KInetics of Procalcitonin to Reduce Unnecessary aNtibiotic Use - Comparing Procalcitonin Kinetics-guided and Absolute Procalcitonin Value-guided Antibiotic Initiation in Reducing Unnecessary Antibiotic Use in Critically Ill Patients

The study aims to compare the efficacy and safety of an absolute procalcitonin (PCT) value-guided antibiotic initiation protocol and a protocol using the kinetics of PCT (the difference between the actual and the previous day value) in hemodynamically stable critically ill patients with suspected new-onset infection on admission or during ICU stay. The main question it aims to answer: * Can the investigators decrease the number of unnecessary AB therapies using the kinetics of PCT insted of using absolute PCT values? * Is it safe to use PCT kinetics together with the clinical picture to guide AB initiation? AB therapy will be initiated according to predefined PCT protocols (Kinetics and Absolute Group). After 72 hours of treatment, an independent multidisciplinary team (infectologist, microbiologist and intensivist) will decide about the necessity of the treatment with all the relevant results in hand.

NCT Number	NCT07211620
Lead Sponsor	Semmelweis University
Conditions	Infection, Sepsis
Enrollment	250 participants
Start Date	2025-11-06
Primary Completion	2027-12 (estimated)
Study Completion	2027-12 (estimated)
Updated on ClinicalTrials.gov	2026-01-09