Bolus remifentanil for chest drain removal in ICU: a randomized double-blind comparison of three modes of analgesia in post-cardiac surgical patients.

PURPOSE: We compared 1 versus 0.5 microg/kg bolus remifentanil versus placebo in alleviating pain due to chest drain removal. Effects on sedation, respiratory rate (RR), oxygen saturation, heart rate (HR) and blood pressure were also evaluated. METHODS: Sixty patients following cardiac surgery were enrolled in this prospective, randomized, double-blind clinical trial. Patients were randomized to 1 or 0.5 microg/kg remifentanil or placebo. All received standardized analgesia. Visual analog scale (VAS) pain scores and cardio-respiratory data were recorded pre-procedure, at drain removal and at 2 min intervals post procedure. RESULTS: Patients receiving remifentanil had statistically significantly less pain than placebo at drain removal [median (25-75%) VAS: 0.5 microg/kg remifentanil 1 (0-2) versus placebo 5 (3-6), P = 0.001; 1.0 microg/kg remifentanil 0 (0-2) versus placebo 5 (3-6), P = 0.0001]. VAS scores between remifentanil groups were equivalent. Remifentanil 1 microg/kg versus placebo at drain removal revealed significant reductions in HR [mean +/- standard deviation (SD): 76 +/- 15 versus 92 +/- 10, P = 0.01], blood pressure [mean +/- SD: 103 +/- 22 versus 131 +/- 14, P = 0.01] and RR [median (25-75%): 10 (8-12) versus 16 (14-18), P = 0.001]. Remifentanil 0.5 microg/kg versus placebo at drain removal revealed significant reductions in blood pressure [mean +/- SD: 116 +/- 19 versus 131 +/- 14, P = 0.02] and RR [median (25-75%): 12 (10-13) versus 18 (16-18), P = 0.001]. SpO(2) at drain removal was significantly reduced when comparing 1 microg/kg remifentanil versus placebo [median (25-75%): 94 (88-97) versus 97 (96-98), P = 0.049] but not 0.5 microg/kg remifentanil versus placebo. Two patients became apnoeic following 1 microg/kg remifentanil, necessitating respiratory support. Sedation scores in all groups were similar. CONCLUSIONS: Bolus remifentanil at the tested doses delivers excellent analgesia, but 1 microg/kg remifentanil results in respiratory depression. Remifentanil bolus at 0.5 microg/kg is safe and effective for chest drain removal after heart surgery in ICU.