Patient-controlled analgesia: a randomized, prospective comparison between two commercially available PCA pumps and conventional analgesic therapy for postoperative pain.

Abstract

Two pumps, 'PA' and 'PB,' with different drug delivery characteristics were available at the time of this study for patient-controlled analgesia (PCA). PB purportedly produces a 'placebo effect' by emitting an audible signal whenever the patient depresses the trigger button. PA emits an audible signal only when the drug is successfully administered into the patient's intravenous line. In a prospective, randomized Latin squares cross-over study, the 2 pumps and conventional therapy were compared for efficacy and cost. Patients in both pump groups used less drug and perceived less pain than those on conventional therapy. However, statistically less anxiety and greater pain relief and patient and nursing satisfaction were reported with PA only. Daily cost including drug, pharmacy and nursing time, pump rental was 33%, PA, versus 23%, PB, more than conventional therapy. Purchase and amortization of the pumps decreases the cost. We conclude that PCA provides superior pain management at minimal additional cost.