Abstract
Purpose
To test the hypothesis that a physiological compensatory mechanism maintains respiratory gas exchange during normovolaemic haemodilution.
Methods
Pulmonary gas exchange capacity was evaluated in seven healthy subjects by measuring the lung diffusion of carbon monoxide (DLCO). During the measurement, various breath-holding times, inspiratory volumes, and sitting or supine positions, were randomly selected in an attempt to alter pulmonary capillary perfusion. KCO was calculated as the percentage of theoretical values of the ratio of DLCO by alveolar volume and normalized by sex, age, and height. Normovolaemic haemodilution (NH) was performed by bleeding an average blood volume of 1 L with simultaneous Dextran 60 replacement to obtain an haematocrit below 35%.
Results
After NH, haemoblogin concentration [Hb] decreased from 14.94 ± 0.96 to 12.5 ± 0.98 g · dl−1 (P < 0.001). KCO decreased (P < 0.02) but remained closely correlated to [Hb] at every lung volume (< 0.02). Breathholding time and body position had no effect.
Conclusion
Moderate NH impairs pulmonary gas exchange capacity in awake, resting healthy subjects. There is no evidence of any compensatory mechanism since the KCO vs [Hb] relationship is unchanged.
Résumé
But
Vérifier l’hypothèse d’un mécanisme physiologique compensateur maintenant la capacité d’échanges respiratoires lors de l’hémodilution normovolémique.
Méthodes
Nous avons évalué les échanges gazeux respiratoires par la mesure du transfert du CO (DLCO) chez sept sujets sains au cours d’une hémodilution normovolémique (NH). Différents temps d’apnée, volumes inspiratoires, et postures ont été sélectionnés aléatoirement afin de modifier la perfusion capillaire pulmonaire. Les résultats ont été normalisés en fonction de l’âge, du sexe, et de la taille par l’expression en pourcentage des valeurs théoriques du KCO (rapport de DLCO sur le volume alvéolaire). La NH a été réalisée par soustraction d’une quantité moyenne de 1 L de sang, remplacée par du Dextran 60.
Résultats
Après NH, le taux d’hémoglobine [Hb] a diminué de 14,94 ± 0,96 à 12,5 ± 0,98 g · dla−1 (P < 0,001). KCO diminuait (P < 0,02) mais restait étroitement corrélé à [Hb] (P < 0,02) quelque soit le volume pulmonaire. Le temps d’apnée et la position étaient sans effet.
Conclusion
La NH modérée diminue la capacité d’échanges respiratoires chez le sujet sain, éveillé et au repos. Il ne paraît pas exister de mécanisme compensateur, puisque la pente de la relation entre KCO et [Hb] n’est pas modifiée.
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References
Messmer K, Lewis DH, Sunder-Plassmann L, Klövekorn WP, Mendier N, Holper K, Acute normovolemic hemodilution. Changes of central hemodynamics and microcirculatory flow in skeletal muscle. Eur Surg Res 1972; 4: 55–70.
Messmer K, Sunder-Plassmann L, Jesch F, Görnandt L, Sinagowitz E, Kessler M, Oxygen supply to the tissues during limited normovolemic hemodilution. Res Exp Med (Berl) 1973; 159: 152–66.
Laks H, Pilon RN, Klovekorn WP, Anderson W, MacCallum JR, O’Connor NE, Acute hemodilution: its effect on hemodynamics and oxygen transport in anesthetized man. Ann Surg 1974; 180: 103–9.
Roseberg B, Wulff K, Hemodynamics following normovolemic hemodilution in elderly patients. Acta Anaesthesiol Scand 1981; 25: 402–6.
Murray JF, Gold P, Johnson BL Jr. Systemic oxygen transport in induced normovolemic anemia and polycythemia. Am J Physiol 1962; 203: 720–4.
Gump FE, Butler H, Kinney JM, Oxygen transport and consumption during acute hemodilution. Ann Surg 1968; 168: 54–60.
von Restorff W, Höfling B, Holtz J, Bassenge E, Effect of increased blood fluidity through hemodilution on general circulation at rest and during exercise in dogs. Pflugers Arch 1975; 357: 25–34.
Hint H, The pharmacology of dextran and the physiological background for the clinical use of rheomacrodex and macrodex. Acta Anaesthesiol Belg 1968; 19: 119–39.
Cotes JE. Transfer factor (diffusing capacity).In: Quanjer PM (Ed.). Bulletin Europeen de Physiopathologie Respiratoire 1983; 19: 39–44.
Cotes JE, Hall AM. The transfer factor for the lung: normal values in adults.In: Arcangeli (Ed.). Normal Values for Respiratory Function in Man. Panminerva Medica, 1970, 43: 327–34.
Billiet L, Baisier W, Naedts JP, Effet de la taille, du sexe, et de l’âge sur la capacité pulmonaire de diffusion de l’adulte normal. J Physiol (Paris) 1963; 55: 199–200.
Fan F-C, Chen RYZ, Schuessler GB, Chien S, Effects of hematocrit variations on regional hemodynamics and oxygen transport in the dog. Am J Physiol 1980; 238: H545–51.
Race D, Dedichen H, Schenk WG Jr. Regional blood flow during dextran-induced normovolemic hemodilution in the dog. J Thor Surg 1967; 53: 578–85.
Roughton FJW, Forster RE, Relative importance of diffusion and chemical reaction rates in determining rate of exchange of gases in the human lung, with special reference to true diffusing capacity of pulmonary membrane and volume of blood in the lung capillaries. J Appl Physiol 1957; 11: 290–302.
Rankin J, McNeill RS, Forster RE, The effect of anemia on the alveolar-capillary exchange of carbon monoxide in man. J Clin Invest 1961; 40: 1323–30.
Hilpert P, Die Änderung der Diffusionskapazität der Lunger für CO durch die Hämoglobinkonzentration des Blutes (German). Respiration 1971; 28: 518–25.
Guleria JS, Pande JN, Markose MM, Gupta RG, Jain BP, Pulmonary function in chronic severe anaemia. Clin Sci 1971; 40: 317–25.
Mohsenifar Z, Brown HV, Schnitzer B, Prause JA, Koerner SK, The effect of abnormal levels of hematocrit on the single breath diffusing capacity. Lung 1982; 160: 325–30.
Dinakara P, Solnick PB, Kaufmann LA, Johnston RE, Blumenthal WS The effect of anemia on pulmonary diffusing capacity with derivation of a correction equation. American Review of Respiratory Disease 1970; 102: 965–9.
Jouasset-Strieder D, Cahill JM, Burne JJ, Gaensler EA, Pulmonary diffusing capacity and capillary blood volume in normal and anemic dogs. J Appl Physiol 1965; 20: 113–6.
Gurtner GH, Fowler WS, Interrelationships of factors affecting pulmonary diffusing capacity. J Appl Physiol 1971; 30: 619–24.
Riepl G, Effects of abnormal hemoglobin concentration in human blood on membrane diffusing capacity of the lung and on pulmonary capillary blood volume. Respiration 1978; 36: 10–8.
Lawson WH Jr. Effect of drugs, hypoxia, and ventilatory maneuvers on lung diffusion for CO in man. J Appl Physiol 1972; 32: 788–94.
Ross JC, Frayser R, Hickam J B, A study of the mechanism by which exercise increases the pulmonary diffusing capacity for carbon monoxide. J Clin Invest 1959; 38: 916–32.
Fung YC, Sobin SS, Theory of sheet flow in lung alveoli. J Appl Physiol 1969; 26: 472–88.
Johnson RL Jr, Hsia CCW, Functional recruitment of pulmonary capillaries. J Appl Physiol 1994; 76: 1405–7.
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Le Merre, C., Dauzat, M., Poupard, P. et al. Pulmonary gas exchange capacity is reduced during normovolaemic haemodilution in healthy human subjects. Can J Anesth 43, 672–677 (1996). https://doi.org/10.1007/BF03017949
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DOI: https://doi.org/10.1007/BF03017949