Study design and participants
Sixty parturients scheduled for elective cesarean section were enrolled in the present study. Patient inclusion criteria were ASA Physical Status II, aged 18 to 45 years, term gestation (≥ 37 weeks), singleton pregnancy, and scheduled for elective cesarean section under combined spinal-epidural anesthesia (CSEA). Exclusion criteria were contraindications to neuraxial anesthesia, BMI ≥ 40 kg·m