A liquid-liquid blood-gas exchange for the treatment of acute respiratory failure: A new blood gas exchange using artificial blood as an oxygen carrier

Abstract

A new liquid-liquid blood gas exchange system was investigated using a veno-venous low flow extracorporeal circuit. A 2 m² hollow fiber dialyzer served as the interface of the blood and oxygen carrier (a 38 percent FC-43, perfluorocarbon emulsion in a buffered electrolyte solution), which was continuously recycled through a bubble oxygenator. Experiments were performed on five mongrel dogs under general anesthesia. Upon the arrest of spontaneous ventilation, the dogs' lungs were inflated with 50% oxygen gas under a positive pressure of 10 cmH₂O. After 10 min of apnea the dogs' PaO₂ decreased to 37 ± 14 mmHg, and the extracorporeal circulation was started at 10 ml/min/kg b./w. At 15 min the PaO₂ had risen to 80 ± 41 mmHg and at 30 min to 121 ± 17 mmHg. The oxygen transfer was 8.3 ± 2.3 ml/min. The extracorporeal circulation was continued 5h, when PaO₂ reached 156 ± 90 mmHg, and PaCO₂ 148 ± 43 mmHg, then stopped. Fifteen minutes later, the PaO₂ had returned to 32 ± 10 mmHg. These findings indicate that our blood gas exchange system can supply a sufficient amount of oxygen to the body under apnea with continuous positive airway pressure.