title: [A method to predict pulmonary blood flow by nitrous oxide washout curve].
abstract: The study was performed to obtain a relationship between the pulmonary blood flow and the tau b (time constant) calculated from multiple-breath nitrous oxide (N2O) washout curve. Elimination of N2O depends on pulmonary blood flow and alveolar ventilation. From the theoretical consideration, tau b can be calculated by the following formula; tau b = Vd[1/Qt-Qs) + 0.47/VA) Vd = N2O volume of distribution in the body Qt = cardiac output, Qs = shunt blood flow VA = alveolar ventilation. Relationship between observed Qt-Qs and observed tau b was admitted to the predicted formula. The method was compared with the thermodilution method in almost simultaneous measurement of the cardiac output. A good correlation was obtained between them (r = 0.87). Washout curve of nitrous oxide can be used for a reliable measurement of pulmonary perfusion.
authors.affiliation: Department of Anesthesiology, Tokyo National Chest Hospital.
authors.forename: Y
authors.initials: Y
authors.lastname: Nomoto
authors.forename: T
authors.initials: T
authors.lastname: Ikegami
authors.forename: Y
authors.initials: Y
authors.lastname: Ohtsaka
authors.forename: N
authors.initials: N
authors.lastname: Nagayama
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008722:Methods; D008875:Middle Aged; D009609:Nitrous Oxide; D011652:Pulmonary Circulation
chemical_list: D009609:Nitrous Oxide