Hip/Shoulder Size Ratio, Vertebral Column Length and the Spread of Spinal Anesthesia in Term Parturient

There are more than twenty factors in the literature defined to effect the spinal anesthesia spread. In patients with a larger hip size and a narrow shoulder size, more cephalad spread of spinal anesthesia induced with a fixed amount of hyperbaric bupivacaine is observed. We hypothesized that the increase in cephalad spread is strongly correlated with the increased hip/shoulder size ratio. Age, weight, height, body mass index, hip size, shoulder size, hip/shoulder size ratio, vertebral column length were recorded for 75 term parturient. The L4-L5 interspace was entered and 2ml 0.5% hyperbaric bupivacaine was given intrathecal in 10 seconds without barbotage. Pearson Correlation Test was performed for the correlation between age, height, weight, body mass index, hip/shoulder size ratio, and vertebral column length