Evaluation of early blood inflammation indicators on the prognosis of patients with severe community-acquired pneumonia

Abstract

Objective To evaluate the prognostic value of early blood inflammatory indicators in patients with respiratory failure caused by severe community-acquired pneumonia. Methods A total of 186 patients diagnosed with respiratory failure due to severe pneumonia on admission were recruited in this study. According to clinical prognosis， they were divided into the death group （n = 42） and improvement group （n = 144）. Twelve cytokines， ferritin， C-reactive protein， procalcitonin， blood routine examination and blood gas analysis results of the patients within two days after admission were analyzed. Pneumonia severity index （PSI） and APACHE Ⅱ scores of the patients were collected. The correlation between the above indicators and prognosis was explored. Results Compared with the improvement group， the levels of IFN-γ， IL-10， IL-6， IL-8， C-reactive protein （CRP）， procalcitonin and ferritin were significantly higher in the death group （all P < 0.05）. Upon admission， the hemoglobin level and platelet count in the death group were significantly lower than those in the improvement group （both P < 0.05）. The PSI and APACHE Ⅱ scores on admission in the death group were significantly higher compared with those in the improvement group （both P < 0.05）. Patients in the death group had higher lactic acid level and lower oxygenation index （OI） compared with their counterparts in the improvement group （both P < 0.05）. Multivariate Logistic regression analysis revealed that IL-6， ferritin， PSI and APACHE Ⅱ scores and lactic acid level were the risk factors for poor prognosis， whereas platelet count was the protective factor for poor prognosis （all P < 0.05）. The receiver operating characteristic （ROC） curve indicated that IL-6，procalcitonin and ferritin were favorable predictors for clinical prognosis of patients. When IL-6 and ferritin levels exceed 11.41 ng/L and 659 μg/L， and platelet count was less than 148.5×109/L， patients were at risk of death. Conclusions In patients with respiratory failure caused by severe community-acquired pneumonia， the increase of blood inflammatory indicators， such as IL-6， ferritin and procalcitonin， suggests high risk death in patients， especially for patients with IL-6 >11.41 ng/L， ferritin>659 μg/L， and platelet count<148.5×109/L. Extensive attention should be paid to lowering the risk of death in these patients.

Keywords

• inflammatory index|cytokines|ferritin|severe pneumonia|respiratory failure|prognosis