Background. The use of C-reactive protein (CRP) and procalcitonin (PCT) as guiding biomarkers in treating severe infections could improve the use of antibiotics. Biomarker dynamics are more reliable than single values in predicting sepsis when making the diagnosis and evaluating the response to antibiotic therapy. Both CRP and PCT used protocols have to be consistent with the clinical context and patient populations.
Objectives: reviewing the use of PCT and CRP in various clinical contexts and the patient population
Sources. We analyzed the most recent studies of these biomarkers for antimicrobial stewardship, including meta-analyses and original trials.
Content. According to several studies, critically ill patients who get antibiotic treatment under the guidance of CRP and PCT see a decrease in antibiotic exposure and related adverse effects. When patients are hospitalized in intensive care units (ICUs), CRP and PCT can be used to distinguish between viral and non-infectious causes of systemic inflammation. In septic patients, CRP levels are reliable to show a high negative predictive value (NPV), especially on day 1 of ICU admission. Consequently, CRP levels decrease during therapy with appropriate antibiotics in the next 3 days.
Implication. In addition to other clinical and laboratory parameters, CRP and PCT provide information about the risk of the bacterial infection worsening or improving under appropriate treatment. These improve antibiotic treatment decisions, allowing individualized treatment regimens with reduced overall antibiotic exposure.