Comparison of postoperative pulmonary functions and outcomes in patients undergoing major open abdominal surgeries between general anaesthesia with thoracic epidural and thoracic continuous spinal anaesthesia: an exploratory randomized study

This is an exploratory randomized, single blinded, parallel group study to compare post operative pulmonary functions and outcomes in patients receiving General anaesthesia with Thoracic epidural versus Thoracic continuous spinal anaesthesia for major open abdominal surgeries that will be conducted in India. The hypothesis is that the pre operative pulmonary functions would be better preserved in regional anaesthesia (thoracic continuous spinal anaesthesia) as compared to general anaesthesia in patients undergoing major abdominal surgeries. Hence, better postoperative pulmonary functions and outcomes in regional anaesthesia. The primary objective would be to compare peak expiratory flow rate at predefined time intervals [preoperative (T0), immediate postoperative (T1), post operative day 1 (T2), post operative day 2 (T3), post operative day 3 (T4)]. The secondary objectives would be to compare breath holding time and SpO2, incidence of postoperative lung atelectasis (ultrasound assessed),  incidence of other postoperative pulmonary complications (pleural effusion, pneumonia, pneumothorax, acute respiratory distress syndrome), change in trans-diaphragmatic excursion (ultrasound assessed Delta TDI) at predefined time points [preoperative (T0), immediate postoperative (T1), post operative day 1 (T2), post operative day 2 (T3), post operative day 3 (T4)] and all cause in-hospital mortality.