MRCP2-1426

MRCP2-1426

A 72-year-old male is admitted to the acute medical unit with a chest infection. His past medical history includes COPD and heart failure. His current medications include salbutamol, tiotropium, bisoprolol and ramipril. On examination you note right basal crepitations. The JVP is at 3 cm above the sternal angle. There is no peripheral oedema. His blood pressure is 150/90 mmHg.

You note that his blood results are as follows:

Na+ 122 mmol/l
Urine osmolarity 380 mosmol/l
Urine sodium 60 mosmol/l
Urea 5.8 mmol/l
Creatinine 60 µmol/l
fT3 5.8 pmol/l (normal range 3.5 – 7.8)
fT4 5.5 pmol/l (normal range 9.0 – 25.0)
TSH 0.1 mU/l (normal range 0.4 – 4.0)
morning cortisol normal

You water restrict the patient to 1.5 litres per day. On day 4 his bloods are reported as follows:

Na+ 120 mmol/l

What would be your plan of action for managing this patient?