The Effects of Pre-Spinal Anesthesia Administration of Crystalloid and Colloid Solutions on Hypotension in Elective Cesarean Section.

Background: Spinal anesthesia is an appropriate alternative for general anesthesia in many operations, particularly in cesarean section. However, the induced hypotension is the main drawback of this method. Therefore, the current study aimed at comparing the effects of crystalloid and colloid solutions used as the preload on the post-spinal hypotension and its complications in females who are candidate for elective cesarean section.

Methods: The current randomized, controlled, double-blind study was conducted on the female candidate of elective cesarean section (n = 96; age range: 20 to 40 years). The patients were in their 37 to 42 weeks of gestational age during the experiments. The systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR) variation, amount of injected ephedrine during surgery, Apgar score at birth, total solution infused after spinal anesthesia, urine output, nausea, and vomiting were comparatively assessed between the two groups.

Results: The percentages of reduction in SBP and DBP variables in the crystalloid solution were higher than those of the colloid group and the differences were statistically significant (P = 0.042 and P = 0.008, respectively). Average percentage of HR changes was more significant in the crystalloid than the colloid group (P = 0.032). In contrary, administration of the two types of solutions did not result in significant differences in the Apgar scores. The prevalence of nausea and vomiting in the colloid group subjects was lower than those of the crystalloid solution group; however, the differences were not significant.

Conclusions: The current study findings recommend colloid solution to prevent hemodynamic instability after spinal anesthesia. However, the costs and availability of the solution and recommendation of anesthesiologist should be considered. Conduction of further clinical trials with larger sample sizes is recommended.