Comparative study of hematological and radiological feature of severe/critically ill patients with COVID-19, Influenza A H7N9 and H1N1 pneumonia

Abstract Objectives This study aimed to explore useful clinical indexes for management of severe/critically ill patients with COVID-19, Influenza A H7N9 and H1N1 pneumonia by comparing hematological and radiological characteristics between them. Methods Severe/critically ill patients with confirmed diagnosis of COVID-19, Influenza A H7N9 and H1N1 pneumonia were retrospectively enrolled. The demographic data, clinical manifestations, hematological parameters, and radiological characteristics of three groups were compared. The influenza A was divided into two groups with/without patient death. Results In this study, 16 cases of COVID-19, 10 cases of influenza A (H7N9), and 13 cases of influenza A (H1N1) who met severe/critically ill criteria were included. Compared with COVID-19, the Influenza A (H7N9 and H1N1) groups had relatively more chronic diseases (80% and 92.3% vs 25%, P༜0.05), higher APACHE Ⅱ scores (16.00 ± 8.63 and 15.08 ± 6.24, vs 5.50 ± 2.58, P༜0.05) and higher mortality rates (40% and 46.2% vs 0%, P༜0.05). The hematological finding indicated that Influenza A H7N9 and H1N1 patients had more significant lymphocytopenia (0.59 ± 0.31 × 109/L and 0.56 ± 0.35 × 109/L vs 0.97 ± 0.33 × 109/L, P < 0.05), elevated neutrophil to lymphocyte ratio (NLR; 14.67 ± 6.10 and 14.64 ± 10.36 vs 6.29 ± 3.72, P < 0.05) compared to COVID-19. Especially in influenza A patients, NLR was significant different between the patients with or without death. Compared with the H7N9 group, ground glass opacity (GGO) on chest CT was more common in the COVID-19 group (P = 0.028), while pleural effusion was relatively rare (P = 0.001). Conclusion Compared to COVID-19, patients with Influenza A (H7N9 and H1N1) had more underlying chronic diseases and higher mortality rates. The NLR can be used as a clinical parameter for the predication of risk stratification and outcome in COVID-19 and Influenza A pneumonia. Manifestations of pleural effusion or GGO in chest CT may be helpful for the identification of different viral pneumonia.