From the Guidelines
Procalcitonin is a useful adjunct in the diagnosis and management of urosepsis, particularly in guiding antibiotic therapy decisions and reducing unnecessary antimicrobial exposure, as evidenced by a recent systematic review and meta-analysis 1.
Key Points
- Procalcitonin levels rise significantly in bacterial infections, including urosepsis, with levels often exceeding 0.5 ng/mL and sometimes reaching 10 ng/mL or higher in severe cases.
- Procalcitonin can help differentiate bacterial infection from other inflammatory conditions and assist in determining the severity of infection.
- Serial measurements of procalcitonin can guide antibiotic therapy decisions, including when to initiate antibiotics and potentially when to discontinue them, with a decrease of 80% from peak or levels below 0.5 ng/mL supporting shortening the duration of antibiotic therapy 1.
- Procalcitonin should be used as part of a comprehensive clinical assessment, rather than in isolation, as false positives and negatives can occur.
- Other markers like C-reactive protein, white blood cell count, and clinical parameters remain important in the overall evaluation of patients with suspected urosepsis.
Clinical Recommendations
- Measure procalcitonin in addition to bedside clinical evaluation in critically ill patients with a new fever and no clear focus of infection, if the probability of bacterial infection is deemed low to intermediate 1.
- Use procalcitonin to guide antibiotic discontinuation, particularly in patients with declining levels or levels below 0.5 ng/mL 1.
- Consider procalcitonin as part of a comprehensive clinical assessment, rather than relying solely on biomarker results, to reduce unnecessary antimicrobial exposure and improve patient outcomes.
From the Research
Usefulness of Procalcitonin in Urosepsis
- Procalcitonin (PCT) has been studied as a potential marker for the diagnosis and monitoring of urosepsis, with some studies suggesting its usefulness in this context 2, 3, 4.
- A study published in 2015 found that PCT was a useful early marker for the diagnosis and differentiation of urosepsis, severe urosepsis, and uroseptic shock following percutaneous nephrolithotomy, with an area under the ROC curve of 0.960 2.
- Another study published in 2016 noted that PCT and lactate can be considered diagnostically relevant biomarkers for urosepsis, and that early imaging to localize the level of obstruction and infectious focus should be carried out 3.
- However, other studies have highlighted the limitations of PCT in differentiating infectious from non-infectious forms of systemic inflammatory response syndrome, and in stratifying morbidity and mortality risk 5, 6.
- Despite these limitations, PCT determination can still be a useful tool for guiding antibiotic stewardship in critical patients, and for diagnosing certain types of infections such as late-onset neonatal sepsis and bacterial meningitis 6.
Clinical Applications of Procalcitonin in Urosepsis
- PCT can be used to monitor the effectiveness of antibiotic therapy in patients with urosepsis, with daily measurements potentially providing valuable information on the patient's response to treatment 2.
- The use of PCT in conjunction with other diagnostic tools, such as blood cultures and ultrasonography, can help to improve the early diagnosis and treatment of urosepsis 3, 4.
- However, the interpretation of PCT values should take into account the patient's clinical context, including the presence of any pre-existing comorbid conditions that may influence PCT levels 5.