Ultrasound-guided Versus Landmark-based Spinal Anesthesia in Obese Parturients Undergoing Cesarean Section

This prospective comparative study aims to evaluate the effectiveness of preprocedural ultrasound-guided marking compared with the conventional anatomical landmark palpation technique for spinal anesthesia in obese parturients undergoing cesarean section.

A total of 100 parturients with a body mass index (BMI) ≥ 30 kg/m² were prospectively allocated to one of two comparison groups according to the puncture site localization technique. In the ultrasound group, the puncture site was identified using preprocedural ultrasound to determine the optimal intervertebral space and needle insertion trajectory. In the landmark group, the puncture site was identified using conventional anatomical landmark palpation.

The primary outcome was the first-attempt success rate, defined as successful cerebrospinal fluid return after the first needle insertion without needle redirection or an additional skin puncture. Secondary outcomes included the number of puncture attempts, needle redirections, need for rescue interventions, incidence of paresthesia and vascular puncture during needle insertion, and procedural times (site identification time, puncture time, and total procedure time).

This study evaluated whether preprocedural ultrasound-guided marking improves the technical performance of spinal anesthesia compared with conventional anatomical landmark palpation in obese parturients undergoing cesarean section.

Inclusion criteria

• Age ≥ 18 years
• Pregnant women undergoing cesarean section
• Body mass index (BMI) ≥ 30 kg/m² at the time of cesarean section
• Scheduled for cesarean section under spinal anesthesia

Exclusion criteria

• Congenital spinal deformities
• History of spinal surgery
• Coagulopathy
• Infection at the puncture site
• Allergy to local anesthetics
• Emergency cesarean section (NICE category 1)