title: Effects of extreme hemodilution during cardiac surgery on cognitive function in the elderly.
abstract: BACKGROUND
  Strategies for neuroprotection including hypothermia and hemodilution have been routinely practiced since the inception of cardiopulmonary bypass. Yet postoperative neurocognitive deficits that diminish the quality of life of cardiac surgery patients are frequent. Because there is uncertainty regarding the impact of hemodilution on perioperative organ function, the authors hypothesized that extreme hemodilution during cardiac surgery would increase the frequency and severity of postoperative neurocognitive deficits.
  
  
  METHODS
  Patients undergoing coronary artery bypass grafting surgery were randomly assigned to either moderate hemodilution (hematocrit on cardiopulmonary bypass >or=27%) or profound hemodilution (hematocrit on cardiopulmonary bypass of 15-18%). Cognitive function was measured preoperatively and 6 weeks postoperatively. The effect of hemodilution on postoperative cognition was tested using multivariable modeling accounting for age, years of education, and baseline levels of cognition.
  
  
  RESULTS
  After randomization of 108 patients, the trial was terminated by the Data Safety and Monitoring Board due to the significant occurrence of adverse events, which primarily involved pulmonary complications in the moderate hemodilution group. Multivariable analysis revealed an interaction between hemodilution and age wherein older patients in the profound hemodilution group experienced greater neurocognitive decline (P = 0.03).
  
  
  CONCLUSIONS
  In this prospective, randomized study of hemodilution during cardiac surgery with cardiopulmonary bypass in adults, the authors report an early termination of the study because of an increase in adverse events. They also observed greater neurocognitive impairment among older patients receiving extreme hemodilution.
authors: Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina 27710, USA. mathe014@mc.duke.edu
authors: Joseph P
authors: JP
authors: Mathew
authors: G Burkhard
authors: GB
authors: Mackensen
authors: Barbara
authors: B
authors: Phillips-Bute
authors: Mark
authors: M
authors: Stafford-Smith
authors: Mihai V
authors: MV
authors: Podgoreanu
authors: Hilary P
authors: HP
authors: Grocott
authors: Steven E
authors: SE
authors: Hill
authors: Peter K
authors: PK
authors: Smith
authors: James A
authors: JA
authors: Blumenthal
authors: J G
authors: JG
authors: Reves
authors: Mark F
authors: MF
authors: Newman
mesh_terms: D000368:Aged / Q000523:psychology*; D000768:Anesthesia, General; D001803:Blood Transfusion; D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000523:psychology*; D003071:Cognition / Q000187:drug effects / Q000502:physiology*; D003072:Cognition Disorders / Q000209:etiology / Q000523:psychology; D005260:Female; D006400:Hematocrit; D006438:Hemodilution / Q000009:adverse effects / Q000523:psychology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D016896:Treatment Outcome