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Titre du document / Document title

How much oxygen does the human lung consume?

Auteur(s) / Author(s)

LOER S. A. (1) ; SCHEEREN T. W. L. (1) ; TARNOW J. (1) ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

(1) Department of Anesthesiology, Heinrich-Heine-University, Düsseldorf, ALLEMAGNE

Résumé / Abstract

Background: The amount of oxygen consumed by the lung itself is difficult to measure because it is included in whole-body gas exchange. It may be increased markedly under pathological conditions such as lung infection or adult respiratory distress syndrome. To estimate normal oxygen consumption of the human lung as a basis for further studies, respiratory gas analysis during total cardiopulmonary bypass may be a simple approach because the pulmonary circulation is separated from systemic blood flow during this period. Methods: Lung oxygen consumption was determined in 16 patients undergoing cardiac surgery. During total cardiopulmonary bypass their lungs were ventilated with low minute volumes (tidal volume, 150 ml; rate, 6 min-1; inspiratory oxygen fraction, 0.5; positive end-expiratory pressure, 3 mmHg). All expiratory gas was collected and analyzed by indirect calorimetry. As a reference value also, whole-body oxygen consumption of these patients was determined before total cardiopulmonary bypass. In a pilot study of eight additional patients (same ventilatory pattern), the contribution of systemic (bronchial) blood flow to pulmonary gas exchange during cardiopulmonary bypass was assessed. For this purpose, the amount of enflurane diffusing from the systemic blood into the bronchial system was measured. Results: The human lung consumes about 5-6 ml oxygen per minute at an esophageal temperature of 28°C. Prebypass whole-body oxygen consumption measured at nearly normothermic conditions was 198 ± 28 ml/min. Mean lung and whole-body respiratory quotients were similar (0.84 and 0.77, respectively). Extrapolating lung oxygen consumption to 36°C suggests that the lung consumes about 11 ml/min or about 5% of total body oxygen consumption. Because the amount of enflurane diffused from the systemic circulation into the bronchial system during cardiopulmonary bypass was less than 0.1%, the contribution of bronchial blood flow to lung gas exchange can be assumed to be negligible. Conclusion: The lung consumes about 5% of whole-body oxygen uptake.

Revue / Journal Title

Anesthesiology    ISSN  0003-3022   CODEN ANESAV 

Source / Source

1997, vol. 86, no3, pp. 532-537 (29 ref.)

Langue / Language

Anglais

Editeur / Publisher

Lippincott Williams & Wilkins, Hagerstown, MD, ETATS-UNIS  (1940) (Revue)

Mots-clés anglais / English Keywords

Oxygen consumption

;

Lung

;

Human

;

Cardiopulmonary bypass

;

Lung function

;

Gas exchange

;

Mots-clés français / French Keywords

Consommation oxygène

;

Poumon

;

Homme

;

Circulation extracorporelle

;

Fonction respiratoire

;

Echange gazeux

;

Mots-clés espagnols / Spanish Keywords

Consumo oxígeno

;

Pulmón

;

Hombre

;

Circulación extracorpórea

;

Función respiratoria

;

Intercambio gaseoso

;

Localisation / Location

INIST-CNRS, Cote INIST : 3042, 35400006443130.0040

Nº notice refdoc (ud4) : 2605706



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