DOUBLE-BLIND RANDOMIZED EVALUATION OF INTERCOSTAL NERVE BLOCKS AS AN ADJUVANT TO SUBARACHNOID ADMINISTERED MORPHINE FOR POSTTHORACOTOMY ANALGESIA

Background and Objectives. Thoracotomy is associated with pain and com promised pulmonary function. Intercostal nerve blocks (INB) and subara chnoid morphine (SM) act on different portions of the pain pathway. Ea ch is effective for post-thoracotomy pain relief. The combination of t hese two modalities in relieving post-thoracotomy pain and improving p ostoperative pulmonary function has not been investigated. Methods. In a double-blind study, 20 patients undergoing lateral thoracotomy for lung resection were randomized to receive 0.5 mg SM preoperatively and INB with bupivacaine (INB+) prior to wound closure or 0.5 mg SM with INB using saline (INB). Visual analog scale pain scores at rest, with cough, and with movement of the ipsilateral arm, forced expiratory vol ume in 1 second (FEV(1)), and forced vital capacity (FVC) were measure d at 4, 24, 48, and 72 hours after the operation. Opioid use was measu red during the initial 24 hours after the operation. Results. At 4 hou rs, the INB+ group demonstrated better FEV(1) (56.6% vs. 40.4% of base line, P < .05) and FVC values (54.6% vs. 39.6% of baseline, P < .05) a nd less resting and cough pain (P < .05). However, FEV(1) continued to decline in the INB+ group at 24 hours to lower than the INB- group al though pain scores were similar beyond 4 hours. Opioid usage during th e first 24 hours was similar (INB-, 16.7 mg vs. INB+, 13.2 mg, P = .7) . Conclusions. Although postoperative INB provided modest improvements in pain and pulmonary function when used as an adjuvant to 0.5 mg SM for post-thoracotomy analgesia, the benefits were transient. The autho rs do not recommend adding INB for patients undergoing lateral thoraco tomy who receive 0.5 mg SM.