Is Procalcitonin Measurement Useful for SARS-CoV-2 Infection Management in the Emergency Department as well as in the ICU?

Numerous interventional studies have validated the usefulness of the dosage of procalcitonin for antibiotic stewardship in lower respiratory tract infections (LRTI). Despite the absence of prospective interventional trials specifically for Covid-19 patients, the measurement of procalcitonin can be part of the standard of care in the emergency room as well as in other LRTIs to help with antibiotic decisions. Most non-complicated SARS-CoV-2 infections have procalcitonin concentrations < 0.25 mu g/l. Furthermore, concentrations > 0.5 mu g/l are usually associated with the risk of severe outcome and/or bacterial co-infection. In intensive care units, procalcitonin is promising in patients with acute respiratory distress syndrome due to Covid-19. In those patients, the prescription of antibiotics must be daily reconsidered, in that the risk of bacterial infection is evolving all along the long-lasting duration of stay, in order to limit the selection of resistant strains and limit antibiotic toxicity.