Risk assessment of infected children with Pseudomonas aeruginosa pneumonia by combining host and pathogen predictors

The current criteria of pneumonia severity, which mainly depend on clinical manifestations and laboratory findings from blood routine tests and X-ray examination, are still of great significance in preliminary diagnosis. However, the utility of traditional severe pneumonia indexes (SPI) without considering high virulence and multidrug resistance of Pseudomonas aeruginosa has limitations. Thus, it is of great value to make a risk assessment, which can serve as a complementary option for incomplete clinical diagnosis. This study aims to determine risk factors related to severe pneumonia and to comprehensively evaluate the risk conditions of infected children with P. aeruginosa pneumonia. We collected the clinical information of 184 hospitalized children with P. aeruginosa pneumonia and measured pathogen data on virulence factors and drug resistance. The risk assessment matrix was formed from the significant host and pathogen predictors, and the risk score was determined by the clinical references and the optimal critical values (OCV) of the receiver operator characteristic (ROC) curves. There were 103 (56%) and 81 (44%) infected children diagnosed as mild and severe pneumonia by SPI, respectively. Seven risk factors were significantly associated with severe pneumonia, including body temperature, respiratory rate, C-reactive protein, elastase, exotoxin-A, exoenzyme-U and multidrug resistances. Among 184 infected children, the risk assessment matrix displayed 62 cases (34%) at high risk, 51 cases (28%) at medium risk, and 71 cases (38%) at low risk in terms of pneumonia severity. On the basis of the SPI preliminary diagnosis, the risk assessment prompted that 31% (32/103) mild patients would be faced with a poorer outcome and 23% (19/81) severe patients might get a better prognosis. Therefore, the well-established assessment indicates that the interplay between host response, antibiotic resistance, and virulence may modulate the severity of P. aeruginosa pneumonia in infected children.