Med Surg - Exam 2 - Ch 57 (Acute Intracranial Probs) Flashcards Preview

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Flashcards in Med Surg - Exam 2 - Ch 57 (Acute Intracranial Probs) Deck (84)
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1

Which components are able to change to adapt to small increases in intracranial pressure (ICP) (select all that apply)?
a. Blood
b. Skull bone
c. Brain tissue
d. Scalp tissue
e. Cerebrospinal fluid (CSF)

a. Blood
c. Brain tissue
e. Cerebrospinal fluid (CSF)

Blood adapts to increased venous outflow, decreased cerebral blood flow (CBF), and collapse of veins and dural sinuses. Brain tissue adapts with distention of the dura, slight compression of tissue, or herniation. Cerebrospinal fluid (CSF) adapts with increased absorption, decreased production, and displacement into the spinal canal. Skull bone and scalp tissue do not adapt to changes in intracranial pressure (ICP).

2

The cerebral perfusion pressure (CPP) is the presure needed to ensure blood flow to the brain. Normal CPP is 60 to 100 mm Hg. Calculate the CPP of a patient whose blood pressure (BP) is 106/52 mm Hg and ICP is 14 mm Hg.

_______ mm Hg

56 mm Hg

Mean arterial pressure (MAP) diastolic blood pressure (DBP) + 1/2 (systolic blood pressure [SBP] - DBP) = 52 + 18 = 70

Cerebral perfusion pressure (CPP) = MAP - ICP = 70 - 14 = 56

3

Calculate the CPP for the patient with an ICP of 24 mm Hg and a systemic BP of 108/64 mm Hg.

_______ mm Hg

45 mm Hg

MAP = DBP + 1/3 (SBP - DBP) = 64 + 15 = 79
CPP = MAP - ICP = 79 - 34 = 45

4

Which factors decrease cerebral blood flow (select all that apply)?
a. Increased ICP
b. PaO2 of 45 mm Hg
c. PaCO2 of 30 mm Hg
d. Arterial blood pH of 7.3
e. Decreased mean arterial pressure (MAP)

c. PaCO2 of 30 mm Hg
e. Decreased mean arterial pressure (MAP)

Cerebral blood flow is decreased when the MAP and the PaCO2 are decreased. The other options increase cerebral blood flow.

5

What are the causes of vasogenic cerebral edema (select all that apply)?
a. Hydrocephalus
b. Ingested toxins
c. Destructive lesions or trauma
d. Local disruption of cell membranes
e. Fluid flowing from intravascular to extravascular space

b. Ingested toxins
e. Fluid flowing from intravascular to extravascular space

6

Which events cause increased ICP (select all that apply)?
a. Vasodilation
b. Necrotic tissue edema
c. Blood vessel compression
d. Edema from initial brain insult
e. Brainstem compression and herniation

a. Vasodilation
b. Necrotic tissue edema
d. Edema from initial brain insult

7

An early sign of increased ICP that the nurse should assess for is
a. Cushing's triad.
b. unexpected vomiting.
c. decreasing level of consciousness (LOC).
d. dilated pupil with sluggish response to light.

c. decreasing level of consciousness (LOC).

8

The nurse recognizes that the presence of Cushing's triad in the patient with which vital sign changes?
a. Increased pulse, irregular respiration, increased BP
b. Decreased pulse, increased respiration, decreased systolic BP
c. Decreased pulse, irregular respiration, widened pulse pressure
d. Increased pulse, decreased respiration, widened pulse pressure

c. Decreased pulse, irregular respiration, widened pulse pressure

9

Increased ICP in the left cerebral cortex caused by intracranial bleeding causes displacement of brain tissue to the right hemisphere beneath the falx cerebri. The nurse knows that this is referred to as what?
a. Uncal herniation
b. Tentorial herniation
c. Cingulate herniation
d. Temporal lobe herniation

c. Cingulate herniation

10

A patient has ICP monitoring with an intraventricular catheter. What is a priority nursing intervention for the patient?
a. Aseptic technique to prevent infection
b. Constant monitoring of ICP waveforms
c. Removal of CSF to maintain normal ICP
d. Sampling CSF to determine abnormalities

a. Aseptic technique to prevent infection

11

When using intraventricular ICP monitoring, what should the nurse be aware of to prevent inaccurate readings?
a. The P2 wave is higher than the P1 wave.
b. CSF is leaking around the monitoring device.
c. The transducer of the ventriculostomy monitor is at the level of the upper ear.
d. The drain of the CSF drainage device was closed for 6 minutes before taking the reading.

b. CSF is leaking around the monitoring device.

12

The patient is being monitored long-term with a brain tissue oxygenation catheter. What range for the pressure of oxygen in brain tissue (PbtO2) will maintain cerebral oxygen supply and demand?
a. 55% to 75%
b. 20 to 40 mm Hg
c. 70 to 150 mm Hg
d. 80 to 100 mm Hg

b. 20 to 40 mm Hg

The normal pressure of oxygen in brain tissue (PbtO2) is 20 to 40 mm Hg. The normal jugular venous oxygen saturation (SjvO2) is 55% to 75% and indicates total venous brain tissue extraction of oxygen; this is used for short-term monitoring. The MAP of 70 to 150 mm Hg is needed for effective autoregulation of CBF. The normal range for PaO2 is 80 to 100 mm Hg.

13

Which drug treatment helps to decrease ICP by expanding plasma and the osmotic effect to move fluid?
a. Oxygen administration
b. Pentobarbital (Nembutal)
c. Mannitol (Osmitrol) (25%)
d. Dexamethasone (Decadron)

c. Mannitol (Osmitrol) (25%)

Mannitol (Osmitrol) (25%) is an osmotic diuretic that expands plasma and causes fluid to move from tissues into the blood vessels. Hypertonic saline reduces brain swelling by moving water out of brain tissue. Oxygen administration is done to maintain brain function. Pentobarbitol (Nembutal) and other barbiturates are used to reduce cerebral metabolism. The corticosteroid dexamethasone (Decadron) is used to treat vasogenic edema to stabilize cell membranes and improve neuronal function by improving CBF and restoring autoregulation.

14

How are the metabolic and nutritional needs of the patient with increased ICP best met?
a. Enteral feedings that are low in sodium
b. Simple glucose available in D5W IV solutions
c. Fluid restriction that promotes a moderate dehydration
d. Balanced, essential nutrition in a form that the patient can tolerate

d. Balanced, essential nutrition in a form that the patient can tolerate

A patient with increased ICP is in a hypermetabolic and hypercatabolic state and needs adequate glucose to maintain fuel for the brain and other nutrients to meet metabolic needs. Malnutrition promotes cerebral edema and if a patient cannot take oral nutrition, other means of providing nutrition should be used, such as tube feedings or parenteral nutrition. Glucose alone is not adequate to meet nutritional requirements and 5% dextrose solutions may increase cerebral edema by lowering serum osmolarity. Patients should remain in a normovolemic fluid state with close monitoring of clinical factors such as urine output, fluid intake, serum and urine osmolality, serum electrolytes, and insensible losses.

15

Why is the Glasgow Coma Scale (GCS) used?
a. To quickly assess the LOC
b. To assess the patient's ability to communicate
c. To assess the patient's ability to respond to commands
d. To assess the patient's coordination with motor responses

a. To quickly assess the LOC

The Glasgow Coma Scale (GCS) is used to quickly assess the LOC with a standardized system. The three areas assessed are the patient's ability to speak, obey commands, and open eyes to verbal or painful stimulus. Although best motor response is an indicator, it is not used to assess coordination.

16

A patient with an intracranial problem does not open his eyes to any stimulus, has no verbal response except moaning and muttering when stimulated, and flexes his arm in response to painful stimuli. What should the nurse record as the patient's GCS score?
a. 6
b. 7
c. 9
d. 11

b. 7

No opening of the eyes = 1; incomprehensible words = 2; flexion withdrawal = 4. Total = 7

17

When assessing the body functions of a patient with increased ICP, what should the nurse assess first?
a. Corneal reflex testing
b. Pupillary reaction to light
c. Extremity strength testing
d. Circulatory and respiratory status

d. Circulatory and respiratory status

Of the body functions that should be assessed in an unconscious patient, cardiopulmonary status is the most vital function and gives priorities to the ABCs (airway, breathing, and circulation).

18

How is cranial nerve (CN) III, originating in the midbrain, assessed by the nurse for an early indication of pressure on the brainstem?
a. Assess for nystagmus
b. Test the corneal reflex
c. Test pupillary reaction to light
d. Test for oculocephalic (doll's eyes) reflex

c. Test pupillary reaction to light

One of the functions of cranial nerve (CN) III, the oculomotor nerve, is pupillary constriction and testing for pupillary constriction is important to identify patients at risk for brainstem herniation caused by increased ICP. The corneal reflex is used to assess the functions of CN V and VII and the oculocephalic reflex tests all cranial nerves involved with eye movement. Nystagmus is commonly associated with specific lesions or chemical toxicities and is not a definitive sign of ICP.

19

A patient has a nursing diagnosis of risk of ineffective cerebral tissue perfusion related to cerebral edema. What is an appropriate nursing intervention for the patient?
a. Avoid positioning the patient with neck and hip flexion.
b. Maintain hyperventilation to a PaCO2 of 15 to 20 mm Hg.
c. Cluster nursing activities to provide periods of uninterrupted rest.
d. Routinely suction to prevent accumulation of respiratory secretions.

a. Avoid positioning the patient with neck and hip flexion.

Nursing care activities that increase ICP are hip and neck flexion, suctioning, clustering care activities, and noxious stimuli. They should be avoided or performed as little as possible in the patient with increased ICP. Lowering the PaCO2 below 20 mm Hg can cause ischemia and worsening of ICP.

20

An unconscious patient with an increased ICP is on ventilatory support. The nurse notifies the health care provider when arterial blood gas (ABG) measurement results reveal what?
a. pH of 7.43
b. SaO2 of 94%
c. PaO2 of 70 mm Hg
d. PaCO2 of 35 mm Hg

c. PaO2 of 70 mm Hg

A PaO2 of 70 mm Hg reflects hypoxemia that may lead to further decreased cerebral perfusion. PaO2 should be maintained at greater than or equal to 100 mm Hg. The pH and SaO2 are within normal range and a PaCO2 of 35 mm Hg reflects a normal value.

21

The nurse is monitoring a patient for increased ICP following a head injury. What are manifestations of increased ICP (select all that apply)?
a. Fever
b. Oriented to name only
c. Narrowing pulse pressure
d. Right pupil dilated greater than left pupil
e. Decorticate posturing to painful stimulus

a. Fever
b. Oriented to name only
d. Right pupil dilated greater than left pupil
e. Decorticate posturing to painful stimulus

The first sign of increased ICP is a change in LOC. Other manifestations are dilated ipsilateral pupil, changes in motor response such as posturing, and fever, which may indicate pressure on the hypothalamus. Changes in vital signs would be an increased SBP with widened pulse pressure and bradycardia.

22

While the nurse performs range of motion (ROM) on an unconscious patient with increased ICP, the patient experiences severe decerebrate posturing reflexes. What should the nurse do first?
a. Use restraints to protect the patient from injury.
b. Perform the exercises less frequently because posturing can increase ICP.
c. Administer central nervous system (CNS) depressants to lightly sedate the patient.
d. Continue the exercises because they are necessary to maintain musculoskeletal function.

b. Perform the exercises less frequently because posturing can increase ICP.

If reflex posturing occurs during range of motion (ROM) or positioning of the patient, these activities should be done less frequently until the patient's condition stabilizes because posturing can cause increases in ICP and may indicate herniation. Neither restraints nor central nervous system (CNS) depressants would be indicated.

23

The patient has been diagnosed with a cerebral concussion. What should the nurse expect to see in this patient?
a. Deafness, loss of taste, and CSF otorrhea
b. CSF otorrhea, vertigo, and Battle's sign with a dural tear
c. Boggy temporal muscle because of extravasation of blood
d. Headache, retrograde amnesia, and transient reduction in LOC

d. Headache, retrograde amnesia, and transient reduction in LOC

A cerebral concussion may include a brief disruption in LOC, retrograde amnesia, and a headache, all of short duration. A basilar skull fracture may have a dural tear with CSF or brain otorrhea, rhinorrhea, hearing difficulty, vertigo, and Battle's sign. A temporal fracture would have a boggy temporal muscle because of extravasation of blood, Battle's sign, or CSF otorrhea.

24

The patient comes to the emergency department (ED) with cortical blindness and visual field defects. Which type of head injury does the nurse suspect?
a. Cerebral contusion
b. Orbital skull fracture
c. Posterior fossa fracture
d. Frontal lobe skull fracture

c. Posterior fossa fracture

The posterior fossa fracture causes occipital bruising resulting in cortical blindness or visual field defects. A cerebral contusion is bruising of brain tissue within a focal area. An orbital skull fracture would cause periorbital ecchymosis (racoon eyes) and possible optic nerve injury. A frontal lobe skull fracture would expose the brain to contaminants through the frontal air sinus and the patient would have CSF rhinorrhea or pneumocranium.

25

The patient has a depressed skull fracture and scalp lacerations with communication to the intracranial cavity. Which type of injury does the nurse record?
a. Linear skull fracture
b. Depressed skull fracture
c. Compound skull fracture
d. Comminuted skull fracture

c. Compound skull fracture

The compound skull fracture is a depressed skull fracture and scalp lacerations with communicating pathway(s) to the intracranial cavity. A linear skull fracture is a straight break in the bone without alteration in the fragments. A depressed skull fracture is an inward indentation of the skull that may cause pressure on the brain. A comminuted skull fracture has multiple linear fractures with bone fragmented into many pieces.

26

A patient with a head injury has bloody drainage from the ear. What should the nurse do to determine is CSF is present in the drainage?
a. Examine the tympanic membrane for a tear.
b. Test the fluid for a halo sign on a white dressing.
c. Test the fluid with a glucose-identifying strip or stick.
d. Collect 5 mL of fluid in a test tube and send it to the laboratory for analysis.

b. Test the fluid for a halo sign on a white dressing.

Testing clear drainage for CSF in nasal or ear drainage may be done with a Dextrostik or Tes-Tape strip but if blood is present, the glucose in the blood will produce an unreliable result. To test bloody drainage, the nurse should test the fluid for a "halo" or "ring" that occurs when a yellowish ring encircles blood dripped onto a white pad or towel within a few minutes.

27

The nurse suspects the presence of an arterial epidural hematoma in the patient who experiences
a. failure to regain consciousness following a head injury.
b. a rapid deterioration of neurologic function within 24 to 48 hours following a head injury.
c. nonspecific, nonlocalizing progression of alteration in LOC occurring over weeks or months.
d. unconsciousness at the time of a head injury with a brief period of consciousness followed by a decrease in LOC.

d. unconsciousness at the time of a head injury with a brief period of consciousness followed by a decrease in LOC.

An arterial epidural hematoma is the most acute neurologic emergency and typical symptoms include unconsciousness at the scene with a brief lucid interval followed by a decrease in LOC. An acute subdural hematoma manifests within 48 hours of an injury. A chronic subdural hematoma develops over weeks or months.

28

Skull x-rays and a computed tomography (CT) scan provide evidence of a depressed parietal fracture with a subdural hematoma in a patient admitted to the ED following an automobile accident. In planning care for the patient, what should the nurse anticipate?
a. The patient will receive life support measures until condition stabilizes.
b. Immediate burr holes will be made to rapidly decompress the intracranial cavity.
c. The patient will be treated conservatively with close monitoring for changes in neurologic status.
d. The patient will be taken to surgery for a craniotomy for evacuation of blood and decompression of the cranium.

d. The patient will be taken to surgery for a craniotomy for evacuation of blood and decompression of the cranium.

When there is a depressed fracture or a fracture with loose fragments, a craniotomy is indicated to elevate the depressed bone and remove free fragments. A craniotomy is also indicated in cases of acute subdural and epidural hematomas to remove the blood and control the bleeding. Burr holes may be used an in extreme emergency for rapid decompression or to aid in removing a bone flap but with a depressed fracture, surgery would be the treatment of choice.

29

When a patient is admitted to the ED following a head injury, what should be the nurse's first priority in management of the patient once a patent airway is confirmed?
a. Maintain cervical spine precautions.
b. Monitor for changes in neurologic status.
c. Determine the presence of increased ICP.
d. Establish IV access with a large-bore catheter.

a. Maintain cervical spine precautions.

In addition to monitoring for a patent airway during emergency care of the patient with a head injury, the nurse must always assume that a patient with a head injury may have a cervical spine injury. Maintaining cervical spine precautions in all assessment and treatment activities with the patient is essential to prevent additional neurologic damage.

30

A 54-year-old man is recovering from a skull fracture with a subacute subdural hematoma that caused consciousness. He has return of motor control and orientation but appears apathetic and has reduced awareness of his environment. When planning discharge of the patient, what should the nurse explain to the patient and family?
a. The patient is likely to have long-term emotional and mental changes that may require professional help.
b. Continuous improvement in the patient's condition should occur until he has returned to pretrauma status.
c. The patient's complete recovery may take years and the family should plan for his long-term dependent care.
d. Role changes in family members will be necessary because the patient will be dependent on his family for care and support.

a. The patient is likely to have long-term emotional and mental changes that may require professional help.

Residual mental and emotional changes of brain trauma with personality changes are often the most incapacitating problems following head injury and are common in patients who have been comatose for longer than 6 hours. Families must be prepared for changes in the patient's behavior to avoid family-patient friction and maintain family functioning and professional assistance may be required. There is no indication the patient will be dependent on others for care but he likely will not return to pretrauma status.