Hypotension is one of the most common immediate complications of spinal anesthesia. Preloading with fluids is one way of preventing hypotension. However hypotension still occurs in many patients which is managed by pharmacological interventions. In this study, we are comparing three modalities which can prevent hypotension. Based on the findings of the study, we want to standardize the care in our hospital.

There are no studies comparing the use of head elevated position and intravenous Ondansetron in reducing spinal induced hypotension in obstetrics. Both these interventions are simple, cost effective and carry negligible risk hence were chosen for the study.

Group H: Parturients will receive head end elevation during and after spinal anaesthesia and will remain in this position till the end of the surgery. They will not receive Inj. Ondansetron prior to spinal anesthesia.

Group O; Parturients will receive Inj. Ondanstron 4 mg i.v five minutes prior to spinal anesthesia.

Group C: Parturients will neither be given head end elevation post spinal anaesthesia nor will receive Inj. Ondansetron i.v prior to spinal anaesthesia.(standard of care)

Standard protocol for perioperative monitoring and administration of spinal anaesthesia will be followed.

Hemodynamic parameters which include systolic, diastolic and mean arterial pressures and heart rate will be measured and recorded before spinal anaesthesia administration, just after spinal anaesthesia, at 1 minute intervals for the first 5 minutes, then at 5 minute intervals till the end of surgery.

 The total dose of ephedrine required will be noted

Sensory block will be assessed using a cold swab and motor block by modified Bromage scale every 3 minutes for 15 minutes, beyond which parturient will be excluded if sensory block is below T6.

 Time from spinal injection to T6 sensory level, maximal sensory block level (MSBL) attained, time at which MSBL was achieved, time to skin incision, time to two segment regression of the sensory block will be recorded.

Other side effects of spinal anesthesia like nausea, vomiting and shivering will be noted.

APGAR at 1minute and 5 minutes will also be recorded.