New study aims to cut unnecessary antibiotics in ICU patients

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Adult (18 years \< ) non-surgical, surgical, or trauma patients * Suspected new-onset infection on admission or during ICU stay * The source of infection is known or highly suspected, and source control has been implemented if needed (i.e., removal of an infected device (e.g., central line, endoprosthesis) * Two PCT values are available - one on the day of suspicion of infection and one 24±4 hours earlier. * Microbiology sampling has to be performed (according to all presumed sources - blood culture -aerobic and anaerobic, lower respiratory tract sample (tracheal aspirate/bronchoalveolar lavage), urine, etc.). * Written informed consent of the patient (or legal guardian if the patient cannot provide consent) Exclusion Criteria: * Septic shock (hypotension requiring vasopressor therapy to maintain mean blood pressure of 65 mmHg or greater and having a serum lactate level greater than 2 mmol/L after adequate fluid resuscitation) * Infections for which long-term antibiotic treatment is strongly recommended (e.g., infective endocarditis, osteoarticular infections, chronic prostatitis, tuberculosis) * Infections related to primary surgical intervention and adequate source control cannot be guaranteed (e.g., fecal peritonitis, pancreatic necrosectomy, infective necrotizing fascitis - i.e., Fournier's gangrene), * Indisputable infections (e.g., hepatic abscess, empyema) * Poor chance of survival (i.e., expected ICU stay less than 24 hours or initial Acute Physiology and Health Evaluation Score II (APACHE II) \>30) * Admissions after cardiopulmonary resuscitation * Severe immunosuppression other than steroid use * stem-cell transplant recipients * solid organ transplant patients * HIV infection with a CD4 count of less than 200 cells/mm3 * Neutropenia with less than 500 neutrophils/mm3 * Patients on ABs within 72 hours before inclusion * Patients in pregnancy or breastfeeding. Women of childbearing age will be screened by a urine pregnancy test before inclusion in the study.