Patient-maintained analgesia with target-controlled alfentanil infusion after cardiac surgery: a comparison with morphine PCA

The performance of a patient-demand, target-controlled alfentanil infusion system was compared with that of a traditional morphine patient-controlled analgesia (PCA) pump in 120 adult patients after cardiac surgery. Patients were randomized to one of the two PCA systems for their postoperative analgesia in the intensive care unit and pain, nausea and sedation scores were recorded every 4 h for the first 24 h. Episodes of hypoxaemia, myocardial ischaemia and haemodynamic instability were also recorded. In patients using the alfentanil system the overall median visual analogue pain score was 2.3 (95% CI 2.3-2.8) compared with 3.0 (95% CI 2.7-3.2) in those using morphine PCA (P < 0.05), but both systems delivered high-quality analgesia. The two groups did not differ with respect to the overall sedation scores, the frequency of postoperative nausea and vomiting, haemodynamic instability, myocardial ischaemia or hypoxaemia.