title: Effect of phenylephrine and ephedrine bolus treatment on cerebral oxygenation in anaesthetized patients.
abstract: BACKGROUND
  How phenylephrine and ephedrine treatments affect global and regional haemodynamics is of major clinical relevance. Cerebral tissue oxygen saturation (Sct(O2) )-guided management may improve postoperative outcome. The physiological variables responsible for Sct(O2) changes induced by phenylephrine and ephedrine bolus treatment in anaesthetized patients need to be defined.
  
  
  METHODS
  A randomized two-treatment cross-over trial was conducted: one bolus dose of phenylephrine (100-200 µg) and one bolus dose of ephedrine (5-20 mg) were given to 29 ASA I-III patients anaesthetized with propofol and remifentanil. , mean arterial pressure (MAP), cardiac output (CO), and other physiological variables were recorded before and after treatments. The associations of changes were analysed using linear-mixed models.
  
  
  RESULTS
  The CO decreased significantly after phenylephrine treatment [▵CO = -2.1 (1.4) litre min(-1), P<0.001], but was preserved after ephedrine treatment [▵CO = 0.5 (1.4) litre min(-1), P>0.05]. The was significantly decreased after phenylephrine treatment [▵ = -3.2 (3.0)%, P<0.01] but preserved after ephedrine treatment [▵ = 0.04 (1.9)%, P>0.05]. CO was identified to have the most significant association with (P<0.001). After taking CO into consideration, the other physiological variables, including MAP, were not significantly associated with (P>0.05).
  
  
  CONCLUSIONS
  Associated with changes in CO, decreased after phenylephrine treatment, but remained unchanged after ephedrine treatment. The significant correlation between CO and implies a cause-effect relationship between global and regional haemodynamics.
authors.affiliation: Department of Anesthesiology and Perioperative Care, University of California, Irvine Medical Center, 101 The City Drive South, Bldg. 53, Rm 227, Orange, CA 92868, USA. lmeng@uci.edu
authors.forename: L
authors.initials: L
authors.lastname: Meng
authors.forename: M
authors.initials: M
authors.lastname: Cannesson
authors.forename: B S
authors.initials: BS
authors.lastname: Alexander
authors.forename: Z
authors.initials: Z
authors.lastname: Yu
authors.forename: Z N
authors.initials: ZN
authors.lastname: Kain
authors.forename: A E
authors.initials: AE
authors.lastname: Cerussi
authors.forename: B J
authors.initials: BJ
authors.lastname: Tromberg
authors.forename: W W
authors.initials: WW
authors.lastname: Mantulin
mesh_terms: D000328:Adult; D000368:Aged; D000768:Anesthesia, General / Q000379:methods; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D018592:Cross-Over Studies; D004809:Ephedrine / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007430:Intraoperative Care / Q000379:methods; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods; D010092:Oximetry / Q000379:methods; D010101:Oxygen Consumption / Q000187:drug effects*; D010656:Phenylephrine / Q000494:pharmacology*; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
chemical_list: D014662:Vasoconstrictor Agents; D010656:Phenylephrine; D004809:Ephedrine