The intravascular oxygenator (IVOX): preliminary results of a new means of performing extrapulmonary gas exchange.
Conventional management of adult respiratory distress syndrome (ARDS) with high minute ventilation, positive end-expiratory pressure (PEEP), and increased fractional inspired oxygen (FIO2) concentrations may worsen pulmonary injury. The intravascular oxygenator (IVOX) is a device made up of several hundred gas permeable hollow fibers that are inserted into the vena cava by femoral venous cutdown. Flow of gas through each fiber adds O2 and removes CO2 from the bloodstream. The purpose of this study was to determine if the IVOX significantly reduces the level of mechanical ventilatory support in ARDS patients. The IVOX was inserted in nine patients, and aborted in one because of technical complications. The IVOX increased PaO2 and reduced PaCO2, but the quantity of gas transfer was not sufficient to allow a reduction in PEEP, FIO2, or minute ventilation. Insertion of the IVOX decreased cardiac index and systemic oxygen delivery despite maximum fluid and inotropic support. Mortality was 80%. Although some gas exchange occurs, the current device does not allow a significant reduction in the level of mechanical ventilatory support and adversely affects systemic oxygen transport.