Effects of Body Roundness Index on Spinal Anesthesia Block Characteristics

Body roundness index (BRI) is based on the assumption that the human body's shape is an ellipse, which combines height and waist circumference. We aimed to investigate the effect of BRI on spinal anesthesia [SA] sensory levels and hypotension in patients undergoing elective surgery. In this observational study, we prospectively enrolled 18-80 years old patients with ASA physical status I-III who underwent single-shot spinal anesthesia using 15 mg 0.5% hyperbaric bupivacaine at L3–L4 intervertebral space for transurethral and lower limb surgery. Maximum sensory blockade level at 15th and 30th min, block regression time to L2 level, hypotension, bradycardia occurrence were recorded. BRI, waist, and hip circumference were found as independent predictive factors in a maximum sensory blockade level at 15th min [OR=65.7 95% CI: 1.304-3310, p=0.036; OR=0.733 95% CI: 0.558-0.963, p=0.026; OR=1.065 95% CI: 1.001-1.133, p=0.047; respectively]. Hypotension after SA was not associated with anthropometric variables. BRI can be used as a new practical tool to predict the increased cephalic spread of local anesthetic in patients undergoing SA.