TY - JOUR T1 - Chest computed tomography and alveolar-arterial oxygen gradient as rapid tools to diagnose and triage mildly symptomatic COVID-19 pneumonia patients JF - ERJ Open Research JO - erjor DO - 10.1183/23120541.00737-2020 SP - 00737-2020 AU - Marlise P. de Roos AU - Iris D. Kilsdonk AU - Pieter-Paul W. Hekking AU - Jan Peringa AU - Nynke G. Dijkstra AU - Peter W.A. Kunst AU - Paul Bresser AU - Herre J. Reesink Y1 - 2021/01/01 UR - http://openres.ersjournals.com/content/early/2021/02/04/23120541.00737-2020.abstract N2 - Purpose In pandemic COVID-19, a rapid clinical triage is crucial to determine which patients are in need for hospitalisation. We hypothesised that chest CT and alveolar-arterial oxygen (A-a) gradient may be useful to triage these patients, since it reflects the severity of the pneumonia-associated ventilation/perfusion abnormalities.Methods A retrospective analysis was performed in consecutive patients (n=235) suspected for COVID-19. The diagnostic protocol included low-dose chest CT and arterial blood gas analysis. In patients with CT-based COVID-19 pneumonia, the association between “need for hospitalisation” and A-a gradient was investigated by multivariable logistic regression model; and, the A-a gradient was tested as predictor for need for hospitalisation using ROC curve analysis and logistic regression model.Results 72 out of 235 patients (mean±sd age 55.5±14.6 years, 40% female) screened by chest CT showed evidence for COVID-19 pneumonia. In these patients, A-a gradient was shown to be a predictor of need for hospitalisation, with an optimal decision level (“cut-off”) of 36.4 mmHg (95% CI 0.70–0.91, p<0.001). The A-a gradient was shown to be independently associated with need for hospitalisation (OR 1.97 [95% CI 1.23–3.15], p=0.005, A-a gradient per 10 points) from CT-SS (OR 1.13 [95% CI 0.94–1.36], p=0.191), NEWS (OR 1.19 [95% CI 0.91–1.57], p=0.321) or peripheral oxygen saturation (OR 0.88 [95% CI 0.68–1.14], p=0.345).Conclusion Low dose chest CT and the alveolar-arterial oxygen gradient may serve as rapid and accurate tools to diagnose COVID-19 pneumonia and to select mildly symptomatic patients in need for hospitalisation.FootnotesThis manuscript has recently been accepted for publication in the ERJ Open Research. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJOR online. Please open or download the PDF to view this article.Conflict of Interest: Dr. de Roos has nothing to disclose.Conflict of Interest: Dr. Kilsdonk has nothing to disclose.Conflict of Interest: Dr. Hekking has nothing to disclose.Conflict of Interest: Dr. Peringa has nothing to disclose.Conflict of Interest: Dr. Dijkstra has nothing to disclose.Conflict of Interest: Dr. Kunst has nothing to disclose.Conflict of Interest: Dr. Reesink has nothing to disclose. ER -