Effectiveness of lumbar wedge in preventing intraoperative hypotension during cesarean delivery in multiple gestation: a retrospective analysis

Supine hypotension syndrome, caused by aortocaval compression of the gravid uterus in the supine position, is a common concern during cesarean delivery, particularly in women with multiple gestations. This retrospective study aimed to determine whether the use of a lumbar wedge reduces intraoperative hypotension in women with multiple gestations undergoing cesarean delivery under spinal anesthesia. A total of 199 women with multiple gestations who underwent cesarean delivery under spinal anesthesia were included. Participants were divided into two groups based on lumbar wedge application: wedge (n = 108) and horizontal (n = 91). The primary outcome was the incidence of intraoperative hypotension, defined as the need for vasopressors (phenylephrine or ephedrine) at least once during surgery. Secondary outcomes included the total administered vasopressor dose and neonatal outcomes. The incidence of intraoperative hypotension was significantly lower in the wedge group than in the horizontal group (70.4% vs. 86.8%; P = 0.005; RR, 0.8; 95% CI, 0.7 to 0.9). Phenylephrine requirements were significantly lower in the wedge group than in the horizontal group (4.0 ± 5.7 vs. 7.0 ± 7.7 µg/min; mean difference, -3.0; 95% CI, -4.9 to -1.1; P = 0.002), as were ephedrine requirements (0.04 ± 0.07 vs. 0.10 ± 0.13 mg/min; mean difference, -0.06; 95% CI, -0.09 to -0.03; P < 0.001). Neonatal cord blood gas values were within normal ranges, although some parameters differed significantly between groups. Specifically, the PCO2 levels of the first and third infants (P = 0.024 and 0.025, respectively), and the HCO3− and base excess values of the second infant (P = 0.025 and 0.011, respectively), differed significantly between the wedge and horizontal groups. The use of a lumbar wedge in patients with multiple gestations was associated with a significant reduction in the incidence of intraoperative hypotension during cesarean delivery under spinal anesthesia. These findings suggest that lumbar wedge positioning may be a simple, low-cost, and easily applicable technique to potentially enhance maternal hemodynamic stability and improve perioperative safety in multiple gestation pregnancies.