Development of an emergency department triage tool to predict acidosis among children with gastroenteritis

Design a triage assessment tool that predicts acidosis in children with vomiting, diarrhea, and dehydration.

A convenience sample of patients aged 3 months to 7 years with vomiting and/or diarrhea were enrolled in the triage area of a pediatric hospital's emergency department (ED). Caretakers of the eligible children completed a parental questionnaire assessing the patient's history of presenting illness. The triage nurse completed a 4-point physical examination assessment form. Collected information from the parental questionnaire and examination findings from the nurses' assessment were analyzed for factors that predicted acidosis in patients which was defined as having a serum bicarbonate level of 16 mmol/L or less or, if unavailable, an end-tidal carbon dioxide of 31 mm Hg or less.

One hundred eighteen of the 130 patients enrolled had either a documented serum bicarbonate level or an end-tidal carbon dioxide and were therefore used in the final analysis for the primary outcome. Twenty-nine patients (25%) had acidosis. Univariate predictors of acidosis were younger age (mean [SD], 1.7 [1.4] vs. 3.1 [2.2] years, P = 0.002), previous evaluation by the primary care physician (62% vs. 33%, P = 0.008), being sent in by the primary care physician (66% vs. 33%, P = 0.002), and a worse overall appearance based on the triage nurse's mark on a 0-cm ("alert/playful") to 10-cm ("lethargic/limp") visual analog scale (3.7 [2.8] vs. 2.4 [2.2] cm, P = 0.013). A regression tree analysis identified age younger than 2 years, dry mucous membranes, and duration of illness more than 2 days as sequential factors predictive of patients at risk for acidosis. This decision tree identified patients with acidosis with an 89.7% sensitivity (95% confidence interval, 71.5%-97.3%) and a 93.6% negative predictive value (95% confidence interval, 81.4%-98.3%).

The stepwise regression tree triage assessment tool dichotomizing patients based on age younger than 2 years, dry mucous membranes, and days of illness more than 2 days was able to predict acidosis with 90% sensitivity in patients presenting to the ED for evaluation of gastroenteritis. Identifying patients with acidosis early in their ED course allows the treating ED physician to focus more attention and resources toward rehydrating this at-risk population of patients with gastroenteritis.