Total extracorporeal lung assist--a new clinical approach

Total extracorporeal lung assist (ECLA) requires a bypass flow approaching cardiac output. Recirculation of venous blood through the oxygenator is minimized with a veno-right ventricular cannulation technique which separates venous drainage from returned oxygenated blood. A case of posttraumatic ARDS was treated with surface-heparinized veno-right ventricular ECLA for 35 days. Cardiac output was stabilized by means of sedation, hypothermia (35 degrees C) and beta blockers (pulse rate less than 90) in order to match the maximal venous drainage achieved (5.5 l/min). A bypass flow around 85% of cardiac output resulted in mean arterial PO2 values between 9-13.6 kPa without any contribution from the lungs. Low platelet counts and a marked bleeding tendency complicated treatment, even though no heparin was used during the last 24 days of ECLA. Weaning from the ventilator was accomplished 2 months after ECLA. Lung function tests show constant improvement.