National Early Warning Score Lactate (NEWS–L): is it good news for pre-hospital care?

It is recognised that elevated blood lactate levels increase the risk of mortality, even in those patients who appear physiologically stable (Vincent et al, 2016). The National Early Warning Score (NEWS) was introduced in the United Kingdom (UK) as a risk management tool in the Emergency Department (ED). Based on easy to establish physiological data, ED staff are better able to appropriately triage patients. Blood lactate has become a vital measure of the body's physiological response to an insult or injury. The authors of this study were assessing whether adding a serum lactate reading (NEWS–L) to the NEWS assessment could improve the triage of patients in the ED.

Using the NEWS and NEWS–L tools, a retrospective cohort study was undertaken at an urban tertiary hospital in South Korea over two consecutive months. The primary outcome was based on patients' scores predicting the likelihood of mortality in 48 hours (primary outcome); whilst secondary outcomes included the need for critical care intervention (defined as Intensive Care Unit admission) and/or advanced airway management in the ED and/or cardiac/cardiovascular drug therapy in the ED; 2-day composite outcome (2-day mortality plus the need for critical care); 7-day mortality; and in-hospital mortality. The NEWS–L score was presented as NEWS + lactate, for example, a NEWS of 3 and a blood lactate of 2mmol/l would give a score of 5 (3+2).