What are the important sepsis criteria that infectious disease (and other) specialists should know?
Sepsis is a term that has been liberally used.
There was an initial sepsis 1 definition and a sepsis 2 definition that was based on something called SURS, or systemic inflammatory response system. That was a very sensitive but not very specific tool.
The sepsis 3 definition now uses the possibility of infection plus organ dysfunction—that is kidney problems, renal problems, pulmonary problems—anything that may be affected by sepsis. The definition has been simplified and removes SURS. It also removes the name "severe sepsis." There's no longer "severe sepsis," only sepsis or septic shock. Septic shock refers to patients who obviously need something to keep their blood pressure up or vasopressors. So the definitions have changed.
What are some of the challenges in diagnosing and managing sepsis?
The challenge that has been presented is that the Surviving Sepsis Campaign 2018 has changed their bundle from a three-hour bundle to a one-hour bundle. One of the bundle elements—probably one of the more important ones—is giving antibiotics within an hour of triage to a patient coming into the facility.
One of the challenges is that unless they present symptoms of obvious septic shock, trying to do the evaluation—getting blood counts, getting lactate levels, getting certain radiographic studies to determine if a patient has an infection—is really hard to do within one hour.
Since people are trying to hit that one-hour barrier, they're often being given antibiotics, and then they ask questions later. What that has lead to is overuse of antibiotics for patients who may not have an infection. An example is a very nice study that was done several years ago that looked at patients who were admitted to critical care with a diagnosis of sepsis, only 40% of which after further study actually had an infection as their presenting reason for that syndrome.
That's some of the challenges—overuse of antibiotics leads to adverse events such as clostridium difficile diarrhea, antimicrobial resistance, side-effects from the antibiotics themselves, and then changing patient's normal bacterial floor, which we now call microbiome. A very nice study done by the CDC earlier this year showed that patients who presented with sepsis who were given antibiotics within 90 days were at higher risk. So we know that unnecessary antibiotics have adverse effects.
We also know, to be fair, that patients who have septic shock or clearly have a sepsis syndrome that timely and appropriate antibiotics does make a difference in outcomes. We have to try to balance those two by not giving unnecessary antibiotics and allowing the clinical to have enough time to decide a) do they have an infection, b) what's the most likely side of the infection, and c) what's the most appropriate antibiotic for that patient at that facility — and that's hard to do within an hour.