%0 Journal Article %A Yincent Tse %A Nidhi Singhal %A Leigh McDonald %A Milan Gopal %A Anupam Lall %A Helen Johnstone %A Timothy Cheetham %T Problem solving in clinical practice: the sick infant with low sodium and high potassium %D 2021 %R 10.1136/archdischild-2019-317756 %J Archives of disease in childhood - Education & practice edition %P 23-27 %V 106 %N 1 %X Many paediatricians will be faced with a sick infant who on investigation is found to have hyponatraemia and hyperkalaemia at some time in their career. The focus of initial management includes the treatment of potentially life-threatening hyperkalaemia with concurrent investigation aiming to elucidate whether the underlying cause reflects a primarily renal or endocrine pathology. We describe the presentation of two infants who each presented with one of the more common underlying diagnoses that led to this biochemical disturbance and discuss the approach to immediate treatment, diagnostic work-up and longer term management. %U https://ep.bmj.com/content/edpract/106/1/23.full.pdf