Incidence and Predictors of Hypotension Following Spinal Anaesthesia in A Tertiary Care Hospital

Background: Spinal anaesthesia is a commonly employed regional anaesthetic technique for infra-umbilical surgeries due to its simplicity and effectiveness. However, hypotension remains the most frequent and clinically significant complication associated with spinal anaesthesia, potentially leading to adverse perioperative outcomes.

Objectives: To determine the incidence of hypotension following spinal anaesthesia and to identify patient- and procedure-related predictors associated with its occurrence in a tertiary care hospital.

Materials and Methods: This prospective observational study was conducted in the Department of Anaesthesiology of a tertiary care teaching hospital over a period of six months. A total of 120 adult patients aged 18–75 years, belonging to ASA physical status I–III and undergoing elective lower abdominal or lower limb surgeries under spinal anaesthesia, were included. Baseline demographic variables, hemodynamic parameters, intrathecal bupivacaine dose, and sensory block height were recorded. Hypotension was defined as a decrease in systolic blood pressure of ≥20% from baseline or an absolute systolic blood pressure <90 mmHg. Data were analyzed using univariate and multivariate logistic regression to identify independent predictors.

Results: Hypotension occurred in 38 out of 120 patients, giving an incidence of 31.7%. On univariate analysis, age >60 years, baseline systolic blood pressure <120 mmHg, and sensory block level ≥T6 were significantly associated with hypotension (p <0.05). Multivariate logistic regression identified age >60 years (OR 2.3), lower baseline systolic blood pressure (OR 2.5), and higher sensory block level (OR 2.9) as independent predictors.

Conclusion: Hypotension following spinal anaesthesia is common and multifactorial. Advanced age, lower baseline systolic blood pressure, and higher sensory block level are significant predictors. Awareness of these factors can aid in early risk stratification and improve perioperative hemodynamic management