Remifentanil infusion does not induce opioid tolerance after cardiac surgery

Remifentanil is being used increasingly during fast-track cardiac surgery. Postoperative hyperalgesia and opioid tolerance have been reported in volunteer studies and in patients after major abdominal surgery with remifentanil infusion. In the present study, the authors evaluated whether high-dose remifentanil infusion induces opioid tolerance in 90 patients undergoing coronary artery bypass surgery with sternotomy.

Prospective, randomized, and double-blind study.

Single-institution, tertiary level, university hospital.

Ninety patients undergoing coronary artery bypass surgery.

Patients were randomized to receive a 3-hour infusion of remifentanil (0.3 microg/kg/min, n = 45) or placebo (n = 45) intraoperatively as adjunct to a standardized sufentanil/propofol-based general anesthesia.

Opioid consumption, pain, and sedation scores, as well as adverse events and patients' satisfaction with pain therapy, were recorded for 48 postoperative hours. There were no differences in postoperative opioid consumption between the groups (median oxycodone consumption in the remifentanil group, 98 mg [range, 29-166] and in the placebo group, 99 mg [42-219]). Pain scores were comparable at rest, but during a deep breath pain scores were lower in the remifentanil group (p = 0.020). Sedation scores, satisfaction with analgesia, and adverse events were similar between the 2 groups. The most common adverse event was nausea, with a 33% incidence in the placebo and 40% incidence in the remifentanil group.

Three-hour remifentanil infusion did not increase postoperative pain or opioid consumption in cardiac surgery patients. The present results suggest that high-dose remifentanil does not elicit opioid tolerance when given during cardiac surgery.