Guide on the Basics of Increased Intracranial Pressure Pt 1

 
Defining Intracranial Pressure
Intracranial pressure (ICP) is the measurement of the brain tissue’s pressure with the cerebrospinal fluid surrounding and cushioning the spinal cord and the brain. How does pressure inside the brain increases?

The pressure inside the brain increases due to traumatic brain injury that can be from the following instances:

 	
Blunt force to the head like being whacked with something hard like a baseball bat, or falling off a building head first
 	
Car accidents
 	
Stroke
 	
Hemorrhage
 	
An aneurysm

All these factors can cause increased pressure that can stress the brain. And it gets worse if, the cranium is still intact. We’ll explain further.


The Cerebrospinal Fluid
Right after the trauma, immediate changes happen inside the cranium.

Inside the skull, you have the dura mater, arachnoid mater, pia mater, and the subarachnoid mater. The subarachnoid mater, much like a moat between the brain and the skull crust, is the primary area where your cerebrospinal fluid rests.

The cerebrospinal fluid (CSF) is a colorless, transparent liquid surrounding and protecting your brain and spinal cord. Aside from helping the brain to float inside the skull, cushioning to prevent injury, the CSF is also responsible for bathing the spine and the brain with nutrients while eliminating waste products. If you are dehydrated, there will be decreased CSF making the brain to touch the sides of the skull which causes headaches.


So, what is the connection between CSF and closed head injuries to lead to increased intracranial pressure?

When the head experienced severe trauma, it instantly swells. If the trauma is a closed head injury, the increasing pressure has nowhere to go but down the brainstem which then causes herniation. If the brain stem herniates, the client’s respiratory rate and autonomic nervous system like your heart rate and blood pressure are severely compromised.

So, when the cranial content, brain tissues, blood, and cerebrospinal fluid are trapped inside the skull where there is little to no room for expansion, thus the increase of intracranial pressure.


Coping Mechanisms and Treatment
When there is increased intracranial pressure, immediate treatment is required. But before it worsens, the body initially compensates. Basically, there are two ways on how increased ICP is managed by the body:

 	
Compensation by the body
 	
Shunted from the cranial compartment

For a Contusion
On the onset of increased pressure inside the cranium, for example, you’ve been whacked by a bat, the body immediately compensates for the tragedy by shunting the cerebrospinal fluid into the subarachnoid space. The body is decreasing pressure from the affected area of the brain to be distributed to other areas so that the swelling can subside. This is how the body compensates for the contusion.
For a Brain Bleed
A bleeding brain creates extra fluid volume inside the brain, and the body will move this fluid into the subarachnoid area. If the moat cannot accommodate the increasing fluid, it will eventually travel down the brainstem and cause herniation which then affects the autonomic nervous system.

So, the body will be trying to continuously shunt the cranial fluid into the cranial compartments, or it will increase its rate of cerebrospinal fluid absorption. If both are unsuccessful, decreased cerebral perfusion will occur. No oxygen is going to go inside the brain which causes it to shut down eventually.


Signs and Symptoms of Increased ICP
If the increasing pressure is not treated immediately, the client will manifest the following signs and symptoms:

 	
Head – headache, altered level of consciousness (ALOC), seizures
 	
GI – nausea and projectile vomiting
 	
Lethargy and weakness
 	
Eyes – pinpoint pupils (early stage) then will progress to blown pupils (late stage)

If the brain has a bleed on just one side, the pupils will look off-set; meaning one of the pupils will be fully-dilated while the other one will be normal. Full-dilation of the pupils will indicate which part of the brain is bleeding.


ICP Nursing Questions with Answers
Now let’s focus on some test questions about intracranial pressure (ICP) that are usually asked on major nursing tests like the NCLEX®.

Let’s begin.
Question #1
Your client has a change in his or her Glasgow Coma Scale (GCS), when do you tell the doctor about it?
Answer:
There are two instances wherein you have to tell the doctor about changes in the GCS of your client.

The first instance is within the first 48 hours. If there is a slight change, either good or bad, immediately inform the doctor about it. Telling the doctor within the first 48 hours of the changes, whether good or bad, is a priority regarding your client care.

For a coma client, if 48 hours have passed and the GCS is eight or less, this is the second instance that the doctor must be alerted. Usually, comatose clients have an endotracheal tube that goes inside their lungs. However, even with the presence of an endotracheal tube and you notice that your client is deteriorating after you’ve done a neurological assessment, you have to inform the doctor the condition ASAP.

Now, if the after 48 hours and the client’s GCS is getting better, there is no need to inform the doctor about it because this is an expected outcome.
Question #2
When do you give an endotracheal tube in terms of your GCS?
Answer:
As mentioned earlier, clients who have a GCS of anything less than eight should have an endotracheal tube. This is due to the knowledge that if the client’s GCS is below eight, his or her condition is highly critical and will probably be inside the neurology ICU.
Question #3
What are the three things that you have to make sure of when positioning your client?
Answer:

 	
You have to keep the client in a neutral position which means that there should be no neck bending, flexing, or any motion. As much as possible, keep your client at a 30-degree neutral position to facilitate cerebral drainage.
 	
Log roll. When moving the client, log roll is a priority. When doing a log roll, you need to have an assistant to keep the client in one straight line. One should hold the head while the other moves the body. Therefore, if you are going to clean your client, coordination is a must.
 	
No flexing (Matrix). As mentioned, make sure that when you are moving your client, there will be no flexing and bending of any part of the body, even the extremities.

Question #4
When it comes to increased carbon dioxide (CO2) levels, what is the number that you have to watch-out-for?
Answer:
Increased CO2 inside the brain will cause blood vessel dilation; which should be avoided. Decreasing the amount of circulation to the brain is another priority so as not to increase the pressure. Therefore, the number that you have to take note of when assessing for CO2 increase is anything greater than 40 mm/Hg.

Anything that is more than 45 mm/Hg is considered a hazard. In hospital settings, the CO2 is usually kept underneath the borderline to maintain an alkalosis, oxygenated state.
Question #5
Do you cluster your care with your ICP clients if your client is in a coma with an endotracheal tube?
Answer:
Clustering care basically means that the medical provider will do all care at specific times instead of constantly going in and bother the client. Cluster care is usually seen in pediatrics with the newborn assessment.

So, when dealing with an ICP client, you have to cluster your neurological assessment depending on the hospital policy – can either be every 15 minutes or hourly, depending on the client’s condition. However, you should not do cluster care for activities of daily living, feeding times, oral hygiene, and monitoring.