As a medical student, sepsis seems like it should be a pretty basic concept. Infection + widespread systemic response–> end organ damage = bad news bears. If you are like me, you probably memorized the SIRS criteria, passed your test, and called it a day, right?
Unfortunately, the real world of medicine doesn’t always work that way-cases are more complicated, patients are sicker than the numbers imply, and sepsis can be fatal. The good news is that there are plenty of updated resources available for aspiring Emergency Medicine physicians that can help learning how to manage sepsis in the ED a little less complicated.
When I started to do some research for the Design Challenge, I realized that my knowledge of sepsis only grazed the surface of what we need to know moving forward as clinicians. I put together a blog post to share what I learned about recent updates to the guidelines in hopes that it will help expand our clinical expectations as students and future physicians.
Bottom line: SIRS is out, qSOFA is (most likely) in. Take a look at what is out there and you be the judge! Enjoy!
Why is sepsis important?
Sepsis is a clinical syndrome with a high mortality rate- reportedly 20 to 50% in-hospital mortality in the ARISE Trial subgroup (Great article comparing the efficacy of Early Goal Directed Therapy vs. conventional care in reducing mortality!)
In 1991, a consensus conference established the definition of sepsis as the clinical sequelae resulting from systemic inflammatory response syndrome, or SIRS, with severe sepsis including end organ dysfunction.
Tempertaure >38C or <36C
Heart Rate >90 bpm
Respiratory rate >20 bpm or PaCO2 <32 mmHG
White blood cell count >12000/mm3 or <4000/mm3 or >10% immature bands
SIRS defines an inflammatory response, it doesn’t necessarily reflect the nature of a widespread infectious process that can lead to end organ damage. SIRS can represent the body’s normal homeostatic response to an insult with some patients meeting the criteria that really aren’t as sick as the numbers imply, while others may fail to fulfill the criteria yet are on the road to full blown septic shock.
What does this translate to: Poor sensitivity and specificity of SIRS criteria for recognizing mortality risk.
Then along came the Sequential Organ Failure Assessment score, aka SOFA, which looks at the following factors:
Blood Pressure and Pressor Use
The presence of 2 or more SOFA criteria carries an increased mortality rate of about 10%.
SOFA stratifies sepsis by evaluating organ function with a higher SOFA score correlating with a higher mortality risk. Since lab values are required to calculate the SOFA score, it often doesn’t help evaluate patients in the pre-hospital or initial ED assessment.
This leads us to the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3).
The Sepsis-3 task force consisted of 19 intensive care specialists from around the world who convened to establish new definitions of sepsis and determine which criteria should be used to determine mortality risk in septic patients.
Sepsis represents life-threatening organ dysfunction caused by a dysregulation host response to infection. This veers from the traditional SIRS definition, which can represent a homeostatic inflammatory response to insult rather than the pathologic widespread organ dysfunction that sepsis encompasses. Organ dysfunction is defined as an acute increase of greater than or equal to two SOFA points, corresponding to an overall mortality risk of 10%
To assess in-hospital mortality outside of the ICU setting, qSOFA should be used:
Respiratory rate > 22
Altered mental status
Systolic BP <100
qSOFA mortality at 6-72 hours:
Sepsis with persistent hypotension requiring vasopressors to maintain a MAP >65mmHG AND a serum lactate >2mmol/L DESPITE adequate volume resuscitation.
Chart courtesy of FOAMcast-check out their blog post on Sepsis Redefined!
How does qSOFA fit in to the initial management of septic patients in the ED?
In the ICU setting, this study associated with Sepsis-3 found that SOFA had a higher predictive value for in-hospital mortality compared to both qSOFA and SIRS. In the non-ICU setting (i.e. the ED), qSOFA had a higher predictive validity for in-hospital mortality making it a useful tool for risk stratifying suspected infection in the Emergency Department.
qSOFA helps predict mortality in the initial management of sepsis. qSOFA is a risk stratifier-it does not represent diagnostic criteria. DO NOT wait to treat patients if they meet less than two criteria. If you suspect sepsis, TREAT!
Click here for a great blog discussing the new definitions with their merits and limitations.
Also, check out this podcast with the lead author of the new definitions, Merv Singer.
That’s it for sepsis for now. Hope this helped on your journey towards becoming an EM physician!
Bone RC, Balk RA, Cerra FB, et al. American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference: definitions for sepsis and organ failure and guidelines for the use of innovative therapies in sepsis. Crit Care Med. 1992;20(6):864-874.
Peake SL, Delaney A, Bailey M, et al. Goal-Directed Resuscitation for Patients with Early Septic Shock.. N Engl J Med. 2014;371:1496-506. DOI: 10.1056/NEJMoa1404380
Rivers, E, Nguyen B, Havstad, S, et al. Early Goal-Directed Therapy in the Treatment of Severe Sepsis and Septic Shock. N Engl J Med. 2001; 345:1368-1377
Warren Seymour, C, Liu, V, Iwashyna, T, et al. Assessment of Clinical Criteria for Sepsis: For the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA. 2016;315(8):762-774
Singer, M, Deutschman, C, Warren Seymour, C, et all. The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-#). JAMA. 2016;315(8):801-810
Vincent JL, Moreno R, Takala J, et al; Working Group on Sepsis-Related Problems of the European Society of Intensive Care Medicine. The SOFA (Sepsis-related Organ Failure Assessment) score to describe organ dysfunction/failure. Intensive Care Med. 1996;22(7):707-710.