Hypernatraemic dehydration in infants with acute gastroenteritis at King Edward VIII Hospital, Durban, South Africa

Abstract

Background. Acute gastroenteritis (AGE) is a leading cause of infant mortality, with hypernatraemic dehydration contributing to increased morbidity and mortality.

Objectives. To determine the prevalence of hypernatraemia secondary to AGE in admitted infants in Durban, South Africa. To describe the feeding choices, nutritional status and outcomes of these patients. To determine the association between admission sodium (Na) level, the rate of Na correction and clinical outcomes

Methods. A retrospective chart review was conducted on cases of hypernatraemic dehydration admitted in 2014 to a South African hospital. Serum Na levels were corroborated with National Health Laboratory Services results. Descriptive and analytical statistics were done using Statistical Package for Social Sciences version 22.

Results. A 12.3% prevalence of hypernatraemia (n=41/334) was found. The majority of infants were formula-fed (76%) with a 21% incidence of malnutrition and 66% HIV exposure rate in this cohort. A high rate of neurological abnormalities (63%), and a 4.9% case fatality rate was found. Shock on admission was present in 92% of patients who developed severe neurological complications. The mean admission Na was higher in those with severe neurological complications (164.2 v. 158.4 mmol/L, p=0.08). The mean rate of Na change was not faster in those with severe neurological morbidity (0.61 v. 0.91 mmol/L/hr; p=0.1).

Conclusion. Hypernatraemic dehydration remains a significant problem in South Africa. High rates of formula feeding may be a contributory factor and the correlation with HIV infection needs investigation. Poor neurological outcomes were noted particularly in those patients presenting with hypernatraemia and shock. Although the mean admission Na level was higher in patients with severe neurological complications, this was not statistically significant in this sample. This study supports the hypotheses that neurological complications in diarrhoea-related hypernatraemia are largely associated with the severity of the dehydration that occurs prior to presentation rather than following rehydration.