Preischemic exogenous surfactant reduces pulmonary injury in rat ischemia/reperfusion

¹ Institute of Anatomy, University of Bern, Baltzerstr. 2, CH-3012 Bern, Switzerland
² Dept of Cardiothoracic and Vascular Surgery, Friedrich Schiller University, Erlanger Allee 101, D-07747 Jena, Germany
³ Dept of Anatomy, Division of Electron Microscopy, University of Göttingen, Kreuzbergring 36, D-37075 Göttingen, Germany
⁴ Dept of Cardiothoracic Surgery, University Hospital of Cologne, Kerpener Str. 62, D-50924 Cologne, Germany

	Abstract

The optimal timing of exogenous surfactant application to reduce pulmonary injury and dysfunction was investigated in a rat lung ischemia and reperfusion injury model.

Lungs were subjected to flush perfusion, surfactant instillation, cold ischemia (4°C, 4h) and reperfusion (60 min). Animals received surfactant before (1), at the end (2) of ischemia, during reperfusion (3) or not at all (4). Control groups included worst case without Perfadex and surfactant (5), no-injury without (6) or with surfactant (7) and ischemia with preischemic surfactant (8). Intraalveolar oedema and blood-air barrier injury were estimated by light and electron microscopic stereology. Perfusate oxygenation and pulmonary arterial pressure (PAP) were determined during reperfusion in 1 to 4.

Intraalveolar oedema was almost absent in 1, 6, 7 and 8, pronounced in 2, 3 and 4, and severe in 5. Blood-air barrier injury was moderate in 1 and 8, slightly pronounced in 2, 3 and 4, extensive in 5 and almost absent in 6 and 7. Perfusate oxygenation was significantly higher in 1 compared with 2 to 4. PAP did not differ between the groups.

In conclusion, exogenous surfactant attenuates intraalveolar oedema formation and blood-air barrier damage and improves perfusate oxygenation in the rat lung, especially when applied before ischemic storage.