Evaluation of Effect of Epidural Anaesthesia on Pulmonary Functions in Patients Undergoing Upper Abdominal Surgery under General Anaesthesia

BackgroundPostoperative respiratory dysfunction is universally observed after abdominal and thoracic surgery. Abnormalities that contributes to reduced lung volume and hypoxemia in postoperative period include impaired central ventilator control, abnormal pulmonary mechanics due to limited abdominal, intercostal, and diaphragmatic muscle contraction and changes in pulmonary circulation and gas exchange. In this study, forced indices are used to compare the pulmonary function tests in postoperative period as they are maximally depend on respiratory muscular effort and are affected the most in this period. Other pulmonary function test parameters are least affected in the immediate postoperative period. Methods 82 patients of ASA (I& II) undergoing upper abdominal surgeries were randomly assigned in two groups, Group GA and Group EGA Patients of both the groups were explained and demonstrated about the pulmonary function testing procedure. Pulmonary function test was done using timed spirogram and the values of forced indices (FEV1, FVC, and PEFR) were recorded before surgery and 30 minutes after surgery. Results Reduction of FEV1 by 29 % - 41 % in patients of GA Group whereas only20 % - 28 % reduction in EGA group. Reduction of FVC by 31 % - 41 % in patients of GA whereas only 21 % - 29 % reduction in EGA group. Patients of GA group showed reduction of PEFR by 28 % - 40 % whereas in EGA group PEFR reduced only by 20 % - 30 %. Hence it can be concluded that epidural analgesia reduces the impact of general anesthesia and pain on pulmonary function in the postoperative period.