Concentrations of lactate and pyruvate in maternal and neonatal blood with different intravenous fluids used for prehydration before epidural anesthesia.

This study assesses the effects of infusion of 1200 ml of four different intravenous solutions before epidural anesthesia for cesarean section on maternal and neonatal whole blood lactate (L), pyruvate (P), excess lactate (XL), L/P ratio, and base excess (BE) in four equal groups of patients. Patients in group I (n = 15) received normal saline; those in group II, Ringer's lactate (RL); those in group III, RL with 20 g of glucose; and those in group IV, Plasma-Lyte A. Maternal venous concentrations of L increased significantly in all groups after infusion, but P increased only in group III. Both XL concentrations and L/P ratios remained unchanged after infusion in group III mothers, but increased in the other three groups. Umbilical venous (UV) and arterial (UA) blood L concentrations (1.85 +/- 0.13, 1 SEM mmol/L in both) were greater in group III than in groups I and II, and P concentrations (0.12 +/- 0.01 mmol/L in both) were significantly greater in group III than in groups I, II, and IV. Both UV XL (0.9 +/- 0.1 mmol/L) and L/P ratio (32 +/- 8) were significantly greater in group IV neonates than in the other groups. However, neither neonatal Apgar scores nor maternal and neonatal BE significantly differed among the four groups. No neonate developed hypoglycemia. It is concluded that all the four intravenous fluids, despite differences in their effects on blood L and P concentrations, produce clinically satisfactory maternal and neonatal outcome.