[Comparison of body height and vertebral column length in Chinese parturients]

Spinal anesthesia (SA) is frequently used in parturients undergoing Cesarean sections (C/S). The body height (BH) is commonly believed to be one of the factors influencing the spread of SA, especially in patients with extremes of the BH. Recent studies, however, show that the spread of SA is not related to the BH but to the vertebral column length (VL). This study aims to evaluate the relationship between the BH and VL in Chinese parturients. 258 parturients without vertebral column abnormality undergoing C/S were included in this study. The VL (between C7 prominence and sacral hiatus) of each patient was measured in the right decubitus position. They were divided into 3 groups according to their BH (group A less than 152 cm; group B = in the range of 153-161 cm; group C greater than 162 cm). In each group correlation between the BH and VL was made by linear regression analysis. Also determined is whether there is significant difference between each two groups by unpaired Student's t-test. A p values less than 0.05 is considered as statistical significance. The results of the present study showed that although there exists correlation between the BH and VL, the correlation coefficient (r value) is small in each group (0.29, 0.13, and 0.31 in Group A, B, and C respectively; p less than 0.05). There is, also, no significant difference of the VL among the three groups. Therefore we concluded that the BH and VL did not closely correlate and therefore BH might contribute little to the spread of SA in the Chinese parturients, including those with extremes of BH.