Due to its rapid onset, dense sensory block, and safety benefits, spinal anaesthesia is the most preferred technique for elective caesarean sections. Up to 70% of parturients face maternal discomfort, nausea, vomiting and potential fetal distress due to one of the most common complication of spinal anaesthesia, hypotension.

 To solve this, vasopressors like ephedrine are used to maintain maternal blood pressure and provide preservation of utero-placental perfusion.

A 5-HT3 receptor antagonist and a common drug for preventing nausea and vomiting, Ondansetron, is suggested to have additional hemodynamic benefits. Through relaxing the Bezold-Jarisch reflex (BJR), which causes bradycardia and vasodilation, Ondansetron is believed to reduce spinal anaesthesia-induced hypotension. With the persistent stabilization of hemodynamics, Ondansetron may result in reduced use of Ephedrine, and thus lessening side effects.

This study intends to determine whether Ondansetron alters the Ephedrine dosage needed to keep hemodynamic stability in elective caesarean sections with spinal anaesthesia. The objective is to better understand the management of spinal anaesthesia-induced hypotension and improve outcomes for both maternal and fetal health.