The Neuro ICU for Beginners

by Andria RN · 6 comments

in ICU,Podcast,Uncategorized

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There are a lot of abbreviations in the Neuroscience ICU and you will almost never hear the layman’s term stroke.  That is what confused me when I began.  I was listening to report and hearing SAH, IVH, ICP, CPP, SDH, DAI, blah blah blah.  Basically, I had no idea what was going on with my patient so thank goodness I was working with a preceptor!

With all the abbreviations- it is really just a matter of knowing what the individual words mean- then you can piece together what is going on inside the patient, especially if you have studied images of the brain and become familiar with the the cerebrovascular system.

Cerebrovascular System: Arteries are sometimes abbreviated as well (e.g. MCA= Middle Cerebral Artery)

NEURO ABBREVIATIONS

SAH: Subarachnoid hemorrhage- bleeding in the subarachnoid space from an aneurysm, often described by the patient as the “worst headache of my life.”

SDH: Subdural hematoma- bleeding between the dura and the arachnoid spaces.

Epidural hematoma: space between the skull and the dura.  Initial loss of consciousness followed by an awake phase and then an extremely rapid decline if the patient is not treated.

IPH: Intraparenchymal hemorrhage- parenchyma is essentially the brain- the neurons and the functional brain cells, so an IPH is basically a bleed into the brain itself.

IVH: Intraventricular hemorrhage- a bleed into the ventricles aka the cavities inside the brain where CSF is produced.

CSF: Cerebrospinal fluid- fluid that acts to protect, cushion and regulate the brain.

DAI: Diffuse axonal injury- tearing or shearing of diffuse areas of white matter usually seen in traumatic brain injury from acceleration/deceleration injuries like auto accidents.  Can also be seen in falls and assaults.  Usually the prognosis is poor but depends on the severity of the injury.

 

Neuroanatomy: since you know that sub=under and epi=above, doesn't this diagram make it easier to understand what subdural, epidural and subarachnoid really mean?

Cerebral AVM: Cerebral Arteriovenous Malformation- this is rare but I did see a few of these patients when I rotated through the Neuro ICU.  An AVM is when your arteries connect to your veins without the capillary bed in between- which means there is no gradual decline of pressure in the blood vessels.  The resulting higher pressure can cause stress to the blood vessels and can result in leaking or rupture.  Treatments vary but can include embolization, open brain surgery and focused radiation to the area to cause scarring and shrinking of the AVM.  Many AVM’s are present at birth and aren’t discovered until the patient’s later teen years.  A rupture of an AVM is a hemorrhagic stroke.

Arteriovenous Malformation

EVD: External ventricular drain (aka “ventric” in RN slang)- is inserted during a procedure called a ventriculostomy- the doctor literally bores out a piece of the patient’s skull and inserts a drain into the ventricle.  This can be done at the bedside or in the OR.  The EVD drains CSF to help reduce ICP and also allows the RN to measure ICP (see below).

External Ventricular Drain, can also measure ICP

ICP Monitor

ICP: Intracranial pressure- measured by the external ventricular drain or an ICP monitor, ICP is the pressure inside the ventricle.  Normal ICP is less than 15 mm Hg and usually in the ICU, an ICP over 20 needs treatment.  It is very dangerous for a patient to have an increased ICP for an extended length of time- therefore- it is essential you know what nursing actions raise ICP so that you avoid them (suctioning, stimulation, & positioning of the patient). Strategies to reduce ICP are diuresis (i.e.. Mannitol, Lasix), EVD placement and can be as extreme as a frontal lobectomy.

CPP: Cerebral perfusion pressure, CPP= MAP – ICP and the goal of treatment is to keep CPP above 70 mm Hg to ensure adequate perfusion of the brain (much like a MAP of 60-70 is the goal to perfuse the kidneys).  Control of blood pressure is crucial to this equation.  If your patient is hypotensive, your MAP and your CPP are reduced and the brain cells might not be getting enough oxygen.  If your patient is hypertensive, your CPP is elevated and you increase the risk for cerebral edema.  We use Labetalol drips fairly frequently to control HTN in our patients with increased ICP.

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EEG: Electroencephalography- measures brain electrical activity and can tell you about seizure activity and general brain activity.

TCD: Transcranial doppler- can be done at the bedside and measures the velocity of blood flow through the brain.  Our unit used this frequently to follow up with SAH patients who are high risk of vasospasm (which is basically a fancy way of saying ischemic stroke).

RANDOM TIDBITS

Hematoma vs Hemorrhage:  Hematoma is a collection of blood while a hemorrhage is actual blood loss (internal or external)

Ischemia: restriction in blood supply

Infarct: damage or death

Penumbra

Penumbra: area of the brain that may still be viable after an ischemic event.  The penumbra surrounds the infarcted area and can be saved if early diagnosis and restoration of perfusion occurs.

Ischemic stroke vs Hemorrhagic: An ischemic stroke is caused when blood flow to the brain is reduced or restricted.  The types of ischemic stroke are embolic and thrombotic.  A hemorrhagic stroke is caused by breakage of blood vessels inside the brain or the rupture of an aneurysm.

Embolic stroke vs Thrombotic stroke: an embolic stroke occurs because a blood clot that formed somewhere else in the body has traveled to the brain and gotten lodged in a small vessel- blocking blood flow to the area of the brain behind it.  A thrombotic stroke occurs when a clot blocks the arteries supplying the brain.  A thrombotic stroke can be of the large vessels or the small vessels (lacunar).

Ischemic stroke patients usually need to remain flat on their back for the first 24 hours to maximize perfusion to their brain.  Hemorrhagic strokes need to have the head of bed elevated to maximize venous drainage.

Hydrocephalus:  literally means “water on the brain” but its actually a CSF problem- either there is an obstruction and the CSF cannot flow properly, or CSF isn’t being reabsorbed or your body is producing too much CSF.  You will get an increase in ICP (intracranial pressure) and the symptoms associated with ICP.

Frontal lobe injuries:  injuries to the frontal lobe can drastically change a patient’s personality.  The patient may be emotionally labile, unaware of social etiquette, sexually impulsive and lose their ability to focus.  These patients are often challenging to care for and require the utmost degree of patience and understanding from the RN.

CEREBRAL ANEURYSM

Aneurysm

A cerebral aneurysm is a weaknesses in the wall of the blood vessel that causes a balloon-like bulging of blood which may be at risk for rupture.  Many unruptured aneurysms are asymptomatic and are found by routine MRI’s or because a patient has a family history of aneurysms.  Sometimes unruptured aneurysms can cause headaches or vision problems. Treatment depends on where the aneurysm is, how big it is, the patient’s risk factors for surgery and/0r the patient’s neck geometry.  Some aneurysms may  be coiled or clipped.

 

Endovascular coiling is a procedure in which a catheter is inserted femorally and threaded up to the aneurysm with the help of X-Ray imaging and fluoroscopy.  Tiny coils are then fed through the catheter into the aneurysm to pack it and reduce the pressure on the aneurysm walls so that it will not rupture (hopefully).  Surgical clipping requires craniotomy.  A clip is applied to the neck of the bulge and its goal is to keep normal blood flow from entering the aneurysm.

Above: Coiling procedure Below: Clipping procedure

If the patient is at low risk or is not a candidate for coiling and clipping, the patient may be kept for observation.  Taking care of a patient with an unruptured aneurysm can feel like you are taking care of a ticking time bond.  Nursing interventions include minimizing stimulation, restricting visitors, keeping lights low and keeping sounds to a minimum.

REDUCING METABOLIC DEMAND

Reducing metabolic demand is crucial to treating ICP problems and may include all or some of the following: sedating patients, preventing seizures, aggressively treating fever, and minimizing activities that raise ICP.

Fentanyl and Propofol are often used for pain and sedation in neuro patients because they allow for more frequent neurological assessments.

Seizure prophylaxis:  Neuro patients are often on Dilantin and/or Keppra to prevent seizure activity.

Central fever or “neuro temps”: neuro patients are often hyperthermic because our temperature control center is in the brain and this is often disturbed when we have a brain injury.  Central fevers are different from peripheral fevers in that they are better treated by external cooling than with antipyretic agents like Acetominophen (although we still can see fever reduction with Tylenol- most often given PR in the neuro patient!).   They are also different in that there is no associated sweating and tachycardia.  Central fevers tend to increase smoothly, roughly one degree an hour as opposed to a peripheral fever which can spike quickly as a result of infection.  In our unit, we began to treat fevers at 38 degrees C (100.4 degrees F) because every 1 degree raise in temperature increases metabolic rate by 10-13%.  Sometimes it’s difficult to distinguish central fever from peripheral fever so you might send fairly frequent blood cultures to be on the safe side.  Monitoring WBC’s isn’t always effective either, because the cerebral inflammatory process will elevate your WBC count just like an infectious process would.  You might see central fever patients on cooling blankets or with a femoral catheter that sends cool water through the patient’s circulatory system- these are called Cool Guards at our facility.  Ice packs to the arm pits and groin are also helpful but need to be changed frequently as ((surprise))- ice melts!.  **Managing shivering in cooled patients is also an issue because shivering increases metabolic demand.  Doctors may prescribe Thorazine to prevent shivering that increases ICP.

Barbituate comas and paralytic agents:  sometimes drastic measures are taken to reduce ICP- these patients are usually 1 RN to 1 patient assignments because they require careful monitoring.  Phenobarbital and Nimbex are examples.

*Nursing actions should be staggered to allow a patient’s ICP to return to baseline after any sort of turning or nursing action.  The head of bed is often placed around 30 degrees to allow for maximum venous drainage but if you have an EVD, you can adjust the head of bed elevation to where the patient’s ICP is minimized and the CPP is maximized.  For the same reason (promotion of venous drainage away from the brain), it is important to keep your patient’s neck neutral even if you have to use towel rolls or sandbags to stabilize the neck.  After suctioning, turning, bathing or stimulation- it may take several minutes for your patient’s ICP to return to baseline- which is why you do not want to cluster nursing activities like you would in other ICU patients.

Herniation: life-threatening and ominous situation where portions of the brain are pushed through openings within the cranial cavity when ICP is elevated.  Vasculature is compressed and/or destroyed and can even be sliced through which results in ischemia and/or necrosis and/or death.  There are different types of herniation: Uncal, Transtentorial, Transcranial and Cingulate.

Midline shift: This is another term you may hear frequently in the Neuroscience ICU.  It refers to the shift of the brain across the center line.  Think about a normal CT, you can clearly see the distinction of the ventricles across the center line.  When a bleed occurs, ICP is increased and the brain is squished to one side.  Midline shift is measured in millimeters- the larger the number- the farther the middle of the brain is from the center line of the skull.  Therefore, bigger numbers = bigger problems.

Normal Head CT with no midline shift

 

Large Intracerebral Hemorrhage with associated Midline shift toward the right


  • shelleyhall

    Another great topic! I was just in NICU on Thursday. I didn’t know what unit I would be on since it can vary from week to week or depending on who my preceptor will be. I enjoyed it though. My preceptor gave me the opportunity to read up on some neuro but I was kinda busy also with the patient I had so I couldn’t get too much reading done. Your podcast really brings some things into the light, Andria.

  • Andria RN

    Ha! I remember those days. You’re so busy trying to stay task oriented and get everything done that the reason the patient is in the ICU escapes you. At least that’s how it was for me for the first few months probably…
    I just posted a new podcast and gave you a little shout out at the end. I really appreciate the suggestions for the podcast and the kind words!

  • Karin

    I am so excited that I found this blog. This is EXACTLY what I am looking for. THANK YOU.
    I am currently in my last semester and will be doing my capstone on the Neuro Science ICU floor starting sometime end of April.

    Is this blog open to questions? I am sure I will have many …

  • Andria RN

    Absolutely – send any questions our way!

  • sam_jaq

    I was just placed for my final nursing rotation at a Neuro-ICU in NYC, and this blog post was exactly what I hoped I might find. Beyond what you have written, do you have any recommendations for material that would be beneficial to read before I start? Thank you for your post.

  • Andria RN

    Congratulations! Every ICU varies on the types of diagnosis and the level of acuity of the patients. The best suggestion would be to contact the clinical educator or nurse manager on your unit and ask this same question (they may have books you could borrow). You could also ask to see their order sets- then you’ll be able to learn the meds on that order set. I would suggest checking out forums from other nurses too- like this one: http://allnurses.com/neuro-intensive-care/
    Hope this helps! Let us know how it goes

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