Incidence of hypotension associated with epidural anesthesia using alkalinized and nonalkalinized lidocaine for cesarean section.

The onset of epidural anesthesia is accelerated by alkalinization of lidocaine with added epinephrine (LE). The possibility that decreases in systolic blood pressure (SBP) are also enhanced was studied in 21 patients having elective cesarean sections. Ten patients given LE + NaHCO3 (0.1 mEq/ml anesthetic solution) compared with 11 given LE alone had significantly (P less than 0.05) greater decreases in SBP (32% vs 19% from baseline values), as well as a greater rate of SBP decline to those minimum values (9%/min vs 3%/min, respectively). These differences were noted despite the fact that patients given LE + HCO3 received no less ephedrine and no more additional anesthetic than controls. Possible adverse effects of SBP reduction on uteroplacental blood flow suggest that caution be used in the use of alkalinized LE in obstetrical patients.