Comparing the Hemodynamic Effects of Spinal Anesthesia in Preeclamptic and Healthy Parturients During Cesarean Section

BACKGROUND: Despite controversies about the safest anesthetic technique for cesarean delivery in severely preeclamptic women, there is evidence that supports the use of spinal anesthesia in this group of patients. OBJECTIVES: This prospective randomized clinical trial was designed to determine the hemodynamic effects of low-dose spinal bupivacaine and the incidence of spinal anesthesia-associated hypotension in severely preeclamptic and healthy parturients undergoing cesarean sections. PATIENTS AND METHODS: Spinal anesthesia was performed with 10 mg (= 2 mL) hyperbaric 0.5% bupivacaine plus 2.5 µg sufentanil in two groups of patients after they received 500 mL of IV lactated Ringer’s solution. Heart rate and blood pressure were recorded before spinal anesthesia and at two minutes intervals for 15 minutes after the block, and then every five minutes until the end of the surgery. Hypotension was defined as more than 25% of decline in the mean arterial blood pressure compared to the baseline in both groups (or systolic blood pressure < 100 mmHg in healthy parturients) and was treated with 5 mg IV ephedrine. The total amounts of intravenous administered fluid and the total doses of ephedrine were recorded for each patient as well. RESULTS: The incidence rate of hypotension among the preeclamptic patients was lower than that of the healthy parturients, despite the former group receiving smaller volumes of intravenous fluids (P < 0.05). The total doses of IV ephedrine for treating hypotension were significantly lower among the preeclamptic patients (3.2 mg in preeclamptic patients versus 7.6 mg in normotensive patients) (P = 0.02). The one-minute Apgar score was significantly lower for the preeclamptic parturients (8.4 ± 0.7 versus 7.2 ± 1.5) (P = 0.001), but there was no significant difference in the five-minute Apgar scores between the two groups. CONCLUSIONS: Our results confirm that low-dose bupivacaine spinal anesthesia is associated with a lower risk of hypotension than previously believed, and it can therefore be safely used in severe preeclamptic women undergoing cesarean delivery.