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Updated: Jun 19, 2025
Surfactant Depletion Combined with Injurious Ventilation Results in a Reproducible Model of the Acute Respiratory Distress Syndrome ARDS
Published on: April 7, 2021
Role of Alveolar-Arterial Difference in Estimation of Extravascular Lung Water in COVID-19-Related ARDS
Martin Kutej1,2, Jiri Sagan3,4, Tereza Ekrtova1
1Department of Anaesthesiology and Intensive Care Medicine, University Hospital Ostrava and Faculty of Medicine, University of Ostrava, Ostrava, Czech Republic.
Background:
The dominant feature of COVID-19-associated ARDS is gas exchange impairment. Extravascular lung water index is a surrogate for lung edema and reflects the level of alveolocapillary disruption. The primary aim was the prediction of extravascular lung water index by the alveolar-arterial oxygen difference. The secondary aims were in determining the relationship between the extravascular lung water index and other oxygenation parameters, the [Formula: see text], end-tidal oxygen concentration, pulmonary oxygen gradient ([Formula: see text] minus end-tidal oxygen concentration), and [Formula: see text].
Methods:
This observational prospective single-center study was performed at the Department of Anaesthesiology and Intensive Care, The University Hospital in Ostrava, The Czech Republic, during the COVID-19 pandemic, from March 20, 2020, until May 24, 2021.
Results:
The relationship between the extravascular lung water index and alveolar-arterial oxygen difference showed only a mild-to-moderate correlation (r = 0.33, P < .001). Other extravascular lung water index correlations were as follows: [Formula: see text] (r = 0.33, P < .001), end-tidal oxygen concentration (r = 0.26, P = .0032), [Formula: see text] minus end-tidal oxygen concentration (r = 0.15, P = .0624), and [Formula: see text] (r = -0.15, P = .01).
Conclusions:
The alveolar-arterial oxygen difference does not reliably correlate with the extravascular lung water index and the degree of lung edema in COVID-19-associated ARDS.
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