title: [Influence of inhaled anesthesia on bispectral index of elderly patients with cognitive decline].
abstract: OBJECTIVE
  To investigate the influence of inhaled anesthesia on bispectral index (BIS) of elderly patients with cognitive decline at loss of consciousness and regain of consciousness, and on deepening of sedation.
  
  
  METHODS
  The patients aged more than 65 years undergoing elective operations from January 2012 to September 2012 were recruited, then 60 cognitive intact patients and 60 cognitive decline patients were screened by mini-mental state examinations. Inhaled anesthesia was administered using sevoflurane. BIS's of the two groups at loss of consciousness and regain of consciousness, and during end-tidal concentration of sevoflurane (CETSev) changing from 0.7% to 2.8% were recorded. The data were compared with independent-samples t test and repeated-measures general linear model of ANOVA.
  
  
  RESULTS
  In the study, 117 patients finshed the investigation, The BIS's of the cognitive decline group at loss of consciousness were significantly higher than those of the cognitive intact group (P<0.01). There were no significant differences at regain of consciousness between the two groups (P>0.05). The BIS's of the cognitive decline group during CETSev changing from 0.7% to 2.8% were significantly lower than those of the cognitive intact group (P<0.05). The BIS's of the cognitive decline group at CETSev 0.7%, 1.05%, 1.4% and 1.75% were significantly lower than those of the cognitive intact group (P<0.05), but there were no significant differences at CETSev 2.1%, 2.45% and 2.8% between the two groups (P>0.05).
  
  
  CONCLUSIONS
  During inhaled anesthesia, the BIS of the elderly patients with cognitive decline at loss of consciousness is higher than that of the patients with cognitive intact, The BIS of elderly patients with cognitive decline on deepening of anesthesia is lower than that of the patients with cognitive intact, especially during light anesthesia, and its mechanisms may attribute to cognitive decline related neurodegeneration and neurotransmitter system dysfunction.
authors.affiliation: Department of Anesthesiology, Peking University Third Hospital, Beijing 100191, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Ni
authors.forename: Yu-lan
authors.initials: YL
authors.lastname: Rong
authors.forename: Dong-lin
authors.initials: DL
authors.lastname: Jia
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.forename: Chen
authors.initials: C
authors.lastname: Yu
authors.affiliation: Research Center of Clinical Epidemiology, Peking University Third Hospital, Beijing 100191, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Li
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Xiang-yang
authors.initials: XY
authors.lastname: Guo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000762:Anesthesia Recovery Period; D000769:Anesthesia, Inhalation; D003071:Cognition / Q000187:drug effects*; D003072:Cognition Disorders / Q000150:complications / Q000503:physiopathology*; D003243:Consciousness / Q000187:drug effects*; D056805:Consciousness Monitors; D017558:Elective Surgical Procedures; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008738:Methyl Ethers / Q000009:adverse effects*; D000077149:Sevoflurane
chemical_list: D008738:Methyl Ethers; D000077149:Sevoflurane