Abstract: Objective To explore the pathogen distribution, changes of cardiorespiratory function and changes of serum inflammatory factors in old patients with cardiac failure complicated with pulmonary infection. Methods A total of 153 cardiac failure patients hospitalized in our hospital from March 2014 to September 2017 were retrospectively analyzed.The patients were divided into pulmonary infected group (n=76) and non-infected group (n=77). Another 82 healthy subjects were served as control group. The respiratory secretions were collected to detect pathogen distribution in infected group. The changes of cardiac and pulmonary functions and peripheral blood inflammatory factors were compared between the three groups. Results A total of 110 pathogens were isolated from infected group, which contained 81 (73.63%) gram negative strains, 27 (24.55%) gram positive strains and 2 (1.82%) fungus. Compared with the control group and non-infected group, the lung function index and pulmonary function decreased significantly in the infected group, containing forced expiratory volume in one second (FEV1), forced vital capacity (FVC), FEV1/FVC, carbon monoxide diffusing capacity (DLCO), maximum mid expiratory flow (MMEF), left ventricular end-diastolic dimension (LVEDD) and left ventricular end-systolic dimension (LVESD). Meanwhile, the serum levels of tumor necrosis factor (TNF) –α, interleukin (IL)-6 and procalcitonin (PCT) weresignificantly higher in the infected group than those in the non-infected group and the control group (P＜0.05).Conclusion Gram negative strains dominate in pulmonary infection of old patients with cardiac failure, and the cardiopulmonary function is significantly decreased due to the infection, whereas the serum levels of inflammatory factors are dramatically increased, which has an auxiliary value in the evaluation of pulmonary infection.

Key words: heart failure, pneumonia, bacterialpulmonary infection, pathogen distribution, cardiac function, pulmonary function, inflammatory factors