A clinician discusses his current approach to tackling sepsis, a challenging condition to identify, prevent, and treat.
Eric Gluck, MD
Around the globe, infections occur in people of all ages. Most of the time, the body can rid itself of the infection without intervention, but when the host is unable to contain the infection, treatment can be required. Pathogenic bacterial infections may require targeted antibiotic therapy aimed at treating the source of the infection. Early administration of appropriate antibiotic therapy is imperative to prevent the infection from spreading to other areas of the body. This may lead to overwhelming inflammation and sepsis if the host is compromised or the infection is left untreated.
According to the Sepsis Alliance, "sepsis is the body's overwhelming and life-threatening response to infection which can lead to tissue damage, organ failure, and death." Globally, there are 18 million cases of sepsis diagnosed each year and the incidence is rising by eight to 10 percent annually. According to the CDC, there were more than 180,000 sepsis-related deaths in 2014 in the United States alone, though some estimates are even higher.
Identifying sepsis can be a challenge, mostly because the body does not differentiate the initial inflammatory phases of sterile inflammation from other underlying disease processes. To avoid unwarranted antibiotics, it is crucial to differentiate bacterial and non-bacterial causes of inflammation. Cultures remain the gold standard for confirmation of bacterial infections; however, they lack ideal sensitivity to identify every pathogen in all patients with suspected sepsis. As such, diagnosis of sepsis often relies on clinical judgment.
As a director of Critical Care Services, I face challenging scenarios that require every tool available, in addition to my clinical judgment. Over the years, clinicians have monitored the biological response to infections by observing fever, white blood cell count (WBC), and blood pressure (BP). Although each parameter provides valuable information to the clinical picture, fever, WBC, and BP are imprecise. Each can be altered in other disease states and/or at times, unaffected by bacterial infection. More than 170 different biomarkers have been proposed for use in the diagnosis, prognosis, and therapy management of patients with sepsis or septic shock. Many of these biomarkers have been identified to aid in the risk assessment of sepsis for patients already in, or headed to, the intensive care unit (ICU). As one of several immunoactive molecules involved in the body's intrinsic immune response when a bacterial infection occurs, Procalcitonin (PCT) provides the best sensitivity and specificity to monitor the host inflammatory response to a bacterial infection to date.
Multiple platforms measure PCT and the results can be returned to clinicians in under one hour. The rapid turnaround enables clinicians in the ICU, emergency departments, and hospital wards to assess the severity of bacterial infection both on presentation and during treatment. PCT, when paired with clinical assessment and other laboratory findings, can aid clinicians in determining the underlying cause of infection and thus precisely tailor therapeutic management to the needs of the individual patient.
Once sepsis is recognized, time is of the essence. Healthcare providers work quickly to determine the source and location of the suspected infection and aim to prescribe appropriate antibiotics to control the source. Culture results can take days to yield results and thus it is important to monitor response to therapy via both clinical and biological markers. The ~24-hour half-life makes PCT an ideal marker. PCT should decline daily and the progress of the patient should be tracked, resulting in any necessary adjustment in antibiotic therapy.
Sepsis can lead to devastating sequelae, including long-term renal dysfunction, loss of cognitive function, and death. Early recognition and appropriate therapy can have a significant impact on overall outcomes. Proactive infection control and processes to identify the etiology of inflammation are important to recognize and treat patients and prevent poor outcome. Using platforms to measure PCT can provide rapid results that enable clinicians to assess the severity of bacterial infection to develop appropriate therapeutic management, which in turn can provide the best outcome for the patient.
Eric Gluck, MD, is the director of Critical Care Services at Swedish Covenant Hospital in Chicago.
[Image courtesy of QIMONO/PIXABAY]
Editor's note: Read more on in-development diagnostic tests for sepsis.