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

Abstract

BackgroundDespite 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.ObjectivesThis 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 MethodsSpinal 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.ResultsThe 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.ConclusionsOur 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.

Ephedrine versus phenylephrine as a vasopressor for spinal anaesthesia-induced hypotension in parturients undergoing high-risk caesarean section: meta-analysis, meta-regression and trial sequential analysis

“…[27][28][29] The same has been observed in other high-risk patients, such as women in labour. 30 The mechanism underlying fetal acidosis associated with ephedrine has been postulated to be associated with placental transfer and stimulation of fetal metabolism. 31 Use of smaller doses of vasopressors in high-risk patients would reduce any adverse effects of placental drug transfer.…”

Comparison of Phenylephrine and Ephedrine in Treatment of Spinal-Induced Hypotension in High-Risk Pregnancies: A Narrative Review

“…Preeclampsia-induced endothelial dysfunction leads to increases in endothelin and thromboxane production, decreased vasodilator synthesis, and sensitizes the vasculature to vasoconstrictors (39). Previous studies indicated that spinal anesthesia-induced hypotension was less frequent and less severe in preeclamptic patients when compared to normotensive parturients, and minimal doses of vasopressors are typically required to restore maternal blood pressure to baseline (35, 36, 40) (Table 2). Similarly, Ituk et al recently conducted a retrospective comparison of phenylephrine and ephedrine for management of spinal-induced hypotension in preeclamptic patients and observed that approximately 50% of patients did not experience hypotension requiring vasopressor treatment following spinal anesthesia (37).…”

Comparison of hemodynamic change following spinal anesthesia in preeclamptic and non-preeclamptic parturients undergoing cesarean section at University of Gondar comprehensive specialized hospital, Northwest Ethiopia.

“…Preeclampsia: A pregnancy-induced increase in blood pressure ≥ 140/90 mmHg after 20 weeks of gestation and proteinuria ≥ 300 mg/24 hrs [10]. Preeclampsia with severity feature/severe preeclampsia: Defined as a systolic arterial blood pressure of 160 mmHg or higher, or a diastolic blood pressure of 110 mmHg or higher, associated with proteinuria > 5 g in 24 hours [10,35]. Change in heart rate: When there was a 20% decrease or increase in heart rate from baseline [6,10,25,26,36].…”

“…But these preemptive measures could put the preeclamptic patients at increased risk of hypertension and pulmonary edema [9]. Due to inconsistent definition, the reported incidence of spinal anesthesia-induced maternal hypotension varies between 7% and 89.2% [10,16]. Therefore, anesthetic management for preeclamptic parturients who undergo cesarean section is challenging for anesthetists [12].…”

“…During obstetric anesthesia, preservation of hemodynamic stability is a big concern for anesthetists [12], especially for preeclamptic parturients who planned to undergo cesarean section [10,12]. However, spinal anesthesia-induced maternal hypotension is still the most frequent complication [20,21].…”