The role of lactate dehydrogenase in hospitalized patients, comparing those with pulmonary versus non-pulmonary infections: A nationwide study.

Abstract

BackgroundLactic dehydrogenase reflects target organ damage, and is associated with mortality in patients with infectious diseases.ObjectiveThe purpose of this study was to examine associations of serum lactic dehydrogenase levels with mortality, target organ damage and length of hospital stay in adults with pulmonary and non-pulmonary infections.MethodsThis nationwide retrospective cohort study comprised patients admitted with infections, to medical and surgical departments in eight tertiary hospitals during 2001-2020. Patients with available serum lactic dehydrogenase levels on admission and one week after were included, and stratified by the source of their infection: pulmonary vs. non-pulmonary. Associations of lactic dehydrogenase levels with mortality and target organ damage were analyzed using multivariable logistic regression models. Quantile regression was used for multivariable analysis of the median length of stay.ResultsThe study included 103,050 patients (45.4% male, median age: 69 years); 44,491 (43.1%) had pulmonary infections. The median serum lactic dehydrogenase levels on admission were higher in patients with pulmonary than non-pulmonary infections (418 vs. 385 units per liter (U/L), p900 U/L), compared with 900 U/L, mortality, but none of the other examined outcomes, was greater among those with pulmonary than non-pulmonary infections.ConclusionsAmong hospitalized patients with infectious diseases, lactic dehydrogenase levels were associated with mortality and target organ damage, and were similar in patients with pulmonary and non-pulmonary infections. Among patients with lactic dehydrogenase levels >900 U/L, mortality was prominently higher among those with pulmonary than non-pulmonary infections.