DOI: 10.1373/clinchem.2012.194969


A 63-year-old white man with a history of schizophrenia plus polysubstance and alcohol abuse was seen by his primary care physician during a routine visit, at which time he was found to have a serum sodium concentration of 113 mmol/L. The patient was contacted by phone and advised to return to Urgent Care for assessment, but he did not respond until 7 days later, at which time his serum sodium concentration was 106 mmol/L.