An open comparison between routine and self-administered postoperative pain relief.

Patients receiving staff-administered analgesics after upper abdominal surgery had higher pain scores than similar patients having self-administered analgesics, but this was associated with a considerably smaller average amount of analgesic given. This survey was subject to observer and patient bias and it was necessary to use 'pethidine equivalents' to enable comparisons to be made between drugs with effects of different duration; thus the striking differences in pain scores and grades can be considered indicative only. They nevertheless support the continued investigation of on-demand systems and make a strong case for a double-blind controlled trial.