The effect of hip shoulder width ratio and vertebral column length on sensory level in term participants posted for lower segment caesarean section under spinal anaesthesia in Indian population: A prospective observational study

Hypotension is the most common complication of spinal anesthesia with high intrathecal spread of local anaesthetic drug especially during caesarean section. Hip Shoulder width Ratio (HSWR) is one of the factors which affects spread of spinal anaesthesia.85 ASA II participants with singleton term pregnancy undergoing elective caesarean section received 12mg hyperbaric bupivacaine intrathecally with 26G Quincke’s spinal needle in L3-4 intervertebral subarachnoid space via midline approach. Post spinal anaesthesia haemodynamic parameters were monitored every 5 minutes for the first 20 minutes and at the end of surgery. Sensory level was assessed by a pinprick test every 5 minutes till 20 minutes and post-surgery. Hypotension was defined as 20% fall from baseline systolic blood pressure at 15 minutes post spinal anaesthesia.We found significant positive correlation between high shoulder width ratio and highest sensory level achieved (p - 0.0005) using mutiple regression analysis and pearson's correlataion. With every unit increased in high shoulder width ratio spinal level significantly increased by 5 units. Hip shoulder width ration and age were significantly correlatwd with incidence of hypotension.Hip-shoulder Width Ratio has a positive effect on cephalad spread of spinal anaesthesia and thus incidence of hypotension. By knowing the Hip-shoulder Width Ratio, it can help anaesthesiologists to predict the spread of spinal anaesthesia and titrate the dose of 0.5% hyperbaric bupivacaine.