ABSTRACT
BACKGROUND: It is well known that intravenous patient controlled analgesia (IV-PCA) is an effective method to reduce the magnitude of postoperative pain. However, we do not know the appropriate time to start the IV-PCA. To determine the appropriate time to minimalize the sympathetic stimulation and shorten the awakening time after general anesthesia, experiments to indicate whether starting an infusion of the IV-PCA before the end of an operation has a minimal hemodynamic change and similar recovery index compared with the control group were done. METHODS: Seventy-eight patients scheduled for a total abdominal hysterectomy were randomly allocated to two groups. In the IV-PCA group (n = 37), we started the infusion of the IV-PCA before the end of the operation and in the control group (n = 41) which received no IV-PCA, we did not use the IV-PCA as a postoperative pain control method. We measured heart rate, blood pressure, postanesthesia recovery score every 10 minutes for 60 minutes and awakening time at the post-anesthesia care unit. RESULTS: The postanesthesia recovery scores on arrival, 10, 20, 30, 40 and 50 minute after arrival at the post-anesthesia care unit were lower in the IV-PCA group than in the control group. In addition the awakening time after vaporizer-off and at the post-anesthesia care unit was longer in the IV-PCA group than in the control group. CONCLUSIONS: We conclude that starting the infusion of the IV-PCA before the end of the operation is not effective in early recovery and awakening.