ABSTRACT
Introduction and Objective: elimination of local anesthetic from subarachnoid space is probably depends on rate of local diffusional surface of anesthetic and its vascular absorption. This study was designed to evaluate the relationship between the spread of hyperbaric spinal anesthesia and duration of spinal block
Materials and Methods: to determine the effects of hyperbaric local anesthetic extension on duration of spinal block we studied 40 ASA Class I, II patients whom were candidate for elective surgery [Inguinal hernia]. We randomly divided them into 2 equal groups. After performing spinal block with 2cc hyperbaric lidocaine 5% the first group was left in horizontal position and the second group in 30 torso elevated position. The patients was monitored for pulse oximetry, ECG and noninvasive BP. BP and HR were checked 5 minutes for 30 minutes and then every 15 minute until the end of study
Results: the decrease in MAP was significantly more obvious in horizontal group than 30degree toros elevated group. Duration of block existing is less in horizontal group than 30degree toros elevated group
Conclusion: placing patients in 30degree elevation of torso, after spinal injection, prolonged the duration of spinal block and lessen the hemodynamic changes of spinal anesthesia