The Journal of Thoracic and Cardiovascular Surgery, Vol 75, 261-266, Copyright © 1978 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
An alternative to breathing
T Kolobow, L Gattinoni, T Tomlinson and JE Pierce
If carbon dioxide is removed by an extracorporeal membrane lung ventilated
with room air, the natural lung can be used for oxygen transport alone; we
have demonstrated this in lambs by maintaining lungs "inflated" with 100
percent oxygen at constant pressure and removing all carbon dioxide through
the membrane lung. This process is a variant of "apneic oxygenation"
without its disadvantages, because the arterial pH, PCO2, and PO2 all
remain normal. No nitrogen washout is needed. These studies were carried
out in five lambs anesthetized and paralyzed for 24 hours. For carbon
dioxide removal, blood from the subclavin artery was pumped through an
extracorporeal membrane lung and was returned into the external jugular
vein. For oxygen delivery, the lungs were inflated through a tracheostomy
tube with 100 percent oxygen to a pressure of 5 cm. H2O. There was no
significant change in arterial blood PO2 after perfusion had begun or at
the end of the perfusion 24 hours later. The arterial PCO2 remained steady,
and there was no change in acid-base balance. The functional residual
capacity (FRC) and static lung compliance remained unchanged. The total
dead space was 10 to 15 ml. All animals recovered and survived in good
health. At equilibrium, alveolar nitrogen partial pressure was always equal
to the partial pressure of nitrogen in the ventilating gas of the membrane
lung and was the sole determining factor in controlling alveolar oxygen
concentration. Direct measurement of pulmonary gas showed alveolar gas at
the level of the carina.