Abstract:Objective To study the significance of the level of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) in serum and bronchoalveolar lavage fluid (BALF), Acute Physiology and Chronic Health Evaluation II (APACHE II) score, and Sequential Organ Failure Assessment (SOFA) score in evaluating the conditions and prognosis of children with severe pneumonia. Methods A total of 76 children with severe pneumonia who were admitted from August 2017 to October 2019 were enrolled as the severe pneumonia group. According to the treatment outcome, they were divided into a non-response group with 34 children and a response group with 42 children. Ninety-four children with common pneumonia who were admitted during the same period of time were enrolled as the common pneumonia group. One hundred healthy children who underwent physical examination in the outpatient service during the same period of time were enrolled as the control group. The serum level of sTREM-1, APACHE II score, and SOFA score were measured for each group, and the level of sTREM-1 in BALF was measured for children with severe pneumonia. The correlation of the above indices with the severity and prognosis of severe pneumonia in children was analyzed. Results The severe pneumonia group had significantly higher serum sTREM-1 level, APACHEII score, and SOFA score than the common pneumonia group and the control group (P < 0.05). For the children with severe pneumonia, the non-response group had significant increases in the levels of sTREM-1 in serum and BALF and SOFA score on day 7 after admission, while the response group had significant reductions in these indices, and there were significant differences between the two groups (P < 0.05). Positive correlation was found between any two of serum sTREM-1, BALF sTREM-1, and SOFA score (P < 0.05). APACHE II score was not correlated with serum sTREM-1, BALF sTREM-1, and SOFA score (P > 0.05). Conclusions The level of sTREM-1 in serum and BALF and SOFA score can be used to evaluate the severity and prognosis of severe pneumonia in children.