Increased intracranial pressure (ICP), Head injury, Hydrocephalus
In applying the Monro-Kellie doctrine, the body can adapt to volume changes within the skull in 3 different ways to maintain a normal ICP. What are they?
(1) CSF volume can be changed by altering CSF absorption or production and by displacing CSF into the spinal subarachnoid space. (2) Changes in intracranial blood volume can occur through the collapse of of cerebral vein and and dural sinuses, regional cerebral vasoconstriction or dilation, and changes in venous outflow. (3) Brain tissue volume compensates through distention of the dura or compression of brain tissue.
late signs of ICP in infants and children
-Bradycardia -Decreased motor response to command -Decreased sensory response to painful stimuli -Alterations in pupil size and reactivity -Extension or flexion posturing -Cheyne-stokes respirations -Papilledema -Decreased consciousness -Coma The Cushing reflex is uncommon in children and is a VERY LATE sign of ICP.
What are conditions that can raise the ICP?
-Traumatic brain injury (TBI) -A mass (e.g., hematoma, contusion, abscess, tumor) -Cerebral edema (from brain tumors, hydrocephalus, head injury, brain inflammation) -Infection *hydrocephalus: is a buildup of fluid in the brain, which is manifested by ventricular enlargement.
Contusion
Bruising of the brain tissue may continue to bleed or have re-bleeding May show focal or generalized manifestations Risk for seizures phenomenon of coup-countercoup injury (see pic) Age related changes between a younger person and older person if they have a brain contusion is onset of symptoms. older people have less brain mass allowing for more room for buildup of pressure resulting in a longer time before symptoms present. A younger person doesn't have and the s/s are faster to display. Bruising of the brain tissue
Diagnostic tests for head injuries
CT scan is considered the gold standard and is the best diagnostic test to evaluate for head trauma bc it allows rapid diagnosis and intervention in the acute care setting. An MRI scan is more sensitive than the CT scan in detecting small lesions. MRI, PET, and evoked potential studies may also be used in the diagnosis and differentiation of head injuries. Transcranial Doppler studies allow for the measurement of cerebral blood flow (CBF) velocity. A cervical spine x-ray series, CT scan, or MRI of the spine may also be indicated since cervical spine trauma often occurs at the same time as a head injury.
Skull Fracture locations
Categorized based off of location of skull fracture and type of fracture Location Types: Frontal fracture -rhinorrhea Orbital fracture -racoon eyes Temporal fracture -battle signs -otorrhea Parietal fracture -Deafness -otorrhea -battle sign Posterior fossa fracture -visual field defects Basilar skull fracture -otorrhea -battles sign -bulging of TM Fracture types: Comminuted Depressed linear Simple Compound *Most skull fractures come with cranial nerve deficits.
Nursing interventions for increased ICP: Drug therapy (continued)
Corticosteroids (decreases inflammation) •Complications associated with the use of corticosteroids include hyperglycemia, increased incidence of infections, and gastrointestinal (GI) bleeding. •Regularly monitor fluid intake and sodium and glucose levels. •Perform blood glucose monitoring at least every 6 hours for any patient receiving corticosteroids until hyperglycemia is ruled out as a concern. •Patients receiving corticosteroids should concurrently be given antacids or histamine (H2)-receptor blockers (e.g., cimetidine [Tagamet], ranitidine [Zantac]) or proton pump inhibitors (e.g., omeprazole [Prilosec], pantoprazole [Protonix, Protonix IV]) to prevent GI ulcers and bleeding. Antiseizure medications (prevent seizure) Antipyretics (for fever management) Sedatives (may mask ICP s/s) Analgesics (pain increases ICP) Barbiturates (decrease metabolic demand by the brain)
Age-Related Differences
Cranial sutures are ossified by age 12 years, with no expansion of the skull after age 5 years. Before the sutures are entirely closed, there is some room for expansion in the case of cerebral edema and increasing ICP. Aging is associated with a reduction in brain size, weight, and number of neurons. Atrophy of neuronal dendrites causes a slowing of neurotransmission and neural processes. These changes, however, are not directly associated with mental function, and cognitive abilities remain intact in the absence of disease, although cognitive function is enhanced with continued stimulation.
Coup/Countrecoup Injuries
Damage from coup-countercoup injury occurs when the brain moves inside the skull due to high-energy or high-impact injury mechanisms. Contusions or lacerations occur both at the site of the direct impact of the brain on the skull (coup) and at a secondary area of damage on the opposite side away from injury (countercoup), leading to multiple contused areas. Countercoup injuries tend to be more severe, and overall patient prognosis depends on the amount of bleeding around the contusion site. This can range from minor to severe.
Diffuse Axonal Injury (DAI)
Diffuse head injury Widespread disruption of axons due to acceleration or deceleration injury. Global cerebral edema leads to decreased LOC and an increased ICP seen in "shaking baby syndrome" 90% of patients with DAI stay in a persistent vegetative state and those who survive the initial event are rapidly triaged to an ICU and watched for s/s of increased ICP. signs include: -a decreased LOC -increased ICP -decortication or decerebration global cerebral edema
What are the causes of a TBI
Falls MVA Firearms (includes war related) Sports-related trauma recreational injuries Men are twice as likely to sustain TBI than women.
Things to consider with a patient with a skull fracture
Major complication is intracranial infections. Start antibiotics promptly. If basilar skull fracture is suspected, NEVER INSERT NG TUBE. You can place an orogastric tube instead. This is because with skull fractures insertion of a NG tube can perforate the brain. Observe for other complications of skull fractures like hematoma, meningeal and brain tissue damage. Perform thorough neuro assessments, LOC cheeks, vital signs monitoring, GCS.
Head injuries are classified using the GCS
Minor: GCS 13-15 Moderate: GCS 9-12 Severe: GCS 3-8
Emergency management of a head injury
Patent airway Stabilize cervical spine Oxygen IV access with two large-bore catheters to infuse normal saline or Lactated Ringer's solution. Intubate if GCS <8 Control external bleeding with sterile pressure dressing Remove patient's clothing Maintain patient warmth -shivering increases metabolism and workload on the brain. Ongoing monitoring Anticipate possible intubation Assume neck injury Administer fluids cautiously (can increase ICP)
Cheyne-Stokes breathing
a distinct pattern of breathing characterized by quickening and deepening respirations followed by a period of apnea
Macewen's sign/ Cracked pot
cracked pot sound on percussion is called what and indicates what
Osmotic diuretics
create an osmolar gradient that draws water across the blood-brain barrier, leading to a decrease in interstitial volume and a subsequent decrease in ICP. Mannitol is the agent used most commonly to achieve ICP control in a variety of conditions, and it has been shown to improve cerebral blood flow. Hypertonic saline is increasingly being used, but research has not clearly determined the volume, tonicity, or most effective method of administration.
Hyperventilation and ICR
spontaneous hyperventilation-Carbon dioxide is a potent vasodilator. Hyperventilation is a compensatory mechanism that causes vasoconstriction, which reduces cerebral blood volume and ICP.
Different types of ICP monitoring devices
•Multiple methods and devices are available to monitor ICP in various sites. •This graphic shows a coronal section of brain showing potential sites for placement of ICP monitoring devices.
Electroencephalogram
An electroencephalogram (EEG) measures and records the brain's electrical activity through multiple electrodes placed on the scalp. This monitoring combination is useful in diagnosing and localizing the area of seizure origin. The EEG is also helpful in identifying psychogenic nonepileptic seizures. The origin of these seizures may be associated with psychological conditions or other physical problems, but they are not caused by electrical activity in the brain.
What are the factors that influence ICP?
Arterial pressure & Venous pressure Intraabdominal & intrathoracic pressure (vomiting, bearing down) Body position (keeping neck midline and HOB at 15-30) Body Temperature (hyperthermia) Blood gases, particularly CO2 levels (hypoxia, hypercarbia)
Scalp Lacerations
Focal injury Increased bleeding due to scalp having difficulty with vasocontraction
How is CPP calculated?
Formulas: CPP=MAP-ICP Map=SBP+2(DBP)/3 BP: 90/42 ICP: 19 Step 1: First calculate the patients Map 42x2=84+90=174/3=58 Map=58 Step 2: subtract the MAP from the ICP to obtain the PCC. 58-19=39 CPP=39 Remember the normal is 60-100. Anything less then 50 is not good. So, this patient is undergoing ischemia to the brain and must be treated.
S/S of increased ICP in a child
Headache Diplopia (blurred vision) Mood swings Seizures drowsiness increased sleeping Lethargy inability to follow commands Slurred speech Papilledema (after 48 hours) Altered level of consciousness Nausea and vomiting, especially in the morning
What is the Monro-Kellie doctrine?
Idea that the head is a closed shell and the three major components (brain, blood, and CSF) are in a state of dynamic equilibrium - as the volume of one goes up, the volume of another must go down. ***only applicable only in situations in which the skull is closed. not valid in person with displaced skull fractures or craniectomy .
Babinski reflex
Infant reflex where if its foot is stroked, the baby's toes fan out
Nursing interventions for increased ICP: Drug therapy
Mannitol (Osmitrol) First line drug is an osmotic diuretic given IV. It acts to decrease the ICP in two ways: -Plasma expansion -Osmotic effect *Careful monitoring of fluid and electrolyte need to be done when giving this drug. •Hypertonic saline (3% sodium Cl) is another drug treatment used to manage increased ICP. -It produces massive movement of water out of edematous swollen brain cells and into blood vessels. -Hypertonic solution requires frequent monitoring of BP and serum sodium levels as intravascular fluid volume excess can occur. -Hypertonic saline has been shown to be just as effective as mannitol when treating increased ICP, and both are often used concurrently when caring for severely brain-injured patients.
Clinical Manifestations of increased ICP "MIND CRUSHED"
Mental Status changes: EARLIEST SIGN (restless, confused, not responding to questions) Irregular breathing: LATE SIGN (Cheyne-Stokes breathing) Nerve changes to optic &oculomotor -double vision -papilledema (swelling of optic nerve) -oculocephalic reflex (Doll's eye) -Pupils (abnormal pupils) Decorticate or Decerebrate posturing Cushing's Triad: LATE SIGN -Increased SBP--widening pulse pressure (SBP-DBP=pulse pressure) -↓ HR, ↓RR (abnormal) Reflex Positive Babinski (toes fan out) Unconscious: LATE Seizures Headache Emesis (vomiting) without Nausea Deterioration of motor function
Concussion
Minor diffuse injury may or may not have LOC Typical sings include: -a brief disruption in LOC (may or may not experience LOC) -amnesia about the event (Retrograde amnesia) -headache Assessing for post concussion syndrome Retrograde amnesia: unable to remember what happened or lead to
CSF Leak
Otorrhea: draining of CSF from the ear rhinorrhea: draining of CSF from the nose *If CSF rhinorrhea or otorrhea occurs, inform the HCP immediately Measures for patients leaking CSF -Head of bed elevated -No sneezing or blowing nose -No NG tube -No nasotracheal suctioning -Measures for immobilized patients -Antiemetics (vomiting increases ICP) -Analgesics (pain increases ICP) -Preop preparation, if needed *CSF leaks have increased r/f meningitis. Because of the increase r/f infection nontracheal suctioning and NG tubes are contraindicated. Prompt prescription of antibiotics is essential in this case.
post-concussion syndrome (PCS)
PCS is not to be confused for Chronic Trauma Encephalopathy (CTE). They're very similar but vary in causes. PCS is a form of TBI and can be the result of one or multiple concussions. CTE is caused not only by multiple concussions, but also by sub-concussive impacts to the brain, where the brain is jolted regularly, but not enough to cause concussion. PCS can occur 2 weeks to 2 months after head injury Persistent headache, lethargy, personality and behavioral changes, dizziness, sensitivity to light, fatigue, shortened attention span, decreased short-term memory, and changes in intellectual ability. Affects the patient's abilities to perform ADL's History of prior concussion or head injury, can progress to more serious conditions like CTE. Diagnosis Typically, if concussion symptoms persist longer than 3 months a patient is diagnosed with PCS. Research is showing that these symptoms can last anywhere from months to years. CTE cannot be diagnosed until after death with a brain biopsy. Discharge instructions: Observe and accurately report for symptoms or changes in the neuro status.
S/S of increased ICP in infants
Poor feeding or vomiting Irritability, restlessness, or lethargy Tense bulging fontanel High-pitched cry Macewen (cracked-pot) sign Increased head circumference Separation of cranial sutures Distended scalp veins Eyes deviated downward ("setting sun" sign) Increased or decreased response to pain
Nursing Interventions: Preventing increased ICP & Monitoring ICP "PRESSURE"
Position -HOB: 15 to 30 degrees -head midline Respiratory -prevent hypoxia & hypercapnia Elevated Temperature: Prevent Systems to monitor Straining activates: Should be avoided vomiting, sneezing, coughing, Valsalva, keep environment calm and avoid restraints. Unconscious patient care avoid over sedating ( because it can mask early s/s of ICP), immobile (at r/f skin breakdown) Rx: Prescriptions -Barbiturates: decrease metabolism -Vasopressors -IV fluids -Anti-hypertensives -Anticonvulsants -Hyperosmotic drugs Edema management
Interventions to Lower Intracranial Pressure
Positioning. The intracranial venous system consists of canals and sinuses, and unlike the peripheral venous system, it lacks valves. Interventions promoting venous outflow from the head decrease cerebral volume and help to lower ICP. Such interventions include head-of-bed elevation and proper alignment of the head and neck with the body. Head-of-bed elevation of 30 degrees is usually recommended to decrease ICP. head-of-bed elevation is recommended as long as the CPP remains at an appropriate level. Activity management. Balance between being efficient and not increasing oxygen demand when providing nursing care is crucial. Clustering of many nursing tasks at once will increase oxygen demand and may compromise cerebral perfusion. Distribution of care procedures over a longer period is preferable. Airway management. Endotracheal suctioning stimulates coughing, which increases ICP. Patients with increased ICP should undergo endotracheal suctioning only when suctioning is indicated. In addition, these patients may need to be sedated before the procedure. Careful assessment is necessary to maintain an adequate airway and minimize complications of increased ICP. Hyperventilation. Prophylactic hyperventilation (PaCO2 ≤25 mm Hg) in TBI is not recommended because it decreases perfusion, which will negatively affect oxygen delivery. Hyperventilation is recommended only as a temporary measure to reduce elevated ICP. Bowel management. Constipation increases intra-abdominal pressure and causes straining when defecating, thereby raising ICP. Stool softeners or laxatives may be necessary to minimize these untoward effects on ICP.
The National Institutes of Health Stroke Scale
The National Institutes of Health Stroke Scale (NIHSS) is an example of one type of specific tool for nurses to use when assessing a patient following stroke. This scale, composed of 11 items, has been widely used and validated. The NIHSS score on admission has been correlated to stroke outcome and is recommended for all patients with suspected stroke.
Glasgow Coma Scale (GCS)
a scoring system used to describe the level of consciousness in a person following a traumatic brain injury. Scored off of three areas: -eye opening response -verbal response -motor response Best score: 15 Comatose: less than 8 Unresponsive: 3
Why a lumbar puncture contraindicated for a patient with an increased ICP?
because it can cause herniation
Intracerbral Hematoma
bleeding within brain tissue usually within frontal and temporal lobes Size and location of hematoma determine patient outcome
Head injuries are categorized
can be either diffuse (occurs over a more widespread area) or focal (injury occurs in a specific location) types: scalp laceration skull fractures concussion diffuse axonal injury contusion hematoma
Decorticate and decerebrate posturing
decerebrate is the worst of the two
What are the major complications of ICP?
inadequate cerebral perfusion and cerebral herniation: sustained increase in ICP can lead to brain stem and cranial compression (fatal complication) & herniation of the brain forcing the cerebellum & brainstem down into the foramen magnum.
cerebral edema
is defined as swelling of the brain variety of causes: -Infection (e.g., meningitis) -head injuries and brain surgery -Mass lesions -Toxic or metabolic encephalopathic conditions (e.g., lead or arsenic intoxication) -vascular insult (anoxic and ischemic episodes) Three types: •Vasogenic cerebral edema (most common) •cytotoxic cerebral edema •interstitial cerebral edema
What is Cerebral blood flow (CBF)
is defined as the amount of blood in mL passing through 100 g of brain tissue in 1 minute. CBF is about 50mL/min/100g of brain tissue. The brain requires a constant supply of O2 and glucose. The brain uses 20% of the body's O2 and 25% of its glucose.
Intracranial Pressure (ICP)
is the pressure inside of the skull. Normal ICP ranges from 5 to 15 mmHg. A sustained pressure >20 mmHg is considered intracranial hypertension and an abnormal finding and must be treated.
What is cerebral perfusion pressure (CPP)?
it's the pressure that pushes the blood to the brain...hence influences the cerebral blood flow (CBF) Normal CPP is 60-100 mmHg. ***When CPP falls to low the brain is not perfused and brain tissue DIES. <50 mmHg is associated with ischemia and neuronal death <30 mmHg results in ischemia and incompatible with life.
subdural hematomas
occurs from bleeding between the dura mater and arachnoid layer of the meninges. A subdural hematoma usually results from injury to the brain tissue and its blood vessels. And can be acute, subacute, or chronic. Different types include: Acute subdural hematomas -within 24 to 48 hours of injury; symptoms related to increased ICP s/s: decreased LOC, headache, ipsilateral pupil dilated and fixed if severe (picture) Subacute subdural hematomas -within 2 to 14 days of the injury, may appear to enlarge over time. Chronic subdural hematomas -weeks or months after injury, more common in older adults -presents as focal symptoms -increased r/f misdiagnosis
What is the gold standard for monitoring ICP?
ventriculostomy; is also called ventricular catherization with an intraventricular catheter (IVC) or external ventricular drainage (EVD). It is considered the gold standard because it directly measures the pressure in the ventricles, facilitates removal/sampling of CSF, and allows for intracranial drug administration CSF can be drained via a ventriculostomy when ICP exceeds the upper pressure parameter set by the physician. Intermittent drainage involves opening the three-way stopcock to allow CSF to flow into the drainage bag for brief periods (30 to 120 seconds) until the pressure is below the upper pressure parameters. There are two options for CSF drainage: intermittent and continuous. Inaccurate reading is caused by: -CSF leaks -Obstruction in catheter/kinks in tubing -Differences in height of bolt/transducer -Incorrect height of drainage system -Bubbles/air in tubing
Pupillary check for Size and Response
•Compare the pupils with one another for size, shape, movement, and reactivity. •If the oculomotor nerve (CN III) is compressed, the pupil on the affected side (ipsilateral) becomes larger until it fully dilates. If ICP continues to increase, both pupils dilate. •Test pupillary reaction with a penlight. The normal reaction is brisk constriction when the light is shone directly into the eye. Also note a consensual response (a slight constriction in the opposite pupil) at the same time. A sluggish reaction can indicate early pressure on CN III (oculomotor nerve). •A fixed pupil unresponsive to light stimulus usually indicates increased ICP. However, it is important to note that there are other causes of a fixed pupil, including direct injury to CN III, previous eye surgery, administration of atropine, and use of mydriatic eye drops.
Important information regarding a ventriculostomy
•It is important to make sure that the transducer of the ventriculostomy is level to the foramen of Monro (interventricular foramen) and that the ventriculostomy system is at the ideal height. •A reference point for this foramen is the tragus of the ear. When the patient is repositioned, the system needs to be re-zeroed. Placement of the subarachnoid bolt is not adjusted by ANYONE except the neurosurgeon who place the device The bolt is stabilized with dressing, and these are not changed or disturbed even to check the site. Leave them alone!