title: Is depth of anesthesia, as assessed by the Bispectral Index, related to postoperative cognitive dysfunction and recovery?
abstract: We randomized 74 patients to either a lower Bispectral Index (BIS) regimen (median BIS, 38.9) or a higher BIS regimen (mean BIS, 50.7) during the surgical procedure. Preoperatively and 4-6 wk after surgery, the patients' cognitive status was assessed with a cognitive test battery consisting of processing speed index, working memory index, and verbal memory index. Processing speed index was 113.7 +/- 1.5 (mean +/- se) in the lower BIS group versus 107.9 +/- 1.4 in the higher BIS group (P = 0.006). No difference was observed in the other two test battery components. Somewhat deeper levels of anesthesia were therefore associated with better cognitive function 4-6 wk postoperatively, particularly with respect to the ability to process information.
authors.affiliation: Department of General Anesthesiology and Outcomes Research, Cleveland Clinic, Cleveland Clinic Lerner College of Medicine of Case Western University, Cleveland, Ohio 44195, USA.
authors.forename: Ehab
authors.initials: E
authors.lastname: Farag
authors.forename: Gordon J
authors.initials: GJ
authors.lastname: Chelune
authors.forename: Armin
authors.initials: A
authors.lastname: Schubert
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Mascha
mesh_terms: D000759:Adjuvants, Anesthesia / Q000008:administration & dosage*; D000368:Aged; D000762:Anesthesia Recovery Period; D018686:Anesthetics, Intravenous / Q000008:administration & dosage*; D003071:Cognition / Q000187:drug effects*; D005260:Female; D005283:Fentanyl / Q000494:pharmacology; D006801:Humans; D007530:Isoflurane / Q000494:pharmacology; D008297:Male; D008568:Memory / Q000187:drug effects*; D008874:Midazolam / Q000494:pharmacology; D008875:Middle Aged; D019148:Neuromuscular Blockade; D009609:Nitrous Oxide / Q000494:pharmacology; D011184:Postoperative Period; D015742:Propofol / Q000494:pharmacology
chemical_list: D000759:Adjuvants, Anesthesia; D018686:Anesthetics, Intravenous; D007530:Isoflurane; D009609:Nitrous Oxide; D008874:Midazolam; D005283:Fentanyl; D015742:Propofol