TY  - JOUR
TI  - Detection of inspiratory recruitment of atelectasis by automated lung sound analysis as compared to four-dimensional computed tomography in a porcine lung injury model
AV  - public
JF  - Critical care
PB  - BioMed Central ; Springer
ID  - heidok24339
VL  - 22
IS  - 50
EP  - 11
CY  - London ; Berline ; Heidelberg
Y1  - 2018///
A1  - Boehme, Stefan
A1  - Toemboel, Frédéric P. R.
A1  - Hartmann, Erik K.
A1  - Bentley, Alexander H.
A1  - Weinheimer, Oliver
A1  - Yang, Yang
A1  - Achenbach, Tobias
A1  - Hagmann, Michael
A1  - Kaniusas, Eugenijus
A1  - Baumgardner, James E.
A1  - Markstaller, Klaus
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/24339/
SN  - 1466-609X
N2  - Background: Cyclic recruitment and de-recruitment of atelectasis (c-R/D) is a contributor to ventilator-induced lung injury (VILI). Bedside detection of this dynamic process could improve ventilator management. This study investigated the potential of automated lung sound analysis to detect c-R/D as compared to four-dimensional computed tomography (4DCT).

Methods: In ten piglets (25 ± 2 kg), acoustic measurements from 34 thoracic piezoelectric sensors (Meditron ASA, Norway) were performed, time synchronized to 4DCT scans, at positive end-expiratory pressures of 0, 5, 10, and 15 cmH2O during mechanical ventilation, before and after induction of c-R/D by surfactant washout. 4DCT was post-processed for within-breath variation in atelectatic volume (? atelectasis) as a measure of c-R/D. Sound waveforms were evaluated for: 1) dynamic crackle energy (dCE): filtered crackle sounds (600?700 Hz); 2) fast Fourier transform area (FFT area): spectral content above 500 Hz in frequency and above ?70 dB in amplitude in proportion to the total amount of sound above ?70 dB amplitude; and 3) dynamic spectral coherence (dSC): variation in acoustical homogeneity over time. Parameters were analyzed for global, nondependent, central, and dependent lung areas.

Results: In healthy lungs, negligible values of ? atelectasis, dCE, and FFT area occurred. In lavage lung injury, the novel dCE parameter showed the best correlation to ? atelectasis in dependent lung areas (R2 = 0.88) where c-R/D took place. dCE was superior to FFT area analysis for each lung region examined. The analysis of dSC could predict the lung regions where c-R/D originated.

Conclusions: c-R/D is associated with the occurrence of fine crackle sounds as demonstrated by dCE analysis. Standardized computer-assisted analysis of dCE and dSC seems to be a promising method for depicting c-R/D.
SP  - 1
ER  -