Interpleural Bupivacaine for Postoperative Analgesia Following Cholecystectomy: A Randomized Prospective Study

The effect of interpleural analgesia on postoperative hospital course was analyzed in a prospective randomized study of patients undergoing cholecystectomy. Control patients were treated in the standard manner with systemic narcotics alone; catheter patients had an interpleural catheter placed at the end of surgery and, in addition, could receive systemic narcotics if necessary. The catheter group received interpleural 0.5% bupivacaine with epinephrine every six hours for a total of four injections. Thirteen patients were in each group. Pain score, pulmonary function and narcotic requirement were measured over the first postoperative day. Catheter patients had a lower average pain score (visual analog scale (VAS), 3.6 versus 5.2), decreased narcotic requirement in the recovery room and improved oxygen saturation (96% versus 93%). However, there was no statistical difference in amount of morphine (catheter, 25 ± 14 mg; control, 31 ± 15 mg), number of narcotic injections (catheter, 3.8 ± 1.5; control, 3.5 ± 1.5), forced vital capacity (catheter, 44% preoperative control, 41% preoperative), recovery room time (catheter, 129 ± 54 minutes, control, 117 ± 39 minutes) or total hospital stay (catheter, 4.1 ± 0.9 days; control, 3.7 ± 0.8 days). Analysis of hourly VAS scores following a bolus indicated that the analgesia disappeared within approximately four hours. The mean time to a request for narcotic following a bolus was 4.2 hours (excluding 17 of a potential total of 52 instances when narcotic was not requested at all). Therefore, the duration of pain relief for subcostal incisions using interpleural 0.5% bupivacaine is approximately four hours. In conclusion, while there are some advantages conferred to patients treated with the intrapleural catheter, it would appear that a bolus regimen more frequent than every six hours would be necessary to maximize any benefit.