Intraoperative vs post-operative morphine improves analgesia without increasing PONV or emergence from ambulatory surgery

Purpose: To compare the timing of administration of morphine in patients un dergoing painful ambulatory surgical procedures to determine whether there was a difference in postoperative nausea or vomiting (PONV), quality of ana lgesia, and recovery profile. Methods: In a double-blinded, placebo-controlled, prospective study, 70 ASA I-II patients were randomized to receive 0.1 mg.kg(-1) morphine intraopera tively (lop) (n=35), or postoperatively (Pop) (n=35), The severity of nause a and pain were measured using visual analog scales (VAS), Results: There was no difference between the groups in postoperative nausea scores or the incidence of PONV. Upon awakening, patients who received Pop morphine had higher pain VAS scores with movement(7.6 +/- 2 vs 5.4 +/- 3, P < 0.003) and at rest (6.9 +/- 3 vs 5.1 +/- 3, P < 0.013) than the top mor phine group, The total number of PCA attempts and analgesic requirements we re similar. Patients who received Pop morphine were able to drink sooner th an the top group (90 +/- 34 vs 111 +/- 38 min, P < 0.05). All other recover y milestones were similar. Times to discharge from hospital were similar. Conclusions: Administration of 0.1 mg.kg(-1) morphine iv intraoperatively i mproves postoperative analgesia upon emergence from painful ambulatory surg ical procedures without increasing the incidence of PONV. There was no incr ease in PONV when morphine was administered intraoperatively rather than po stoperatively.