- Poster presentation
- Open Access
Lung sound amplitude measured by vibration response imaging is influenced by the presence of secretions
© Lev et al. 2011
- Published: 1 March 2011
- Arbitrary Unit
- Left Lung
- Breath Sound
- Effective Removal
- Acoustic Effect
There is no valid estimation of the presence of airway secretions in mechanically ventilated patients. Secretions may amplify breath sounds by increasing turbulence in the airways or alternatively decrease breath sounds by obstructing air flow. Vibration response imaging (VRI) was recently suggested as a tool to assess secretion removal following physiotherapy . The objective of our analysis was to describe the acoustic effects of secretion removal by measuring the lung sound amplitudes pre and post airway suction in both lungs.
Twenty-two recordings pre-suction and 22 recordings post-suction (19 patients) were performed with VRI while the mode of ventilation remained constant. The sound amplitude measurements before and after the suction procedure were compared.
The finding that the VRI signal amplitude decreased after a suction procedure in ventilated patients suggests that secretions are usually noisy. This effect was more pronounced on the right side probably due to expected more efficient secretion removal. We suggest that effective removal of secretions may be inferred by a combination of a decrease in VRI signal coupled with an increase in air flow rate.
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.