Comparison of effects of rapid colloid loading before and after spinal anesthesia on maternal hemodynamics and neonatal outcomes in cesarean section.

Background: The effects of colloid loading after spinal anesthesia on hemodynamics in parturients during cesarean section have not been fully understood. This study tested the hypothesis that colloid loading after spinal blockade can reduce hypotension compared with preloading, and affect neonatal outcomes.

Methods: A prospective, randomized, double-blinded study was performed in 54 healthy parturients (ASA I or II) undergoing elective cesarean section. Patients were randomly allocated into one of three groups to receive rapid infusion of 6% hydroxyethylstarch (HES) (70 kDa/0.5) before spinal anesthesia (15 ml x kg(-1), HES preload group, n = 18), or rapid infusion of HES after induction of spinal anesthesia (15 ml x kg(-1), HES coload group, n = 18), or no rapid infusion (control, n = 18). The incidence of hypotension, and the amount of ephedrine used to treat hypotension was compared. Neonatal outcomes were also assessed by pH, base excess, lactate concentration, and Apgar scores.

Results: The incidence of hypotension was significantly lower in HES preload and HES coload groups than control group (P < 0.01). Although systolic blood pressure decreased after spinal blockade in all groups, the lowest SBP after spinal blockade until delivery was significantly higher in fluid loading groups than control (P < 0.001). Similarly, total dose of ephedrine to treat hypotension was lower in fluid loading groups (P < 0.001). Umbilical cord pH, umbilical lactate concentration, and the incidence of neonates with Apgar score <7 were similar.

Conclusions: Colloid loading after induction of spinal anesthesia was similarly effective in reducing hypo- tension compared with preloading in cesarean section.