Systemic Inflammatory Response Syndrome, Quick Sequential Organ Function Assessment, and Organ Dysfunction: Insights From a Prospective Database of ED Patients With Infection

Abstract

Background: A proposed revision of sepsis definitions has abandoned the systemic inflammatory response syndrome (SIRS), defined organ dysfunction as an increase in total Sequential Organ Function Assessment (SOFA) score of ≥ 2, and conceived "qSOFA" (quick SOFA) as a bedside indicator of organ dysfunction. We aimed to (1) determine the prognostic impact of SIRS, (2) compare the diagnostic accuracy of SIRS and qSOFA for organ dysfunction, and (3) compare standard (Sepsis-2) and revised (Sepsis-3) definitions for organ dysfunction in ED patients with infection.

Methods: Consecutive ED patients admitted with presumed infection were prospectively enrolled over 3 years. Sufficient observational data were collected to calculate SIRS, qSOFA, SOFA, comorbidity, and mortality.

Results: We enrolled 8,871 patients, with SIRS present in 4,176 (47.1%). SIRS was associated with increased risk of organ dysfunction (relative risk [RR] 3.5) and mortality in patients without organ dysfunction (OR 3.2). SIRS and qSOFA showed similar discrimination for organ dysfunction (area under the receiver operating characteristic curve, 0.72 vs 0.73). qSOFA was specific but poorly sensitive for organ dysfunction (96.1% and 29.7%, respectively). Mortality for patients with organ dysfunction was similar for Sepsis-2 and Sepsis-3 (12.5% and 11.4%, respectively), although 29% of patients with Sepsis-3 organ dysfunction did not meet Sepsis-2 criteria. Increasing numbers of Sepsis-2 organ system dysfunctions were associated with greater mortality.

Conclusions: SIRS was associated with organ dysfunction and mortality, and abandoning the concept appears premature. A qSOFA score ≥ 2 showed high specificity, but poor sensitivity may limit utility as a bedside screening method. Although mortality for organ dysfunction was comparable between Sepsis-2 and Sepsis-3, more prognostic and clinical information is conveyed using Sepsis-2 regarding number and type of organ dysfunctions. The SOFA score may require recalibration.

Keywords: SIRS; emergency medicine; infection; organ dysfunction; qSOFA.