Procalcitonin and Antimicrobial Utilization in Critically Ill Cancer Patients with Sepsis

Studies have demonstrated that the use of a procalcitonin (PCT)-guided algorithm in combination with clinical judgment was associated with reduced antibiotic use without impacting mortality or treatment failure. Though several studies have evaluated the use of PCT in critically ill patients, there are limited studies that evaluated PCT in patients with cancer and many of the currently available studies have excluded immune-compromised patients.

This is a randomized controlled trial that aims to evaluate the impact of a procalcitonin-guided algorithm on antibiotic utilization in critically ill cancer patients with sepsis. In addition, the study aims to evaluate the predictive value of PCT for predicting mortality and positive cultures.

Procalcitonin (PCT) has been widely studied to guide antibiotic use in critically ill septic patients. Using an algorithm for antibiotic de-escalation guided by PCT levels in septic patients with respiratory tract infections was associated with lower antibiotics exposure without increasing mortality or treatment failure. Furthermore, the current Surviving Sepsis Guidelines suggest that PCT levels may help clinicians in their decision of empiric antibiotics discontinuation especially in patients with suspected sepsis and low PCT values with no other evidence of infection (low level of evidence, GRADE 2C).

Reducing the use of antibiotics is a global health care priority. Using a PCT-guided algorithm in combination with clinical judgment was associated with reduced antibiotic use without increasing morbidity or mortality. Though PCT has been widely studied as a diagnostic, prognostic, and theragnostic inflammatory marker in patients with sepsis, there are limited studies that evaluated PCT in patients with cancer and many of the currently available studies have excluded immune-compromised patients. Furthermore, studies have reported elevated inflammatory markers, including PCT, in patients with cancer as a result of the malignancy itself or treatment complications. This may suggest that PCT alone may possibly be less useful for differentiating infectious from non-infectious sources of fever in cancer patients. However, serial PCT levels may be more useful in cancer patients, compared to a single level.

Sepsis is common in cancer patients; however, there are limited studies evaluating the clinical impact of obtaining PCT levels in this patient population. Therefore, this study will evaluate the impact of obtaining serial PCT levels on the number of antibiotic days in cancer patients with sepsis. In addition, the study aims to evaluate the predictive value of PCT for predicting mortality and positive cultures.

Study Objectives The main objective of this study is to evaluate the impact of a PCT-guided algorithm on the duration of antimicrobial therapy in critically ill cancer patients with sepsis. The main research question being asked is whether providing the clinical team with daily PCT levels, along with a PCT-based algorithm to guide antimicrobial management, would have an impact on the duration of antibiotic therapy. In addition, the study intends to assess the role of PCT in predicting mortality and positive cultures in the cancer septic patient population.

Eligibility Criteria:
Inclusion Criteria:

* Age ≥ 18 years old
* Expected to remain in the ICU for at least 48 hours
* Patient meets the SEPSIS-3 criteria for sepsis defined as having a SOFA score change of 2 or more and suspected infection.
* Patient on antibiotics for suspected infection

Exclusion Criteria:

* Patient code is DNR
* Patient receiving antibiotics for surgical prophylaxis
* Consent cannot be obtained
* Patients who are expected to require antibiotics for more than 14 days
* Patients who have PCT levels ordered as part of their routine clinical care
* Patients who are followed by the Infectious Disease team.
* Patient with life expectancy \<24 hours.