Effect of patient’s position on the success rate of subarachnoid block in parturient undergoing caesarean section: A prospective cohort study

Effect of patient’s position on the success rate of subarachnoid block in parturient undergoing caesarean section: A prospective cohort study - Background: Technical aspect including proper position is important in subarachnoid block (SAB). The success rate in different positions has not been compared in parturient. The present study was conducted to evaluate the effect of lateral decubitus knee-chest position with a 45degree head-up tilt on the first attempt success of the spinal tap. Materials and Methods: Parturients undergoing lower segment cesarean section (LSCS) were included in the study, with two groups of 100 each, based on the position in which spinal tap was performed, Lateral decubitus knee-chest position (Group-L) and Lateral decubitus knee-chest position with 45-degree head-up tilt (Group-LH). Results: A successful cerebrospinal fluid (CSF) tap on the first attempt was achieved in 69% of patients in group LH and 55% in group L (odds ratio 1.82, 95% CI 1.02–3.25, p = 0.041). The mean time to perform the spinal tap was significantly shorter in group LH. Group L exhibited a faster onset (p = 0.002) but slower recovery (p = 0.002) of the sensory blockade. The incidence of motor blockade, bloody spinal taps, analgesic supplementation, nausea, and headache were similar between the two groups. However, hypotension and vomiting occurred more frequently in group L. Conclusion: 45-degree head-up tilt in lateral decubitus knee-chest position improves the first-attempt success rate of spinal tap with slower onset of the sensory blockade, faster recovery, fewer chances of the inadvertent high block, and fewer complications compared to lateral decubitus knee-chest position. A 45-degree tilt with lateral decubitus position may be helpful in improving success of subarachnoid block in parturients considered difficult spinal taps. Keywords: Parturient; Position; Subarachnoid; Head; Up; CSF.