Height, weight, and the spread of subarachnoid hyperbaric bupivacaine in the term parturient.

Using a standardized technique, spinal anesthesia was induced in 50 term parturients to study the correlation between patient height, weight, and body mass index (BMI) and the spread of sensory blockade. All patients received 12 mg hyperbaric bupivacaine while in the right lateral decubitus position on a horizontal operating table. Immediately after drug injection, the women were turned to the supine horizontal position with left uterine displacement. Fifteen minutes after drug injection, the level of analgesia to pinprick was measured. Linear regression analysis revealed no significant correlation between height (146-175 cm), weight (57.3-93.6 kg), or body mass index (21-38 kg/m2) and the spread of spinal anesthesia (T7-C8). It is concluded that, in term parturients, patient height, weight, or BMI does not significantly affect the spread of hyperbaric spinal anesthesia.