An automated system for testing the accuracy of patient-controlled analgesia devices

A system was developed to test the accuracy of patient-controlled analgesia devices in situations simulating clinical use. Bolus requests are made automatically at predetermined intervals, and the infusate delivered is measured and recorded without the need for operator presence. To ensure clinical relevance, the bolus request times used in this study corresponded to a pattern typical of those requested by patients on the ward. Graseby, Abbott Provider 5500 and IVAC patient-controlled analgesia devices were tested and found to deliver reasonably accurately over a 24 h period. However, when an infusion was started in an unprimed system or after a period of no bolus requests in a bolus-only mode the Graseby and IVAC machines under-delivered. This system provides a means of testing patient-controlled analgesia devices operating in any delivery mode.