Postoperative titration of intravenous morphine
Background and objective Intravenous morphine titration is used to obtain postoperative pain relief, but few studies have assessed the appropriate regimen. In a quality programme, we performed a prospective non-randomized study of morphine titration in a postanaesthesia care unit (PACU).
Methods Four regimens of morphine titration were studied: every 10 (group 1, n = 400) or 5min (group 2, n = 400) with a maximum of five intravenous boluses; every 5min, without any limitation in the number of boluses (groups 3 and 4, n = 400 each); in groups 1, 2, and 3, subcutaneous morphine was administered 4 h after titration. In group 4, administration of subcutaneous morphine was allowed only 2h after titration. A visual analogue pain scale (VAPS) > 30 mm was required to administer morphine and pain relief was defined as a VAPS [less-than-or-equal] 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 from group 4 had the lowest VAPS (26±17mm) and the highest percentage of pain relief (73%) at the end of the PACU period. The number of sedated patients 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 5min with an unlimited number of boluses and early subcutaneous administration provided the best analgesic regimen.(Published Online August 16 2006)
(Accepted September 2000)
Key Words: analgesics; opioid; morphine; pain; postoperative.
c1 Correspondence: F. Aubrun.