Forewarned Is Forearmed

Anticipating clinical deterioration and possibly averting it makes good sense. Early warning systems (EWSs) are designed on this premise. They have several components: (1) a numerical score derived from a clinical monitoring sheet with sections blocked off in colors (usually red, orange, and green) to indicate the seriousness of the sign and the score it should be given; (2) this score must elicit an action, such as increasing the monitoring frequency or calling a senior resident and/or attending for assistance; (3) a rapid response to that call; and (4) appropriate action taken. “Track and trigger” is a term used to describe the overall plan.¹ 

EWSs are now used routinely on many hospital wards in well-resourced settings.² Scoring systems were developed in single hospitals, and so there is a great diversity of systems. Some scores are binary, and others are color coded; some have opted for simplicity and ease of use by using fewer indicators, and others are time consuming with a large number of indicators, including behavior and level of concern (including that of the family).² In many instances, the score is weighted. Furthermore, the response to monitoring concerns differs; some units have a rapid response team, and others have a medical emergency team.^3,4 There is always the assumption that there will be a positive response to alerts, namely a move to intensive care or initiation of higher-level ward care and nursing. Because there is so much variation in scores and responses, it has not been possible to compare like with like or group data together for meta-analysis. And because it is a score based on many indicators, it is difficult to tease out what are the most important early warning signs. When sensitivity and specificity of the scores have been reported, they range from 64% to 71% and 82% to 95%, respectively.^5,–8 

EWSs have only been used in a handful of low-resource settings.⁹ They are seen as complicated and requiring extra, well-trained nurses, which makes them hard to introduce in crowded, understaffed wards run by less well-trained staff. In this issue of Pediatrics, Rosman et al¹⁰ report the validation of a simple early warning score introduced into a pediatric ward of the University Teaching Hospital of Kigali in Rwanda. The score is based on vital signs (excluding blood pressure), altered consciousness, use of oxygen, and evidence of respiratory distress. No score is weighted, and the maximum score is 6. Children were enrolled who deteriorated after 24 hours of admission, and their outcome and scores were compared with those of case controls who had not deteriorated. Children were aged 0 to 18 years (excluding children in the ICUs), and 79 case patients and 79 controls were enrolled from the pediatric ward. A score of ≥3 achieved a positive predictive value of >85% and a negative predictive value of >90%. This is better than reported results from high-income settings.^11,12 Eighty-four percent of the children with scores ≤3 died.

It is unclear when the scores were taken and how long the interval was before a responder arrived or an action was taken. It is no surprise that children with unstable vital signs do poorly; the real question is, what are the earliest signs of impending trouble, and how can they be picked up soon enough to prevent deterioration and death?¹³ A multicenter study of EWSs in 2018 found no reduction in all-cause mortality compared with usual care, making it all the more important to identify the most important elements of the system.¹⁴ 

Monitoring is not done well in most poorly resourced settings, and any efforts to improve this are exciting. But this score needs to be validated in many more children and in different settings. In Kigali, the pediatric department admits 2242 children per year in a 66-bed unit consisting of a pediatric ward, a neonatal unit, an emergency department, and intensive care. It is a smallish department with a low turnover of admissions. We are not told how the beds are allocated nor how many nurses are on the ward in which the study took place. Children who deteriorated in the first 24 hours of admission were excluded, but this is a time period during which children need close monitoring.

EWSs, when fully used, have benefit beyond monitoring that are harder to quantify. Communication is improved between nurses, senior nurses, and doctors. Nurses feel empowered to act, and actions are more focused.¹⁵ Communication needs to be clear, and the triggers of situation, background, assessment, and recommendation are often used.¹⁶ Teamwork improves, and staff have a sense of support.¹⁷ 

Investigators in Kigali have made a start in trying to find a dependable score, but it is only the beginning. Implementation requires leadership, local champions, and a belief that it is adding value to their work.¹⁸ Medical hierarchies need to be leveled, and every success along the way, however small, should be shared and celebrated.

EWS

early warning system