Comparison of different approaches to combined spinal epidural anesthesia (CSEA) under the guidance of ultrasound in cesarean delivery of obese patients: a randomized controlled trial

BACKGROUND: Combined spinal epidural anesthesia (CSEA) is commonly performed in cesarean deliveries. However, it is difficult to perform in obese parturients because of positioning challenges. The aim of this study was to compare the effect of different approaches to CSEA under the guidance of ultrasound. METHODS: One hundred obese patients (BMI ≥ 30 kg/m(2)) who underwent elective cesarean section were randomly enrolled. Patients were assigned to a median approach group and a paramedian approach group randomly. Clinical characteristics were compared between groups. First-attempt success rate, the median positioning time and total operation time, ultrasonic predicted anesthesia puncture depth, actual puncture depth, anesthesia adverse reactions, complications after anesthesia, and patients’ satisfaction with the epidural puncture were recorded. RESULTS: The first-attempt success rate was significantly different between the two groups [92% (46/50) vs. 76% (38/50), P = 0.029]. The median positioning time and total operation time in the paramedian approach group were higher than those in the median approach group (227.7 s vs. 201.6 s, P = 0.037; 251.3 s vs. 247.4 s, P = 0.145). The incidence of postanesthesia complications in the paramedian approach group was significantly lower than that in the median approach group (2% vs. 12%, P = 0.026), and patient satisfaction was higher in the paramedian approach group than in the median approach group (P = 0.032). CONCLUSION: The ultrasound-guided paramedian approach for CSEA is time-consuming, but it can effectively improve the success rate of the first puncture, reduce the incidence of anesthesia-related adverse reactions, and improve patient satisfaction. Trial registration: This study was registered with the Chinese Clinical Trial Registry (ChiCTR1900024722) on July 24, 2019