What is the clinical significance of procalcitonin (PCT)?

From the Guidelines

Procalcitonin is a valuable biomarker for guiding antibiotic therapy decisions, particularly in respiratory infections and sepsis, and its levels can be used to support the discontinuation of empiric antibiotics in patients who initially appeared to have sepsis, but subsequently have limited clinical evidence of infection, as suggested by the most recent guidelines 1.

Key Points

• Procalcitonin levels can be used to guide antibiotic therapy decisions, with normal levels typically below 0.1 ng/mL and values above 0.5 ng/mL suggesting possible bacterial infection 1.
• The use of procalcitonin to guide therapy has been associated with a reduced risk of mortality and a reduction in antibiotic exposure, as demonstrated by a meta-analysis of 11 RCTs involving 4,482 patients 1.
• Procalcitonin levels of less than 0.5 µg/L or levels that decrease by greater than or equal to 80% from peak levels may guide antibiotic discontinuation once patients stabilize, as suggested by several RCTs 1.
• A recent systematic review and meta-analysis of 16 studies and greater than 5000 patients showed that PCT-guided antibiotic discontinuation appeared to decrease antibiotic utilization by 1 day and improve mortality, although the evidence was of low certainty 1.

Clinical Use

• Procalcitonin can be used to support the discontinuation of empiric antibiotics in patients who initially appeared to have sepsis, but subsequently have limited clinical evidence of infection, as suggested by the Surviving Sepsis Campaign guidelines 1.
• The measurement of procalcitonin levels can be used to support shortening the duration of antimicrobial therapy in sepsis patients, as suggested by the guidelines 1.
• Procalcitonin can be used in conjunction with clinical assessment to guide antibiotic therapy decisions, but decisions should not be made solely based on changes in procalcitonin levels, as emphasized by the guidelines 1.

From the Research

Procalcitonin Guidance in Sepsis

• Procalcitonin (PCT) algorithms for antibiotic treatment decisions have been studied in various settings, suggesting that PCT-guided therapy may reduce antibiotic exposure without increasing mortality rate 2, 3, 4.
• PCT-guided therapy has been shown to reduce the duration of antimicrobial therapy in patients with severe sepsis and septic shock 2, 3, 4.
• The use of PCT guidance has no adverse impact on mortality and length of ICU stay in adult patients with suspected or confirmed sepsis 3, 4.

Reduction of Antibiotic Usage

• PCT guidance can safely reduce antibiotic usage when used to discontinue antibiotic therapy in adult ICU patients and when used to initiate or discontinue antibiotics in adult patients with respiratory tract infections 4.
• Procalcitonin-based algorithms can safely reduce antibiotic use in stable, low-risk patients with respiratory infections and in critically ill patients with suspected sepsis 5.
• The reduction in antibiotic exposure has been associated with a decrease in the incidence of infection-associated adverse events, such as new infections by Clostridioides difficile or multidrug-resistant organisms 6.

Clinical Outcomes

• PCT guidance has been shown to reduce 28-day mortality in patients with sepsis 6.
• The use of PCT guidance has also been associated with a reduction in the cost of hospitalization 6.
• The length of antibiotic therapy has been reduced in patients receiving PCT-guided therapy compared to standard care 3, 4, 6.