Comparative Study of Effect of Spinal Anesthesia in Sitting and Lateral Positions on the Onset Time of Sensory Block and Hemodynamic Condition in Cesarean Section: A Randomized Clinical Trial

BACKGROUND: Spinal anesthesia is the method of choice for the cesarean section. Hypotension is a common complication of this method. OBJECTIVES: This study aimed to compare the effect of spinal anesthesia in the sitting and lateral positions on the onset time of sensory block and hemodynamic condition in cesarean sections. METHODS: In this clinical trial, 106 elective cesarean section candidates under spinal anesthesia were selected and randomly divided into two groups: spinal anesthesia in the sitting position (group S) and the lateral position (group L). The onset time of the sensory block, quality of sensory and motor block, hemodynamic condition, frequency of hypotension, nausea, and vomiting, and the doses of ephedrine and atropine were compared between both groups. Data were analyzed with SPSS version 16 software at a 95% confidence level. RESULTS: There was no statistically significant difference between the two groups in terms of age. The frequency of hypotension in L and S groups was 24.5% and 57.7%, respectively (P = 0.001), in minute 6 after spinal anesthesia and 5.7% and 36.5%, respectively (P < 0.001), in minute 8 after spinal anesthesia. The mean time to reach the sensory level of T6 was 1.30 ± 0.43 min versus 4.54 ± 2.12 min (P < 0.001), motor block score in minute 5 was 2.98 ± 0.14 versus 2.82 (P = 0.044), and ephedrine dose was 11.5 mg and 16.92 mg in the L and S groups, respectively (P = 0.010). The maximum sensory-motor block and satisfaction of women with spinal anesthesia were significantly higher in the lateral position than in the sitting position (P < 0.05). CONCLUSIONS: Cesarean sections under spinal anesthesia in the lateral position than in the sitting position lead to a more rapid sensory and motor block, reduced ephedrine consumption, and enhanced satisfaction of women.