Evaluation of correlation between hip shoulder width ratio and sensory level of subarachnoid block in adult patients - A prospective observational study.

BACKGROUND AND AIMS: Easily measurable anthropometric parameters may aid in predicting the level of spinal anaesthesia. Some studies have demonstrated a significant correlation between hip-shoulder width ratio (HSR) and level of spinal anaesthesia in lateral position. We hypothesised that even sitting position for subarachnoid injection will result in positive correlation between HSR and sensory level of spinal anaesthesia. So, we aimed to study correlation between HSR and sensory level of subarachnoid block in sitting position after administering 3 ml of 0.5% hyperbaric levobupivacaine.

METHODS: After institutional ethics committee approval and trial registration, 58 patients aged 18 to 60 years and of American Society of Anesthesiologists physical status I and II were included. The primary objective was to assess the relationship between HSR and the sensory block level. The secondary objectives included correlation between patient's age, height, weight, body mass index (BMI), vertebral column length, and sensory level. Descriptive analysis was performed using mean and standard deviation for quantitative variables. Pearson correlation coefficient was used to evaluate the association between quantitative variables.

RESULTS: Higher HSR correlated moderately with higher sensory block levels (r = 0.550, P < 0.001). Multiple linear regression analysis demonstrated that HSR, height, and BMI have statistically significant effects on the spread of spinal anaesthesia with HSR being the strongest factor.

CONCLUSION: HSR is a simple, reliable predictor of sensory block height with hyperbaric levobupivacaine in adult patients.