title: Optimized hyperventilation preserves 2,3-diphosphoglycerate in severe traumatic brain injury.
abstract: BACKGROUND
  The concentration of 2,3-diphosphoglycerate (2,3-DPG/Hct) increases as a physiological occurrence to pH increase and hyperventilation. This response was tested in patients with severe traumatic brain injury (TBI).
  
  
  METHODS
  The concentration of 2,3-DPG/Hct was measured daily for six days in eleven patients with severe TBI in need of optimized hyperventilation because of intracranial hypertension.
  
  
  RESULTS
  There was correlation between pH and the concentration of DPG/Hct. The concentration of 2,3-DPG/Hct remained predominantly within normal levels with slight increase in the sixth day of the study. The concentration of 2,3-DPG/Hct correlated significantly with measured partial pressure of oxygen that saturates 50% the hemoglobin of the blood (P50st), confirming the consistency of our data.
  
  
  CONCLUSIONS
  The expected physiological response of a progressive increase in concentration of 2,3-DPG/Hct to hyperventilation was not observed. This fact may be explained by the intermittent and not sustained hyperventilation as dictated by the protocol of optimized ventilation.
authors.affiliation: Campinas State University, Campinas, São Paulo, Brazil. raynebt@yahoo.com.br
authors.forename: Rayne Borges
authors.initials: RB
authors.lastname: Torres
authors.forename: Renato Giuseppe Giovanni
authors.initials: RG
authors.lastname: Terzi
authors.forename: Antônio Luís Eiras
authors.initials: AL
authors.lastname: Falcão
authors.forename: Nelci Fenalti
authors.initials: NF
authors.lastname: Höehr
authors.forename: Venâncio Pereira
authors.initials: VP
authors.lastname: Dantas Filho
mesh_terms: D019794:2,3-Diphosphoglycerate / Q000097:blood*; D018806:APACHE; D000293:Adolescent; D000328:Adult; D001784:Blood Gas Analysis; D001930:Brain Injuries / Q000097:blood* / Q000628:therapy; D016022:Case-Control Studies; D002648:Child; D004912:Erythrocytes / Q000737:chemistry; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D008297:Male; D008875:Middle Aged; D012121:Respiration, Artificial
chemical_list: D019794:2,3-Diphosphoglycerate