Enhance venous drainage. Elevate head 30° If in a cervical collar, check fit. Hyperosmolar therapy. Hyperventilation. CSF Drainage. Decompression. So we were manipulating CPP via the MAP or brain metabolism. The other half of the equation, ICP, can be manipulated using the Monro-Kellie Doctrine. Here are 5 ways that we can decrease ICP. To review, the skull has a fixed volume with usually just three contents, brain, blood and CSF. In the setting of increased ICP, reduction in the volume of one of these should result decreased pressure. Enhance venous drainage – and thus reduce the volume of blood. You can do this by head elevation. Also bear in mind that if a patient has a cervical collar, it could be impeding venous drainage. Hyperosmolar therapy – with the idea being to decrease the volume of the brain. Hyperventilation – not to be used regularly, but in the acute setting it can reduce cerebral blood flow, and thus blood volume. CSF Drainage – decreasing ICP through reducing the CSF volume. Decompression – works by expanding the volume and making the skull no longer a locked box.