6533b872fe1ef96bd12d3130

RESEARCH PRODUCT

Intraoperative tramadol reduces shivering but not pain after remifentanil–isoflurane general anaesthesia. A placebo-controlled, double-blind trial

subject

description

Background and objective Postoperative shivering and pain are frequent problems in patients recovering from anaesthesia with particularly high incidences being observed after remifentanil–isoflurane-based general anaesthesia. The opioid tramadol is generally effective in preventing shivering and treating pain, but its effects are not characterized after remifentanil-based general anaesthesia. This randomized, placebo-controlled, double-blind study evaluated the effects of intraoperative intravenous tramadol on postoperative shivering and pain after remifentanil-based general anaesthesia. Methods After Ethics Committee approval, 60 patients scheduled for lumbar disc surgery were included. Surgery was performed under general anaesthesia (remifentanil, isoflurane). Patients were randomly assigned to receive 2 mg kg −1 tramadol in 30 mL 0.9% saline infused intravenously ( n = 30) or 30 mL saline ( n = 30) 45–30 min before skin closure. The following parameters were assessed every 10 min for 2 h: shivering, pain, postoperative nausea and vomiting, sedation, heart rate, non-invasive blood pressure and peripheral oxygen saturation. The primary outcome variable was the incidence of shivering during the first 2 postoperative hours. Secondary variables were: shivering intensity, pain, postoperative nausea and vomiting, sedation, heart rate, non-invasive blood pressure and peripheral oxygen saturation. Results Shivering was less frequent in patients treated with tramadol (20% vs. 70%, P = 0.0009) and was of lower intensity (severe shivering: 10% vs. 46.7%, P = 0.003). Pain scores were similar between the groups and all other secondary outcome variables failed to reveal significant differences. Conclusions Compared with placebo, intraoperative intravenous administration of 2 mg kg −1 tramadol reduces the incidence and extent of postoperative shivering without alterations in pain perception after lumbar disc surgery under remifentanil–isoflurane-based general anaesthesia.