Effect of waist circumference and body mass index on the level of spinal anesthesia

Abstract

Background: We aimed to determine the effects of waist circumference and body mass index on spinal anesthesia levels. In total, 120 surgical patients who were between 18 and 65 years old and in the American Society of Anesthesiologists' (ASA) I-III risk groups enrolled in this study. Patients were classified into three groups, depending on their weight. After a spinal block, we noted the time needed for the sensory block to reach the T10 level, the maximum sensory block level, the time needed for the sensory block to reach the maximum sensory block level, the time needed before the start of the motor block, and the Bromage scale for each patient. Results: We observed no significant demographic differences in age, gender, or ASA risk class between the groups; however, we found a statistically significant difference between the groups' BMIs and waist circumferences. For the time needed for the spinal block to reach the T10 level, we observed a statistically significant difference between groups I, II, and III, and we also found a statistically significant difference between the groups' comparing Bromage scales. Moreover, we found a statistically significant difference between the groups' time needed (in minutes) for the block to reach the maximal upper dermatomal block level and, as BMIs and waist circumferences increased, the time needed to reach the maximal upper dermatomal block level. We also noted a statistically significant difference in waist circumference variability. Conclusions: This study shows that body mass index and waist circumference can be used and interpreted as independent parameters reflecting the increasing incidence of obesity.