Abstract
Introduction: Mechanical ventilation in the presence of pulmonary fibrosis is challenging as it may require high inspiratory pressure to ensure gas exchange, increasing the risk for ventilator-induced injury. Physiologically variable ventilation (PVV), a mode that mimics the variability of spontaneous breathing, has proven beneficial in various models of pulmonary disease, but its potential advantages in lung fibrosis have not been investigated. We assessed the benefits of PVV over conventional pressure-controlled ventilation (PCV) using an experimental model of lung fibrosis.
Methods: Lung fibrosis was induced by nebulized bleomycin in rabbits. After 50 days, animals were randomized to receive 6 hours of PCV (n=10) or PVV (n=11). The PVV pattern was pre-recorded in spontaneously breathing rabbits. Respiratory mechanics and blood gases were assessed hourly, end-expiratory lung volume and shunt fraction were measured before and after the 6-hour ventilation.
Results: The application of 6 hours of PCV increased respiratory tissue elastance (H, 58±14% [mean ± half-width 95% CI]) and damping (G, 36±13%), as well as decreased end-expiratory lung volume (EELV, -26±7%), oxygenation ratio (PaO2/FiO2, ‑14±5%) and elevated intrapulmonary shunt (Qs/Qt, 85±71%). The time-matched changes after the application of PVV were significantly lower for H (41±6%), G (22±9%), EELV (-13±6%), PaO2/FiO2 (‑3±5%) and Qs/Qt (20±22%, p<0.05 for all).
Conclusions: Prolonged application of PVV, in comparison with PCV, prevented the deterioration of gas exchange, respiratory tissue mechanics and intrapulmonary shunt by reducing lung derecruitment in a model of lung fibrosis.
Footnotes
Cite this article as: European Respiratory Journal 2021; 58: Suppl. 65, PA2427.
This abstract was presented at the 2021 ERS International Congress, in session “Prediction of exacerbations in patients with COPD”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2021