Krogh Cylinder: Lethal Corners

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A pathologic or iatrogenic decrease in PCD can result in the development of either an anoxic or a hypercapnic lethal corner or both, simultaneously.

When PCD is reduced without a concurrent reduction in metabolism or during an increased metabolic need, the Krogh model predicts the formation of a lethal corner. The presence of a lethal corner is the harbinger of severe physiologic distress. So detecting the presence of a lethal corner is vital. Theoretically a lethal corner can form even in the presence of normal Fick values.
The Krogh cylinder model seems to suggest that an anoxic lethal corner and a hypercapnic lethal corner should develop simultaneously. However in the clinical setting each can develop independently without the other being present. But the worst outcomes occur when they are both present at the same time.

Perfusion Theory is an educational platform for the Oxygen Pressure Field Theory (OPFT). August Krogh’s theoretical concept of the oxygen pressure field is explained and then applied to clinical applications in perfusion practice.