Stratified and prognostic value of admission lactate and severity scores in patients with community-acquired pneumonia in emergency department: A single-center retrospective cohort study

BACKGROUND: Community-acquired pneumonia (CAP) is a potentially life-threatening condition. The aim of this study is to investigate the stratified and prognostic value of admission lactate and severity scores (confusion, urea >7 mmol/L, respiratory rate ≥30/min, blood pressure <90 mm Hg systolic and/or ≤60 mm Hg diastolic, and age ≥65 years [CURB65], pneumonia severity index [PSI], sequential organ failure assessment [SOFA], qSOFA) in patients with CAP in emergency department. METHODS: Adult patients diagnosed with CAP admitted between January 2017 and January 2019 were enrolled and divided into severe CAP (SCAP) group and nonSCAP (NSCAP) group according to international guidelines, death group, and survival group according to 28-day prognosis. Predicting performance of parameters above was compared using receiver operating characteristic curves and logistic regression model. Cox proportional hazard regression model was used to identify variables independently associated with 28-day mortality. RESULTS: A total of 350 patients with CAP were enrolled. About 196 patients were classified as SCAP and 74 patients died after a 28-day follow-up. The levels of CURB65, PSI, SOFA, qSOFA, and admission lactate were higher in the SCAP group and death group. SOFA showed advantage in predicting SCAP, while qSOFA is superior in predicting 28-day mortality. The combination of SOFA and admission lactate outperformed other combinations in predicting SCAP, and the combination of qSOFA and lactate showed highest superiority over other combinations in predicting 28-day mortality. CONCLUSION: The SOFA is a valuable predictor for SCAP and qSOFA is superior in predicting 28-day mortality. Combination of qSOFA and admission lactate can improve the predicting performance of single qSOFA.