Effect of maternal body mass index on the dosage of metaraminol for preventing hypotension after spinal anesthesia

OBJECTIVE: ) of prophylactic continuous infusion of metaraminol in parturients with different body mass index (BMI) undergoing cesarean delivery under spinal anesthesia, and to investigate the influence of maternal BMI on the required dose of metaraminol for preventing post-spinal hypotension, thereby providing a basis for clinical individualized medication. METHODS: and 95% confidence interval (95% CI) of metaraminol for both groups. RESULTS: and 95% CI of metaraminol for preventing post-spinal hypotension in Group S was 1.84 mg/h (95% CI: 1.76-1.89 mg/h); the corresponding value for Group O was 2.28 mg/h (95% CI: 2.19-2.43 mg/h). The relative potency ratio between Group O and Group S was 1.24. There were no statistically significant differences in the incidence of maternal adverse reactions or fetal umbilical cord blood gas analysis parameters between the two groups . CONCLUSION: The dose of metaraminol required to prevent hypotension after spinal anesthesia for cesarean delivery is influenced by maternal BMI. Obese parturients (BMI ≥ 30 kg/m²) require a higher dose of metaraminol. Therefore, it is reasonable to individualize the prophylactic dose of metaraminol based on maternal weight (BMI) in clinical practice. TRIAL REGISTRATION: The trial protocol was registered in the Chinese Clinical Trial Registry on June 29, 2024, with the registration number ChiCTR2400086366.