(450) Refractory hypotension with combined spinal epidural and prophylactic phenylephrine infusion during scheduled cesarean delivery

Prophylactic phenylephrine infusion is commonly used to manage regional anesthetic-induced hypotension during cesarean deliveries, aiming to stabilize maternal blood pressure and maintain uteroplacental perfusion to prevent fetal and maternal effects. This study evaluates the incidence of refractory hypotension with combined spinal epidural (CSE) despite the use of prophylactic phenylephrine infusion. 

Study Design:

This retrospective cohort study included all scheduled cesarean deliveries (CD) at term from August 2023 to September 2023, excluding patients with acute indications for CD. All patients received CSE for neuraxial anesthesia. Hypotension was defined as a systolic BP < 90 mmHg or a diastolic BP < 60 mmHg with a 20% decrease from baseline BP. Patients with hypotension post-CSE were compared to those without hypotension. Data on additional vasopressor requirements and neonatal outcomes were collected. Statistical analyses performed included chi-squared, Fisher's exact, and Kruskal-Wallis tests.  

Results:

Among 170 patients undergoing scheduled cesarean delivery with CSE, 60% experienced hypotension despite prophylactic phenylephrine. Fetal heart rate deceleration occurred in 13.7% of hypotensive patients versus 5.9% of non-hypotensive patients (p=0.09). Median umbilical cord pH was 7.29 [7.25, 7.31] in hypotensive patients and 7.3 [7.27, 7.33] in non-hypotensive patients (p=0.03). Neonatal ICU admission rates were similar between groups. Rescue vasopressors were used in 75.5% of hypotensive cases and 32% of non-hypotensive cases (p< 0.01). 

Conclusion:

The study highlights that while prophylactic phenylephrine infusion is used to prevent hypotension during cesarean deliveries, 60% of patients still experience significant hypotension, requiring additional interventions. Further research is necessary to understand risk factors and interventions for refractory hypotension during combined spinal epidural anesthesia in scheduled cesarean deliveries to optimize maternal and neonatal outcomes.