Impulse Oscillometry Versus Spirometry to Detect Bronchiolitis Obliterans Syndrome in Bilateral Lung Transplant Recipients: A Prospective Diagnostic Study.

BACKGROUND: Chronic lung allograft dysfunction (CLAD), and especially bronchiolitis obliterans syndrome (BOS), remain dominant causes of morbidity and mortality after lung transplantation. Interest is growing in the forced oscillation technique, of which impulse oscillometry (IOS) is a form, as a tool to improve our understanding of these disorders. However, data remain limited and no longitudinal studies have been published, meaning there is no information regarding any capacity IOS may have for the early detection of CLAD. METHODS: We conducted a prospective longitudinal study enrolling a consecutive sample of adult bilateral lung transplant recipients with healthy lung allografts or CLAD and performed ongoing paired IOS and spirometry tests on a clinically determined basis. We assessed for correlations between IOS and spirometry and examined any predictive value either modality may hold for the early detection of BOS. RESULTS: We enrolled 91 patients and conducted testing for 43 mo, collecting 558 analyzable paired IOS and spirometry tests, with a median of 9 tests per subject (interquartile range, 5-12) and a median testing interval of 92 d (interquartile range, 62-161). Statistically significant moderate-to-strong correlations were demonstrated between all IOS parameters and spirometry, except resistance at 20 Hz, which is a proximal airway measure. No predictive value for the early detection of BOS was found for IOS or spirometry. CONCLUSIONS: This study presents the first longitudinal data from IOS after lung transplantation and adds considerably to the growing literature, showing unequivocal correlations with spirometry but failing to demonstrate a predictive value for BOS.

Adverse cardiac outcomes after pulmonary function testing with recent myocardial infarction.

ATS/ERS Guidelines list pulmonary function testing (PFT) within one month of myocardial infarction (MI) as a contraindication, based on expert opinion. This retrospective review of 136 patients undergoing Coronary Artery Bypass Graft (CABG) surgery identified 21 patients who had PFTs despite MI in the preceding month (MI + PFT group). The MI + PFT Group had zero incidence of MI or serious cardiac arrhythmia between PFTs and surgery. Comparison of post-operative outcomes between the MI + PFT Group and all other CABG patients showed no significant differences. In this small sample size, PFTs appear safe within one month of MI.