PURPOSE: The impact of preoperative pulmonary function tests (PFT) on patients undergoing cardiac surgery has not been quantified in the current era. This study investigated PFTs that predict postoperative complications in patients undergoing primary elective coronary artery bypass grafting (CABG) with or without valve surgery.
METHODS: Between January 1997 and July 2004, 2,742 (1799 male, mean age 66±12 years) patients undergoing primary CABG with or without valve surgery underwent PFTs preoperatively. Logistic regression analysis was used to characterize patients undergoing PFTs and to explore how these variables and other patient variables related to hospital death, respiratory failure, mediastinitis, tracheostomy, and long-term mortality.
RESULTS: Preoperative PFTs were performed for a variety of reasons, and patients who underwent these tests were more likely to have preoperative dyspnea (51%), heart failure (43%), chronic pulmonary disease (51%), and a history of smoking (77%). Low FEV1 percent predicted was a risk factor for all the above complications except tracheostomy; tracheostomy was associated with higher PaCO2 and lower FVC percent predicted. There was no sharply defined cutoff point at which preoperative PFTs predicted a marked increased risk of these complications. Five-year survival (79%) was related to lower FEV1 percent predicted, but early postoperative survival was more significantly associated with FVC percent predicted.
CONCLUSION: Poor PFT findings increased the postoperative mortality, pulmonary complications and sternal infection. However, there was no particular threshold value distinguishing a marked increase in respiratory risks.
CLINICAL IMPLICATIONS: PFT's should be performed to screen for undetected pulmonary disease. Optimization of preoperative respiratory treatment may have a role in reduction of these risks. Modifications in surgical and postoperative management should be considered in patients with abnormal preoperative PFT findings.
DISCLOSURE: Indergit Gill, None.