Enhancement of tissue Po2 of strangulated bowel by topical application of sodium nitroprusside.
The Po2 was measured in the tissue of the ileal wall of dogs before, during, and up to one hour after reversible occlusion of segmental arteries. The occlusion was then released and the reoxygenation of the bowel wall was observed. Sodium nitroprusside (50 mg in 100 ml of solution) applied topically to the ischemic segment enhanced reoxygenation as compared to control animals. Nitroprusside absorbed into the portal system did not cause hypotension, as is usual with systemic administration, because nitroprusside is inactivated by passage through the liver. Topically applied sodium nitroprusside alleviates intestinal ischemia by direct local vasodilatation and relaxation of smooth muscle spasm in the ischemic bowel wall. The intraperitoneal use of sodium nitroprusside should be clinically evaluated in situations where visceral perfusion is impaired.