Different drugs for prevention of post subarachnoid block shivering. Randomized, controlled, double blind study

5-HT3 receptor antagonists for the prevention of perioperative shivering undergoing spinal anaesthesia: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

Perioperative shivering (POS) is a common complication in patients undergoing spinal anaesthesia. The present study investigated the efficacy of 5-HT₃ receptor antagonists in preventing POS following spinal anaesthesia.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Pubmed, Embase, the Web of Science and Cochrane Library were searched from database establishment on 31 July 2019.

ELIGIBILITY CRITERIA

Randomised controlled trials that reported the effects of 5-HT₃ receptor antagonists in the prevention of POS in patients after spinal anaesthesia.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted data. The primary outcome of the present study was the incidence of POS. The risk of bias for the included studies was assessed according to the Cochrane Handbook. The quality of primary outcome was evaluated by Grading of Recommendations Assessment, Development and Evaluation. Trial sequential analysis for the primary outcome was performed to reduce the type 1 error caused by repeated meta-analysis and the required information size was calculated.

RESULTS

A total of 13 randomised controlled trials consisting of 1139 patients were included. The overall incidence of POS was significantly lower in the 5-HT₃ receptor antagonists group (risk ratio 0.31; 95% CI 0.26 to 0.38; p<0.01; I²=0%). Subgroup analysis for different types of 5-HT₃ receptor antagonists and timing of administration produced similar results. Also, patients had a lower incidence of postoperative nausea and vomiting after administrating 5-HT3 receptor antagonists. No statistically significant differences in drug-related adverse effects were observed. Grading of Recommendations Assessment, Development and Evaluation revealed a high level of evidence. The cumulative z-curve crossed the trial sequential monitoring boundary.

CONCLUSIONS

The present study revealed that prophylactic 5-HT₃ receptor antagonists were an effective measure for reducing the incidence of POS in patients after spinal anaesthesia. However, further studies investigating the different types of surgeries are required.

PROSPERO REGISTRATION NUMBER

CRD42019148191.

Comparative effectiveness of pharmacologic interventions to prevent shivering after surgery: a network meta-analysis

INTRODUCTION

Although many drugs have been studied to prevent postoperative shivering, their comparative effectiveness is unknown. We attempted to assess the comparative effectiveness of the pharmacologic strategies to prevent shivering after surgery including intravenous (IV) and intrathecal (IT) meperidine, IV and IT dexmedetomidine, IV and IT clonidine, nefopam, tramadol, ketamine, and serotonin receptor antagonists.

EVIDENCE ACQUISITION

We implemented a frequentist network meta-analysis of randomized trials. Random effect model was selected according to deviance information criteria. The incidence of moderate or severe shivering and the overall incidence of postoperative shivering were compared in all patients and subgroups of general and spinal anesthesia.

EVIDENCE SYNTHESIS

Seventy trials with 6062 participants were included. All interventions except clonidine IT and dexmedetomidine IT significantly decreased the incidence of moderate or severe shivering. All interventions except clonidine IT significantly decreased the overall incidence of shivering. Nefopam IV was ranked best regarding both the incidence of moderate or severe shivering (odds ratio [OR] 0.04, 95% confidence interval [CI] 0.04-0.25, SUCRA 86.2, moderate quality-evidence), and the overall incidence of shivering (OR 0.07, 95% CI 0.03 to 0.15, SUCRA 85.7, moderate quality-evidence), which was consistent in the subgroups of anesthesia.

CONCLUSIONS

Nefopam was ranked best regarding both severity and incidence of postoperative shivering. In addition to nefopam, tramadol, meperidine IV and IT, and dexmedetomidine IV were ranked high. However, there was significant heterogeneity regarding the individual drug regimen and surgery type, precluding firm conclusion. Further randomized trials are required to compare the efficacy of the drugs with high rank.