Reduced Reliability of Procalcitonin (PCT) as a Biomarker of Bacterial Superinfection: Concerns about PCT-Driven Antibiotic Stewardship in Critically Ill COVID-19 Patients-Results from a Retrospective Observational Study in Intensive Care Units

Giancarlo Ceccarelli; Francesco Alessandri; Giuseppe Migliara; Valentina Baccolini; Giovanni Giordano; Gioacchino Galardo; Carolina Marzuillo; Corrado De Vito; Alessandro Russo; Massimo Ciccozzi; Paolo Villari; Mario Venditti; Claudio M Mastroianni; Francesco Pugliese; Gabriella d'Ettorre

doi:10.3390/jcm12196171

Reduced Reliability of Procalcitonin (PCT) as a Biomarker of Bacterial Superinfection: Concerns about PCT-Driven Antibiotic Stewardship in Critically Ill COVID-19 Patients-Results from a Retrospective Observational Study in Intensive Care Units

J Clin Med. 2023 Sep 24;12(19):6171. doi: 10.3390/jcm12196171.

Authors

Giancarlo Ceccarelli^{1

2}, Francesco Alessandri^{1

2

3}, Giuseppe Migliara^{1

2}, Valentina Baccolini^{1

2}, Giovanni Giordano^{1

2

3}, Gioacchino Galardo¹, Carolina Marzuillo², Corrado De Vito², Alessandro Russo⁴, Massimo Ciccozzi⁵, Paolo Villari², Mario Venditti^{1

2}, Claudio M Mastroianni^{1

2}, Francesco Pugliese^{1

2

3}, Gabriella d'Ettorre^{1

2}

Affiliations

¹ Hospital Policlinico Umberto I, 00161 Rome, Italy.
² Department of Public Health and Infectious Diseases, University of Rome Sapienza, 00185 Rome, Italy.
³ Intensive Care Unit, Department of General, Specialistic Surgery, University of Rome Sapienza, 00185 Rome, Italy.
⁴ Infectious and Tropical Disease Unit, Department of Medical and Surgical Sciences, 'Magna Graecia' University of Catanzaro, 88100 Catanzaro, Italy.
⁵ Unit of Medical Statistics and Molecular Epidemiology, University Campus Bio-Medico of Rome, 00128 Rome, Italy.

Abstract

Background: The aim of this study was to assess whether procalcitonin levels is a diagnostic tool capable of accurately identifying sepsis and ventilator-associated pneumonia (VAP) even in critically ill COVID-19 patients.

Methods: In this retrospective, observational study, all critically ill COVID-19 patients who survived for ≥2 days in a single university hospital and had at least one serum procalcitonin (PCT) value and associated blood culture and/or culture from a lower respiratory tract specimen available were eligible for the study.

Results: Over the research period, 184 patients were recruited; 67 VAP/BSI occurred, with an incidence rate of 21.82 episodes of VAP/BSI (95% CI: 17.18-27.73) per 1000 patient-days among patients who were included. At the time of a positive microbiological culture, an average PCT level of 1.25-3.2 ng/mL was found. Moreover, also in subjects without positive cultures, PCT was altered in 21.7% of determinations, with an average value of 1.04-5.5 ng/mL. Both PCT and PCT-72 h were not linked to a diagnosis of VAP/BSI in COVID-19 patients, according to the multivariable GEE models (aOR 1.13, 95% CI 0.51-2.52 for PCT; aOR 1.32, 95% CI 0.66-2.64 for PCT-72 h).

Conclusion: Elevated PCT levels might not always indicate bacterial superinfections or coinfections in a severe COVID-19 setting.

Keywords: COVID-19; ICU; PCT; SARS-CoV-2; biomarker; critically ill; intensive care unit; procalcitonin.

Grants and funding

This research was supported by EU funding within the MUR PNRR Extended Partnership initiative on Emerging Infectious Diseases (Project no. PE00000007, INF-ACT).