Lippincott Nursing Pocket Card

Increased Intracranial Pressure (ICP)

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Recognizing and Managing Increased Intracranial Pressure (ICP)

The cranium is a rigid bony structure that contains 3 main components: brain tissue, cerebrospinal fluid (CSF), and blood. The pressure in the cranium is normally less than 20 mm Hg. Increased intracranial pressure (ICP) occurs when there is an increase in the volume of one or more components which cannot be offset by a volume reduction or displacement in some other component.

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Conditions Associated with Increased ICP

The development of increased ICP may be acute or chronic. It is a common clinical problem in neurology or neurosurgical units. Many diseases or insults can result in increased ICP:

  • Increase in brain volume
    • Cerebral edema (trauma, ischemia, hyperammonemia, encephalitis, high altitude)
    • Hematoma
    • Tumor
    • Abscess
    • Blood clots  
  • CSF Dysregulation
    • Increase in cerebrospinal fluid (infection, choroid plexus tumor)
    • Decreased re-absorption of CSF (obstructive hydrocephalus, meningitis)
  • Increase in blood volume
    • Increased cerebral blood flow (hypercarbia, aneurysms)
    • Venous stasis from venous sinus thromboses
    • Elevated central venous pressures (severe heart failure)
  • Other causes
    • Idiopathic intracranial hypertension
    • Skull deformities such as craniosynostosis
    • Vitamin A intoxication
    • Tetracycline use
Acute intracranial hypertension (AIH) is a clinical syndrome in which homeostatic mechanisms are overwhelmed causing a rapid increase in intracranial pressure (ICP). AIH is a medical emergency requiring immediate treatment to prevent irreversible neurologic damage or death. Patients at risk for AIH should be monitored in a critical care setting.
 

Signs and Symptoms of Increased ICP

Conditions associated with chronically increased ICP may first present insidiously. Headaches may be the only symptom of chronic intracranial hypertension. Chronic intracranial hypertension can cause vision loss due to pressure on the optic nerve. Intracranial volume may increase steadily over months with minimal symptoms and no change in the level of consciousness, and yet present dramatically with an acute deterioration of consciousness when compensatory mechanisms are exceeded.

There should be a high clinical suspicion of increased ICP for patients presenting with acute headache, papilledema, and vomiting. The patient may describe the headache as throbbing pain which worsens with actions that further increase ICP such as coughing, sneezing, recumbency or exertion. Other initial signs and symptoms of increased ICP include nausea, blurred vision, restlessness, irritability, and confusion. The clinical presentation of AIH can be mistaken for other problems, such as drug or alcohol intoxication, migraine headache, infection, or post-ictal state. 

Level of consciousness will decrease progressively as ICP gets worse. The Glasgow Coma Scale (GCS) is the most common scoring system used to objectively describe the patient’s level of consciousness. The GCS is composed of three objective tests: eye, verbal, and motor responses. The lowest possible total GCS is 3, indicative of deep coma, while the highest is 15. GCS scores help facilitate communication among healthcare providers and provide guidance for diagnostic workup and therapeutic intervention.
 
Glasgow Coma Score (Teasdale & Jennett, 1974)
Feature Response Score
Best eye response
If local injury, edema, or otherwise unable to be assessed, mark "Not testable (NT)"
Spontaneously
To verbal command
To pain
No eye opening
Not testable
4
3
2
1
NT
Best verbal response
If intubated or otherwise unable to be assessed, mark "Not testable (NT)"
Oriented
Confused
Inappropriate words
Incomprehensible sounds
No verbal response
Not testable
5
4
3
2
1
NT
Best motor response
If on sedation/paralysis or unable to be assessed, mark "Not testable (NT)"
Obeys commands
Localizes pain
Withdrawal from pain
Flexion to pain
Extension to pain
No motor response
Not testable
6
5
4
3
2
1
NT
 

Increased ICP may cause protrusion or herniation of brain tissue through one of the rigid intracranial barriers.  Signs of brain herniation include pupillary dilatation, hemiplegia, impaired oculocephalic movements, increased motor tone, flexion or extension to pain (posturing), and respirations containing sighs, deep yawns, or pauses. The Cushing reflex, which consists of hypertension, bradycardia, and diminished respiratory effort, is a preterminal condition indicating impending brainstem herniation. Emergency treatment is warranted.

Managing Increased ICP

Nursing measures are targeted to assessing for changes in the neurologic exam, preserving cerebral blood flow through optimizing cerebral perfusion pressure (CPP), and protecting the brain from secondary injury.
 
The ABCs of Managing Increased Intracranial Pressure (Hussein et al, 2017)
  Strategy Intervention
A    Airway
  • Monitor airway patency.
  • Intubation, if needed, to prevent hypoxemia and hypercapnia.
B Blood pressure
  • Monitor cerebral perfusion pressure (CPP).
  • Maintain adequate blood pressure to optimize CPP.
C Calm
  • Decrease stimulation by providing a calm, quiet environment.
  • Minimize nursing interventions and space them out as able.
  • Provide intravenous (IV) sedatives as needed.
D Decompression
  • Insert a nasal* or oral gastric tube to decompress the stomach
E Edema
  • Monitor intracranial pressure if a catheter has been placed.
  • Monitor for changes in the neurologic exam.
  • Administer osmotic diuretics or hypertonic saline as ordered.
Eyes
  • Monitor pupillary responses to light and corneal reflexes.
Elevate the head
  • Raise the head of the bed to 30 degrees to facilitate jugular venous outflow.
F Fluids and electrolytes
  • Monitor for fluid and electrolyte imbalances that might indicate abnormal anti-diuretic hormone (ADH) levels.
  • Administer IV fluids and electrolytes.
Food
  • Provide enteral nutrition either through a feeding tube or orally if cleared by a speech pathologist.
Family
  • Provide family education and support. Participate in advanced care planning.
G Glasgow Coma Scale (GCS)
  • Monitor GCS hourly and report changes to a provider.
H Hip flexion
  • Avoid hip flexion which increases intra-abdominal and intrathoracic pressure.
Hyperventilation
  • Hyperventilation is used to lower carbon dioxide levels if other measures to lower ICP are ineffective.
Hyperthermia
  • Prevent hyperthermia to lower the metabolic requirements of the brain.
Herniation
  • Monitor for impending herniation: unilateral or bilateral pupil dilation, coma, posturing, Cushing’s reflex (hypertension, bradycardia, bradypnea).
I ICP monitoring
  • Monitor ICP and inform provider of sustained ICP>20.
  • Monitor the effect of nursing care on ICP and minimize treatments or stimuli which increase it.
Infection
  • Strict aseptic technique when applying or changing dressings to ICP monitoring devices or ventricular drainage systems.
*Note: Nasogastric tubes are contraindicated with basilar skull fractures.

The prompt recognition and management of patients with increased ICP requires knowledge of at-risk patient populations and the signs and symptoms of elevated ICP. Acute intracranial hypertension resulting from rapid elevation of intracranial pressure is a medical emergency requiring immediate stabilization of airway, breathing and circulation followed by immediate brain imaging for confirmation and diagnosis of the underlying etiology. ICP monitoring, and in certain cases CSF drainage, is a cornerstone of management. The neuroscience ICU nurse provides a calm, quiet environment, vigilant monitoring, and interventions to optimize cerebral blood flow and prevent complications.
 
References:

Hussein, M., Zettel, S., Suykens, A.M. (2017). The ABCs of managing increased intracranial pressure. Journal of Nursing Education and Practice, 7(4), 6-14.

Teasdale, G. & Jennett, B. (1974). Assessment of Coma and Impaired Consciousness: A Practical Scale. The Lancet, 304(7872). doi: https://doi.org/10.1016/S0140-6736(74)91639-0

The Glasgow Structured Approach to Assessment of the Glasgow Coma Scale. Royal College of Physicians and Surgeons of Glasgow. Retrieved from: https://www.glasgowcomascale.org/what-is-gcs/