Subarachnoid and epidural dexmedetomidine for the prevention of post-anesthetic shivering: a meta-analysis and systematic review

BACKGROUND: Post-anesthetic shivering incurs discomfort to patients or even exacerbates their condition. However, no ideal drug has been well established for preventing post-anesthetic shivering. Currently, subarachnoid and epidural dexmedetomidine have demonstrated to have an anti-shivering effect. METHODS: An electronic search was conducted to identify randomized placebo-controlled trials reporting shivering and then compared subarachnoid and epidural dexmedetomidine with placebo in adults undergoing selective surgery. Data assessment and pooling were analyzed by Review Manager 5.3, STATA 15.0 and GRADE-pro 3.6 software. RESULTS: Twenty-two studies (1389 patients) were subjected to this meta-analysis. The incidence of post-anesthetic shivering decreased from 20.10% in the placebo group to 10.30% in the dexmedetomidine group (RR, 0.48; 95% CI, 0.39–0.59; Z=6.86, P<0.00001, I(2)=32%). Non-Indian, epidural-space route and cesarean subgroups indicated a better anti-shivering effect. In the subarachnoid-space route subgroup, a dosage of >5 μg showed significantly superior anti-shivering effects than that of ≤5 μg. Subarachnoid and epidural dexmedetomidine increased the incidence of bradycardia, had no impact on nausea and vomiting, shortened the onset of block and lengthened the duration of block and analgesia. However, its effect on hypotension and sedation remained uncertain. The overall risk of bias was relatively low. The level of evidence was high, and the recommendation of voting results was strong. CONCLUSION: Dexmedetomidine as a subarachnoid and epidural adjunct drug could decrease the incidence of post-anesthetic shivering in a dose-dependent manner. However, caution should be taken in patients with original bradycardia.