Case 1

A 72-year-old male presents to your department. He was diagnosed with carcinoma of the bronchus 3 months ago. He was well, but has now become confused and appears dehydrated. He has a postural drop. A bone scan last week was unremarkable. His bloods reveal sodium 140 mmol/L, potassium 4.3 mmol/L, creatinine 110 mmol/L with a calcium of 4.4 mmol/L. His albumin is normal.