AEROSOL BOLUS DISPERSION IN PATIENTS WITH BRONCHIOLITIS OBLITERANS AFTER HEART-LUNG AND DOUBLE-LUNG TRANSPLANTATION

Bronchiolitis obliterans (BO) is one of the main late complications in patients after lung transplantation. Because BO is located in small a irways, conventional lung function tests are supposed to be rather ins ensitive to detect early stages of this disease, In this study, the ca pability of the aerosol bolus dispersion test to detect BO was tested in 12 subjects with heart-lung and double-lung transplantation. Four o f these patients had histological evidence of BO, The broadening (disp ersion) of inhaled boluses consisting of monodispersed inert test part icles during respiration was repeatedly measured in each subject, Addi tional measurements of spirometric and bodyplethysmographic measuremen ts were performed, Patients with evidence of BO showed significantly i ncreased aerosol bolus dispersion and significantly reduced maximal ai rflow parameters, Calculation of receiver operating characteristics (R OCs) revealed that from all lung function parameters under considerati on, aerosol bolus dispersion divided by the maximum expiratory flow ra te at 50% of vital capacity (MEF50) and MEI50 had the highest sensitiv ity and specificity for the detection of BO, Both parameters showed a sensitivity and specificity of 100%, Therefore, it may be speculated t hat even in early stages of disease, the combination of MEF50 measurem ent with aerosol bolus dispersion measurements may be a powerful tool for the detection of BO in patients with lung transplantation.