Desflurane or Propofol Anesthesia in Elderly Obese Patients Undergoing Total Knee Replacement

You are invited to participate in a research study assessing your mental status in the first days after your surgery and how you will be doing in the 2 years following the surgery. The investigators hope to learn more about the incidence of postoperative confusion and a possible relation with 2 anesthesia techniques that are routinely used. The first one is an anesthesia technique that uses the inhaled anesthetic gas desflurane and the second one is an anesthesia technique that uses the anesthetic propofol administered by infusion in a vein. The investigators are also looking to see if there is a relationship between anesthesia technique and cardiovascular outcomes. You were selected as a possible participant in this study because at your age this phenomenon appears to have a greater incidence.