Sepsis is a potentially fatal condition that strikes an estimated 750,000 people each year in the United States. Defined as the body’s reaction to infection (whether bacterial, viral, fungal, or parasitic), sepsis is the most common underlying cause of mortality in non-coronary ICUs. It can rapidly lead to systemic inflammatory reactions and, eventually, organ dysfunction or failure. People who are at greatest risk of developing sepsis include patients who are very young or very old, those with compromised immune systems, those who are hospitalized and are very sick, and individuals with invasive devices (eg, urinary catheters or breathing tubes).

Early recognition of sepsis, specific clinical interventions, and timely initiation of appropriate therapy are critical for helping patients survive this potentially devastating condition. Unfortunately, sepsis can be difficult to distinguish from other, non-infectious conditions in critically ill patients, especially for those with clinical signs of acute inflammation and negative microbiological results. The condition can be challenging to manage in the early phases of the disease because it may be difficult to decide on the appropriate therapeutic measures for each individual patient. Oftentimes, by the time an accurate diagnosis is made, patients may have progressed to the final stages of the disease. The need for more effective strategies to help intervene in and manage sepsis is urgent.

Procalcitonin to Diagnose & Monitor Sepsis

A novel biomarker called procalcitonin (PCT) is now being recognized as a useful tool in the diagnostic process for sepsis. PCT can contribute to the risk assessment and optimization of patient management and clinical decisions. It is the prohormone of calcitonin (CT). CT is secreted by the C-cells of the thyroid after hormonal stimulation, but PCT is different in that it can be produced by numerous cell types and organs after proinflammatory stimulation, especially when caused by bacterial infection.

“The need for more effective strategies to help intervene in
and manage sepsis is urgent.”

PCT has an early and highly specific increase in response to severe systemic bacterial infections and sepsis. In healthy people, plasma PCT concentrations are found to be below 0.05 ng/mL; however, very high values have been observed during acute disease conditions with severe systemic reaction to an infection. In septic conditions, increased PCT levels can be observed 3 to 6 hours after an infectious “challenge.” PCT can increase to 1,000 ng/mL in patients with severe sepsis or septic shock.

An Additional Sepsis Management Tool

Among several laboratory parameters in clinical investigations, PCT has been shown to be critically useful. Studies have indicated that PCT has shown the best performance for differentiating patients with sepsis from those with a systemic inflammatory reaction not related to an infectious cause. Moreover, PCT has demonstrated itself to be the most reliable laboratory parameter that has made a significant contribution to the clinical diagnosis of sepsis. Conversely, information obtained from interleukin-6, interleukin-8, and C-reactive protein had less impact on the clinical diagnosis of sepsis on admission. The integration of PCT into diagnostic and treatment algorithms can be beneficial for earlier recognition and treatment of sepsis. This novel biomarker can also help optimize antibiotic treatment decisions and assist clinicians in developing more targeted use of their clinical resources. When applied in clinical settings, PCT can help support the goal of improving outcomes for patients with sepsis.


Uzzan B, Cohen R, Nicolas P, Cucherat M, Perret GY. Procalcitonin as a diagnostic test for sepsis in critically ill adults and after surgery or trauma: a systematic review and meta-analysis. Crit Care Med. 2006;34:1996-2003.

Müller B, Becker KL. Procalcitonin: how a hormone became a marker and mediator of sepsis. Swiss Med Wkly. 2001;13:595-602.

Jensen JU, Hein L, Lundgren B, et al; for the The Procalcitonin And Survival Study (PASS) Study Group. Procalcitonin-guided interventions against infections to increase early appropriate antibiotics and improve survival in the intensive care unit: a randomized trial. Crit Care Med. 2011 May 12. [Epub ahead of print].

Textoris J, Wiramus S, Martin C, Leone M. Antibiotic therapy in patients with septic shock. Eur J Anaesthesiol. 2011;28:318-324.

Mann EA, Wood GL, Wade CE. Use of procalcitonin for the detection of sepsis in the critically ill burn patient: A systematic review of the literature. Burns. 2011;37:549-558.