The analgesic effect of remifentanil on prevention of withdrawal response associated with the injection of rocuronium in children: no evidence for a peripheral action

Median Effective Dose of Remifentanil for the Prevention of Pain Caused by the Injection of Rocuronium: An Age-Stratified Study

INTRODUCTION

Rocuronium intravenous pain is common in induction of general anesthesia. The aim of our study was to determine the median effective dose (ED₅₀) of prophylactic intravenous remifentanil for the prevention of rocuronium injection pain and to explore the effect of age on the ED₅₀.

METHODS

Eighty-nine adult patients undergoing elective general anesthesia, ASA I or II, regardless of gender or weight, were stratified according to age: group R1 18-44 years, group R2 45-59 years, and group R3 60-80 years. The initial dose of prophylactic remifentanil before rocuronium injection was set at 1 μg/kg lean body weight (LBW). The remifentanil doses were adjusted according to the degree of injection pain using the Dixon sequential method, with a ratio of 1.1 between adjacent doses. Injection pain was graded, and the occurrence of injection pain and adverse reactions were recorded. The ED₅₀ and 95% confidence intervals (CIs) of remifentanil were calculated using the Dixon-Massey formula. Patients were asked whether they recalled feeling any injection pain in the post-anesthesia care unit (PACU).

RESULTS

The ED₅₀ (95% CIs) of prophylactic remifentanil for the prevention of rocuronium injection pain were 1.266 μg/kg (1.186-1.351 μg/kg), 1.188 μg/kg (1.065-1.324 μg/kg), and 1.070 μg/kg (1.014-1.129 μg/kg) LBW in group R1, group R2, and group R3, respectively. No adverse reactions to remifentanil occurred in any group. In PACU, 84.6, 86.7, and 85.7% of patients who experienced injection pain had memories of the pain in group R1, group R2, and group R3, respectively.

CONCLUSIONS

Prophylactic intravenous remifentanil can prevent rocuronium injection pain, and its ED₅₀ decreases with age, with 1.266 μg/kg (18-44 years), 1.188 μg/kg (45-59 years), and 1.070 μg/kg LBW (60-80 years), respectively.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT05217238 (registration date 18 Dec 2021).

Patterns of zolpidem use among Iraq and Afghanistan veterans: A retrospective cohort analysis

BACKGROUND

Although concern exists regarding the adverse effects and rate of zolpidem use, especially long-term use, limited information is available concerning patterns of zolpidem use.

OBJECTIVE

To examine the prevalence and correlates of zolpidem exposure in Iraq and Afghanistan Veterans (IAVs).

METHODS

A retrospective cohort study of zolpidem prescriptions was performed with National Veterans Health Administration (VHA) data. We gathered national VA inpatient, outpatient, and pharmacy data files for IAV's who received VA care between fiscal years (FY) 2013 and 2014. The VA pharmacy database was used to identify the prevalence of long term (>30 days), high-dose zolpidem exposure (>10mg immediate-release; >12.5mg extended-release) and other medications received in FY14. Baseline characteristics (demographics, diagnoses) were identified in FY13. Bivariate and multivariable analyses were used to examine the demographic, clinical, and medication correlates of zolpidem use.

RESULTS

Of 493,683 IAVs who received VHA care in FY 2013 and 2014, 7.6% (n = 37,422) were prescribed zolpidem in FY 2014. Women had lower odds of high-dose zolpidem exposure than men. The majority (77.3%) of IAVs who received zolpidem prescriptions had long-term use with an average days' supply of 189.3 days and a minority (0.9%) had high-dose exposure. In multivariable analyses, factors associated with long-term zolpidem exposure included age greater than 29 years old, PTSD, insomnia, Selim Index, physical 2-3 conditions, opioids, antidepressants, benzodiazepines, atypical antipsychotics, and stimulants. High dose exposure was associated with PTSD, depression, substance use disorder, insomnia, benzodiazepines, atypical antipsychotics, and stimulant prescriptions.

CONCLUSION

The current practices of insomnia pharmacotherapy in IAVs fall short of the clinical guidelines and may reflect high-risk zolpidem prescribing practices that put Iraq and Afghanistan Veterans at risk for adverse effects of zolpidem and poor health outcomes.

Pharmacological and non-pharmacological interventions for reducing rocuronium bromide induced pain on injection in children and adults

BACKGROUND

Rocuronium bromide is a routinely used muscle relaxant in anaesthetic practice. Its use, however, is associated with intense pain on injection. While it is well established that rocuronium bromide injection causes pain in awake patients, anaesthetized patients also tend to show withdrawal movements of the limbs when this muscle relaxant is administered. Various strategies, both pharmacological and non-pharmacological, have been studied to reduce the incidence and severity of pain on rocuronium bromide injection. We wanted to find out which of the existing modalities was best to reduce pain on rocuronium injection.

OBJECTIVES

The objectives of this review were to assess the ability of both pharmacological and non-pharmacological interventions to reduce or eliminate the pain that accompanies rocuronium bromide administration.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2013, Issue 7), MEDLINE via Ovid SP (1966 to July 2013) and EMBASE via Ovid SP (1980 to July 2013). We also searched specific websites. We reran the searches in February 2015 and will deal with the 11 studies of interest found through this search when we update the review.

SELECTION CRITERIA

We included all randomized controlled trials (RCTs) that compared the use of any drug or a non-pharmacological method with control patients, or those receiving no treatment to reduce the severity of pain with rocuronium injection. Our primary outcome was pain on rocuronium bromide injection measured by a pain score assessment. Our secondary outcomes were rise in heart rate and blood pressure following administration of rocuronium and adverse events related to the interventions.

DATA COLLECTION AND ANALYSIS

We used the standardized methods for conducting a systematic review as described in the Cochrane Handbook for Systematic Reviews of Interventions. Two authors independently extracted details of trial methodology and outcome data from reports of all trials considered eligible for inclusion. We made all analyses on an intention-to-treat basis. We used a fixed-effect model where there was no evidence of significant heterogeneity between studies and a random-effects model if heterogeneity was likely.

MAIN RESULTS

We included 66 studies with 7840 participants in the review, though most analyses were based on data from fewer participants. In total there are 17 studies awaiting classification. No studies were at a low risk of bias. We noted substantial statistical and clinical heterogeneity between trials. Most of the studies reported the primary outcome pain as assessed by verbal response from participants in an awake state but some trials reported withdrawal of the injected limb as a proxy for pain after induction of anaesthesia in response to rocuronium administration. Few studies reported adverse events and no study reported heart rate and blood pressure changes after administration of rocuronium. Lidocaine was the most commonly studied intervention drug, used in 29 trials with 2256 participants. The risk ratio (RR) of pain on injection if given lidocaine compared to placebo was 0.23 (95% confidence interval (CI) 0.17 to 0.31; I² = 65%, low quality of evidence). The RR of pain on injection if fentanyl and remifentanil were given compared to placebo was 0.42 (95% CI 0.26 to 0.70; I² = 79%, low quality of evidence) and (RR 0.10, 95% CI 0.04 to 0.26; I² = 74%, low quality of evidence), respectively. Pain on injection of intervention drugs was reported with the use of lidocaine and acetaminophen in one study. Cough was reported with the use of fentanyl (one study), remifentanil (five studies, low quality evidence) and alfentanil (one study). Breath holding and chest tightness were reported with the use of remifentanil in two studies (very low quality evidence) and one study (very low quality evidence), respectively. The overall rate of complications was low.

AUTHORS' CONCLUSIONS

The evidence to suggest that the most commonly investigated pharmacological interventions reduce pain on injection of rocuronium is of low quality due to risk of bias and inconsistency. There is low or very low quality evidence for adverse events, due to risk of bias, inconsistency and imprecision of effect. We did not compare the various interventions with one another and so cannot comment on the superiority of one intervention over another. Complications were reported more often with use of opioids.

EC50 and EC95 of remifentanil to prevent rocuronium-induced withdrawal movements in children

Background

Intravenous administration of rocuronium induces intense pain in most patients (60-100%). This could be harmful during anesthesia induction because of the unintended reflex movement of an unconscious patient in response to the pain. Previous studies have reported that remifentanil effectively reduces rocuronium-induced pain and withdrawal movements. This study was designed to evaluate the EC₅₀ and EC₉₅ of remifentanil to prevent withdrawal movements in children.

Methods

We enrolled a total of 171 pediatric patients scheduled for general anesthesia in this study. Remifentanil was administrated by target-controlled infusion. Effect-site target concentrations ranged from 0.5 to 3.0 ng/ml. At each concentration, experiments were repeated in 10-20 patients. Propofol 2 mg/kg and rocuronium 0.9 mg/kg were administrated after equilibration of plasma and effect-site target remifentanil concentration. The withdrawal movements were graded on a 4-point scale. The EC₅₀ and EC₉₅ of remifentanil to prevent rocuronium-induced withdrawal movements were determined by using a logistic regression model.

Results

The logistic regression model showed that the probability of preventing rocuronium-induced withdrawal movement was as follows: exp (-3.49 + 2.07 × remifentanil concentration) / (1 + exp [-3.49 + 2.07 × remifentanil concentration]). EC₅₀ and EC₉₅ were 1.69 ng/ml (95% confidence intervals [CIs], 1.42-1.87) and 3.11 ng/ml (95% CIs, 2.79-3.72), respectively.

Conclusions

Administration of remifentanil at an effect-site target concentration of 3.1 ng/ml could effectively prevent rocuronium-induced withdrawal movements.

Pharmacological and non-pharmacological intervention for rocuronium-induced withdrawal movement in the Korean population: a meta-analysis of 41 studies including 4,742 subjects

BACKGROUND

We purposed to systemically review studies investigating the prophylactic effect of both pharmacological and non-pharmacological modalities against rocuronium induced withdrawal movement (RIWM) in the Korean population.

METHODS

Literature search was performed using MEDLINE, EMBASE, CENTRAL, Koreamed, KMBASE, KISS and RISS up to March 2014. Randomized controlled trials (RCTs) comparing pharmacological and non-pharmacological interventions with placebo aimed for the Korean population were included. Outcome measures were the incidence and severity of RIWM. We conducted subgroup analyses according to each intervention method.

RESULTS

Data were analyzed from 41 RCTs totaling 4,742 subjects. The overall incidence of RIWM was about 80% (range 56-100%). Incidence and severity of RIWM were significantly reduced with lidocaine (risk ratio [RR] 0.60, 95% CI 0.49-0.74; standardized mean difference [SMD] -0.74, 95% CI -1.05 to -0.44), opioids (RR 0.28, 95% CI 0.18-0.44; SMD -1.71, 95% CI -2.09 to -1.34) and hypnotics (RR 0.36, 95% CI 0.25-0.52; SMD -2.20, 95% CI -2.62 to -1.79). Regardless of tourniquet use, lidocaine showed a prophylactic effect against incidence and severity of RIWM: tourniquet (RR 0.36, 95% CI 0.21-0.62; SMD -1.51, 95% CI -2.15 to -0.86); non-tourniquet (RR 0.58, 95% CI 0.47-0.71; SMD -0.74, 95% CI -1.05 to -0.44). Dilution and slow injection of rocuronium decreased incidence and severity of RIWM: dilution (RR 0.47, 95% CI 0.39-0.56; SMD -1.64, 95% CI -2.47 to -0.81); slow injection (RR 0.34, 95% CI 0.17-0.70; SMD -2.13, 95% CI -2.74 to -1.51).

CONCLUSIONS

The greater part of pharmacological and non-pharmacological interventions showed prophylactic effect against the incidence and severity of RIWM in the Korean population.

Pharmacological prevention of rocuronium-induced injection pain or withdrawal movements: a meta-analysis

Rocuronium is reported to be associated with injection pain or withdrawal movement (IPWM). This meta-analysis assessed the efficacy of different pharmacological treatments used to decrease the incidence of the rocuronium-induced IPWM. We searched the Cochrane Library, Embase and PubMed for randomized controlled trials comparing a pharmacological drug with a placebo to prevent the rocuronium-induced IPWM and found 37 studies with 5,595 patients. Overall incidence of rocuronium-induced IPWM was 74%. Pretreatment with opioids [risk ratio (RR) 0.16; 95% confidence interval (95% CI) 0.09-0.29], lidocaine (0.47; 0.35-0.64), and ketamine (0.41; 0.22-0.77) were effective in decreasing IPWM. Lidocaine pretreatment with venous occlusion (0.40; 0.32-0.49) and opioids pretreatment with venous occlusion (0.77; 0.61-0.96) were also effective. Mixing sodium bicarbonate (NaHCO3) with rocuronium (0.15; 0.06-0.34) was also efficacious in reducing IPWM. Indirect comparison shows that the RR of NaHCO3 admixture and pretreatment with opioids were lower than that of the other four interventions (pretreatments of ketamine or lidocaine, and lidocaine or opioids with venous occlusion). This meta-analysis suggests that opioids, lidocaine, ketamine, and NaHCO3 are effective in decreasing rocuronium-induced IPWM. Considering the efficacy and convenience, pretreatment with opioids without venous occlusion is recommended for reducing rocuronium-induced IPWM.