The demographic data of the patients,type and site of surgery will be noted. Preoperative hemoglobin, serum electrolytes and blood urea will be recorded. The intraoperative factors like duration of surgery and anaesthesia,use of intravenous fluids ,blood loss, number blood units transfused and opioid use will be studied at the time of surgery. The time to emergence and extubation following the completion of surgery will be noted.