Which client is at the greatest risk for developing delirium?

Ms. Rivera, 78, admitted for uncontrolled diabetes. She reports insomnia, frequently asks staff for reassurance, and recently started sertraline for anxiety. She is alert, oriented, and ambulatory with assistance.

Mr. Wilcox, 87, admitted for new-onset atrial fibrillation. He lives independently, is hard of hearing, and has not brought his hearing aids to the hospital. He is receiving diltiazem IV and is on continuous cardiac monitoring. He reports feeling "confused by all the wires and machines."

Mr. Daniels, 85, post-hip fracture repair. He is receiving morphine IV for pain, is bedbound, and has no family nearby. His chart notes mild cognitive impairment and a recent history of wandering in his assisted living facility.

Mrs. Tran, 91, with dementia, admitted from a skilled nursing facility for urosepsis. She is febrile, disoriented, and receiving IV antibiotics. Her medication list includes furosemide, lorazepam PRN for anxiety, and oxybutynin for bladder spasms.