Patient controlled oral analgesia with morphine

Abstract

Purpose: When using strong oral opioids for postoperative pain management, demand titration is desirable. A device for patient controlled oral analgesia (PCORA) and first results of its use for oral titration of morphine are presented.

Methods: The PCORA-device is a modified Baxter-PCA-on-demand system (maximum bolus volume: 0.5 ml; flow rate for filling bolus volume: 0.5 ml.hr-1). The demand PCORA-volumes were measured at specific time intervals and PCORA was compared with customarily prescribed pain therapy (CPPT) for postoperative pain management. On the first postoperative day, 20 orthopaedic ASA I or II patients received, in a randomised, cross-over trial, either PCORA (300 min) followed by CPPT (300 min) (Group I) or vice versa (Group II). The PCORA-device permitted a maximum dose of 15 mg morphine per 60 min and CPPT was performed by the ward doctor or nurse. Pain intensity (101-point numerical rating scale) and side effects were evaluated at 30 min intervals.

Results: The accuracy of the bolus volume delivered by the PCORA-device was 89.2 +/- 0.85% (mean +/- SEM), of manufacturer's specifications. PCORA pain intensity decreased over time whereas CPPT pain intensity did not (P < 0.001). PCORA-morphine requirements were 61.5 +/- 5.2 mg (Group I) and 52.5 +/- 8.5 mg (Group II) (NS; mean +/- SEM). The handling of the PCORA-device presented no problem to any patient.

Conclusion: Patient controlled oral analgesia is an effective and non-invasive mode of postoperative pain management. The PCORA-device is reliable and easy to use.