ABSTRACT
Background
Objective: To compare peri-Operative hemodynamic stability in elective lower segment Cesarean Section under spinal anesthesia with 0.5% or 0.75% injection Bupivacaine.
Methods: This was randomized controlled trial conducted at Department of Anesthesiology Combined Military Hospital Kharian; Study was conducted from November 2023 to February 2024  Total 74 patients (37 in each group) were included in the study. Patients were randomly divided into two groups with the help of random numbers generated through excel. In Group-A patients were administered 0.5% Bupivacaine solution and in Group-B patients were administered 0.75% of Bupivacaine solution. Heart rate (HR), electrocardiogram (ECG), non-invasive blood pressure (NIBP) and pulse oxymetery (SpO2) readings were taken every three minutes for the first half an hour and every fifteen minutes thereafter.  Hypotension, bradycardia was noted down as per standard operational definition. Any side effects/adverse events such as hypotension, bradycardia, nausea and vomiting were documented and managed as per institutional protocol.
Results: Results of this study showed that systolic, diastolic blood pressure and heart rate showed no significant difference between groups at baseline, 10, 20 and 30 minutes respectively. No significant difference was seen between study groups for hypotension (p-value=0.643), bradycardia (p-value=0.691), nausea (p-value=0.235) and vomiting (p-value=0.235) respectively. Frequency of nausea was higher in 0.75% bupivacaine.
Conclusion: Results of this study demonstrate no significant difference between 0.5% and 0.75% bupivacaine for hemodynamic changes as well as for bradycardia, hypotension and nausea/vomiting. 
Key Words: Hemodynamic, Elective, Cesarean Section, Spinal anesthesia, Bupiva