Hypotension following spinal anaesthesia during LSCS is a known entity caused due to the sympathetic nerve blockade where hypotension has been described as a fall in SBP to 80% of baseline. Hypotension can cause nausea,vomiting in the pregnant mother and also potentially cause decreased perfusion to the fetus. Vasopressor drugs have become treatment of choice for both prevention and treatment of hypotension.
Ephedrine has been prophylactically used for preventing hypotension utilising its beta agonist effect.The current standard is to administer a continuous phenylephrine infusion to prevent hypotension. However Phenylephrine which acts by alpha-2 agonist action can cause a reflex fall in heart rate and decreased cardiac output. The use of norepinephrine has been recently thought of as a possible drug to maintain blood pressure following subarachnoid block. And as it has a dual alpha and beta action, it has a lower tendency to cause cardiac depressant effects.

Studies have been done to compare Phenylephrine and Norepinephrine for management of post spinal hypotension with respect to their safety, efficacy and effect on neonatal outcome. But studies comparing manually titrated infusions are very less.
 The primary aim of this study is to compare manual variable titrated infusion of phenylephrine and norepinephrine in preventing post subarachnoid block hypotension.  The secondary aim of this study will be to compare incidences of maternal bradycardia, fetal acid-base balance, Apgar score and the requirements of vasopressor doses.