Postoperative titration of intravenous morphine

Background and objective Intravenous morphine titration is used to obtain p ostoperative pain relief, but few studies have assessed the appropriate reg imen. in a quality programme, we performed a prospective non-randomized stu dy of morphine titration in a postanaesthesia care unit (PACU). Methods Four regimens of morphine titration were studied: every 10 (group 1 , n=400) or 5 min (group 2, n=400) with a maximum of five intravenous bolus es; every 5 min, without any limitation in the number of boluses (groups 3 and 4, n=400 each); in groups 1, 2, and 3, subcutaneous morphine was admini stered 4 h after titration. In group 4, administration of subcutaneous morp hine was allowed only 2 h after titration. A visual analogue pain scale (VA PS) > 30 mm was required to administer morphine and pain relief was defined as a VAPS less than or equal to 30 mm. Results After morphine titration, VAPS was lower and the number of patients with pain relief was greater in patients from groups 3 and 4. Patients fro m group 4 had the lowest VAPS (26+/-17 mm) and the highest percentage of pa in relief (73%) at the end of the PACU period. The number of sedated patien ts increased in groups 3 (62%) and 4 (61%) compared with group 1 (27%). No significant differences in morphine-related adverse effects were observed. Conclusion Intravenous morphine titration every 5 min with an unlimited num ber of boluses and early subcutaneous administration provided the best anal gesic regimen.