Comparison of effect of narcotic and epidural analgesia on postoperative respiratory function

A prospective, randomized comparison was made of the value of meperidine versus epidural analgesia when used for the relief of pain after cholecystectomy in twenty patients without cardiopulmonary disease. Respiratory function was assessed the day before surgery and at 3 to 4 hours and 24 hours after operation by the bedside measurement of expiratory peak flow, vital capacity, and arterial blood gases. The two groups of patients were comparable as to age, height, weight, smoking habits, preoperative peak flow, vital capacity, and duration of operation. The arterial oxygen tension and oxygen saturation were significantly greater and carbon dioxide tension lower in the epidural analgesia group 24 hours after operation. At this time peak flow rates and vital capacity were not different. However, at 3 to 4 hours postoperatively, vital capacity was significantly greater in the epidural anesthesia group. This might account for the differences in arterial blood gases the following day. These findings suggest that epidural analgesia is valuable in the early postoperative period after upper abdominal surgery.