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174 Cards in this Set
- Front
- Back
akinetic mutism
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unresponsiveness to the environment; the patient makes no movement or sound but sometimes opens the eyes
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altered LOC level of consciousness
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may exhibit:
-not oriented -does not follow commands -needs persistent stimuli to achieve a state of alertness |
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autoregulation
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ability of cerebral blood vessels to dilate or constrict to maintain stable cerebral blood flow despite changes in systemic arterial blood pressure
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brain death
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irreversible loss of all functions of the entire brain
1. coma 2. absence of brain stem reflexes 3. apnea |
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coma
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a clinical state of unarousable unresponsiveness in which ther are no purposeful responses to internal or external stimuli, although nonpurposeful responses to painful stimuli and brain stem reflexes may be present
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craniotomy
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a surgical procedure that involves entry into the cranial vault
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craniectomy
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a surgical procedure that involves removal of a portion of the skull
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Cushing's response
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brain's attempt to restore blood flow by increasing arterial pressure to overcome the increased intracranial pressure
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Cushing's triad
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three classic signs - bradycardia, hypertension, and bradypnea - seen with pressure on the medulla as a result of brain stem herniation
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decerebration
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an abnormal body posture associated with a sever brain injury, characterized by extreme extension of the upper and lower extremities
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decortication
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an abnormal posture associated with severe brain injury, characterized by abnormal flexion of the upper extremities and extension of the lower extremities
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epidural monitor
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a sensor placed between the skull and the dura to monitor intracranial pressure
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epilepsy
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a group of syndromes characterized by paroxysmal transient disturbances of brain function
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fiberoptic monitor
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a system that uses light refraction to determine intracranial pressure
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herniation
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abnormal protrusion of tissue through a defect or natural opening
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intracranial pressure aka ICP
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pressure exerted by the volume of the intracranial contents within the cranial vault
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locked-in syndrome
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condition resulting from a lesion in the pons in which the patient lacks all distal motor activity (tetraplegia) but cognition is intact. pt is unable to speak
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microdialysis
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procedure in which an intracranial catheter is inserted near an injured area of brain to measure lactate, pyruvate, glutamate, and glucose levels
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migraine headache
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a sever, unrelenting headache often accompanied by symptomes such as nausea, vomiting, and visual disturbances
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Monro-Kellie hypothesis
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theory that states that due to limited space for expansion within the skull, an increase in any one of the cranial contents - brain tissue, blood, or CSF - causes a change in the volume of the others
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persistant vegetative state
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condition in which the unresponsive patient resumes sleep wake cycles after coma, but is devoid of cognitive or affective mental function
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primary headache
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a headache for which no specific organic cause can be found
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seizures
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paroxysmal transient disturbance of the brain resulting from a discharge of abnormal electrical activity
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status epilepticus
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episode in which the patient experiences multiple seizure bursts with no revoery time in between
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secondary headache
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headache identified as a symptom of another organic disorder (eg brain tumor, HTN)
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subarachnoid screw or bolt
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device placed into the subarachnoid space to measure ICP
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transsphenoidal
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surgical approach to the pituitary via the sphenoid sinuses
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ventriculostomy
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a catheter placed in one of the lateral ventricles of the brain to measure ICP and allow for drainage of fluid
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What is the first priority for a patient with altered LOC
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obtain and maintain a patent airway
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duration of coma
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usually limited to 2-4 weeks
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initial clinical manifestations of altered LOC may include...
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subtle behavioral changes, such as restlessness or increased anxiety
pupils become sluggish |
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as the patient's LOC decrease, changes will ultimately include...
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decreased pupillary response
decreased eye opening response decreased verbal responses decreased motor responses eventually coma |
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What 3 things does the Glascow Coma Scale measure?`
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1. eye opening
2. verbal response 3. motor response Scale 3-15. |
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a 3 on the Glascow Coma Scale may indicate...
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severe impairment of neurologic function
brain death pharmacological inhibition of the neurologic response |
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What does a 15 on the Glascow Coma Scale indicate?
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that the patient is fully responsive
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If a patient is comatose and has localized signs such as abnormal pupillary and motor responses, what is assumed?
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that neurologic disease is present, until proven otherwise
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If a patient is comatose but pupillary light reflexes are preserved, what is suspected?
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a toxic or metabolic disorder
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What are the top three most common diagnostic procedures to identify the cause of unconsciousness?
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CT
MRI EEG |
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What are the less common procedures to detect the cause of unconciousness, after CT MRI AND EEG?
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PET
SPECT |
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potential complications for the patient with alterd LOC
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respiratory failure
pneumonia pressure ulcers aspiration DVT contractures complications associated with immobility |
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What is the first priority for a patient with altered LOC?
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obtain and maintain a patent airway
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Why should BP and HR be monitored in a patient with altered LOC?
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to ensure adequate perfusion to the body and brain
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pupillometer
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a portable automated device with a screen and digital video camera that measures pupil size and reactivity
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How serious is flaccidity?
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results from the most severe neurologic impairment
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equal, normally reactive pupils in an unconscious patient, suggests..
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that coma is toxic or metabolic in origin
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progressive dilation of pupils in an unconscious patient suggests...
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increasing ICP
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fixed dilated pupils in an unconscious patient suggests...
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injury at level of midbrain
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the corneal reflex examination tests which cranial nerves?
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V and VII
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asymmetry in the face of an unconscious patient is a sign of...
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paralysis
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drooling vs. spontaneous swallowing (swallowing reflex) in an unconscious patient, tests CN...
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X and XII
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a stiff neck in an unconscious patient suggests...
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subarachnoid hemorrhage or meningitis
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absence of spontaneous neck movement in an unconscious patient suggests...
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fracture or dislocation of cervical spine
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goals for patients with r/t altered LOC
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maintenance of a clear airway
(major goal is to compensate for the absence of the protective reflexes - coughing, blinking, swallowing) protection from injury attainment of fluid volume balance achievement of intact oral mucous membranes maintenance of normal skin integrity absence of corneal irritation attainment of effective thermoregulation effective urinary elimination bowel continence accurate perception of environmental stimuli maintenance of intact family or support system absence of complications |
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possible interventions to maintain airway in an unconscious patient
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most important*
HOB 30 degreses lateral or semiprone position suctioning and oral hygiene chests physiotherapy and postural drainage auscultate chest q8h intubation and mechanical ventilation |
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What should be done before suctioning and why?
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hyperoxygenation to prevent hypoxia
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possible interventions to protect an unconscious patient
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2 siderails during the day
3 siderails at night prevent injury from lines, tubes, restraints, damp bedding, dressings, etc protect the patient's dignity |
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possible interventions to maintain fluid balance and manage nutritional needs
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assess hydration status
administer required IV fluids |
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possible interventions to provide mouth care in an unconscious patient
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inspect for dryness, inflammation, and crusting
clean and rinse carefully thin coating of petrolatum move ET tube to opposite side of the mouth daily to prevent ulcerations |
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if the mouth of an unconscious patient is not kept clean,
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they are at risk for parotitis
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kinesthetic mean...
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sensation of movement
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vestibular means...
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sensation of equilibrium
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interventions to maintain skin and joint integrity
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turning and repositioning schedule
avoid shearing force and friction maintain correct body position passive exercise to prevent contractures splints or foam boots specialty beds |
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preserving corneal integrity in an unconscious patient
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cleanse with cotton balls moistened with sterile normal saline
artificial tears q2h as prescribed eye patches used cautiously b/c of potential for corneal abrasion |
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when is periorbital edema normal?
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after cranial surgery
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interventions to maintain body temperature in an unconscious patient
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remove all bedding except for sheet
room cooled to 65 deg F, unless elderly administer acetaminophen as prescribed cool sponge baths electric fan for surface cooling hypothermia blanket frequent temp monitoring to prevent excessive temp decrease |
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How do you take the temperature of an unconscious patient?
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never NPO
rectal or tympanic preferred to axillary |
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slight temperature elevation may be caused by...
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dehydration
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very high temperatures can be caused by...
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damage to the temp center in the brain or severe intracranial infection
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interventions to prevent urinary retention in an unconscious patient
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palpate or scan bladder at intervals
catheterization monitor for skin breakdown monitor for infection |
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interventions to promote bowel function in an unconscious patient
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listen for bowel sounds
measure girth of the abdomen monitor number and consistency of BM rectal exam for signs of fecal impaction |
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interventions to provide sensory stimulation to the unconscious patient (if ICP is not an issue)
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maintain usualy day and night patterns for activity and sleep
touch and talk to patient, encourage family to do so also orient the pt to time and place <q8h sounds from usual environment favorite TV programs |
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when arousing from coma, what may happen and what should the nurse do
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many patients experience a period of agitation when arousing from coma, which is actually a positive sign. at this time, reduce stimulation and only have one person talk to the patient at a time
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interventions to meet the need of an unconscious patient's family
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clarifies information about patient's condition
permits family to be involved in care listens to and encourages ventilation of feelings and concerns supports decisionmaking about posthopitalization mangaement support groups |
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what are the contents of the rigid cranial vault and how much are there of each
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brain tissue - 1400 g
blood 75 mL CSF 75 mL |
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normal ICP in the lateral ventricles
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10 - 20 mmHg
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Most common cause of increased ICP
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head injury
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causes of increased ICP
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head injury, brain tumors, subarachnoid hemorrhage, toxic and viral encephalopathies
increase in PaCo2, leading to increased cerebral blood flow |
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increased ICP from any cause does what?
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decreases cerebral perfusion
stimulates further swelling herniation (which is dire and frequently fatal) |
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S/S early stages of cerebral ischemia
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HTN
slow bounding pulse respiratory irregularities |
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compensatory mechanisms for cerebral edema
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autoregulation
decreased production and flow of CSF |
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the brain can maintain a steady perfsusion pressure if ...
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the arterial SBP is 50 - 100 mmHg
AND ICP < 40 mm Hg |
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CPP =
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CPP = mean arterial pressure - ICP
normal is 70-100 mmHg |
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normal CPP
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70-100 mm Hg
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if CPP <50
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irreversible brain damage
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if CPP = 0
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cerebral circulation ceases
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When ischemia occurs in the brain, what center does what?
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the vasomotor center triggers an increase in arterial pressure in an effort to overcome the increased ICP
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late sign of decreased cerebral blood flow
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Cushing's response
-increase SBP -widening of pulse pressure -decreased HR |
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grave sign of decreased cerebral blood flow, usually followed by herniation
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Cushing's triad
-decreased HR -HTN -decreased Respiration |
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earliest signs of increasing ICP
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change in LOC
slowing of speech delay in response to verbal suggestions |
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late signs of increased ICP
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coma
abnormal motor responses (decortication, decerebration, flaccidity) |
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3 complications of increased ICP
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brain stem herniation
diabetes insipidus SIADH |
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S/S diabetes insipidus
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decreased secretion of ADH
-excessive urine output -decrease urine osmolality -serum hyperosmolarity |
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therapy for DI
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administration of fluids
electrolyte replacement vasopressin (desmopressin, DDAVP) therapy |
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S/S SIADH
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increased secretion of ADH
-volume-overload -decreased urine output -serum sodium concentration becomes dilute |
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therapy for SIADH
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fluid restriction <800 cc /day
no free water in severe cases - 3% hypertonic saline solution - but change in serum sodium should not exceed a correction rate of 1.3 mEq/L/hour |
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Rapid correction of sodium imbalance greater than 1.3 mEq/L./hour may result in...
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central pontine myelinolysis, resulting in tetraplegia with CN deficits
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medical management of increased ICP
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-administer osmotic diuretics
-restrict fluids -drain CSF -control fever -maintain systemic BP and oxygenation -reduce cellular metabolic demands -no corticosteroids if TBI -possible judicious use of hyperventilation , only for a short duration, only if ICP is refractory to other measures |
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are corticocosteroids give if TBI leading to increased ICP
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no
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equipment to monitor ICP
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ventriculostomy
subarachnoid bolt epidural or subdural catheter fiberoptic transducer-tipped catheter in subdural space or ventricle |
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ventriculostomy aka ventricular catheter monitoring
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used for continuous monitoring ICP
transducer records the pressure in the form of an electrical impulse allows CSF to drain during acute increases in pressure to drain blood from ventricle access for intraventricular admin of meds and instillationof air or a contrast agent |
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complications of ventriculostomy
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infection
meningitis ventricular collapse occlusion by brain tissue or blood |
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interpreting incracranial pressure waveforms on an oscilloscope
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A waves (plateau waves) - transient, paroxysmal, recurring elevation of ICP that may last 5-20 min and range in implitude from 50 -100 - have clinical significance - indicate changes in vascular volumewithin the intracranial compartment that are beginning to compromise cerebral perfusion. reflects ischemia before overt S/S of raised ICP are seen clinically
B waves - less clinically significant but if seen in a series in a pt with depressed consciousness may precede appearance of A waves - may be seen in patient with intracranial HTN and decreased intracranial compliance C waves - significance unknown - appear to be r/t rhythmic variations of the systemic arterial BP and respirations |
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if increased ICP when are corticosteroids (ie dexamethasone) used vs not used
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used - if brain tumor is the cause
not used - if TBI is the cause |
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methods to decrease cerebral edema
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osmotic diuretics
if brain tumor - dexamethasone fluid restriction |
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methods to maintain cerebral perfusion
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improvements in CO made using fluid volume and inotropic agents such as Dobutrex (dobutamine hydrochlorideand Levophed (norepinephrine bitartrate)
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how is the effectiveness of CO to maintain cerebral perfusion reflected?
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by a CPP > 70 mm Hg
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hyperventilation r/t ICP
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hyperventilation leads to a decrease in PaCo2 and vasocontriction of cerebral vessels, decreasing ICP
-may not be so beneficial -use only is other therapies refractory |
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PaCo2 should be maintained at
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30-35 mm Hg
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controlling CSF volume r/t ICP
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can drain with a ventriculostomy but caution b/c excessive drainage may result in collapse of the ventricles and herniation
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why is controlling fever important to control ICP
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fever increases cerbral metabolism and the rate at which cerebral edema forms
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why should shivering be avoided when reducing fever?
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shivering is associated with increased oxygen consumption, increased level of circulating catecholamines, and increased vasocontriction
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methods to maintain oxygenation
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monitor arterial blood gas and pulse oximetry
HgB saturation can be optimized to provide oxygen more efficiently at the cellular level |
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methods to reduce metabolic demands
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if pt unresponsive to conventional treatment - high does of barbituates
paralyzing agents such as propofol (Diprivan) |
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goals for a patient with increased ICP
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maintain a patent airway
normalization of respiration adequate cerebral tissue perfusion through reduction in ICP restoration of fluid balance absence of infection absence of complications |
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Cheyne-Stokes respirations may result from
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increased pressure on the frontal lobes or deep midline structure
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hyperventilation may result from...
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pressure in the midbrain
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irregular respirations that eventually cease result from
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pressure on the pons and medulla
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PaCo2 should be maintained at or above
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> 60 mm Hg
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to decrease intraabdominal or intrathoracic pressure
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no coughing or sneezing
no Vasalva maneuver -stool softeners (but not enemas or cathartics) -when moving, instruct pt to exhale |
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During nursing interventions, ICP should not increase more than
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ICP should not increase more than 25 mm Hg and should return to baseline within 5 minutes
-if so pt may need sedation and a paralytic agent before |
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for the patient receiving mannitol, the nurse observes for complications such as
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heart failure and pulmonary edema
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what urine output may indicate the development of diabetes insipidus
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greater than 250 mL/hr for 2 consecutive hours
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S/S meningitis
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fever
chills nuchal rigidity increasing or persistent headache |
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what is the primary complication of increased ICP
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brain herniation
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Order in which S/S of increased ICP can be seen, early to late
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1. Disorientation, restlessness, increased respiratory effort, purposeless movements, mental confustion
2. Pupillary change, impaired extraocular movement 3. Weakness in one extremity or on one side of the body 4. Headache that is constant, increasing in intensity, and aggravated by movement or straining LATER 5. LOC deteriorates until pt is comatose 6. Pulse and respiratory rate decrease or become erratic, BP increases, temp increases, pulse pressure widens, fluctuating pulse 7. alterd respiratory patterns (ie Cheyne-Stoke and ataxic breathing) 8. Projective vomiting 9. Hemiplegia, decordticate, decerebrate, or bilateral flaccidity 10. Loss of brain stem reflexes, incl. pupillary, corneal, gag, and swallowing reflexes (ominous sign of approaching death) |
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Medications that may be prescribed before supratentorial and infratentorial intracranial surgery
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-antiseizure meds - phenytoin (Dilantin) or phenytoin metabolite (Cerbyx) before to reduce the risk of post-op seizures
-corticosteroids - dexamethasone (Decadron) - if brain tumor to reduce cerebral edema -fluids restricted -hyperosmotic agent - mannitol -diuretic agent - furosemide (Lasix) - IV before and sometimes during -antibiotics if a chance of contamination -to reduce anxiety - diazepam (Valium) |
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ongoing postop management for cranial surgery
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reducing cerebral edema
relieving pain preventing seizures monitoring ICP |
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mannitol
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used to reduce cerebral edema, works by increasing serum osmolality and drawing free water from areas of the brain. the fluid is then excreted by osmotic diuresis
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dexamethasone (Decadron)
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corticosteroid to reduce cerebral edema. if post cranial surgery.. IV q6h for 24-72h, route changed to oral asap, dosage tapered over 5-7 days
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acetaminophen
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usually prescribed post cranial surgery for temp exceeding 99.6 and for pain
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meds to decrease pain post cranial surgery
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codeine IV
morphine sulfate |
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what should be given to patients after supratentorial neurosurgical procedures?
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antiseizure meds such as phenytoin or diazepam b/c of the high risk for seizures
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potential complications of intracranial surgery
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increased ICP
bleeding and hypovolemic shock fluid and electrolyte disturbances infection seizures |
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when does cerebral edema peak after brain surgery
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24-36 hours after surgery, producing decreased responsiveness the second post-op day
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After cranial surgery, when might a clot be suspected?
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If the patient does not awaken as expected or whose condition deteriorates
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After cranial surgery, what is suspected if the patient has any new neurologic deficits, especially a dilated pupil on the operative side?
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an intracranial hematoma
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Patients undergoing surgery for brain tumor often receive large doses of corticosteroids and therefore tend to develop hyperglycemia. Serum glucose levels are measured...
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every 4-6 hours. These patients are also prone to gastric ulcers, so H2 blockers are prescribed to suppress the secretion of gastric acid. The patient also is monitored for bleeding and assessed for gastric pain.
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what should be monitored if DI develops post op
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serum potassium levels
intake and output urine specific gravity q1h |
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is SIADH usually self limited?
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yes
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If the patient complains of a salty taste or post nasal drip...
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this can be caused by CSF trickling down the throat
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Before and after cranial surgery, what is a very important med to administer...
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anti-seizure meds may prevent the development of seizures in subsequent months or years
|
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on to seizures...
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...
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automatisms
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involuntary motor activity, such as lip smacking or repeated swallowing
|
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after a seizure, the patient is at risk for
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hypoxia
vomiting aspiration |
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what complication is associated with long term use of antiseizure meds?
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bone loss, so patients should be assessed for low bone mass and osteoporosis and give instruction about other strategies to reduce their risk for osteoporosis
|
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simple partial seizures
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only a finger or hand may shake, or mouth may jerk
may talk unintelligibly, may be dizzy, may experience unusual sensations -no loss of consciousness |
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two types of seizures
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partial seizures - begin in one part of the brain
generalized seizures - involve electrical discharges in the whole brain |
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complex partial seizures
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-either remains motionless
-ormoves automatically but inappropriately for time and place -may experience excessive emotions of fear, anger, elation, or irritability -does not remember episode when it is over |
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generalized seizures
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involve both hemispheres, causing both sides of the body to react
-intense rigidity may occur followed by generalized tonic-clonic contraction -characteristic epileptic cry from contractions of the diaphragm and chest muscles -tongue often chewed -incontinence -after 1-2 minutes movements begin to subside, patient relaxes, lies in a deep coma, and breathes noisily, respirations abdominal, often confused and hard to arouse for hours -many report headache, sore muscles, fatigue, and depression |
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special needs of women with epilepsy
|
-increase in seizure frequency during menses
-effectiveness of OC's decreases with antiseizure meds -risk for congenital fetal anomaly 2-3x greater for their pregnancies |
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What is the leading cause of new onset epilepsy in the elderly?
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cardiovascular disease
|
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elderly patients on antiseizure meds must be monitored closely for
|
adverse and toxic effects
osteoporosis |
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major complications for patients with epilepsy
|
status epilepticus
medication side effects also, osteoporosis from antiseizure meds |
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what should the activity level for a person with epilepsy be
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moderate is therapeutic, excessive should be avoided
|
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ketogenic diet
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may be helpful for control of seizures of some patient, especially children
-high-protein, low-carb |
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alcohol and seizures
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seizures are known to occur with alcohol intake
|
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side effects of phenytoin (Dilantin)
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gingival hyperplasia
-to prevent or control, oral hygiene after each meal, gum massage, daily flossing, regular dental care |
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signs of antiseizure med toxicity
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drowsiness
lethargy dizziness difficulty walking hyperactivity confusion inappropriate sleep visual disturbances |
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seizure triggers include
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alcohol
electrical shocks stress caffeine constipation fever hyperventilation hypoglycemia lack of sleep |
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toxic effects of carbamazepine (Tegretol)
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severe skin rash, blood dyscrasias, hepatitis
|
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toxic effects of clonazepam (Klonopin)
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hepatotoxicity, thrombocytopenia, bone marrow failure, ataxia
|
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toxic effects of gabapentin (Neurontin)
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leukopenia, hepatotoxicity
|
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toxic effects of lamotrigine (Lamictal)
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severe rash (Steven-Johnson syndrome)
|
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toxic effects of phenytoin (Dilantin)
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severe skin reaction, peripheral neuropathy, ataxia, drowsiness, blood dyscrasias
|
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toxic effects of topiramate (Topamax)
|
nephrolithiasis
|
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toxic effects of valproate (Depakote, Depakene)
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hepatotoxicity, skin rash, blood dyscrasias, nephritis
|
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what common antiseizure meds are associated with kidney problems if at toxic levels
|
topiramate (Topamax)
valproate (Depakote) |
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how long does status epilepticus last?
|
at least 30 minutes, even within loss of consciousness
|
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factors that precipitate status epilepticus
|
withdrawal of antiseizure meds
fever concurrent infection |
|
cumulative effects produced by status epilepticus
|
-vigorous muscular contractions impose a heavy metabolic demand and can interfere with respirations-respiratory arrest at the height of each seizure produces venous congestion an hypoxia of the brain - repeated episodes of cerebral anoxia and edema can lead to irreversible and fatal brain damage
|
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meds for status epilepticus to halt seizures
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Valium, Ativan, or Cerebyx
IV injection of glucose if caused by hypoglycemia if initial treatment unsuccessful, general anesthesia with a short acting barbituate can be used |
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postictal the nurse should monitor..
|
respiratory and cardiac function b.c. of the risk for delayed depression of respiration and BP secondary to admin of antiseizures meds and sedatives
|
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foods that contain tyramine and can trigger a migraine
|
chocolate
cheese coffee dairy products |
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how does alcohol affect blood vessels
|
causes vasodilation
|