title: Effects of Single Low Dose of Dexamethasone before Noncardiac and Nonneurologic Surgery and General Anesthesia on Postoperative Cognitive Dysfunction-A Phase III Double Blind, Randomized Clinical Trial.
abstract: Postoperative cognitive dysfunction (POCD) is a multifactorial adverse event most frequently in elderly patients. This study evaluated the effect of dexamethasone on POCD incidence after noncardiac and nonneurologic surgery.
  
  
  
  One hundred and forty patients (ASA I-II; age 60-87 years) took part in a prospective phase III, double blind, randomized study involving the administration or not of 8 mg of IV dexamethasone before general anesthesia under bispectral index (BIS) between 35-45 or 46-55. Neuropsychological tests were applied preoperatively and on the 3rd, 7th, 21st, 90th and 180th days after surgery and compared with normative data. S100β was evaluated before and 12 hours after induction of anesthesia. The generalized estimating equations (GEE) method was applied, followed by the posthoc Bonferroni test considering P<0.05 as significant.
  
  
  
  On the 3rd postoperative day, POCD was diagnosed in 25.2% and 15.3% of patients receiving dexamethasone, BIS 35-45, and BIS 46-55 groups, respectively. Meanwhile, POCD was present in 68.2% and 27.2% of patients without dexamethasone, BIS 35-45 and BIS 46-55 groups (p<0.0001). Neuropsychological tests showed that dexamethasone associated to BIS 46-55 decreased the incidence of POCD, especially memory and executive function. The administration of dexamethasone might have prevented the postoperative increase in S100β serum levels.
  
  
  
  Dexamethasone can reduce the incidence of POCD in elderly patients undergoing surgery, especially when associated with BIS 46-55. The effect of dexamethasone on S100β might be related with some degree of neuroprotection.
  
  
  
  www.clinicaltrials.gov NCT01332812.
authors.affiliation: Department of Anesthesia, LIM 8 -Laboratory of Anesthesiology, Faculdade de Medicina da Universidade de São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Livia Stocco Sanches
authors.identifier: 0000-0003-1520-5570
authors.initials: LS
authors.lastname: Valentin
authors.affiliation: Department of Anesthesia, LIM 8 -Laboratory of Anesthesiology, Faculdade de Medicina da Universidade de São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Valeria Fontenelle Angelim
authors.initials: VF
authors.lastname: Pereira
authors.affiliation: Department of Surgery, Duke University Health System, Durham, North Carolina, United States of America.
authors.forename: Ricardo S
authors.initials: RS
authors.lastname: Pietrobon
authors.affiliation: Department of Biochemistry, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.|Department of Anesthesia and Perioperative Medicine, Hospital de Porto Alegre, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Andre P
authors.initials: AP
authors.lastname: Schmidt
authors.affiliation: Center of Sciences of the Life and Health, Universidade Católica de Pelotas, Pelotas, Rio Grande do Sul, Brazil.
authors.forename: Jean P
authors.initials: JP
authors.lastname: Oses
authors.affiliation: Department of Biochemistry, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Luis V
authors.initials: LV
authors.lastname: Portela
authors.affiliation: Department of Biochemistry, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Diogo O
authors.initials: DO
authors.lastname: Souza
authors.affiliation: Department of Surgery, Duke University Health System, Durham, North Carolina, United States of America.
authors.forename: João Ricardo Nickenig
authors.initials: JR
authors.lastname: Vissoci
authors.affiliation: Department of Anesthesia, LIM 8 -Laboratory of Anesthesiology, Faculdade de Medicina da Universidade de São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Vinicius Fernando da
authors.initials: VF
authors.lastname: Luz
authors.affiliation: Department of Anesthesia, LIM 8 -Laboratory of Anesthesiology, Faculdade de Medicina da Universidade de São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Leticia Maria de Araujo de Souza
authors.initials: LM
authors.lastname: Trintoni
authors.affiliation: Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina, United States of America.
authors.forename: Karen C
authors.initials: KC
authors.lastname: Nielsen
authors.affiliation: Department of Anesthesia, LIM 8 -Laboratory of Anesthesiology, Faculdade de Medicina da Universidade de São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Maria José Carvalho
authors.initials: MJ
authors.lastname: Carmona
mesh_terms: D000368:Aged; D003072:Cognition Disorders / Q000209:etiology / Q000517:prevention & control* / Q000523:psychology; D003907:Dexamethasone / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011300:Preoperative Care; D013514:Surgical Procedures, Operative / Q000009:adverse effects*
chemical_list: D003907:Dexamethasone