Comparison of hydroxyethyl starch 6% and crystalloids for preloading in elective caesarean section under spinal anesthesia

Abstract

Background: Although controversial, many studies have shown effectiveness of colloid loading as a substitute for crystalloids on reducing the incidence of hypotension in spinal anesthesia. This study was conducted to compare the effects of three intravenous fluid regimens on hemodynamic changes following spinal anesthesia in cesarean section. The regimens included 6% Hydroxyethylstarch 130/0.4 (HES) as a colloid and two crystalloids (lactated ringer's solution and sodium chloride 0.9%).

Material & method: In a double-blind clinical trial, 90 otherwise healthy parturients candidate of elective caesarean section were randomly allocated to receive lactated ringer's solution (1000 ml), sodium chloride 0.9% (1000 ml) or HES (7.5 mL/Kg) as preloading before spinal anesthesia. Hemodynamic parameters including blood pressure and heart rate, umbilical cord blood pH and the neonatal Apgar score were compared among the three groups.

Results: There was no difference in the basic hemodynamic measurements among the three groups. The incidence of hypotension and required dose of ephedrine was lower in HES group (p=0.008). There was no significant difference in umbilical cord blood PH or Apgar scores among intervention groups.

Conclusion: Preloading with HES is more effective than crystalloids in prevention hypotension after spinal anesthesia without significant difference in Apgar score and umblical cord blood pH.

Keywords: Caesarian section; Crystalloid; Hydroxyethylstarch; blood pressure; spinal anesthesia.