Effect of Oxytocin Bolus Versus Slow Infusion on Haemodynamic Stability During Caesarean Section Under Spinal Anaesthesia

This study compares two standard ways of giving oxytocin (a medicine that helps the uterus contract) after the baby is born during a planned caesarean section performed under spinal anaesthesia. One group of women will receive oxytocin as a quick injection into the vein. The other group will receive the same dose of oxytocin as a slow infusion over 15 minutes. The researchers want to find out which method causes less drop in blood pressure and other heart-related changes, while still providing good contraction of the uterus and preventing excessive bleeding.

Inclusion Criteria: * Adult female patients aged 18 to 40 years * American Society of Anesthesiologists (ASA) physical status class I or II * Singleton pregnancy at 37 to 42 weeks gestational age * Scheduled for elective caesarean section under spinal anaesthesia * Written informed consent obtained Exclusion Criteria: * Patients with anticipated hemodynamic instability including severe preeclampsia/eclampsia, placenta previa with active bleeding, placental abruption, or hemorrhagic shock * Pre-existing cardiovascular disease including ischemic heart disease, valvular heart disease, cardiomyopathy, or arrhythmias * Baseline systolic blood pressure \< 100 mmHg or heart rate \> 100 bpm before spinal block * Known hypersensitivity to oxytocin * Failed spinal anaesthesia requiring conversion to general anaesthesia * Patients receiving medications that may alter the hemodynamic response to oxytocin (beta-blockers, calcium channel blockers, ACE inhibitors, or angiotensin receptor blockers) * Pre-existing anaemia (Hb \< 8 g/dL)