Introduction:

Few studies have been interested in Mixed Ventilatory Impairment (MVI) which is    characterized by the coexistence of both obstruction and restriction.

Objective:

To describe etiological and functional profiles of MVI.

Patients and methods:

This was a retrospective study including 9546 patients, who consulted our PFT department from January 2016 to December 2022. According to ATS/ERS recommendations, MVI is confirmed when both FEV1/FVC and TLC are below the Low Limit of Normal. Only 47 patients were diagnosed with MVI In this study group.   16 patients performed measurement of DLCO among them 11 patients completed   6-minutes-walk test (6MWT).

Results:

In MVI group, mean age was 49.55±20.49 years. Means values of FEV1, FVC, FEV1/FVC ratio and TLC were 40.14±15.03%, 53.36±16.80%, 59.55±10.08% and 63.9±14.20%, respectively. Means values of DLCO, 6-minutes-walk-distance and minimal oxygen saturation were 52.62±23.34%, 455.27±118.64 m, 91.18±6.69%, respectively. The etiological survey showed a variety of pathologies: Chronic Obstructive Pulmonary Disease (COPD) 32.6%, among them 10.86% associated COPD and obesity, Interstitial Lung Disease (ILD) 30%, lung cancer 15.9%, Bronchial Dilatation (BD)15.2%, tuberculosis 15.2%, sarcoidosis 15.2%, the association asthma-COVID19 infection 6.4%, diaphragmatic paralysis 4.3% and rare cases of myopathy, Marfan syndrome, ciliary dyskinesia, scoliosis and pneumonectomy.

Conclusion:

MVI occurs infrequently and is more commonly caused by a mixture of pulmonary parenchymal and non-pulmonary disorders. COPD, ILD, lung cancer, tuberculosis and BD compose the majority of etiologies in our sample.