Sepsis

Sepsis is the single most expensive diagnosis in the U.S., costing the healthcare system over $24 billion annually. It is also associated with almost 50% of all in-hospital deaths. Yet, most people have little understanding of its causes or treatments.

Everyone has an infection before, such as a cold, the flu, pneumonia, or a urinary tract infection. It is often difficult for a doctor to tell whether certain types of infections (such as respiratory infections) are caused by bacteria or viruses. Because there can be serious consequences to leaving a bacterial infection untreated, often physicians will prescribe an antibiotic without knowing whether the infection is bacterial or viral. Typically, an infection will resolve within a few days, if treated appropriately.

But what happens when an infection gets worse, or is not controlled? Sometime the body’s immune system, which is already engaged in fighting the pathogen, creates too much inflammation. This so-called ‘inflammatory cascade’ launched by the immune system can actually become harmful. This is what we call ‘sepsis’. Sepsis is thus defined as a dysregulated immune response to any acute infection. A common misconception is that sepsis only arises from certain types of bugs (such as MRSA) or only in certain types of people (such as the elderly). In fact, sepsis can affect people of any age, and can arise in response to any kind of infection.

Sepsis can progress rapidly, and, if left untreated, can be fatal. Even when treated properly, the mortality rate is around 20%. It has been shown that for patients with bacterial sepsis, a delay in antibiotics of a single hour can increase the relative risk of mortality by ~7%. However, treating patients with antibiotics who don’t have bacterial infections causes unnecessary side effects and raises costs. It is thus critical to deliver rapid diagnostic information to a physician, so that antibiotics can be started ASAP if there is high concern for bacterial sepsis.

The current way in which sepsis is diagnosed is not necessarily specific for infections, but rather looks for signs of general inflammation in patients with a suspected infection. Diagnosing infections directly is quite difficult; the gold-standard measure for the presence of infection, a blood culture, is only positive in about 30% of patients with infections. Thus, a negative blood culture does not rule out the presence of an infection. Newer methods are thus needed that can rapidly distinguish infections without relying on pathogens in the bloodstream.

In February 2016, the Sepsis Definitions Task Force put out its most recent guidelines for defining sepsis. In the same issue of JAMA, Edward Abraham, MD, called for new biomarkers/diagnostics for sepsis, writing that, “… a major limitation continues to be the identification of patients whose organ system dysfunction is truly secondary to an underlying infection rather than other causes.” We at Inflammatix look forward to being part of the solution to the sepsis problem with our HostDx™ diagnostics.

 

Sepsis Links