Spinal Anesthesia Evaluation

Tuffier's line is commonly used as a landmark for estimating lumbar vertebral levels during spinal anesthesia. However, its accuracy can vary depending on factors such as age, sex, BMI, and posture. This study evaluates the consistency of an alternative landmark, the "ASIS line" (a line connecting both Anterior Superior Iliac Spines), for identifying lumbar levels in the lateral decubitus position. Researchers will mark both the ASIS line and Tuffier's line on participants and use ultrasound to verify the exact vertebral level where each line crosses the spine. The goal is to determine if the ASIS line provides a more consistent and reliable estimation of lumbar levels compared to Tuffier's line.

This prospective, double-blinded, randomized clinical trial aims to examine the effects of combining isobaric bupivacaine with dexmedetomidine administered intrathecally (IT), compared to the combination of isobaric bupivacaine administered intrathecally and dexmedetomidine administered intravenously (IV), on spinal anesthesia prolongation time in minutes, time of regression from Bromage score 3 to 0.