Posted on February 17, 2016
Since the initial discovery of penicillin by Sir Alexander Fleming in 1928, antimicrobial use has been the backbone of infectious diseases management. While it is widely recognized that inappropriate antibiotic use can lead to antimicrobial resistance, up to 50% antimicrobial agents prescribed in the inpatient setting is considered to be inappropriate or unnecessary.1 The Center for Disease Control and Prevention has estimated that antibiotic-resistant organisms are responsible for more than 2 million infections and 23,000 deaths annually in the United States. The economic impact of antibiotic resistance varies, but may be as high as $20 billion in excess direct healthcare costs and $35 billion due to lost productivity to society.2
Procalcitonin (PCT) is a biomarker that can be used to assist clinicians in the diagnosis and management of bacterial infection. PCT is a 116 amino acid precursor of calcitonin, calcitonin is secreted by thyroid C-cells. Under normal circumstances, PCT concentration is found to be less than 0.05ng/mL but in response to bacterial infection accompanied by systemic inflammation, PCT is produced in large quantities. PCT has an early and highly specific increase in response to systemic bacterial infections and sepsis. It is detectable within 2 to 4 hours upon infectious insult and peaks within 6 to 24 hours.
The use of PCT has been studied extensively in lower respiratory tract infections and sepsis, as well as its role to reduce duration of antimicrobial therapy.
Evidence for procalcitonin use in lower respiratory tract infection (LRTI): In a meta-analysis and systematic review by Li et al, randomized controlled trials with a total of 3,431 patients with suspected respiratory tract infections were evaluated. 3 While the use of PCT-guided therapy did not impact mortality, ICU admission, or length of hospital stay, a high degree of heterogeneity in these outcomes were noted. The use of PCT in LRTI resulted in a 31% decrease in antibiotic prescriptions and a reduction in antibiotic duration of 1.3 days without significantly impacting the overall hospital length of stay.
Evidence for procalcitonin use in sepsis: A number of studies have been conducted to evaluate the benefits of procalcitonin in the management of sepsis, including:
Hohn et al. conducted a retrospective analysis of the impact of PCT-guided algorithm to reduce length of antibiotic therapy in septic patients. 4 One hundred forty-one (141) patients were included in the study, primary outcomes included: antibiotic day on ICU, ICU re-infection rate, 28-day mortality rate, ICU length of stay (LOS), mean antibiotic costs (per patient) and ventilation hours. The study showed a reduction of antibiotic therapy duration by 1 day per year (p=0.02), a 35.1% reduction in ICU re-infection rate (p=0.014), a reduction in ventilation hours by 42 hours per year (p=0.008) and ICU LOS was shortened by 2.7 days per year (p<0.001). There was no statistical significance for 28-day mortality and mean cost for antibiotic therapy outcome.
In another systematic review by Heyland et al., 5 articles were evaluated. PCT-guided strategies were associated with a significant reduction in antibiotic days (mean difference -2.14 days, p<0.00001).5 No effects on hospital mortality, ICU and overall hospital LOS were observed.
While the use of PCT does not improve mortality and/or length of stay, there is overwhelming evidence to attest to the use of a PCT-guided strategy for significantly reducing antibiotic therapy duration.
When to utilize procalcitonin?
*Credits to Nebraska Medicine Procalcitonin (PCT) Guidance
It is important to note that decisions on antimicrobial therapy should not be based solely on procalcitonin serum concentration but rather should be placed into clinical context of the patient’s overall clinical status:
If you want to learn more about procalcitonin testing and how to set up testing at your facility, here are some considerations:
Helpful resources on PCT:
Written for clinicians