were related to extensive interindividual variability in the clinical duration and total clinical action time of rocuronium.

A blinded randomized study comparing intubating conditions after either rocuronium 0.6 mg·kg-1 or remifentanil 2 µg·kg-1 in elderly patients

BACKGROUND

To facilitate tracheal intubation, either a neuromuscular blocking agent or a bolus dose of remifentanil can be administered. We hypothesized that rocuronium 0.6 mg·kg^-1 provided a larger proportion of excellent intubating conditions compared to remifentanil 2 µg·kg^-1 in patients above 80 years.

METHODS

A total of 78 patients were randomized to either rocuronium 0.6 mg·kg^-1 or remifentanil 2 µg·kg^-1 . General anaesthesia was initiated with fentanyl and propofol. Two minutes after the administration of either rocuronium or remifentanil, tracheal intubating conditions were evaluated using the Fuchs-Buder scale by a blinded investigator, and our primary outcome was the proportion of patients presenting intubating conditions deemed as excellent. Further outcomes included the Intubating Difficulty Scale (IDS), hoarseness or sore throat 24 h postoperatively, and intervention against hypotension.

RESULTS

No difference in the occurrence of excellent intubating conditions was found comparing the rocuronium group with the remifentanil group; 10 (28%) versus 15 (39%) (p = .29), respectively, relative risk = 0.72. Interventions against hypotension were used in 24 (67%) versus 28 (74%) (p = .51), respectively. Hoarseness and sore throat 24 h postoperatively were found in 37% versus 35% p = .86, and 14% versus 5% p = .20, respectively. The IDS score was 2 versus 2 p = .48.

CONCLUSION

No difference in intubating conditions was found 2 min after the administration of either rocuronium 0.6 mg·kg^-1 or remifentanil 2 µg·kg^-1 in patients aged above 80 years. Intubation conditions were less than optimal in a large proportion of this patient population.

CLINICAL TRIALS REGISTRATION

NCT04287426.

Neuromuscular block in patients 80 years and older: a prospective, controlled study

Background

An increasing number of patients older than 80 years are undergoing anesthesia, but little information is available regarding pharmacodynamic effects of myorelaxants in this population. This study aims to compare the time course of rocuronium neuromuscular block in patients ≥ 80 years with those of younger adults.

Methods

Under total intravenous anesthesia with propofol and sufentanil, time course of a bolus of rocuronium 0.6 mg/kg neuromuscular block was assessed with acceleromyography in patients ≥ 80 and in patients 20–50 years old. Onset time, clinical duration, duration until 90% and 100% recovery of baseline were determined.

Results

Data from 32 patients were analyzed, 16 were ≥ 80 years and 16 were 20–50 years old. Demographic data are shown in Table 1. In the group ≥ 80, onset time was 190 s ± 46 s compared to 123 s ± 40 s in the group 20–50, P < 0.001 and the clinical duration was 52 [48–69.5] min and 36 [34–41] min, respectively, P < 0.001. Duration to 90% recovery of baseline was 77.5 [71–88.5] min and duration to 100% recovery of baseline was 91.2 [82.2–98] min in patients ≥ 80 years and the corresponding values in the patients 20–50 years old were 53.5 [49–55.5] min and 59.5 [56.5–70.25] min, respectively, P < 0.001.

Conclusion

Compared to younger adults rocuronium shifted in patients ≥ 80 years from a rapid onset, intermediate acting compound to a slower onset, long-acting compound.

Trial registration

ClinicalTrials.gov identifier: NCT03551652 (29/05/2018).

Effects of prophylactic atropine on the time to tracheal intubation with the pre-administration of remifentanil

BACKGROUND

Pre-administration of remifentanil in target-controlled propofol and remifentanil anaesthesia could prolong the time of onset of muscle relaxation owing to haemodynamic effects, thereby prolonging the time to tracheal intubation. Although the sympatholytic effects of remifentanil result in bradycardia and hypotension, these responses can be attenuated by the administration of atropine. Therefore, we investigated whether prophylactic administration of atropine could prevent the prolongation of the time to tracheal intubation.

METHODS

Sixty-four patients were included in this study. They were randomised into Group A (atropine 0.5 mg, n = 32) and Group S (saline 0.9%, n = 32), immediately before the pre-administration of remifentanil. The primary outcome was the time to tracheal intubation and the secondary outcomes were rocuronium onset time, time to loss of consciousness (LOC), time to reach a value of 60 on the bispectral index (BIS) and haemodynamic variables.

RESULTS

The median [Interquartile range] of the time to tracheal intubation was 240 [214, 288]s in Group S and 190 [176, 212]s in Group A(median difference: 50 s, 95% confidence interval: 27-80 s, P = .001). Rocuronium onset time was significantly decreased in Group A compared to that in Group S (129 [110, 156] vs 172 [154, 200], P = .001). The times to LOC and reach 60 on the BIS were not significantly different between the two groups. Cardiac output(CO) and heart rate were less decreased in Group A than in Group S (P = .02, P < .001, respectively).

CONCLUSIONS

Prophylactic administration of atropine could compensate for the reduction in CO in cases pre-administered with remifentanil in target-controlled propofol and remifentanil anaesthesia. This in turn prevented the prolongation of rocuronium onset time and reduced the time to tracheal intubation.