Patient-controlled analgesia. Experience of two new machines.

Two modern patient-controlled analgesia pumps have been evaluated in the laboratory and in clinical use. Both machines generally performed satisfactorily and patients achieved good pain relief from self-administered morphine. The relative merits of the two pumps are discussed and although the on demand analgesic computer is preferred, a substantial investment of time on the ward is required to provide continuous patient-controlled analgesia.