Anaesthetic care regarding fluid therapy is crucial in preventing perioperative hypovolaemia or hypervolaemia, both of which are recognized factors contributing to increased morbidity and prolonged hospital stay. Intraoperative fluid management is crucial for hemodynamic stability, and predicting fluid responsiveness is essential for optimal patient outcomes. Fluid responsiveness can be predicted using both invasive and non-invasive methods. The invasive approaches include arterial pulse pressure and systolic pressure variation, pulse contour analysis, and central venous pressure. Non-invasive techniques comprise of passive leg raise test, inferior vena cava ultrasound, tidal volume challenge test, end-expiratory occlusion test, bioimpedance, bioreactance, and echocardiography. 

Tidal volume challenge (TVC)has been observed to accurately predict fluid responsiveness in mechanically ventilated patients in operating room. Prediction of fluid responsiveness using tidal volume challenge test has been studied on the basis of changes in cardiac output and stroke volume variation. The measurement involves insertion of invasive catheter which has its own technical challenges.  Recently, non- invasive monitoring of these parameters using thoracic bioimpedance has been found to reliably predict cardiac output and stroke volume variation in comparison to invasive techniques. However, it has cost implications. Sonographic assessment of internal jugular vein distensibility index (IJVDI) has recently been observed to correlate with fluid responsiveness. It is a safe and easy non-invasive technique used for hemodynamic monitoring. We hypothesize that changes in IJVDI will be able to predict fluid responsiveness in accordance with changes in cardiac index /stroke volume variation during tidal volume challenge test. Hence we aim to evaluate the internal jugular vein distensibility index as a predictor of intraoperative fluid responsiveness during tidal volume challenge in patients undergoing elective surgery under general anaesthesia. The study will be conducted in the department of anaesthesiology ,Maulana azad medical college and associated lok nayak hospital,new delhi.