title: Clinical reliability of measured and calculated oxygen parameters in surgical patients: influence of hyperventilation.
abstract: The acid-base and oxygen status were assessed in patients undergoing abdominal surgery. We determined the measured and calculated parameters described by Siggaard-Andersen in arterial and mixed venous blood before, during and after a controlled hyperventilation. In these dynamic conditions, the mixed venous calculated p50 showed the most interesting variations. Derived values in arterial blood were unreliable since: 1) fitting to hyperbolic tangent function is not possible when SaO2 greater than 0.98; 2) in these patients, the arterio-venous difference in CtO2 is different from 2.3 mmol/L. The acute changes in calculated p50 are in agreement with the effect of hyperventilation on oxygen status.
authors.affiliation: Laboratoire de Biochimie A, Hôpital Saint Antoine, Paris, France.
authors.forename: M
authors.initials: M
authors.lastname: Vaubourdolle
authors.forename: B
authors.initials: B
authors.lastname: Beneteau-Burnat
authors.forename: B
authors.initials: B
authors.lastname: Just
authors.forename: A
authors.initials: A
authors.lastname: Lienhart
authors.forename: J
authors.initials: J
authors.lastname: Giboudeau
mesh_terms: D000005:Abdomen / Q000601:surgery; D001158:Arteries; D001784:Blood Gas Analysis / Q000592:standards*; D006801:Humans; D006985:Hyperventilation / Q000097:blood*; D016031:Liver Transplantation; D010100:Oxygen / Q000097:blood*; D012121:Respiration, Artificial; D013514:Surgical Procedures, Operative; D014680:Veins
chemical_list: D010100:Oxygen