title: Impact of Norepinephrine on Regional Cerebral Oxygenation During Cardiopulmonary Bypass.
abstract: OBJECTIVE
  Norepinephrine is used to increase mean arterial pressure during cardiopulmonary bypass. However, it has been suggested that norepinephrine could constrict cerebral arteries, reducing cerebral blood flow. The aim of this study, therefore, was to explore whether there was an association between doses of norepinephrine to maintain mean arterial pressure at ≈80 mmHg during cardiopulmonary bypass and cerebral oxygen saturation measured using near-infrared spectroscopy.
  
  
  METHODS
  Observational study.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Patients undergoing cardiac surgery (n = 45) using cardiopulmonary bypass.
  
  
  METHODS
  Norepinephrine was administered to maintain mean arterial pressure ≈80 mmHg during cardiopulmonary bypass.
  
  
  RESULTS
  From initiation of cardiopulmonary bypass to removal of the aortic cross-clamp, norepinephrine dose, mean arterial pressure, partial pressure of arterial carbon dioxide, partial pressure of arterial oxygen, hemoglobin, and pump flow values were averaged over 1 minute, giving a total of 3,460 data points entered as covariates in a linear mixed model for repeated measurements, with cerebral oxygen saturation measured using near-infrared spectroscopy as outcome. There was no statistically significant association between norepinephrine dose to maintain mean arterial pressure and cerebral oxygen saturation (p = 0.46) in this model.
  
  
  CONCLUSIONS
  Administration of norepinephrine to maintain mean arterial pressure ≈80 mmHg during cardiopulmonary bypass was not associated with statistically significant changes in cerebral oxygen saturation. These results indicated that norepinephrine could be used to increase mean arterial pressure during cardiopulmonary bypass without reducing cerebral oxygen saturation.
authors.affiliation: Department of Anesthesiology, Oslo University Hospital, Oslo, Norway. Electronic address: uxovha@ous-hf.no.
authors.forename: Ove Andreas
authors.initials: OA
authors.lastname: Hagen
authors.affiliation: Department of Anesthesiology, Oslo University Hospital, Oslo, Norway; Faculty of Medicine, University of Oslo, Oslo, Norway.
authors.forename: Lars Øivind
authors.initials: LØ
authors.lastname: Høiseth
authors.affiliation: Department of Anesthesiology, Oslo University Hospital, Oslo, Norway.
authors.forename: André
authors.initials: A
authors.lastname: Roslin
authors.affiliation: Department of Anesthesiology, Oslo University Hospital, Oslo, Norway.
authors.forename: Svein Aslak
authors.initials: SA
authors.lastname: Landsverk
authors.affiliation: Department of Cardiothoracic Surgery.
authors.forename: Per Reidar
authors.initials: PR
authors.lastname: Woldbaek
authors.affiliation: Oslo Centre of Biostatistics and Epidemiology, Research Support Services.
authors.forename: Are Hugo
authors.initials: AH
authors.lastname: Pripp
authors.affiliation: Department of Neurosurgery, Oslo University Hospital, Oslo, Norway; University of Bergen, Bergen, Norway.
authors.forename: Rolf
authors.initials: R
authors.lastname: Hanoa
authors.affiliation: Department of Anesthesiology, Oslo University Hospital, Oslo, Norway; Faculty of Medicine, University of Oslo, Oslo, Norway.
authors.forename: Knut Arvid
authors.initials: KA
authors.lastname: Kirkebøen
mesh_terms: D000328:Adult; D000368:Aged; D062186:Arterial Pressure; D001923:Brain Chemistry / Q000187:drug effects*; D002245:Carbon Dioxide / Q000097:blood; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000627:therapeutic use*; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption / Q000187:drug effects*; D019265:Spectroscopy, Near-Infrared; D014662:Vasoconstrictor Agents / Q000627:therapeutic use*
chemical_list: D014662:Vasoconstrictor Agents; D002245:Carbon Dioxide; D010100:Oxygen; D009638:Norepinephrine
keywords: cardiopulmonary bypass; norepinephrine; oximetry