Final answer:
Delirium is a state of confusion and disorientation. The main causes include pulmonary failure, MI, heart failure, COPD, drugs, and reduced sensory input.
Step-by-step explanation:
Delirium is a state of confusion and disorientation that is often caused by underlying medical conditions or medications. The main causes of delirium include pulmonary failure, MI (heart attack), heart failure, COPD, drugs, and reduced sensory input. However, one cause of delirium that is not listed is a small venous reserve of oxygen.