What is the target level of arterial carbon dioxide (CO2) to maintain in a patient with a CVA and increased ICP?

In patients with a cerebrovascular accident (CVA) and elevated intracranial pressure (ICP), careful management of arterial carbon dioxide (CO2) levels is crucial for optimizing cerebral perfusion and minimizing further neurological deterioration. Maintaining a target CO2 level around 35 mmHg is considered ideal in this context.

When CO2 levels drop to around 35 mmHg, it leads to mild respiratory alkalosis, which can help to cause vasoconstriction and potentially decrease cerebral blood flow. This is a protective mechanism in patients with increased ICP, as excessive blood flow can exacerbate the pressure within the cranial cavity. Keeping CO2 levels within this range also helps prevent significant cerebral ischemia, maintaining adequate oxygen delivery.

In contrast, lower CO2 levels, specifically those around 30 mmHg or below, may result in excessive vasoconstriction and reduced cerebral perfusion, which can lead to complications in patients already suffering from cerebral injury. On the other end, CO2 levels above 40 mmHg can promote vasodilation and increased cerebral blood flow, potentially worsening the elevated ICP.

Thus, the goal of targeting a CO2 level of approximately 35 mmHg aligns with the overall aim of mitigating risks associated with increased ICP while ensuring