Clinical Significance of Basic Laboratory Parameters in Predicting the Use of Various Methods of Oxygen Supplementation in COVID-19

Introduction: The severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection resulted in significant worldwide morbidity and mortality. The aim of our study was to evaluate the results of laboratory tests performed on patients on admission to the hospital between groups of patients requiring and not requiring oxygen supplementation, and to find predictive laboratory indicators for the use of high-flow nasal oxygen therapy (HFNOT)/continuous positive airway pressure (CPAP)/bilevel positive airway pressure (BPAP). Materials and Methods: We retrospectively analysed the data of consecutive patients hospitalised in the Pulmonology Department of the Temporary COVID Hospital in Poznan from February to May 2021. On admission to the department, the patients had a panel of laboratory blood tests. Results: The study group consisted of 207 patients with a mean age of 59.2 ± 15.0 years of whom 179 (72%) were male. During hospitalisation, oxygen supplementation was required by 87% of patients. Patients requiring oxygen supplementation and/or the use of HFNOT/CPAP/BPAP had lower lymphocyte counts and higher levels of urea, C-reactive protein, D-dimer, troponin, glucose, lactate dehydrogenase (LDH) as well as higher white blood cell and neutrophil counts, The parameter that obtained the highest area under curve value in the receiver operator curve analysis for the necessary use of HFNOT/CPAP/BPAP or CPAP/BPAP was LDH activity. Conclusions: Among the basic parameters assessed on admission to the temporary hospital, LDH activity turned out to be the most useful for assessing the need for CPAP/BPAP active oxygen therapy. Other parameters that may be helpful for predicting the need for HFNOT/CPAP/BPAP are serum levels of urea, D-dimer and troponin.