Patient-controlled versus nurse-controlled pain treatment after coronary artery bypass surgery

Background: Pain after coronary artery bypass surgery persists for several days. A continuous intravenous infusion of an opioid adequately accomplishes good pain control in the intensive care unit, but it is often not suitable on the ordinary ward. Patient-controlled analgesia (PCA) with intermittent injections delivered by one of the new devices now available could be an alternative to conventional nurse-controlled analgesia (NCA) based on intermittent injections. The aim was to compare these two techniques with respect to efficacy and the amount of opioid used. Methods: Forty-eight patients randomly received PCA or NCA with ketobemidone following extubation after coronary artery bypass grafting. Drug consumption, pain assessment with the visual analogue score (VAS) and possible side effects were evaluated from extubation to the end bf the second postoperative day. Results: On the day of surgery the VAS scores did not differ between the groups. From the afternoon of the first postoperative day the VAS scores were higher in the NCA group with mean values at 3-4 out of 10 as compared with mean values around 2 in the PCA group (P<0.01). During the study period the patients in the PCA group received more ketobemidone as compared with the NCA group, 61.9+/-24.0 mg and 36.3+/-20.2 mg, respectively (P<0.01). Additional oral analgesics were used in 12 of the patients in the NCA group compared with none in the PCA group. The few side effects reported were equally distributed between the two groups. Conclusion: PCA treatment after coronary artery bypass surgery resulted in better pain treatment and the use of more opioid without an increase in side effects compared with traditional NCA treatment.