Neurologic 7% Flashcards
Raccoon Eyes
Indication of basal skull fracture involving anterior fossa
Dripping of fluid from nose or ear of patient with basal skull fracture highly suggestive of a cerebrospinal fluid (CSF) leak.
CSF Leakage
Leakage from the nose or ear canal indicates a tear in the dura.
Dural tears increase the risk of infection.
Nursing care: Provide a sterile field for the drainage, nasal packing could lead to increased intracranial pressure (ICP).
Recombinant Tissue Plasminogen Activator (rt-PA)
Fibrinolytic Agent
Must be initiated within 3 hours of onset of symptoms
Complications:
Intracranial bleeding
Seizure (suggestive of intracranial hemorrhage).
Therapeutic Hypothermia
Reduces the metabolic demand of the brain.
Most important intervention to prevent anoxic encephalopathy is the prompt restoration of cerebral oxygenation through basic life support and advanced cardiovascular life support.
This often includes hypothermia immediately afterwards.
Why keep a neurological patient’s head in neutral head position?
Keeping the head and neck in a neutral position allows optimal venous drainage through the jugular veins.
Cerebral Perfusion Pressure (CPP) = ?
CPP = mean arterial pressure (MAP) - ICP
Goal CPP of at least 60 mm Hg.
Ex. ICP is 40 mm Hg, MAP must be at least 100 mm Hg to keep CPP at least 60 mm Hg.
Increase in ICP
Positive Pressure Ventilation (increases intrathoracic pressure)
Hypoxia (leads to vasodilation
Which of the following should not be used to determine central response to pain?
- Sternal Rub
- Trapezius Squeeze
- Nailbed Pressure
- Supraorbital Pressure
Nailbed Pressure
Nailbed pressure is peripheral pain.
Can be used to determine whether the patient can feel and withdraw such as checking for paralysis
Neurologic Change Early Signs
Change in LOC is the best indicator for change in neurologic function.
Reflection of cerebral and reticular activating system functioning.
Pupil changes may be early but usually follow LOC
Changes in motor function usually are an indication of a focal lesion in one of the cerebral hemispheres.
Vital sign changes are a late sign of intracranial hypertension.
Neurologic Change Late Signs
Elevated blood pressure
Dysrhythmias (Bradycardia)
Posturing
Major Sources of Intracranial Hypertension after Craniocerebral Trauma
Cerebral Edema and Expanding Lesions (e.g. hematoma)
Computated Tomography (CT) Scan of Head
Performed initially following stroke-like symptoms to identify intracranial hemorrhage
Angiogram
Visualizes extracranial and intracranial vasculature
Would be performed if intracranial hemorrhage is identified on a CT scan
Definitively show the location and size of any aneurysmal dilation
Lumbar Puncture
Collection of cerebrospinal fluid (CSF) by lumbar puncture
Can identify if and what infective organisms are present
If organism is bacterium, CSF will be cloudy and the glucose level will be decreased.
Contraindicated in patient with clinical indications of intracranial hypertension because herniation may occur
Evoked Potentials
Evoked potential studies measure the electrical responses in brain waves in response to sensory stimuli and are not indicated.
Cerebrospinal Fluid (CSF)
Test positive for glucose
Glucose in the CSF is 60% of the glucose in the serum.
Compensation
Ability of the brain contents to be shifted to prevent intracranial hypertension when intracranial volume increases
- Cerebrospinal fluid (CSF) production decreases
- Reabsorption is increased
- CSF is shunted to the lumbar spine
- Central nervous system hypertension causes hypocapnia, alkalosis, and vasoconstriction which reduce the amount of blood in the cranium.
- Eventually part of the brain is shifted out of the cranium (i.e., herniation)
Autoregulation
Relates to the ability of the crebral vessels to change size to normalize blood flow.
Cranial Nerves V (trigeminal), VII (facial), IX (glossopharyngeal), X (vagus), and XII (hypoglossal)
Important for eating without the danger of aspiration.
Control gag and swallow response
Must be intact bilaterally to protect the patient’s airway.
Decerebrate Posturing
Abnormal extension
Arms extended and hyperpronated
Decorticate Posturing
Abnormal flexion
Arms flexed against the chest
Early Sign of Uncal Herniation
First sign is ipsilateral pupil dilation with a sluggish reaction as a result of pressure on cranial nerve III.
Motor weakness may occur but would be on the contralateral side.
Contusion can act as a mass lesion and cause a unilateral shift and uncal herniation.
A scalp laceration located over a depressed skull fracture requires what?
Immediate surgery because there is a direct route between the outside environment and the brain, increasing risk for infection.
Meningitis
Classic clinical presentation includes: Headache Stiff neck High fever Kernig sign Brudzinski sign