A 70 year old female is brought to your ED with a 2 day history of worsening confusion. She is usually independent and lives in her own home. There is a history of colon cancer, hypertension and high cholesterol.

Vital signs:

BP 120/70

PR 90/min

RR 22/min

What are the common causes of confusion in cancer patients?

What is your approach to investigation of the causes of this patients confusion?

What tests would you do?