Pulmonary Function Tests in Patients Undergoing Coronary Artery Bypass Graft Surgery and its Correlation with Outcome.

Background: Pulmonary complications are one of the most common causes of postoperative morbidity and mortality after coronary artery bypass graft (CABG) surgery. There is paucity of data of CABG in abnormal pulmonary function tests (PFT) in Indian population.

Objectives: To study correlation of PFT with clinical outcome in patients undergoing CABG.

Methods: Three hundred seventy patients aged 35 to 65 years who underwent CABG between May 2015 and November 2016 and ready to participate were included for this prospective observational study. Each patient was subjected to detailed clinical history, clinical examination and PFT. Primary outcome measures were post CABG ventilator stay, intensive care unit (ICU) stay, and hospital stay. Fisher's exact tests was used to compare qualitative data whereas Mann-Whitney U test was used to find the significant difference between quantitative variables.

Results: Higher percentage of patients whose forced expiratory volume in one second (FEV1) was abnormal had longer ventilator stay, ICU stay and hospital stay as compared patients whose FEV1 was normal. Restrictive disease, obstructive disease, and mixed disease patients had longer ventilator stay, ICU stay and hospital stay as compared patients whose spirometry was normal.

Conclusion: Abnormal PFT was independent strong predictor of prolonged ventilation, longer length of ICU and hospital stay.