Application of metagenomic next-generation sequencing in patients with severe pneumonia complicated with sepsis and nonsevere pneumonia complicated with sepsis

Sepsis is an organ dysfunction syndrome. The incidence of sepsis in intensive care unit (ICU) patients is as high as 75%, and the mortality rate is high. To explore the diagnostic value and clinical application of metagenomic next-generation sequencing (mNGS) in patients with severe pneumonia complicated with sepsis and nonsevere pneumonia complicated with sepsis. A retrospective study was conducted. BALF of 89 patients with pneumonia in a time hospital was collected, and synchronized mNGS and routine microbial comprehensive tests (CMTs) were performed. The diagnostic value of mNGS and CMT in patients with severe pneumonia complicated with sepsis and nonsevere pneumonia complicated with sepsis was compared, and the diagnostic value of mNGS for severe pneumonia complicated with sepsis was analyzed. We detected samples from 89 patients with more bacterial species than viruses and fungi. A total of 57 pathogens were detected, including 39 bacteria, 11 fungi, and 7 viruses. Of the 56 dominant species identified by mNGS, 38 were bacteria, 11 were fungi, and 7 were viruses. CMT identified a total of 12 dominant species, including 10 bacteria, 2 fungi, and 0 viruses, from the 89 samples. The ability of CMT to detect pathogens was much lower than that of mNGS (56 VS 12). A total of 82 positive results were detected by the mNGS method, and 53 positive results were detected by the CMT method. The percentage of mNGS-positive samples was significantly higher than that of CMT-positive samples. The sensitivity and specificity of mNGS for diagnosis were 0.901 and 0.069, respectively, while the positive predictive value (PPV) and negative predictive value (NPV) were 50.6% and 40%, respectively. The sensitivity and specificity of CMT were 0.408 and 0.273, respectively, while the positive predictive value (PPV) and negative predictive value (NPV) were 86.9% and 3.75%, respectively. The use of mNGS to detect pathogens in BALF improves the sensitivity and specificity of bacterial identification in patients with severe pneumonia and sepsis and nonsevere pneumonia and sepsis. mNGS has obvious advantages over CMT in detecting viruses and identifying infections. It is of clinical significance to guide medication according to mNGS.