The effect of 0.5 L 6% hydroxyethyl starch 130/0.42 versus 1 L Ringer's lactate preload on the hemodynamic status of parturients undergoing spinal anesthesia for elective cesarean delivery using arterial pulse contour analysis

Abstract

Purpose: Fluid loading attenuates the hypotensive response to spinal anesthesia (SA). This study aimed to compare the preload efficacy of 0.5 L hydroxyethyl starch (HES) versus 1 L Ringer's lactate (R/L) in the prevention of hypotension after SA for elective cesarean delivery (CD). Assessment of maternal hemodynamic variables using FloTrac/Vigileo™ and neonatal outcome constituted secondary outcomes.

Methods: Thirty-two ASA I/II parturients scheduled for elective CD were preloaded with either 1 L R/L (Group R/L, n = 16) or 0.5 L HES 6% 130/0.42 (Group T, n = 16) approximately 25 min before SA. Hypotension, defined as a 20% decrease of systolic arterial pressure (SAP) from baseline or SAP <100 mmHg, was treated with vasopressors according to a predetermined algorithm. The overall duration of hypotensive episodes and the total amount of vasopressors administered determined the severity of the hemodynamic instability.

Results: The incidence of hypotension was 73.3% in Group R/L and 46.7% in Group T. HES compared to R/L preload was associated with a shorter overall duration of hypotensive episodes (p < 0.001), a significantly less usage of ephedrine and phenylephrine (p = 0.015 and p = 0.029, respectively) and a greater impact, although not statistically significant, on cardiac index (CI) and stroke volume index (SVI). Although no statistical difference was detected between groups over time, there was a significant drop in CI, SVI and SAP within groups (p < 0.001) up to 14 min after SA. No difference was recorded in neonatal outcome.

Conclusions: Preloading with 0.5 L HES 130/0.42 produced more stable hemodynamics compared to 1 L R/L solution in obstetric patients.