MRCP2-4405
A 56-year-old man presents with a confirmed right adenocarcinoma of the bronchus. He reports weight loss over the past few months and a persistent cough, but is still able to work and care for his family. The following investigations were conducted:
Haemoglobin (Hb): 130 g/l (normal range: 115-155 g/l)
White cell count (WCC): 6.2 × 109/l (normal range: 4.0-11.0 × 109/l)
Platelets (PLT): 180 × 109/l (normal range: 150-400 × 109/l)
Sodium (Na+): 142 mmol/l (normal range: 135-145 mmol/l)
Potassium (K+): 4.2 mmol/l (normal range: 3.5-5.0 mmol/l)
Creatinine (Cr): 110 μmol/l (normal range: 50-120 μmol/l)
Which of the following tests would be most useful in determining his eligibility for surgery?