Laboratory Correlates of Dehydration Severity in Children with Acute Gastroenteritis in a Saudi Pediatric Emergency Department: A Retrospective Observational Study Laboratory Correlates of Pediatric Dehydration

Abstract

Background: Assessment of dehydration severity is central to the management of children with acute gastroenteritis (AGE), but clinical signs alone have imperfect reliability and laboratory tests are not recommended routinely for every child. This study examined the clinical and laboratory correlates of dehydration severity among children presenting to a pediatric emergency department.
Methods: A retrospective observational study was conducted at Maternity and Children Hospital, Dammam, Saudi Arabia, using records from January to December 2023. Children aged ≥1 month and <14 years who presented with AGE and had laboratory testing were eligible. Dehydration was categorized as mild, moderate, or severe according to the documented clinical assessment framework used in routine care. Demographic, clinical, vital-sign, hematologic, renal, electrolyte, glucose, and acid-base variables were compared across severity groups using chi-square/exact tests or one-way analysis of variance, as appropriate.
Results: The analysis included 215 children: 126 (58.6%) with mild, 30 (14.0%) with moderate, and 59 (27.4%) with severe dehydration. Vomiting duration differed across severity groups (p=0.049), whereas most other historical variables did not. Respiratory rate was the only vital sign that differed significantly (p=0.005). Hemoglobin (p=0.012), serum creatinine (p=0.049), and urea (p<0.001) varied across dehydration categories; RDW and serum sodium, potassium, and chloride did not. Hypoglycemia was substantially more frequent in severe dehydration (59.3% of severe cases; p<0.001), and metabolic acidosis was reported only in the severe group (p<0.001).
Conclusions: Selected biochemical abnormalities—particularly urea, creatinine, glucose, and acid-base status—were associated with documented dehydration severity, whereas RDW and routine electrolytes did not distinguish severity groups. These findings support targeted laboratory assessment in clinically higher-risk children rather than routine testing in all AGE presentations. Because of the retrospective design and possible incorporation of laboratory findings into routine severity classification, the results should be interpreted as exploratory associations rather than independent diagnostic validation.