Out with SIRS, in with SOFA and qSOFA
3/14 update — EMCRIT Podcast finally out with some great material from Scott Weingart’s interview with Merv Singer, lead author on the new sepsis 3.0 definitions. Specifically, Merv takes on arguments that SOFA and qSOFA will only make sure that we don’t catch people til they’ve hit rock bottom, as far as disease severity goes: http://emcrit.org/podcasts/sepsis-3/
This week, the Society of Critical Care Medicine and the European Society of Intensive Care Medicine unveiled the Third international consensus definitions for Sepsis and Septic Shock, based on some groundbreaking research (1). This is big — it has the potential to change the way we look at sepsis.
The problem with the old definition
The old definition of sepsis — SIRS (2/4 of WBC>10.5, tachycardia, tachypnea, fever) + suspected or confirmed source of infection — had some issues. It tended to capture lots of people with non-infectious or non-life threatening infections. Not to mention this definition was last visited in 2001.
For example, if someone just got in a car crash they may come to the ER with an elevated heart rate, fast breathing, and a temperature (maybe it was hot outside). They may even have a laceration which looks infected. While they need immediate attention to their wounds, they probably don’t have a life threatening infection.
Another example is low risk infections. If a health person develops a non-specific cough, malaise and congestion, they will likely develop a fever and a white count (2/4 SIRS) and will definitely have a source of infection. So they technically meet the definition for Sepsis. But 99% of healthy people with a minor infection, even if it turns out to be bacterial, do not need to be hospitalized and started on IV fluids and antibiotics.
The other problem with the old definition is that it often missed up to 1/8 very septic ICU patients (2).
Not all infection is sepsis
For me, it starts with their new definition of sepsis: “life-threatening organ dysfunction due to dysregulated host responses to infection.” This definition highlights the fact that not all infection is life threateni ng— that we need to be better at honing in on life threatening infection and better at excluding non-life threatening infection (or syndromes that aren’t infectious at all).
SOFA and qSOFA
In order to do this, a large retrospective study was conducted that compared the accuracy of four different tools for detecting Sepsis. Out of the four tools compared — SIRS, SOFA (Sequential Organ Failure Assessment), qSOFA (quick SOFA), and LODS (Logistical Organ Dysfunction System) — SOFA and qSOFA faired the best, capturing the sickest patients while excluding the not sick patients. While I won’t go into all the details, let me quickly attempt to explain SOFA and qSOFA. SOFA is a scoring system best conducted in an ICU setting because it requires a lot of labs to be drawn. In fact, SOFA faired best in an ICU setting. qSOFA is sort of a screening tool version of SOFA and involves only three questions that can be remembered with the mnemonic HAT: Hypotension (systolic BP<100), Altered Mental Status (GCS<13), and Tachypnea (RR>22). qSOFA faired best in a non-ICU setting (wards, ED, etc.)
One last thing: in these new guidelines, severe sepsis doesn’t exist (see the table from the folks at FOAMcast). This makes sense, though, if we’re defining sepsis now as life threatening end organ damage — all sepsis is severe:
So that’s my quick breakdown of the new guidelines. Pretty exciting, as this has the potential to be a game changer. As residents we deal with the SIRS criteria nearly daily to determine how concerned we should be when someone starts to get sick. There’s still a lot of work to do in validating these guidelines, but it’s exciting to see what will happen!
Want more? Here are some links to the best summaries and commentaries I’ve found so far for the new guidelines:
- Blog: FOAMcast — Sepsis: Redefined
- Blog: Life In The Fast Lane — Sepsis Definitions and Diagnosis
- Videos: The JAMA multimedia page
- Editorial: New Definitions for Sepsis and Septic Shock: Continuing Evolution but With Much Still to Be Done — Editorial by Edward Abraham
- Original Article: The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3)
(1) Levy MM, Fink MP, Marshall JC. 2001 SCCM/ESICM/ACCP/ATS/SIS International Sepsis Definitions Conference. Critical care medicine. 31(4):1250–6. 2003.
(2) Kaukonen KM, Bailey M, Bellomo R. Systemic Inflammatory Response Syndrome Criteria for Severe Sepsis. The New England journal of medicine. 373(9):881. 2015.
