Sepsis Series, part III
Sepsis: Enter Sepsis-3
Most recently, in February of 2016, Sepsis-3 introduced a new definition of sepsis
Sepsis = “life-threatening organ dysfunction due to dysregulated host response to infection.”
Putting an emphasis on the high morbidity and mortality associated with sepsis, Sepsis-3 aimed to accentuate that all sepsis is dangerous and limited the sepsis spectrum to “sepsis” and “septic shock.”
The new definition of sepsis no longer uses SIRS criteria, as many of the sickest patients are unable to mount a robust immune response to infection. Instead the new consensus definition places emphasis on the presence of organ dysfunction using the scoring systems of the Sequential Organ Failure Assessment (SOFA) and Quick SOFA (qSOFA) scores to define sepsis
qSOFA: altered mental status, tachypnea >22, and systolic BP <100 better outside the ICU, but not validated in the ED specifically
A qSOFA score of 2 points predicts a poor outcome with an 8% mortality rate, while 3 qSOFA has a >20% mortality7
Validated in patients with suspected infection; therefore serves as a risk stratification tool rather than a sepsis screening tool
So post Sepsis-3: sepsis = suspected infection + qSOFA
Proposed screening tests for sepsis have also been evolving in recent years, as determining which clinical presentation features are associated with higher mortality is crucial in initiating early aggressive therapy and determining level-of-care assignment.
Lactate has been a long-standing screening tool to aid in risk-stratification of patients with severe sepsis, with elevated levels, particularly those ≥4 mmol/L, corresponding to higher mortality rates8,9.
The Early Warning Score (EWS) has come into use as a validated method of detecting early signs of clinical deterioration. The EWS combines SIRS criteria with non-laboratory indications of acute organ dysfunction, i.e. blood pressure and mental status change.
A modified version, National EWS (NEWS) has been retrospectively validated as a screening tool for severe sepsis from the emergency department with a NEWS of ≥3 having a 92% sensitivity for severe sepsis and a specificity of 77%10, meaning higher NEWS scores should trigger evaluation for severe sepsis to aid in early recognition.
The presence of Acute Organ Dysfunction independently serves as a predictor of mortality in the septic patient, with an increasing number of organ dysfunctions corresponding with an increased mortality in a linear fashion11.
1 AOD: 4% mortality 2 AOD: 14% mortality
3 AOD: 30% mortality 4 AOD: 55% mortality
***Don’t forget to check back next week as our Sepsis Series continues!***
8) Shapiro et al. Serum Lactate as a Predictor of Mortality in Emergency Department Patients with Infection. Ann Amerg Med 2005; 45(5):524-538.
9) Mikkelsen et al. Serum lactate is associated with mortality in severe sepsis independent of organ failure and shock. Critical Care Medicine 2009; 37(5):1670-1677.
10) Keep et al. National early warning score at Emergency Department triage may allow earlier identification of patients with severe sepsis and septic shock: a retrospective observational study. Emerg Med J 2016;33:37–41.
11) Shapiro et al. The association of sepsis syndrome and organ dysfunction with mortality in emergency department patients with suspected infection. Ann Emerg Med 2006;48(5):583-90, 590.