A 43-year-old with suspected CAP has a negative procalcitonin at presentation but meets clinical and radiographic criteria for bacterial CAP. What is ...

Question

A 43-year-old with suspected CAP has a negative procalcitonin at presentation but meets clinical and radiographic criteria for bacterial CAP. What is the role of procalcitonin in initial antibiotic decisions?

Accepted Answer

A negative procalcitonin rules out bacterial CAP; withhold antibiotics

Answer

Use procalcitonin to decide initial antibiotics in all cases

Answer

Do not use procalcitonin to withhold initial antibiotics when clinical diagnosis of CAP is established

Answer

Start antivirals only

Answer

Use procalcitonin threshold >0.5 ng/mL to diagnose CAP

us-abim MCQ (SBA): CAP (Biomarkers)

A 43-year-old with suspected CAP has a negative procalcitonin at presentation but meets clinical and radiographic criteria for bacterial CAP. What is the role of procalcitonin in initial antibiotic decisions?