Maternal Haemodynamic Changes During Spinal Anaesthesia for Caesarean Section

Background Spinal anaesthesia is widely preferred for elective caesarean sections because of its rapid onset and safety advantages. However, sympathetic blockade frequently results in maternal hypotension, which may compromise uteroplacental perfusion. Despite preventive measures, hypotension remains common, and reliable preoperative predictors of haemodynamic instability are limited. Objective This study aimed to assess maternal mean arterial pressure (MAP) changes following spinal anaesthesia, determine the incidence and temporal pattern of hypotension, and examine the association between early MAP decline (ΔMAP) and vasopressor requirement. Methods This prospective observational study included 100 parturients undergoing elective caesarean section under spinal anaesthesia at the Department of Obstetrics and Gynaecology and Anaesthesia at the associated hospital of Government Medical College, Datia, Madhya Pradesh, India. Demographic and obstetric characteristics were recorded. Haemodynamic parameters were measured at baseline and at serial intervals up to 120 minutes. Hypotension was defined as systolic blood pressure <90 mmHg or a ≥20% reduction from baseline. The primary outcome was the change in MAP (ΔMAP) within the first 30 minutes. Serial comparisons and multivariable logistic regression analyses were performed to evaluate temporal trends and associations. Results The mean age was 27.4 ± 4.6 years, and the baseline MAP was 91.9 ± 3.8 mmHg. Hypotension occurred in 78 (78%) participants, and 34 (34%) required vasopressors. MAP declined significantly at five and 10 minutes post-spinal (p ≤ 0.003), indicating early haemodynamic compromise, followed by recovery after 15 minutes. The mean reduction from baseline to minimum MAP was 20.3 mmHg (p < 0.001). Age, BMI, gravidity, and baseline MAP were not significantly associated with hypotension. Greater reductions in MAP (ΔMAP) were significantly associated with vasopressor requirement (adjusted odds ratio (OR) 3.6, 95% confidence interval (CI) 1.90-6.78; p < 0.001). Conclusions Spinal anaesthesia is associated with frequent early hypotension. Greater declines in MAP were associated with increased vasopressor use, reflecting the severity of haemodynamic compromise rather than an independent predictive factor. These findings provide descriptive insights into perioperative haemodynamic patterns in routine clinical practice.