Hypoglycaemia was common in acute gastroenteritis in a prospective hospital-based study, but electrolyte imbalances were not.

Aim: Using routine blood sampling in a gastroenteritis diagnostic workup is debatable. This study examined the relationship between the severity of acute gastroenteritis and blood test abnormalities.

Methods: We prospectively enrolled children under five years of age referred for outpatient or inpatient management for gastroenteritis from February 2014 to April 2016. The four study hospitals cared for 30% of Norwegian children. The severity of gastroenteritis was assessed using Vesikari scores. Blood samples were analysed at each hospital.

Results: The 659 children had a median age of 19 months. The rotavirus was found in 314/514 children with stool samples (61%). Severe gastroenteritis, indicated by a Vesikari score of ≥11, was found in 392/549 (71%) with completed scores, but only 40 of 649 (6%) assessed for dehydration were more than 5% dehydrated. None had sodium <130 mmol/L. Glucose of 3.0-3.3 mmol/L was detected in 52/578 (9%) and <3.0 mmol/L in 33/578 (6%). Hypoglycaemia, elevated urea, low bicarbonate and negative base excess were associated with disease severity. The duration of vomiting and the rotavirus infection were associated with hypoglycaemia. Elevated urea, low bicarbonate and negative base excess had high specificities, but low sensitivities.

Conclusion: Hypoglycaemia was common in acute gastroenteritis, but major electrolyte disturbances were infrequent.