Despite maximal mechanical ventilatory support, many patients die from hypoxia in the setting of potentially reversible pulmonary failure from causes such as ARDS, pneumonia and pulmonary embolism. The specter of a pulmotoxic terrorist attack, as well as the recent onset of the severe acute respiratory syndrome (SARS) epidemic, underscores the pressing need for additional pulmonary supportive care measures. The purpose of this study was to see if was possible to deliver a significant amount of oxygen to a large animal, with induced hypoxia, by perfusing the abdomen with oxygenated neat perfluorocarbon.
6 pigs, weighing 45 to 55 kg, were rendered hypoxic by ventilating them with subatmospheric inspired oxygen concentrations (FIO2) ranging from 18%-10%, resulting in baseline arterial oxygen pressures (PaO2) of 88 to 24 mmHg, respectively. Peritoneal perfusion was then performed in 3 animals with oxygenated perfluorocarbon and 3 control animals with oxygenated saline.
The most clinically relevant results occurred at an FIO2 of 16%. At this level we observed an average increase in the PaO2 of 13.9 mmHg, from a PaO2 of 46.3 mmHg (82.2% saturation) to a PaO2 of 60.2 mmHg (91.4% saturation). Although the animals were maintained essentially normocarbic, the addition of peritoneal perfusion with oxygenated perfluorocarbon decreased the PaCO2 from 44 to 38 mmHg. None of the control experiments demonstrated any significant gas exchange effect.CONCLUSIONS: In our model we observed clinically relevant increases in arterial oxygen saturation from 82.2% to 91.4%. The results of these preliminary studies show that the peritoneal surface can serve as a supplemental “artificial lung” when perfused with oxygenated perfluorocarbon.
This technique may have a potential role in the supportive care of patients dying from hypoxia in the setting of a reversible lung injury.
J.S. Friedberg, None.