title: Cerebrovascular response to acute metabolic acidosis in humans.
abstract: OBJECTIVE
  Evaluation of the cerebrovascular response (delta CBV/delta PaCO2) during baseline metabolic conditions and acute metabolic acidosis.
  
  
  METHODS
  15 healthy subjects, 5 m, 10 f, 56 +/- 10 yrs were investigated. For acidification, NH4Cl was given orally. CBV was measured using Near Infrared Spectroscopy (OXYMON) during normo-, hyper- and hypocapnia.
  
  
  RESULTS
  Acute metabolic acidosis was realised: mean delta BE -2.7 mEq.L-1 (p < 0.001) with mean delta PaCO2 -0.2 kPa (p < 0.01). During normo-, hyper- and hypocapnia, CBV values of 3.51, 4.82 and 2.55 mL.100 g-1 were calculated during baseline metabolic conditions and 3.70, 4.86 and 2.63 mL.100 g-1 during acute metabolic acidosis. The CBV/PaCO2 response showed a hockeystick configuration with the point of infliction around normocapnia. delta CBV/delta PaCO2 reactivity from normo- to hypercapnia and from normo- to hypocapnia was calculated; no significant differences in delta CBV/delta PaCO2 were found in both metabolic conditions.
  
  
  CONCLUSIONS
  Cerebrovascular reactivity to CO2 does not alter during acute metabolic acidosis.
authors.affiliation: Department of Pulmonology, Rijnstate Hospital Arnhem, PO 9555, 6800 TA Arnhem, The Netherlands.
authors.forename: Marjo
authors.initials: M
authors.lastname: van de Ven
authors.forename: Willy N
authors.initials: WN
authors.lastname: Colier
authors.forename: Bregina T
authors.initials: BT
authors.lastname: Kersten
authors.forename: Berend
authors.initials: B
authors.lastname: Oeseburg
authors.forename: Hans
authors.initials: H
authors.lastname: Folgering
mesh_terms: D000138:Acidosis / Q000139:chemically induced / Q000503:physiopathology*; D000208:Acute Disease; D000368:Aged; D000643:Ammonium Chloride / Q000008:administration & dosage; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019265:Spectroscopy, Near-Infrared
chemical_list: D000643:Ammonium Chloride