Perfusion index derived from a pulse oximeter can predict the incidence of hypotension during spinal anaesthesia for lower segmental caesarean section -A prospective observational study

This study is a prospective observational study.Hypotension during spinal anaesthesia for caesarean delivery is a result of decreased vascular resistance  due to sympathetic blockade and decreased cardiac output  due to blood pooling in blocked areas of the body. Change in baseline peripheral vascular tone due to pregnancy may affect the degree of such hypotension. Hypotension in the mother leads to maternal as well as fetal complications. Thus ,the prediction of possible hypotension will aid in preventing the associated  complications. Low blood pressure resulting from reduced systemic vascular resistance  leads to a higher perfusion index owing  to enhancement  in the pulsatile component caused by vasodilatation. The perfusion index  derived  from a  pulse oximeter has been used for assessing peripheral perfusion dynamics due to changes in peripheral vascular tone . Higher   perfusion index  was associated with increased risk of hypotension.