Patient‐controlled analgesia: a new method for old

Abstract
Patient-controlled analgesia (PCA) has successfully made the transition from a research tool for the investigation of pain, to a wider clinical utility as method of pain control. Reliable and sophisticated PCA systems have been commercially available for some time. The technique has been most commonly used for control of postoperative pain, but has also been successfully used during labour, after burns, in acute painful medical conditions and in terminal care. It is generally more effective than the traditional methods of postoperative pain control but not automatically so. The choice of opioid, the settings chosen for demand dose and the lockout interval will greatly influence the effectiveness of this method of analgesia. Psychological variables are also important in predicting the efficacy of PCA.