Effects of bupivacaine versus levobupivacaine on pulmonary function in patients with chronic obstructive pulmonary disease undergoing urologic surgery: a randomized, double-blind, controlled trial.

BACKGROUND There are limited data to determine the impact of subarachnoid blockade with local anesthetics on perioperative pulmonary function. The effects of local anesthetics used in spinal anesthesia are very important in terms of respiratory function in patients with chronic obstructive pulmonary disease (COPD). OBJECTIVE The aim of this study was to evaluate the effects of bupivacaine versus levobupivacaine on pulmonary function in patients with COPD undergoing urologic surgery. METHODS Patients were randomized into 2 groups: group B (n = 25) received 3 mL of hyperbaric 0.5% bupivacaine; group L (n = 25) received 3 mL of isobaric 0.5% levobupivacaine. Both agents were administered intrathecally. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), peak expiratory flow rate (PEFR), vital capacity (VC), and FEV1/FVC ratio were measured using spirometry 10 and 30 minutes after spinal anesthesia and 30 minutes after completion of the operation. An arterial blood gas test was performed before and after spinal anesthesia. RESULTS Fifty male patients aged 40 to 80 years completed the study. There were no differences in the results of preoperative and postoperative FVC, FEV1, PEFR, VC, FEV1/FVC ratio, and arterial blood gas between the bupivacaine (n = 25) and levobupivacaine (n = 25) groups. However, patients who took bupivacaine showed a significant decrease in intraoperative PEFR at 30 minutes compared with baseline, a result not seen in patients who took levobupivacaine (P = 0.036 and P = 0.282, respectively). CONCLUSIONS In 50 patients with moderate COPD undergoing urologic surgery, hyperbaric bupivacaine caused a decrease in intraoperative PEFR compared with baseline because of higher level block; however, the effects of hyperbaric bupivacaine and isobaric levobupivacaine on pulmonary function in these patients showed equally effective potencies for spinal anesthesia.