Assessment of variations in perfusion index derived from photoplethysmography during tracheal intubation and extubation in adult patients undergoing elective surgery

The Perfusion index (PI) isa continuous, non-invasive, cost effective, indirect measure of peripheralperfusion, monitored by photoplethysmography. It has been suggested that PI canbe used as a complimentary haemodynamic parameter for early detection of haemodynamicinstability in trauma and critically ill patients, in lieu of it being avaluable adjunct for early detection of acute hemodynamic responses to centralhypovolemia. Stress response during intubation and extubation during generalanaesthesia is known to cause a change in the peripheral vasomotor tone,leading to haemodynamic changes. There is an associated increase in heart rate(HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and meanarterial pressure (MAP). This increase in the peripheral vasomotor tone, leadsto a decrease in peripheral perfusion, and is thereby, expected to cause anassociated fall in the PI. Thereis paucity of literature with regard to changes in perfusion index andhaemodynamic parameters during tracheal intubation and extubation in adultpatients undergoing elective surgery under general anaesthesia. Our studyhypothesis is that perfusion index changes  with haemodynamicparameters during tracheal intubation and extubation in adult patients undergoingelective surgery under general anaesthesia. The aim of our study is to study changesin  perfusion index and haemodynamicparameters   during tracheal intubationand extubation in adult patients undergoing elective surgery under generalanaesthesia.