What are the major changes in the definition of “sepsis” under the 3rd International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3)?

Under Sepsis-3 [1], sepsis is defined as a “life-threatening organ dysfunction caused by a dysregulated host response to infection (suspected or confirmed)”. Systemic inflammatory response syndrome (SIRS) is no longer defined as part of the sepsis spectrum, and its criteria have been replaced by the Sequential Organ Failure Assessment (SOFA) with a change in score ≥2 (Table) having >10% in-hospital mortality. Septic shock is defined as hypotension requiring vasopressors to maintain a MAP ≥65 mm Hg and a lactate >2 mmol/L (18 mg/dL) despite adequate volume (>40% in-hospital mortality).

A bedside clinical tool “quickSOFA” (qSOFA), not meant to substitute for SOFA, is also proposed to identify patients primarily outside of the ICU who may be at high risk of adverse outcomes, based on the following criteria: systolic blood pressure ≤100 mmHg, respiratory rate ≥22/min, and altered mental status. A qSOFA score ≥2 is associated with poorer outcomes [1,2].

So what do these new guidelines mean for clinicians? Under the new terminology, “sepsis” now refers only to what was previously considered severe sepsis with or without shock, and those who may need more aggressive therapy, closer monitoring and possible transfer to an ICU [1,2]. As the guidelines stress, however, failure to meet qSOFA or SOFA criteria should by no means lead to a deferral or delay in evaluation or treatment of infection deemed necessary by clinicians, and SIRS criteria may still be useful in identification of infection [1].

It remains to be seen whether limiting the definition of sepsis to only patients with associated organ dysfunction will translate into an overall earlier diagnosis and improved prognosis for this condition.

Using SIRS criteria (ie, 2 or more of the following, heart rate >90/min, respiratory rate >20/min  or PaC02 <32 mm Hg, temperature<36 C or >38 C, WBC <4,000 or >12,000 or bandemia >10%) in patients suspected of having a potentially serious infection still makes sense if the goal is to identify it “upstream” before organ dysfunction or shock sets in.  Stay tuned!


Table. Sequential (sepsis-related) organ failure assessment (SOFA) score (adapted from ref.1)____________________________________________________________________________________________________


Parameter                                0                      1                      2                      3                      4


Pa02/Fi02                           ≥400                 <400                <300                 <200*          <100*

Platelets (no./mL)           >150,000         <150,000         <100,000         <50,000       <20,000

Bilirubin (mg/dL)            <1.2                  1.2-1.9              2.0-5.9             6.0-11.9       >12.0

MAP (mm Hg) or VP      MAP≥70         MAP<70          DPA≤5           DPA 5.1-15        DPA>15

Glascow Coma Scale       15                    13-14            10-12                    6-9                 3-6

Creatinine (mg/dL)        <1.2                 1.2-1.9           2.0-3.4                  3.5-4.9        >5.0

OR U.O.  (mL/dL)                                                                                              <500                <200


MAP= mean arterial pressure, VP=vasopressor (includes agents other than dopamine), DPA=dopamine (in mcg/kg/min for ≥1 hour);U.O.= urine output

*With respiratory support


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  1. Singer MS, Deutschman CS, Seymour CW, et al; The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA. 2016;315[8]:801-810. https://jamanetwork.com/journals/jama/fullarticle/2492881  
  2. Jacob JA. New Sepsis Diagnostic Guidelines Shift Focus to Organ Dysfunction. JAMA. 2016;213[8]:739-740. https://www.ncbi.nlm.nih.gov/pubmed/26903319


Contributed by Erik Kelly MD, Mass General Hospital, Boston, MA

What are the major changes in the definition of “sepsis” under the 3rd International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3)?