Lactate dehydrogenase and C-reactive protein as predictors of respiratory failure in CoVID-19 patients

Highlights • Elevated LDH and CRP serum concentrations are associated to respiratory failure in CoVID-19 patients.
Objective The dramatic worldwide CoVID-19 infection requires the identification of a reliable and inexpensive tool to quickly discriminate patients with a more unfavorable outcome. Methods We performed routine laboratory tests suitable to identify tissue damage and inflammatory status in 123 consecutive CoVID-19 patients admitted to the Emergency Department of the hospital of Piacenza (Emilia-Romagna, Northern Italy). The results were correlated with patients’ respiratory function evaluated by the partial pressure of arterial oxygen to fraction of inspired oxygen ratio (PaO2/FiO2). Results: The most common laboratory abnormalities were lymphocytopenia and elevated values of C-reactive protein (CRP) and lactate dehydrogenase (LDH). Aspartate aminotransferase (AST), alanine aminotransferase (ALT) and creatine kinase (CK) were also increased. The respiratory performance (PaO2/FiO2) showed a strong inverse correlation with LDH (r= 0.62, r2 0.38, p value< 0.0001) and CRP (r= 0.55, r2 0.31, p value< 0.0001). PaO2/FiO2 values also showed a significant inverse correlation with age (r= -0.37, p< 0.0001), AST (r= -0.31, p