From Baghdad to Germany: Use of a New Pumpless Extracorporeal Lung Assist System in Two Severely Injured US Soldiers

Abstract

The authors describe a new extracorporeal pumpless interventional lung assist system (iLA) that was implemented in two US soldiers with severe acute respiratory distress syndrome received from enemy action in Iraq, who were at risk for critical hypoxemia/hypercapnia. The system is characterized by a new low-resistance gas exchange membrane that is integrated in an arterial-venous bypass established by cannulation of the femoral artery and vein. Cardiovascular stability is essential to produce sufficiently high blood flow rates over the gas exchange unit. After implantation of the interventional lung assist, oxygenation increased and carbon dioxide elimination improved rapidly. Ventilator settings were able to be adjusted to the decreased pulmonary gas exchange needs, making protective lung strategies possible. Air transport of both patients with the running iLA system was uneventful. The iLA was removed after 15 and 8 days of continuous operation, respectively, and both soldiers were successfully weaned from mechanical ventilation. Interventional, extracorporeal pump-free pulmonary support opens up new possibilities for pulmonary protection due to ease of use, effectiveness, and low costs; however, there is concern of distal limb ischemia. Experiences to date are encouraging, although randomized studies are lacking, and the procedure carries significant risks.