Effects of intra-pulmonary percussive ventilation on the viscoelastic properties of secretions

Introduction Some instrumental techniques for bronchial clearance generate percussions in the bronchopulmonary tree. This study aimed to investigate the effect of intra-pulmonary percussive ventilation (IPV) devices on the rheology of secretions under well-controlled conditions and, if necessary, to determine the optimal frequency and oscillatory amplitude parameters required. Methods Sputum samples were collected from patients with respiratory disease. Each sample was then subdivided into 5 subsamples of equal quantity. On the one hand, the subsamples were placed independently in a circuit simulating the usual breathing pattern of an adult patient. On the other hand, an IPV device was connected to the circuit to generate percussions. Each of the 5 subsamples was exposed to a different IPV setting. After the session, each subsample was collected for analysis of rheological properties using a rheometer. Results 200 subsamples were analysed. No statistically significant differences were found between conditions for any of the rheological variables studied. Conclusion The results of this study showed no effect of intrapulmonary percussions on the rheology of secretions under controlled conditions. However, these results need to be confirmed under in vivo conditions.