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Assessing Dehydration Employing End-Tidal Carbon Dioxide in Children With Vomiting and Diarrhea
Stephen B Freedman1, David W Johnson2, Alberto Nettel-Aguirre3
1From the Section of Pediatric Emergency Medicine and Gastroenterology, Department of Pediatrics.
Insights
End-tidal carbon dioxide (EtCO2) monitoring is not a reliable tool for assessing dehydration severity in children presenting with gastroenteritis. This study found EtCO2 measurements lack the accuracy to predict significant dehydration in pediatric patients.
Area of Science:
- Pediatric Emergency Medicine
- Clinical Assessment
- Gastroenterology
Background:
- Serum bicarbonate levels are indicators of dehydration severity in children with gastroenteritis.
- Previous research suggests a correlation between end-tidal carbon dioxide (EtCO2) and serum bicarbonate in children undergoing intravenous rehydration.
Purpose of the Study:
- To evaluate the predictive capability of end-tidal carbon dioxide (EtCO2) for estimating weight change, a marker of dehydration, in pediatric patients experiencing vomiting and/or diarrhea.
Main Methods:
- A prospective cohort study enrolled children aged 3 months to 10 years presenting to the emergency department (ED) with vomiting and/or diarrhea.
- End-tidal carbon dioxide (EtCO2) measurements were taken post-triage.
- Weight change, determined by serial measurements until symptom resolution, served as the standard for assessing dehydration; receiver operating characteristic (ROC) curve analysis was used to identify a cut-point for predicting 5% or greater dehydration.
Main Results:
- The study included 195 children; 169 had EtCO2 measurements (median 30.4 mmHg).
- Among 158 children with follow-up weights, the median weight change was +0.72%, with 4% experiencing 5% or greater weight gain (indicating dehydration).
- Receiver operating characteristic (ROC) curve analysis showed an area under the curve of 0.34 for EtCO2 predicting 5% or greater dehydration, indicating limited accuracy.
Conclusions:
- End-tidal carbon dioxide (EtCO2) measurement demonstrates insufficient accuracy to reliably predict 5% or greater dehydration in children with vomiting and/or diarrhea.
- EtCO2 monitoring is not recommended as a tool for assessing dehydration severity in this pediatric population presenting to the emergency department.
Objective:
Serum bicarbonate reflects dehydration severity in children with gastroenteritis. Previous work in children receiving intravenous rehydration has correlated end-tidal carbon dioxide (EtCO2) with serum bicarbonate. We evaluated whether EtCO2 predicts weight change in children with vomiting and/or diarrhea.
Methods:
A prospective cohort study was conducted. Eligible children were 3 months to 10 years old and presented for emergency department (ED) care because of vomiting and/or diarrhea. End-tidal carbon dioxide measurements were performed after triage. The diagnostic standard was weight change determined from serial measurements after symptom resolution. A receiver operating characteristic curve was constructed to identify a cut-point to predict 5% or more dehydration.
Results:
In total, 195 children were enrolled. Among the 169 (87%) with EtCO2 measurements, the median (interquartile range [IQR]) was 30.4 (27.8 to 33.1). One hundred fifty-eight had repeat weights performed at home; the median (IQR) weight change from ED presentation to well weight was +0.06 (-0.14 to +0.30) or +0.72% (-1.2% to +2.1%). Sixteen percent (25/158) had 3% or more and 4% (6/158) had 5% or more weight gain (ie, percent dehydration). One hundred sixteen (60%) completed home follow-up and had acceptable EtCO2 recordings. Receiver operating curve analysis revealed an area under the curve of 0.34 (95% confidence interval, 0.06 to 0.62) for EtCO2 as a predictor of 5% or more dehydration.
Conclusions:
The limited accuracy of EtCO2 measurement to predict 5% or more dehydration precludes its use as a tool to assess dehydration severity in children. End-tidal carbon dioxide monitoring does not have the ability to identify those children with 5% or more dehydration in a cohort of children with vomiting and/or diarrhea presenting for ED care.
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