Nausea and vomiting, a cause for concern?

Answers on p 379. A 72 year old man with manic depression, who had recently started lithium treatment, presented to casualty with a two day history of severe nausea and vomiting. His serum urea and electrolytes were normal (sodium 139 mmol/l, potassium 4.1 mmol/l, creatinine 94 mmol/l, and urea 5 …