Introduction Respiratory failure and persistent pulmonary hypertension are important causes of mortality in term infants. Extracorporeal membrane oxygenation reduces mortality but is associated with morbidity. The lung assist device (LAD) is a novel gas exchange device that supplements mechanical ventilation. LAD (MC3 Inc., Ann Arbor, MI) is a pumpless, low pressure extracorporeal oxygenator. It has improved gas exchange in adult animals.
Purpose To test the feasibility of the LAD in juvenile piglets with hypoxia-induced pulmonary hypertension.
Methods The LAD was attached between the carotid artery and jugular vein of 4-week-old acutely instrumented piglets (n = 3). Pulmonary hypertension was acutely induced by hypoxia (FiO2 = 10%). Gas exchange, pulmonary pressure, hemodynamic variables, and cardiac output were measured with and without flow through the device.
Results Successful LAD cannulation was achieved in all 3 animals with no complications. The LAD increased PaO2 from 26 mm Hg (pre-device) to 530 mm Hg (post-device) and decreased PaCO2 from 45 mm Hg (pre-device) to 5 mm Hg (post-device) (n = 2). In the three animals, systemic arterial pressure decreased by 1-9%, cardiac output remained stable, and hematocrit decreased by 1-10%. Acidosis developed in one animal. In one animal, pulmonary arterial pressures decreased by 62% (Figure) and systemic oxygenation improved marginally (PaO2 increased by 12%) with initiation of flow through LAD.
Conclusion These preliminary results demonstrate the feasibility and potential of a novel pumpless low-pressure gas exchange assist device that is perfused by the cardiac output to maintain perfusion, improve gas exchange, and decrease pulmonary hypertension.