Final answer:
The first step in the work up of this patient would be to conduct a comprehensive physical examination, including a detailed history and a neurological examination. Possible causes for the patient's symptoms include urinary tract infection (UTI), delirium, and medication side effects. Urine tests, such as urinalysis and urine culture, can be ordered to check for the presence of infection or other abnormalities.
Step-by-step explanation:
The first step in the work up of this patient would be to conduct a comprehensive physical examination, including a detailed history and a neurological examination. The patient's symptoms of altered mental status, sleep disturbances, hallucinations, and pain upon urination suggest possible underlying medical conditions that need to be investigated further.
Based on the information provided, some possible causes for the patient's symptoms include urinary tract infection (UTI), delirium, and medication side effects. A thorough physical examination can help identify any signs of infection, evaluate the patient's mental status, and assess for any other physical abnormalities.
Additionally, urine tests, such as urinalysis and urine culture, can be ordered to check for the presence of infection or other abnormalities.