 EXPECTED RESULTS: The primary outcome is a 25 relative reduction in the incidence of POCD at 3 postoperative months. Secondary outcomes are the reduction of POCD incidence at 1 postoperative year, a reduction in postoperative hearing loss and vestibular impairment at 3 months, a reduction in the incidence of delirium. Hospital length of stay and 90 day mortality will also be assessed. This present study could have a high socio-economic impact, reduce healthcare costs and patient morbidity and mortality with a simple not expensive intraoperative intervention. 