PURPOSE: To compare the effect of combined intrathecal morphine and sufentanil with low-dose iv sufentanil during propofol anesthesia for fast-track cardiac surgery. METHODS: Twenty-four consecutive patients with normal cardiopulmonary function who were scheduled for elective cardiac surgery were randomized to receive either a continuous iv infusion of sufentanil 0.9 to 1.8 microg x kg(-1) x min(-1) (13 patients), or a single lumbar intrathecal dose of sufentanil 50 micro g and morphine 500 micro g (11 patients). We prospectively studied perioperative analgesia, time to extubation and early postoperative maximal inspiratory capacity in the two groups. In the intensive care unit, the medical and nursing staff were blinded to the analgesic technique. RESULTS: Intrathecal sufentanil morphine allowed a shorter duration of intubation (104 +/- 56.5 min vs 213 +/- 104 min; P = 0.01), reduced the need for postoperative analgesia with nicomorphine (equipotent to morphine) (0.7 +/- 0.4 mg x hr(-1) vs 1.2 +/- 0.4 mg x hr(-1); P = 0.008) and improved postoperative maximal inspiratory capacity (53.4 +/- 16.1 vs 38.4 +/- 12.5% of the norm; P = 0.05). CONCLUSION: In low-risk patients undergoing coronary artery bypass graft or valve surgery, combined intrathecal sufentanil and morphine with a target-controlled infusion of propofol satisfies the goals of fast-track cardiac surgery.