Increased Intracranial Pressure

The skull is a closed box · Week 5
The skull holds three things in a fixed space: brain tissue, blood, and cerebrospinal fluid (CSF). The box cannot stretch. So if you add volume, such as a bleed, a tumor, swelling, or extra CSF, something has to give. Pressure rises and squeezes the brain. Drag the pressure up and watch the signs show up.

Inside the skull

Three parts share one fixed space. As pressure climbs, the brain gets squeezed and pushed down.
Drag the pressure slider to begin.
Normal ICPbrain, blood, and CSF in balance
Intracranial pressureNormal
↓ HRbradycardia, a slow heart rate
↓ RRslow, uneven breathing
↑ BPwide pulse pressure
Cushing's triad is a LATE, ominous sign of dangerously high ICP. It means the brainstem is being squeezed. The three parts are a slow heart rate (↓HR), slow or uneven breathing (↓/irregular RR), and a rising blood pressure (↑BP) with a widening pulse pressure. Early signs are just headache, nausea, vomiting. If ICP is not controlled, the brain herniates. In uncal herniation, brain tissue presses on the brainstem, which runs breathing and heart rate.