Transintestinal oxygenation with perfluorocarbon: investigation of perfusion rate

Perfluorocarbons are structurally similar to hydrocarbons but with the hydrogen atoms replaced by fluorine. In general, perfluorocarbons have an excellent oxygen and carbon dioxide carrying capacity. We studied the suitability of oxygenated perfluorocarbon as an agent for transintestinal oxygenation and measured its perfusion rates under different conditions.

We used FC-77 (Sumitomo 3M, Tokyo, Japan) perfluorocarbon and a rat hypoventilation model (room air, 20 breaths/min, a tidal volume of 10 ml/kg). Oxygenated FC-77 was perfused through the small intestine for 4 hours. Rats were allocated to 3 experimental groups according to the perfusion rate and a control group: Group 1 (n=6), 10 ml/min; Group 2 (n=6), 2.5 ml/min; Group 3 (n=6), 0.75 ml/min; Group 4 (n=6) served as a control (hypoventilation only). Arterial blood samples were drawn every 30 minutes. Standard blood gas analysis was performed.

After four hours of perfusion, the PaO2 levels in Groups 1 to 3 were significantly better than Group 4 (p<0.01, Group 1: 141.7 +/- 18.0 mmHg, Group 2: 145.2 +/- 25.1 mmHg, Group 3: 120.5 +/- 21.2 mmHg, Group 4: 67.4 +/- 7.2 mmHg). PaCO2 levels in Groups 1 and 2 were significantly better than Groups 3 and 4 (p<0.01, Group 1: 42.6 +/- 7.2 mmHg, Group 2: 52.1 +/- 7.7 mmHg, Group 3: 78.2 +/- 22.8 mmHg, Group 4: 75.3 +/- 10.3 mmHg).

In the present settings, 8 ml/kg/min was adequate for oxygenation and CO2 clearance. This approach promises to become another modality for respiratory assistance.