Prevalence and Risk Factors of Hypotension in Patients Undergoing Caesarean Section with Spinal Anaesthesia at Muhimbili National Hospital.

Background: Spinal anaesthesia is a common regional technique for caesarean sections, but is associated with hypotension in up to 80% of patients. Preventive measures include; intravenous fluid preloading, left uterine displacement, compression stockings, and vasopressors. This study aimed to determine the prevalence and risk factors of hypotension during spinal anaesthesia in pregnant patients undergoing caesarean section at Muhimbili National hospital.

Methods: A descriptive cross-sectional study was conducted at Muhimbili National Hospital's Obstetric theatre, involving patients who received spinal anaesthesia during caesarean section from August 2021 to January 2022. The study excluded patients with sedation, anti-hypertensive, pregnancy-induced hypertension, modified Bromage score, or combination anaesthesia. Data was collected, and analysed using SPSS version 20.

Results: A total of 300 patients were enrolled (calculated sample size 270 plus 10% margin). Of these, 33.3% underwent elective caesarean section and 66.7% emergency caesarean section. Most patients (92%) received 0.5% hyperbaric bupivacaine, while 8% received 5% heavy lidocaine. Hypotension occurred in 56.7% of patients (95% CI: 0.511-0.623). Risk factors included preload <10 mL/kg, higher sensory block levels, and absence of wedge positioning.

Conclusion: Hypotension during spinal anaesthesia for caesarean section is common. Preventive measures, including adequate fluid preload, wedge positioning, and careful monitoring of sensory block height, are essential to improve maternal hemodynamic stability.