Comparatively Analysis of Adverse Events amongst 0.5% Hyperbaric Bupivacaine and 0.75% isobaric Bupivacaine at Same Dose 12mg in Patients Undergoing Caesarean Sections

Abstract

Background: Spinal anaesthesia is the preferred technique for caesarean section, with bupivacaine widely used intrathecally. The baricity and concentration of bupivacaine affect haemodynamic stability and maternal adverse events.

Objective: To compare adverse events associated with 0.5% hyperbaric bupivacaine and 0.75% isobaric bupivacaine at a fixed dose of 12 mg in elective caesarean sections.

Methods: A comparative cross-sectional study was conducted at DHQ Hospital South City Okara, including 40 ASA I–II parturients aged 20–40 years scheduled for elective caesarean section. Patients were randomly assigned to two groups: Group A received 0.5% hyperbaric bupivacaine, and Group B received 0.75% isobaric bupivacaine. Haemodynamic parameters and adverse events—including hypotension, bradycardia, nausea, vomiting, shivering, and headache—were recorded intraoperatively. Data were analyzed using SPSS, with p ≤ 0.05 considered statistically significant.

Results: Adequate sensory block up to T4 dermatome was achieved in all patients. Incidences of hypotension, bradycardia, nausea, vomiting, and shivering were significantly higher in the 0.75% isobaric group compared to the 0.5% hyperbaric group. The 0.5% hyperbaric group showed better haemodynamic stability and fewer adverse events.

Conclusion: At an equivalent dose, 0.5% hyperbaric bupivacaine provides effective spinal anaesthesia for caesarean section with fewer adverse events and better haemodynamic stability compared to 0.75% isobaric bupivacaine. This formulation may be preferred for safer maternal outcomes.