REPOSE Study: Reducing Delirium by Enhancing Postoperative Sleep With Suvorexant

Inclusion Criteria: 1. Age 65 and older 2. Undergoing non-cardiac, non-intracranial surgery, any surgical procedure not involving the skull, brain, cerebrovascular structures 3. Scheduled postoperative inpatient overnight stay 4. Able to give informed consent or has legally authorized representative able to give informed consent on their behalf 5. English-speaking Exclusion Criteria: 1. Inmate of correctional facility 2. Body mass index\> 40 3. Legal blindness 4. Unable to perform study related questionnaires and assessments 5. Use of outpatient sedating sleep aids \> 2 times per any week in 1 month preceding day of surgery. Sedating sleep aids, \*See list Below. 6. History of psychotic disorder, including schizophrenia, schizoaffective disorder, schizophreniform or brief psychotic disorder. 7. History of liver failure with documented international normalized ratio (INR) of \>1.2 or with history of hepatic encephalopathy 8. History of severe sleep apnea or obesity hypoventilation syndrome requiring home bilevel positive airway pressure therapy or home ventilator or other forms of noninvasive ventilation 9. Chronic lung disease requiring home oxygen therapy 10. History of narcolepsy 11. Use of systemic (oral, intravenous, intramuscular, subcutaneous) moderate or strong CYP3A inhibitors within 1 week prior to surgery, \*See list below 12. Use of systemic (oral, intravenous, intramuscular, subcutaneous) moderate or strong CYP3A inducers within 1 week prior to surgery, \*See list below. 13. Current or planned administration of digoxin, or is currently experiencing digoxin toxicity 14. Undergoing surgery that will result in inability to take medications by mouth including laryngectomy, tracheostomy, and oral resection/reconstructive surgery 15. Undergoing surgery that will require postoperative strict bowel rest, including gastrectomy, esophagectomy, and pancreaticoduodenectomy 16. Undergoing surgery in an area that will make it unsafe to wear a headband, such as scalp or forehead procedures. 17. Inappropriate for study inclusion based on the judgement of the principal investigator Exclusionary Medications: Moderate CYP3A inhibitors: Amprenavir, Aprepitant, Atazanavir, Ciprofloxacin, Diltiazem, Erythromycin, Fluconazole, Fosamprenavir, Imatinib, Verapamil, grapefruit juice. Strong CYP3A inhibitors: Ketoconazole, Itraconazole, Posaconazole, Clarithromycin, Nefazodone, Ritonavir, Saquinavir, Nelfinavir, Indinavir, Boceprevir, Telaprevir, Telithromycin, Conivaptan Moderate/Strong CYP3A inducers: Apalutamide, Carbamazepine, Enzalutamide, Ivosidenib, lumacaftor, Mitotane, Phenytoin, Rifampin, St. John's wort, Bosentan, Cenobamate, Dabrafenib, Efavirenz, Etravirine, Lorlatinib, Pexidartinib, Phenobarbital, Primidone, Sotorasib. Sedating sleep aids: Mirtazapine, Trazodone, Flurazepam, Temazepam, Triazolam, Estazolam, Quazepam, Clonazepam, Lorazepam, Midazolam, Alprazolam, Diazepam, Zolpidem, Zaleplon, Eszopiclone, Diphenhydramine, Doxylamine, Hydroxyzine, Suvorexant, Doxepin