Abstract: Clinical and Pathological Features of Severe Influenza A H1N1 Influenza Virus Pneumonia（Report of 24 Cases） Liguanhua Zhangli Liyuechuan Jiawei Zhangdongrui Gaoshulian Zhaoyong Abstract Object：To research the main clinical features of critically ill patients with influenza A H1N1 influenza virus pneumonia, try to find the relationship between airway secretions and cardiopulmonary pathology change with continuous hypoxemia. Methods: It was a retrospective analysis of the critically ill patients with influenza A H1N1 influenza virus pneumonia admitted in RICU. Result: Average age of 24 patients was 48.25±19.73 years old. 15 of them were pregnant women, obesity and who suffered chronic underlying diseases. The main symptoms of them were progressive shortness of breath, cough and myalgia. 91.67% patients had found multiple lung consolidation shadow by X-ray. After admission, airway secretions were collected, and the protein concentration of which was 34.1g/L-37.7g/L in 5 cases. Their LDH concentration was 792U/L- 1890U/L. White blood cell count was 722/ml-1470/ml, included 21-44% neutrophils, 11.1-56% mononuclear cells, 2.7-11% eosinophils, 1.8-5.4% basophils. Pathological changes of these patients were hyaline membrane formation, alveolar cavity collapse, myocardial cell degeneration and focal myocardial necrosis. Intubation and mechanical ventilation in 6 cases, 5 of them dead and the mortality rate was 20.83%. Conclusion: Those patients who suffered underlying diseases, maternal and who hadn’t been subject to effective and timely application of antiviral drugs after onset. LDH and protein in airway secretions increased, count of inflammatory cells increased was the performance of lung pathological damage. Effect of Mechanical ventilation was not satisfied in part of patients who had diffuse lung consolidation in X-ray, and the related complications leaded to exacerbation or death in part of them.

Key words: Viral pneumonia, Airway secretions, Cytology, Pathology, Mechanical ventilation.