THE EFFECTS OF CERVICAL EPIDURAL-ANESTHESIA WITH BUPIVACAINE ON PULMONARY-FUNCTION IN CONSCIOUS PATIENTS

Cervical epidural anesthesia (CEA) can affect diaphragmatic function. We investigated the effects of CEA on the diaphragm muscle performance , breathing pattern, and respiratory drive of 10 healthy patients unde rgoing hand surgery before and after the administration of 0.25% and 0 .375% bupivacaine. The lung volumes and flows, respiratory rate (RR), minute ventilation, respiratory cycle time, occlusion pressure, maxima l inspiratory pressure (MIP), and hand grip strength were determined. ETCO2 and SpO(2) were continuously monitored. The diaphragmatic excurs ion was evaluated using ultrasonography. Although CEA allowed painless hand rehabilitation, both 0.25% and 0.375% bupivacaine impaired diaph ragmatic excursion, with values decreasing from 5.6 to 4.4 and 3.3 cm (P < 0.05), respectively, during forced sniff maneuvers. In the 0.25% and 0.375% bupivacaine groups, the values of MIP decreased from 74 to 56 and 44 cm H2O, forced vital capacity decreased from 3.8 to 3.2 and 2.8 L, and hand grip strength decreased from 43.3 to 27.8 and 20.5 kg force, respectively (P < 0.05). The tidal volume decreased from 0.8 to 0.6 and 0.5 L in the 0.25% and 0.375% bupivacaine groups, respectivel y, the RR increased from 14 to 18 breaths/min in both groups, and the occlusion pressure increased from 1.5 to 2.1 and 2.9 cm H2O in the 0.2 5% and 0.375% bupivacaine groups, respectively (P < 0.05). ETCO2, incr eased from 35.2 to 38.1 and 39.3 mm Hg in the 0.25% and 0.375%; bupiva caine groups, respectively, and SpO(2), decreased by 2% +/- 1% in the 0.375% bupivacaine group. CEA affects diaphragmatic function and the r esulting lung volumes and MIP values. The observed alterations in brea thing pattern and the significant increase in ventilatory drive may be caused by changes in the diaphragmatic muscle tension and an augmente d CO2 load. Ln conclusion, we do not recommend this technique for rout ine postoperative hand rehabilitation using the studied bupivacaine co ncentrations. Implications: We studied cervical epidural anesthesia in healthy patients undergoing hand surgery). The technique allowed pain less rehabilitation but affected breathing pattern, diaphragmatic func tion, and respiratory drive. We cannot recommend this technique for ro utine clinical use.