title: Influence of norepinephrine and phenylephrine on frontal lobe oxygenation during cardiopulmonary bypass in patients with diabetes.
abstract: OBJECTIVE
  Although utilization of vasopressors recently has been associated with reduced cerebral oxygenation, the influence of vasopressors on cerebral oxygenation during cardiopulmonary bypass in patients with diabetes is unknown. The aim of this study was to document the impact of norepinephrine and phenylephrine utilization on cerebral oxygenation in patients with and without diabetes during cardiopulmonary bypass.
  
  
  METHODS
  Prospective, clinical study.
  
  
  METHODS
  Academic medical center.
  
  
  METHODS
  Fourteen patients with diabetes and 17 patients without diabetes undergoing cardiac surgery.
  
  
  METHODS
  During cardiopulmonary bypass, norepinephrine (diabetics n = 6; non-diabetics n = 8) or phenylephrine (diabetics n = 8; non-diabetics n = 9) was administered intravenously to maintain mean arterial pressure above 60 mmHg.
  
  
  RESULTS
  Mean arterial pressure, venous temperature, arterial oxygenation, and frontal lobe oxygenation (monitored by near-infrared spectroscopy) were recorded before anesthesia induction (baseline) and continuously during cardiopulmonary bypass. Frontal lobe oxygenation was lowered to a greater extent in diabetics versus non-diabetics with administration of norepinephrine (-14±13 v 3±12%; p<0.05). There was also a trend towards a greater reduction in cerebral oxygenation in diabetics versus non-diabetics with administration of phenylephrine (-12±8 v -6±7%; p = 0.1) during cardiopulmonary bypass.
  
  
  CONCLUSIONS
  Administration of norepinephrine to restore mean arterial pressure during cardiopulmonary bypass is associated with a reduction in frontal lobe oxygenation in diabetics but not in patients without diabetes. Administration of phenylephrine also were associated with a trend towards a greater reduction in frontal lobe oxygenation in diabetics. The clinical implications of these findings deserve future consideration.
authors.affiliation: Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada; Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada. Electronic address: patrice.brassard@kin.ulaval.ca.
authors.forename: Patrice
authors.initials: P
authors.lastname: Brassard
authors.affiliation: Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada; Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada.
authors.forename: Claudine
authors.initials: C
authors.lastname: Pelletier
authors.affiliation: Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada.
authors.forename: Mickaël
authors.initials: M
authors.lastname: Martin
authors.affiliation: Research Center of the Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Canada.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Gagné
authors.affiliation: Research Center of the Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Canada; Faculty of Pharmacy, Université Laval, Québec, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Poirier
authors.affiliation: Department of Cardiac Surgery, Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, Canada.
authors.forename: Philip N
authors.initials: PN
authors.lastname: Ainslie
authors.affiliation: Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia-Okanagan, Kelowna, British Columbia, Canada.
authors.forename: Manon
authors.initials: M
authors.lastname: Caouette
authors.affiliation: Research Center of the Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Canada; Department of Anesthesiology, Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, Canada.
authors.forename: Jean S
authors.initials: JS
authors.lastname: Bussières
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000187:drug effects; D002315:Cardiopulmonary Bypass; D003920:Diabetes Mellitus / Q000378:metabolism* / Q000503:physiopathology; D005260:Female; D005625:Frontal Lobe / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000494:pharmacology*; D010101:Oxygen Consumption / Q000187:drug effects*; D010656:Phenylephrine / Q000494:pharmacology*; D011446:Prospective Studies; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
chemical_list: D014662:Vasoconstrictor Agents; D010656:Phenylephrine; D009638:Norepinephrine
keywords: cardiopulmonary bypass; diabetes mellitus; frontal lobe; norepinephrine; phenylephrine