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.