Analysis Of The Clinical Characteristics Of Idiopathic Pulmonary Fibrosis With Pneumonia And The Risk Factors Of Poor Prognosis In Hospital

Objective To investigate the clinical characteristics of patients with idiopathic pulmonary fibrosis(IPF)and pneumonia and analyse the risk factors leading to poor prognosis when they are in hospital.Methods 160 IPF patients and pneumonia were enrolled in the retrospective research.The data of demographic characteristics,clinical presentation,laboratory test of initial admission,pulmonary function examination,imaging features,treatment,pneumonia severity index(PSI)scores and the etiology of these patients during their stay in hospital were collected.These patients were divided into a good prognosis group and a poor prognosis group of hospitalized according to the clinical outcome of the patients at discharge,the clinical outcome included one of the following situations: respiratory failure,hospitalized in the intensive care unit,the days in hospital was increased,combined with hospital infection or death.Firstly,analyzed the clinical characteristics of two groups by t test,u test and 2?test.Then analyzed the risk factors of poor prognosis in these patients by logistic regression.Next,drewROC curve of single factor and multiple factors after regression analysis,respectively.At last,compared the area under curve(AUC)to predict the prognosis of these patients and found out the cut-off value at the maximum value of Youden index for each variable,respectively.Results In the comparation of the good prognosis and poor prognosis group among hospitalized,we found that the detected rate of pathogen in these patients with poor prognosis was higher(P value< 0.05),among them,the major pathogen of the patients with good prognosis were atypical pathogens(50%),and the Mycoplasma pneumoniae occupied the first place(50%),and the major pathogen of the patients with poor prognosis were bacterium(43.3%),most of them was Gram-negative bacteria(33.3%)and Pseudomonas aeruginosa occupied the first place(13.3%).In the comparison of two groups,fever,respiratory rate,heart rate,neutrophil ratio,C-reactive protein(CRP),oxygen pressure,oxygen saturation,whether to use the antibiotics covering Pseudomonas,whether to use the hormone therapy,PSI scores had statistical difference(all P value< 0.05),then put these factors whose P value< 0.1 in the single factor analysis into logistic regression analysis,the results showed that the level of CRP(OR=1.047,95%CI:1.002~1.093),oxygen saturation(OR=0.779,95%CI:0.648~0.935)and PSI scores(OR=1.042,95%CI:1.009~1.077)were independent influence factors of hospitalized prognosis in IPF with pneumonia(P < 0.05).The ROC curve was drawn.The maximum value of the Youden index was cut-off value.The cut-off values of CRP level,blood oxygen saturation level and PSI score were 12mg/L,94% and 81 respectively.The combined AUC(0.851)of the three factors was larger than the single factor C reactive protein AUC(0.649),blood oxygen saturation AUC(0.683),and PSI score AUC(0.709).ConclusionAmong the patients with IPF and pneumonia,between good prognosis group and poor prognosis group,fever,faster respiratory rate,faster heart rate,increased neutrophil ratio,higher blood CRP level,lower arterial oxygen pressure,lower arterial oxygen saturation,and high PSI score were more likely to occur in patients with poor prognosis.The pathogeny detection of two groups with different prognosis was different.The pathogens in good prognosis group were mainly infected by atypical pathogens,among which Mycoplasma pneumoniae were the most common,the most common in the poor prognosis group was bacterial infection,and gram-negative bacilli were the most common,and Pseudomonas aeruginosa occupied the first place.The blood CRP level,arterial oxygen saturation level and PSI scores were independent factors in the hospitalization of patients with IPF and pneumonia.The combination of three factors including C reactive protein,blood oxygen saturation and PSI score should be selected as the first choice to predict poor prognosis in patients with IPF and pneumonia,and the cut-off values of CRP level,blood oxygen saturation level and the PSI score were 12mg/L,94% and 81 points,respectively.