Using procalcitonin-guided algorithms to improve antimicrobial therapy in ICU patients with respiratory infections and sepsis.

PURPOSE OF REVIEW: In patients with systemic bacterial infections hospitalized in ICUs, the inflammatory biomarker procalcitonin (PCT) has been shown to aid diagnosis, antibiotic stewardship, and risk stratification. Our aim is to summarize recent evidence about the utility of PCT in the critical care setting and discuss the potential benefits and limitations of PCT when used for clinical decision-making.

RECENT FINDINGS: A growing body of evidence supports PCT use to differentiate bacterial from viral respiratory infections (including influenza), to help risk stratify patients, and to guide decisions about optimal duration of antibiotic therapy. Different PCT protocols were evaluated for these and similar purposes in randomized controlled trials in patients with varying severities of predominantly respiratory tract infection and sepsis. These trials demonstrated effectiveness of monitoring PCT to de-escalate antibiotic treatment earlier without increasing rates of relapsing infections or other adverse outcomes. Although serial PCT measurement has shown value in risk stratification of ICU patients, PCT-guided antibiotic escalation protocols have not yet shown benefit for patients.

SUMMARY: Inclusion of PCT data in clinical algorithms improves individualized decision-making regarding antibiotic treatment in patients in critical care for respiratory infections or sepsis. Future research should focus on use of repeated PCT measurements to risk-stratify patients and guide treatment to improve their outcomes.