Assessing Dehydration Employing End-Tidal Carbon Dioxide in Children With Vomiting and Diarrhea

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.