Résumé
BACKGROUND: This study was performed to accurately discover the correlation between the epidural depth and physical measurements. METHODS: We measured the L2-3, L3-4 epidural depth pre-marked on the needle shaft only when the block was successful. Correction of the depth was made by the angulation of the needle from the perpendicular line (with regard to both the x- and y-axis) to the skin. Height and weight from the medical record was noted and neck, waist, and hip circumferences of each subject was measured. Physical parameters such as waist/neck (waist circumference-to-neck circumference ratio), waist/height (waist circumference-to-height ratio), waist/hip (waist circumference-to-hip circumference ratio), weight/neck (weight- to-neck circumference ratio), weight/height (weight-to-height ratio) and body mass index (BMI) were calculated. Peason's correlation and a regression test between the epidural depth and the physical mea surements were performed. RESULTS: Significant correlation with epidural depth was found in weight, waist, hip, neck, BMI, waist/height, waist/hip, weight/neck, and weight/height. With the regression test, we found weight to be the most important for predicting epidural depth (R square = 0.330, P < 0.05). CONCLUSIONS: Weight has the highest predictive value for lumbar epidural depth.