Persistently elevated early warning scores and lactate identifies patients at high risk of mortality in suspected sepsis.

Objective: In the UK, the National Early Warning Score (NEWS) is recommended as part of screening for suspicion of sepsis. Is a change in NEWS a better predictor of mortality than an isolated score when screening for suspicion of sepsis?.

Methods: A prospectively gathered cohort of 1233 adults brought in by ambulance to two UK nonspecialist hospitals, with suspicion of sepsis at emergency department (ED) triage (2015-2017) was analysed. Associations with 30-day mortality and ICU admission rate were compared between groups with an isolated NEWS ≥5 points prehospital and those with persistently elevated NEWS prehospital, in ED and at ward admission. The effect of adding the ED (venous or arterial) lactate was also assessed.

Results: Mortality increased if the NEWS persisted ≥5 at ED arrival 22.1% vs. 10.2% [odds ratio (OR) 2.5 (1.6-4.0); P < 0.001]. Adding an ED lactate ≥2 mmol/L was associated with an increase in mortality greater than for NEWS alone [32.2% vs. 13.3%, OR 3.1 (2.2-4.1); P < 0.001], and increased ICU admission [13.9% vs. 3.7%, OR 3.1 (2.2-4.3); P < 0.001]. If NEWS remained ≥5 at ward admission (predominantly within 4 h of ED arrival), mortality was 32.1% vs. 14.3%, [OR 2.8 (2.1-3.9); P < 0.001] and still higher if accompanied by an elevated ED lactate [42.1% vs. 16.4%, OR 3.7 (2.6-5.3); P < 0.001].

Conclusion: Persistently elevated NEWS, from prehospital through the ED to the time of ward admission, combined with an elevated ED lactate identifies patients with suspicion of sepsis at highest risk of in-hospital mortality.