Clonidine versus tramadol for post spinal anesthesia shivering: A meta-analysis of randomized controlled trials

OBJECTIVES: To compare clonidine with tramadol for shivering control following spinal anesthesia. METHODS: The literature was searched updated to August 2020, and only randomized controlled trials comparing clonidine and tramadol for shivering control following spinal anesthesia were eligible for this study. RESULTS: Fourteen studies with 960 patients were identified. Clonidine demonstrated a lower effective rate of shivering control (OR: 0.59; 95% CI: 0.40-0.88; p=0.009; I(2)=36%), but with decreased occurrence of nausea, vomiting, and dizziness. Clonidine increased the occurrence of bradycardia, hypotension, and sedation compared to tramadol. CONCLUSION: Tramadol is more effective for shivering control than clonidine, but with increased occurrence of nausea, vomiting, and dizziness. PROSPERO No: CRD42020207979