The procalcitonin test may be used, along with other tests and examinations, to help detect or rule out sepsis in a seriously ill person. It has primarily been used in people who seek care at emergency departments or who are admitted to intensive care units (ICUs) with signs and symptoms that may be due to sepsis.
The procalcitonin test may be used to help:
Determine the risk that a critically ill person will progress to severe sepsis and septic shock, or the risk of the person dying
Detect the development of a secondary bacterial infection in a person who has tissue damage due to trauma or surgery, or a viral illness such as pneumonia
Guide antibiotic treatment and/or monitor effectiveness—the test may be used in helping to decide whether antibiotics should be started or stopped for patients with lower respiratory infections and whether antibiotics can be discontinued in patients with sepsis
The procalcitonin test may be ordered when a seriously ill person has signs and symptoms that suggest a systemic or severe bacterial infection and/or sepsis. Signs and symptoms of sepsis may include:
Chills, shivering, fever
Clammy or sweaty skin
Extreme pain or discomfort
Confusion or disorientation
Less frequent urination
The test may be ordered when a person has an infection, like pneumonia or meningitis, and it is not known whether the cause is bacterial or non-bacterial. Sometimes the test may be ordered when a child has signs and symptoms that suggest a urinary tract infection.
A series of procalcitonin tests may be ordered at intervals when a healthcare practitioner wants to monitor antibiotic treatment and/or decide whether treatment can be safely discontinued.
The test may occasionally be ordered when someone has tissue damage from trauma, surgery, or a burn, or a viral illness such a pneumonia and a healthcare practitioner suspects that the person may have developed a secondary bacterial infection.
Procalcitonin results are interpreted in conjunction with findings from clinical evaluations as well as other laboratory tests.
Low levels of procalcitonin in a seriously ill person may indicate a low risk of developing sepsis and progression to severe sepsis and/or septic shock but do not exclude it.
Low levels may indicate that the person's symptoms are due to a cause other than a bacterial infection, such as a viral infection. A low level may also indicate a localized infection that has not spread or become systemic, or a systemic infection that is less than six hours old.
High levels indicate a high probability of sepsis and also suggest a higher risk of progression to severe sepsis and septic shock. High levels may also been seen in people with serious bacterial infections, such as meningitis.
Moderate elevations may be due to a non-infectious condition or due to an early infection and, along with other findings, should be reviewed carefully. They may also be seen in children with kidney infections.
Decreasing procalcitonin levels over time in a person being treated for sepsis or a bacterial infection indicate a response to therapy. Stable or increasing procalcitonin levels may indicate the need for continued therapy.
Very high levels of procalcitonin can be seen with medullary thyroid cancer, but the test is not used to diagnose or monitor this condition.
The procalcitonin test is not considered a replacement for the performance of other laboratory tests. Rather, it provides additional information that may allow appropriate treatment to be initiated or discontinued sooner.
Early detection of systemicbacterial infections, including bacterial pneumonia and bacterial meningitis, is important because they can be life-threatening and can be readily treated. However, the use of antibiotics in non-bacterial conditions may cause delays in proper treatment and can lead to more antibiotic-resistant bacteria.
The procalcitonin test is being studied in additional populations, expanding beyond critically ill ICU patients. As more data are gathered, its clinical usefulness will be better understood and its intended use(s) more fully defined.
This article was last reviewed on April 10, 2017. | This article was last modified on April 10, 2017.
The review date indicates when the article was last reviewed from beginning to end to ensure that it reflects the most current science. A review may not require any modifications to the article, so the two dates may not always agree.
The modified date indicates that one or more changes were made to the article. Such changes may or may not result from a full review of the article, so the two dates may not always agree.