What is the target end-tidal CO2 value when hyperventilating a patient with cerebral herniation?

The target end-tidal CO2 value for a patient experiencing cerebral herniation is set to approximately 30 mmHg. This is primarily because hyperventilation in this context is used to reduce intracranial pressure (ICP) by causing vasoconstriction of cerebral blood vessels, which in turn reduces cerebral blood flow. The mechanism behind this involves the relationship between carbon dioxide levels and blood vessel dilation; when CO2 levels decrease, blood vessels constrict.

In cases of cerebral herniation, maintaining a lower end-tidal CO2 helps manage elevated ICP, hence the target range is set at around 30 mmHg. It is essential for practitioners to regularly monitor end-tidal CO2 to ensure that the levels remain within this target range while initiating hyperventilation as a therapeutic intervention. Adjusting to higher or lower values could lead to insufficient management of ICP or other complications.