Haemodynamic Impact of Sitting versus Immediately Lying Down Position after Spinal Anaesthesia in Elective Caesarean Section: A Randomised Double-blinded Clinical Study

Abstract

Introduction: Spinal anaesthesia is widely preferred over General Anaesthesia (GA) for caesarean sections due to its avoidance of airway complications and its ability to keep patients awake during childbirth. However, a common challenge associated with spinal anaesthesia is hypotension, which is caused by reduced sympathetic tone and aortocaval compression from the gravid uterus. Various methods, such as intravenous (i.v.) fluid preloading and vasopressors, are used to manage hypotension, but it remains a significant concern. Aim: To compare the incidence of hypotension and the optimal duration of the sitting posture after subarachnoid block. Materials and Methods: This randomised double-blind clinical study involved 120 parturients undergoing spinal anaesthesia for caesarean sections, participants were assigned to three groups: S30, S60 (seated for 30 or 60 seconds postinduction), and L (laid down immediately). Haemodynamic parameters were monitored at specified intervals throughout the procedure. Appropriate tests of statistical significance, such as One-way Analysis of Variance (ANOVA) and the Chi-square test, were performed. Results: The demographic and anaesthesia characteristics of the study groups were comparable (p-value>0.05). Heart Rate (HR) was significantly higher in group L compared to groups S30 and S60 at 1, 2, 3, and 5 minutes postspinal anaesthesia (p-value<0.001). Systolic Blood Pressure (SBP) was significantly lower in group L compared to S30 and S60 at 2, 3, 5, 15, and 20 minutes (p-value<0.05). Mean Arterial Pressure (MAP) showed significant differences between groups at 1, 2, 3, 5, 10,15 and 20 minutes (p-value<0.05). Group L took less time to reach the T6 dermatome sensory level (3.8±1.9 min) compared to S30 (4.2±2.3 min) and S60 (5.41±1.7 min) (p-value=0.001). The motor block regression time was significantly shorter in S60 (151.7±20.4 min) and S30 (165.3±25.5 min) compared to L (179.3±19.7 min) (p-value<0.001). Conclusion: The study concluded that allowing patients to sit for 30 or 60 seconds after spinal anaesthesia for caesarean sections reduces the incidence of hypotension and improves haemodynamic stability compared to the immediately lying down position. The time to achieve a T6 sensory block was shorter in the immediately lying down position.

Keywords

• bupivacaine
• diastolic blood pressure
• hypotension
• subarachnoid block
• systolic blood pressure