Spinal anaesthesia is the most common modality for patients undergoing infraumbilical surgeries. Hypotension is the most common complication, which can be avoided by early prediction of fluid status of the patients and optimizing it. The present study was  conducted in the Department of Anaesthesia and Intensive care, Government medical college, Amritsar after approval from institutional thesis and ethics committee. 100 patients will be randomized into 2 groups of 50 each on the basis of inferior vena cava compressibility index noted using ultrasound before giving spinal anaesthesia with a cutoff of 40%. Group A with inferior vena cava compressibility index <40% and Group B inferior vena cava compressibility index >40%. Spinal anaesthesia will be administered to all patients and co-loading will be done with ringer lactate. Haemodynamic monitoring of heart rate, diastolic blood pressure, systolic blood pressure, mean arterial pressure, peripheral oxygen saturation (spo2), and electrocardiography along with perfusion index and pleth variability index will be done. The primary objective of the study will be to assess the efficacy of inferior vena cava compressibility index with hypotension and its sensitivity and specificity in predicting hypotension. Secondary objectives will be total amount of  doses of vasopressor used, side effects and complications and to see the correlation of perfusion index and pleth variability index with inferior vena cava compressibility index in predicting hypotension.