Preoperative Prediction of Pneumonia after CABG surgery: a retrospective cohort study

Abstract

Title. Preoperative Prediction of Pneumonia after CABG surgery; a retrospective cohort study.

Introduction. Pulmonary care is an important part of the postoperative care after Coronary Artery Bypass Graft (CABG) surgery since pulmonary functions decreases significantly. Pulmonary dysfunction and associated complications are the major cause of increased morbidity, mortality and hospital length of stay in the period following cardiac CABG surgery.

Aim. The aim of this study is to develop a prognostic model that predicts the likelihood of developing pneumonia after CABG Surgery.

Research questions. 1. Which preoperative factors can predict the occurrence of pneumonia in patients who undergo coronary artery bypass surgery? 2. Which set of prognostic factors will be adopted in the risk-model, in order to predict the likelihood of developing pneumonia after coronary artery bypass surgery?

Method. We conducted a retrospective cohort study on patients who underwent CABG surgery. Two datasets were used developed in different time periods. Because the datasets contained unique variables, after merging the datasets missing values occurred. Multiple imputation (MI) was applied as a solution for this problem. Prognostic factors were determent by the use of backward elimination.

Results. A multivariate analysis was performed and three variables were identified and adopted into the prognostic model, respectively productive cough, FEV1 (forced expiratory volume) and recent myocardial infarction.

Conclusion. A prognostic model predicting the likelihood of developing pneumonia after CABG surgery has been developed. The benefit of this model is that it can be used in the preoperative period. Therefore interventions can be taken adequately to prevent pneumonia after CABG surgery.

Recommendations. A validation study to validated the models’ performance in new individuals.