Ultrasound versus C-arm fluoroscopic-guided subarachnoid block in patients with predicted difficulty for subarachnoid block posted for infraumbilical surgeries: A prospective randomized controlled study

Background: Subarachnoid block (SAB) is a preferred anesthetic technique for infraumbilical surgeries. However, in obese patients, landmark identification for SAB can be difficult, increasing the risk of procedural failure and complications. This study is determined to compare the efficacy of ultrasound (USG)-guided, C-arm fluoroscopy-guided, and anatomical landmark-guided SAB in obese patients. Methods: Sixty patients of 18-80 years with BMI ≥30 kg/m² of American Society of Anaesthesiologist Physical Status (ASA PS) II-III scheduled for infraumbilical surgeries were randomized into three equal groups: Group A, Group B, and Group C for USG-guided, C-arm-guided, and Landmark-guided SAB, respectively. Each received 0.5% hyperbaric bupivacaine intrathecally using a 25-G Quincke's needle. Total time taken for the procedure, number of spinal needle insertion attempts, patient satisfaction score, success rate, and complications in each group were recorded. Results: All groups were comparable demographically. Group B had the significantly highest total time taken for the procedure, 380.4 ± 46.2 seconds, compared to Group A, 273.6 ± 7.5 seconds, and Group C, 165.7 ± 23.2 seconds. The number of spinal needle insertion attempts was lowest in Groups A and B, with higher patient satisfaction scores. Complications occurred only in Group C. Conclusion: Imaging modalities-guided SAB in obese patients took a prolonged procedure time but had fewer spinal needle insertion attempts and better patient satisfaction than the landmark-guided SAB. Between the imaging modalities, USG-guided SAB was faster, required fewer needle insertions, and gave better patient satisfaction than C-arm guided SAB.