Pulmonary effects of bupivacaine and ropivacaine in parturients undergoing spinal anesthesia for elective cesarean delivery.

To study the change of maternal pulmonary function when ropivacaine and bupivacaine were used in spinal anesthesia for cesarean section, 40 ASA physical status I and II parturient scheduled to undergo cesarean section were randomly divided into bupivacaine and ropivacaine groups. Bupivacaine 9 mg and ropivacaine 14 mg were intrathecal injected respectively. FVC, FEV1 and PEFR were measured with spirometry before anesthesia and 2 h after intrathecal injection. Anesthesia level, the degree of motor block and VAS were also recorded. Results: The final level of sensory blockade was not different between groups. Forced vital capacity was significantly decreased with bupivacaine (3.0 ± 0.4 L to 2.7 ± 0.3 L, P < 0.05) and ropivacaine (2.9 ± 0.4 L to 2.5 ± 0.4 L, P < 0.05) while there were no difference between two groups. Forced expiratory volume during the first second and Peak expiratory flow rate were not decreased in each group. The degree of motor block in group R was less than group B at 2 h after intrathecal injection. Conclusions: Decreases in maternal pulmonary function tests were similar following spinal anaesthesia with bupivacaine or ropivacaine for cesarean section. The clinical maternal effects of these alterations appeared negligible.