A brain injured patient is a person who has damage to the brain due to one or more of the following: trauma, infections, malignancies (tumors), strokes, poisoning, etc. The causes of brain injury commonly lead to the development of an increased Intracranial Pressure. Intracranial pressure (ICP) is the pressure within the head and when increased, it causes pressure on the brain which can lead to a lot of deleterious effects. Increased ICP is usually due to fluid build-up inside the head.
Brain injuries can cause increased ICP in various ways such as:
– Trauma causes damaged blood vessels which lead to increased blood volume inside the head. Trauma can also cause edema in the brain.
– Hemorrhagic strokes result from bleeding into the brain which increases ICP.
– Tumors can block the drainage of cerebrospinal fluid (CSF) causing it to build up inside the head. Tumors also increase ICP with their excessive growth.
– Infections can cause brain edema or block drainage of CSF.
There are many other ways through which brain injuries can lead to elevated ICP. The following are reasons why an ICP monitor should be employed in the treatment of patients with brain injury.
Reasons for Using an ICP Monitor in a Brain Injured Patient
Early Detection of Problems in the Unconscious: Increased ICP manifests with symptoms and signs such as headaches, visual disturbances, pupillary size asymmetry, etc. A brain injured patient may be unconscious or neurologically impaired and so may not be able to tell the doctor that he or she has such symptoms. The signs of raised ICP may also not be easily elicited in such patients. Therefore, an ICP monitor is used to check the level of ICP and ensure it is not elevated.
Decisions on Treatment: Increased ICP affects the modes of treatment that can be offered to a patient. For example, in brain injury caused by infections, a lumbar puncture which is done to collect cerebrospinal fluid (CSF) for diagnosis is usually one of the first procedures done. When it is done in the presence of elevated ICP, it can be fatal to the patient. Thus, the use of an ICP monitor can help to limit the use of avoidable and possibly adverse treatment.
Treatment: Some methods of ICP monitoring can also be used to drain excess fluid when the ICP becomes markedly raised.
To Prevent Permanent Neurologic Damage: In a patient with a brain injury, there is the possibility of permanent damage to the brain and nerves. Increased ICP increases the likelihood of such damage occurring. Elevated ICP may also damage the brain on its own by reducing the cerebral perfusion pressure (the pressure of the blood that is supplied to the brain).
To Monitor Progress and Outcome: Reduction in ICP towards normal levels is a sign of resolving brain injury. ICP that is increased despite therapy and drainage points to a poor outcome in a brain injury patient.Increased ICP Can Be Fatal: Persistently elevated ICP can lead to brain herniation. This is usually fatal if the ICP is not rapidly decreased.