Comparison of colloid versus crystalloid preload for prevention of hypotension during spinal anesthesia for elective cesarean section in women with positive supine stress test

ABSTRACT

If parturient prone to develop caval compression in the supine position were identified before delivery; this might be a method of predicting hypotension during cesarean section under spinal anesthesia. Colloid preloading is thought to be superior to crystalloid in reducing the risk for spinal anesthetic induced hypotension. It is postulated that parturients preoperalively susceptible to the supine position would benefit the most from colloid preloading. The aim of this study is to compare colloid versus crystalloid preload for prevenilon of hypotension during spinal anesthesia for elective cesarean section in women with positive supine stress test [SST]. Forty healthy women, with term singleton normal pregnandes presenling for elective cesarean section under spinal anesthesia were included in the study. All patients were positivefir supine stress test [SST], they were divided into 2 equal groups [20 palients each], crystalloid preload group [group I] and colloid preload group [group II]. IViaternal hypotension, nausea, vomiting or dizziness and ephedrine requirements were recorded during the study. Induction-to-uterotomy interval, uterotomy-to-delivery interval and inlraoperative blood loss, were also recorded. Moreover, Apgar score and umbilical artery add-base status at delivery were measured. Our results showed that in patients received crystalloid preload [group I] the frequendes of occurrence of decreased systolic blood pressure below 100 mmHg or 20% from baseline, occurrence of vomiting, nausea or dizziness were 14[70%], 7[35%], 9[45%], and 7[35%], respectively, while, in palients received colloid preload [group II] were 6[30%], 1[5%], 2[10%], and 1[5%], respectively. So, patients received crystalloid preload showed a higher frequency of hypotension, vomiting, nausea and dizziness compared to colloid group [P<0.05], and also a greater need for ephedrine, mean[+SD] was 21[11.4] in group I compared to 7.25.3]mg in group II[P<0.05]. Pregnant women with a positive preoperative supine stress test constitute a subset at increased risk for clinically significant hypotension during cesarean delivery under spinal anesthesia. These women seem more likely to benefit from prophylaclic colloid solution preload