Intra-abdominal and Intrapelvic Surgery Clinical Trial
Official title:
Comparison of Total Intravenous Anesthesia With Sevoflurane-based Balanced Anesthesia on Postoperative Cognitive Dysfunction in Elderly Patients for Major Elective Intra-abdominal Surgery
Post-operative cognitive dysfunction (POCD) is a fairly well-documented clinical phenomenon. Most patients will receive general anesthesia during surgery. Two groups of general anesthetics are used for this purpose. We hypothesize that the incidence of POCD is not different in patients received intravenous anesthetics only or sevoflurane (a volatile anesthetic-based general anesthesia) for their major intra-abdominal surgery.
Patients who are 60 years old or older for laparoscopic abdominal surgery will be randomly assigned into two groups: 1) sevoflurane-based general anesthesia group, and 2) propofol-based general anesthesia group. Each group will need 221 patients to detect 1/3 of decrease or increase in the rate of POCD of one group compared with another group at about one week after surgery, assuming the overall rate of POCD at this time is about 40% at this time. Considering about 10% loss to follow-up, we will have 250 patients in each group. In addition, investigators will need 184 subjects in the control group. The data of these control subjects will be used to normalize the data of the two studied groups to diagnose POCD. The subjects in control groups will also be elderly but without the exposure to anesthesia and surgery. ;