Patient-controlled analgesia: a double-blind study in burn patients

A double-blind controlled study was performed to assess the efficacy and safety of patient-controlled analgesia in burn patients. This method was compared with conventional analgesic therapy consisting of intermittent intravenous morphine injections. Twenty-four adult patients hospitalised for burn injuries participated in the study. The McGill Pain Questionnaire, visual analogue scales and verbal-numeric scales were administered at regular intervals to measure various components of the patients' pain experience, degree of pain relief, anxiety levels, adverse side effects and overall treatment efficacy. Although statistical significance was found in only one measure, the results suggested better pain control in patients who were administered morphine by patient-controlled analgesia as compared with intermittent injections. Analysis of the side effects showed no difference between the groups. The amount of morphine administered over the trial period was also similar for the two groups but considerable interpatient variability was seen. Although further research is needed to determine the conditions for optimal use of patient-controlled analgesia, it is concluded that it is a safe, effective and improved method for controlling pain in selected burn patients.