Combining qSOFA criteria with initial lactate levels: Improved screening of septic patients for critical illness

To determine if the addition of lactate to Quick Sequential Organ Failure Assessment (qSOFA) scoring improves emergency department (ED) screening of septic patients for critical illness.

This was a multicenter retrospective cohort study of consecutive adult patients admitted to the hospital from the ED with infectious disease-related illnesses. We recorded qSOFA criteria and initial lactate levels in the first 6 h of ED stay. Our primary outcome was a composite of hospital death, vasopressor use, and intensive care unit stay ≤72 h of presentation. Diagnostic test characteristics were determined for: 1) lactate levels ≥2 and ≥4; 2) qSOFA scores ≥1, ≥2, and =3; and 3) combinations of these.

Of 3743 patients, 2584 had a lactate drawn ≤6 h of ED stay and 18% met the primary outcome. The qSOFA scores were ≥1, ≥2, and =3 in 59.2%, 22.0%, and 5.3% of patients, respectively, and 34.4% had a lactate level ≥2 and 7.9% had a lactate level ≥4. The combination of qSOFA ≥1 OR Lactate ≥2 had the highest sensitivity, 94.0% (95% CI: 91.3-95.9).

The combination of qSOFA ≥1 OR Lactate ≥2 provides substantially improved sensitivity for the screening of critical illness compared to isolated lactate and qSOFA thresholds.