Although the devastating consequences of sepsis are well-known (1), the diagnosis of this clinical syndrome has proven to be highly challenging (2). Until recently, sepsis was defined by two or more systemic inflammatory response syndrome (SIRS) criteria in the presence of infection (3). However, after countless editorials and studies decrying the weaknesses of this definition (4, 5), a Task Force was convened to update the definition (6).
Sepsis-3 declared sepsis to be “life-threatening acute organ dysfunction due to a dysregulated host response to infection,” removing systemic inflammation from the definition. However, there is not yet a diagnostic test to confirm sepsis or even a “dysregulated host response.” To identify the syndrome in clinical practice, Sepsis-3 recommends a threshold of 2 or more new Sequential Organ Failure Assessment (SOFA) points in a patient with clinically suspected or confirmed infection.
Along with the new definition and clinical operationalization, Sepsis-3 also introduced a new clinical tool—the quick SOFA (qSOFA) score. This three-point measure is based on physical examination alone: respiratory rate 22/min or greater, altered mentation, and systolic blood pressure of 100 mg or less (6). The score can be used to rapidly identify non-ICU patients at the highest risk for poor outcomes, defined as a prolonged ICU stay or in-hospital death. The parsimonious qSOFA tool was validated in multiple datasets and outperforms SIRS criteria at identifying patients at risk for poor outcomes (7). In the Sepsis-3 validation study, only 24% of infected patients had a qSOFA greater than or equal to 2, but these patients accounted for 70% of the poor outcomes (7). As such, qSOFA is not a screening tool but rather a grave alarm bell of potential impending decompensation in patients with infection.