ABSTRACT
Background. Secondary infections in patients receiving extracorporeal membrane oxygenation (ECMO) are difficult to identify as many signs traditionally associated with infection, such as temperature, are partially controlled by the ECMO circuit. This study analyzes the utility of procalcitonin (PCT) as a diagnostic marker in identifying secondary infections in patients receiving ECMO with influenza or COVID-19. Methods. A single center retrospective study was performed on patients receiving ECMO with underlying influenza or COVID-19 from November 2017 to October 2021. Patient demographics, time receiving ECMO, culture data, and PCT levels were extracted. The first PCT within three days of an infection designated positive was compared to negative values, PCT extracted from patients without an identified infection or any PCT 10 days after the most recent infection. Furthermore, PCT levels were compared by type of pathogen as well as site of infection via Mann-Whitney U tests. Results. 84 patients (77% males) met inclusion criteria with median age of 43 (interquartile range (IQR): 35-51). Median ECMO time was 416 hours (IQR: 232-824), with 64 (76%) of the patients admitted for COVID-19. A total of 276 (3.3 per patient) PCT were ordered during the study period. Of the 92 infections identified, 33 (36%) had an associated PCT value with 19 (58%) PCT collected on the day of positive culture, 10 (32%) within one day, and 4 (12%) collected two to three days after positive culture. There was no significant difference between median PCT value among the infection group (1.0 IQR: 0.40-1.19) compared to the non-infectious group (1.27 IQR: 0.47-4.26, p= 0.19), between Gram-positive and Gram-negative infections (1.09 IQR: 0.43-2.70 vs. 0.95 IQR: 0.4-1.29 p= 0.35) or between bloodstream infections and respiratory infections (1.3 IQR 0.45-2.70 vs. 0.55 IQR: 0.4-1.38, p=0.35). PCT does not decline after infection is identified (Figure 1). Procalcitonin Trends Conclusion. While PCT has been proposed as a potential diagnostic marker for secondary infections in patients receiving ECMO, this single center study did not demonstrate utility of PCT in identifying secondary infections. Furthermore, there was no association of PCT levels with either the site of infection or type of infectious organism. (Figure Presented).