qSOFA and Lactate for Nurse-Led Identification of High-Risk Septic Patients: A Prospective Observational Study

Early identification of patients with sepsis at risk of deterioration is essential to reduce mortality. The quick Sequential Organ Failure Assessment (qSOFA) score is a widely used bedside tool but has limited sensitivity. Emerging evidence suggests that combining qSOFA with lactate levels (qSOFA-lactate) may improve predictive performance.

The aim of this study was to evaluate the prognostic accuracy of the qSOFA-lactate score in predicting 30-day all-cause mortality among hospitalised patients with sepsis and to assess its applicability in nurse-led clinical assessments.

A prospective observational study was conducted at the Intermediate Care Unit of Alto Vicentino Hospital in Santorso, from 1 October 2022 to 1 February 2025. Consecutive adult patients admitted from the emergency department to the Intermediate Care Unit (IMCU) with a diagnosis of sepsis were enrolled. Clinical data, vital signs and laboratory values were collected at admission. The qSOFA-lactate score was calculated by summing qSOFA points and lactate level categories. Predictive performance was analysed using ROC curves, net reclassification improvement (NRI) and decision curve analysis (DCA).

A total of 370 patients were included, with a 30-day mortality rate of 16.0% (n = 59). qSOFA-lactate showed modestly higher discrimination (AUROC: 0.724) than qSOFA (AUROC: 0.706) and lactate alone (AUROC: 0.671; p = 0.040). Risk reclassification was directionally favourable (NRI 0.114; 27 net correct reclassifications, 7.3 per 100 patients). Decision curve analysis showed higher net benefit for qSOFA-lactate across 10%-25% decision thresholds.

qSOFA-lactate modestly improves risk stratification as an adjunct to qSOFA without adding bedside complexity. It can slightly improve early decision-making (reclassification and net benefit) and may support timely intervention in acute care settings.

The qSOFA-lactate score is a practical, nurse-friendly adjunct that can strengthen early sepsis assessment and clinical decision-making. Its integration into standard nursing evaluations could facilitate rapid recognition and appropriate care escalation for high-risk patients.