An investigation of the current literature on the effectiveness of patient-controlled analgesia methods.

The purpose of this investigation was to determine, through current research in the literature, if a background basal infusion should routinely be used to improve the efficacy of traditional-demand patient-controlled analgesia (PCA) and would the safety of the PCA technique be maintained with the addition of a continuous infusion. Of the nine studies investigating PCA with and without continuous infusion, six found no improvement in pain control with the addition of a continuous infusion. The patients receiving continuous infusion did not make fewer demands than the control group, nor did they report lower pain scores. The addition of a continuous background infusion to PCA diminishes the inherent safety of the PCA modality of pain management. Many studies reported an increased incidence of side effects with the addition of a continuous infusion. This modality of PCA should be reserved for use in patients in whom traditional-demand PCA does not satisfy analgesic requirements.