Role of total lung stress on the progression of early COVID-19 pneumonia
Silvia Coppola, Davide Chiumello, Mattia Busana, Emanuele Giola, Paola Palermo, Tommaso Pozzi, Irene Steinberg, Stefano Roli, Federica Romitti, Stefano Lazzari, Simone Gattarello, Maria Michela Palumbo, Peter Herrmann, Leif Saager, Michael Quintel, Konrad Meissner, Luigi Camporota, John J. Marini, Stefano Centanni, Luciano Gattinoni
Abstract
We investigated if the stress applied to the lung during non-invasive respiratory support may contribute to the coronavirus disease 2019 (COVID-19) progression. Single-center, prospective, cohort study of 140 consecutive COVID-19 pneumonia patients treated in high-dependency unit with continuous positive airway pressure ( n = 131) or non-invasive ventilation ( n = 9). We measured quantitative lung computed tomography, esophageal pressure swings and total lung stress. Patients were divided in five subgroups based on their baseline PaO 2 /FiO 2 (day 1): non-CARDS (median PaO 2 /FiO 2 361 mmHg, IQR [323–379]), mild (224 mmHg [211–249]), mild-moderate (173 mmHg [164–185]), moderate-severe (126 mmHg [114–138]) and severe (88 mmHg [86–99], p < 0.001). Each subgroup had similar median lung weight: 1215 g [1083–1294], 1153 [888–1321], 968 [858–1253], 1060 [869–1269], and 1127 [937–1193] ( p = 0.37). They also had similar non-aerated tissue fraction: 10.4% [5.9–13.7], 9.6 [7.1–15.8], 9.4 [5.8–16.7], 8.4 [6.7–12.3] and 9.4 [5.9–13.8], respectively ( p = 0.85). Treatment failure of CPAP/NIV occurred in 34 patients (24.3%). Only three variables, at day one, distinguished patients with negative outcome: PaO 2 /FiO 2 ratio (OR 0.99 [0.98–0.99], p = 0.02), esophageal pressure swing (OR 1.13 [1.01–1.27], p = 0.032) and total stress (OR 1.17 [1.06–1.31], p = 0.004). When these three variables were evaluated together in a multivariate logistic regression analysis, only the total stress was independently associated with negative outcome (OR 1.16 [1.01–1.33], p = 0.032). In early COVID-19 pneumonia, hypoxemia is not linked to computed tomography (CT) pathoanatomy, differently from typical ARDS. High lung stress was independently associated with the failure of non-invasive respiratory support.