(493) Assessing the Utilization and Influence of Procalcitonin on Antibiotic Decision-Making in the ICU

Introduction: Procalcitonin (PCT) is regarded as a promising biomarker to aid in the management of relevant bacterial infections. There is robust data to support the use of PCT-based strategies in sepsis and pneumonia (PNA). In critically ill patients, PCT-guided antibiotic therapy protocols have been associated with a reduction in antibiotic exposure, intensive care unit (ICU) length of stay, and mortality. This study sought to assess the utilization of PCT and evaluate its impact on the antibiotic decision-making process in the ICU at a large academic medical center.

Methods: This was a retrospective descriptive study of patients who had at least one PCT level addressed by an ICU team from June 2022 through May 2023. Collected data included indication for level, number of PCT levels per encounter, timing of levels in relation to antibiotic initiation, and management of antibiotic therapy following result. Potential factors that have been associated with falsely elevated PCT levels, including trauma, acute kidney injury, renal replacement therapy, acute respiratory distress syndrome, and presence of active COVID-19 infection, were also collected. A subgroup analysis was conducted based on indication and FDA approved PCT cut-off levels.

Results: A total of 280 patients had at least one PCT level addressed in the ICU. Most patients had an indication of PNA (221/280, 79%) and had only one PCT level drawn during admission (186/280, 66%). Of the patients with PNA that received antibiotics and whose PCT was < 0.25 ng/mL, 8% had antibiotic therapy escalated (6/77), 12% de-escalated (9/77), 31% discontinued (24/77), and 49% had no change in therapy (38/77). When the PCT value was >0.25 ng/mL in patients who received antibiotics for PNA, 9% had therapy escalated (12/127), 12% de-escalated (15/127), 10% discontinued (13/127), and 69% had no change (87/127). Of patients in the PNA group whose PCT was >0.25 ng/mL, 92% (120/131) had at least one factor that could falsely elevate PCT and PCT trending was utilized in 33% (40/120) of those patients.

Conclusions: In conclusion, PCT demonstrated a lack of impact on provider decision-making in the ICU at a large academic medical center. Further, PCT levels were frequently ordered in patients with factors associated with PCT elevation and levels were unlikely to be trended.