To explore the clinical diagnostic features and therapeutic status of severe and critical influenza A(H1N1)viral pneumonia.

The clinical data of 6 patients of severe and critical influenza A(H1N1) viral pneumonia were analyzed retrospectively from January to February 2019 in Medicine Intensive Care Unit (ICU) of Infectious Disease Hospital of Yunnan Province.

All of the 6 patients had fever and cough (6/6), and followed by dyspnea and bloody sputum (4/6). The levels of neutrophil percentage, procalcitonin(PCT) and lactate dehydrogenase (LDH) elevated in 5 patients. Lymphocyte count decreased in 3 cases, CD4⁺ lymphocyte count decreased in 2 cases, c-reactive protein (CRP) levels elevated in 6 cases. Four patients had elevated N-terminal pro-brain natriuretic peptide (Nt-proBNP) and D-dimer levels, 3 patients had elevated alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, and 2 patients had elevated creatinine levels. Bronchoalveolar lavage fluid (BALF) and endotracheal aspirate culture showed that there were 1 patient of Candida Parapsilosis, 1 patient of Acinetobacter BaumannⅡ, 1 patient of Chryseobacterium Indologenes and 1 patient of Chromobacterium Prodigiosum. Chest CT examination showed that in all of the 6 patients, multiple infiltration and ground-glass, with streaky and netty equi-interstitial shadows in bilateral lungs, mainly in the lower-middle lobe and extrapulmonary zone. All patients were treated with anti-infection, immunomodulator, corticosteroids, mechanical ventilator assisted ventilation, continuous venous-venous hemodiafiltration (CVVHDF) and lung lavage therapy and so on. All of the 6 patients were cured, and the lower lung dorsal segment of 2 patients left over grid-like proliferative fibrous lesions.

Early identification, timely and effectively antiviral treatment, reduction of secondary bacterial and fungal infections are the keys to the treatment of severe and critical viral pneumonia of influenza A (H1N1).