How is sepsis defined and what is sepsis-induced organ dysfunction?

Updated: Oct 07, 2020
  • Author: Andre Kalil, MD, MPH; Chief Editor: Michael R Pinsky, MD, CM, Dr(HC), FCCP, FAPS, MCCM  more...
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Sepsis is defined as life-threatening organ dysfunction due to dysregulated host response to infection, and organ dysfunction is defined as an acute change in total SOFA score of 2 points or greater secondary to the infection cause (see Table 1 below). [1]

Table 1. Sepsis-Related SOFA Score (adapted from Singer et al) (Open Table in a new window)



0 Points

1 Point

2 Points

3 Points

4 Points




≥400 mm Hg


<400 mm Hg


<300 mm Hg


<200 mm Hg

(with respiratory support)


<100 mm Hg

(with respiratory support)


Platelet count


≥150 x 103/µL










Bilirubin level


<1.2 mg/dL


1.2-1.9 mg/dL


2-5.9 mg/dL


6-11.9 mg/dL


>12 mg/dL


MAPc ≥70 mm Hg

MAP >70 mm Hg

Dopamine <5 or

dobutamine (any dose)e

Dopamine 5.1-15 or

epinephrine ≤0.1 or

norepinephrine ≤0.1e

Dopamine >15 or

epinephrine >0.1 or

norepinephrine >0.1e

Central nervous system

GCSd score













Urine output

<1.2 mg/dL

1.2-1.9 mg/dL

2-3.4 mg/dL


3.5-4.9 mg/dL



>5 mg/dL


aPaO2=Partial pressure of oxygen.

bFiO2=Fraction of inspired oxygen.

cMAP=Mean arterial pressure.

dGCS=Glasgow Coma Scale (range, 3-15, with higher indicating better function).

eCatecholamine doses administered as µg/kg/min for ≥1 hour.

Sepsis-induced organ dysfunction is defined by an acute change in total SOFA score of 2 points or greater secondary to the infection cause. [1] For screening purposes, a shorter version of the SOFA score, termed quick SOFA (qSOFA), demonstrated to have reasonable accuracy in the settings outside the ICU. [1] The qSOFA is defined by two or more of a total of the following three components: altered mental status, respiratory rate of 22 or higher, and systolic blood pressure of 100 mm Hg or less. While the qSOFA is not as robust as the total SOFA score, there is no requirement for laboratory tests and easier reassessment make the qSOFA a potential tool for screening a possible infection as a source of a new sepsis episode in settings with lower resources than standard ICUs. However, the qSOFA still needs prospective validation in future cohort studies.

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