Abstract

Background and Objectives: Obesity presents significant challenges in neuraxial anesthesia due to difficult surface anatomical landmarks, leading to increased failure rates and complications. Since Bier first described spinal anesthesia in 1899, the traditional method for identifying the subarachnoid space has been through anatomical landmarks. Conventional palpation techniques often prove unreliable in these patients. Neuraxial ultrasound aims to enhance accuracy by visualizing sonoanatomy, potentially improving success rates and patient outcomes. This study was done to evaluate the effectiveness of preprocedural ultrasound-assisted midline approach compared to the traditional landmark-guided technique in obese patients undergoing lumbar subarachnoid block. Methods: A prospective observational study was conducted in 90 obese patients (BMI > 25 kg/m²) aged between 18 and 80 years scheduled for elective surgery under spinal anesthesia at Travancore Medical College, Kollam. Patients were divided into two groups: ultrasound-assisted (USG) and surface landmarkguided (SLG). Detailed history, physical examination, and informed consent were obtained. A portable USG machine with curved array probe was utilised for pre procedure marking. Key variables measured included first-attempt success rate, number of needle passes, time for space identification, and total procedure time. Data was analysed using statistical package for social sciences version 25. Results: The first-attempt success rate was significantly higher in the USG group (51.1%) compared to the SLG group (15.6%). The mean time for space identification was longer in the USG group (119.64 ± 48.69 seconds) than in the SLG group (28.56 ± 15.65 seconds), but the total procedure time was shorter in the USG group (281 ±85.657 seconds) compared to the SLG group (414.44 ± 218.835 seconds). Patient satisfaction and reduced number of needle passes were also better in the USG group. Conclusion: This study demonstrates that the ultrasound-guided technique significantly improves the first attempt success rate of spinal anesthesia and enhances patient satisfaction in obese patients. Despite the longer time required for space identification, the overall procedure time is reduced with ultrasound guidance. These findings suggest that incorporating ultrasound guidance into clinical practice could enhance the efficacy of spinal anesthesia in obese patients, highlighting its potential as a valuable tool in modern anesthetic practice.

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Data Sharing Statement

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