Chapter 16 Determinants and Assessment of Cerebral Function Flashcards
1) A patient, admitted with the diagnosis of stroke, has left hemiparesis involving the face, arm, and leg. The nurse explains that this stroke most likely involves which artery?
1. Right vertebral
2. Left posterior communicating
3. Left middle cerebral
4. Right middle cerebral
Answer: 4
Explanation: 1. The right vertebral area is not the most common site of damage causing a stroke.
2. The posterior communicating arteries are part of the circle of Willis, but are not the most common areas involved in stroke.
3. The middle cerebral arteries supply blood to the lateral surfaces of the frontal, temporal, and parietal lobes. These arteries are often involved in stroke. The motor fibers cross so the left side of the brain controls the right side of the body.
4. The middle cerebral arteries supply blood to the lateral surfaces of the frontal, temporal, and parietal lobes. These arteries are often involved in stroke. The motor fibers cross so the right side of the brain controls the left side of the body.
2) A patient recovering from a frontal craniotomy is positioned with the head of the bed elevated 45 degrees at all times. What rationale would the nurse provide for this position?
1. The brain will compress the cerebral veins less in this position.
2. The ventricles of the brain will drain better in this position.
3. This position allows for less pain for the patient.
4. The cerebral spinal veins are valveless and drain by gravity.
Answer: 4
Explanation: 1. This statement is not physiologically correct.
2. This statement is not physiologically correct.
3. There is no reason that pain would be reduced in this position.
4. The cerebral spinal veins drain best via gravity, an important characteristic to remember when caring for patients with the risk for increased intracranial pressure as would be present in intracranial surgeries.
3) The nurse is providing care for a patient who sustained a severe head injury. The nurse would intervene to prevent which occurrence that increases cerebral blood flow?
1. Oversedation
2. Hypothermia
3. Fever
4. Paralysis
Answer: 3
Explanation: 1. Sedation will decrease cerebral blood flow.
2. Hypothermia will decrease cerebral blood flow.
3. Fever increases the body’s metabolic rate and will increase cerebral blood flow.
4. Paralysis, often initiated chemically, will decrease cerebral blood flow.
4) The nurse is providing care for a patient who is at risk for developing an increase in intracranial pressure due to swelling of the brain. The nurse is aware that this increased brain size must be accompanied by which other change if intracranial pressure is to remain stable?
1. There will be an increase in the blood flow to the brain.
2. There is a decrease in the blood-brain barrier.
3. There must be a decrease in another of the intracranial compartments.
4. There will be an increase in the production of cerebrospinal fluid.
Answer: 3
Explanation: 1. Blood flow to the brain would decrease as more space is taken up by the brain.
2. The blood-brain barrier does not increase or decrease in response to changes in the brain.
3. The contents of the intracranial vault include the brain, cerebral blood volume, and cerebrospinal fluid. The Monro-Kellie hypothesis states that as the content of one of the intracranial compartments increases, it is at the expense of the other two. The correct answer is that if there is an increase in the volume of brain tissue, there will need to be a decrease in another of the intracranial compartments.
4. An increased amount of cerebrospinal fluid would increase the pressure in the intracranial vault.
5) A nurse is monitoring the intracranial pressure of a patient with a closed-head injury. Which pressure would the nurse evaluate as requiring no additional intervention?
1. 12 mm Hg
2. 22 mm Hg
3. 25 mm Hg
4. 30 mm Hg
Answer: 1
Explanation: 1. The normal intracranial pressure ranges from 0 to 15 mm Hg.
2. This pressure exceeds normal.
3. This pressure exceeds normal.
4. This pressure exceeds normal
6) A nurse is providing care for a patient with increased intracranial pressure and is monitoring cerebral perfusion pressure. The nurse compares measurements to which critical normal value?
1. 50 mm Hg
2. 70 mm Hg
3. 120 mm Hg
4. 30 mm Hg
Answer: 2
Explanation: 1. The cerebral perfusion pressure (CPP) critical value is higher than 50 mm Hg.
2. To ensure adequate cerebral oxygenation, the CPP must be maintained at greater than 70 mm Hg.
3. CPP of 120 mm Hg is high and will result in a loss of autoregulation. This is not the critical value to which the nurse compares actual measurements.
4. A CPP of 30 mm Hg is low and will result in loss of autoregulation. This is not the critical value to which the nurse compares actual measurements.
7) A patient with a head injury has a mean arterial pressure of 70 mm Hg and an intracranial pressure of 20 mm Hg. Which cerebral perfusion pressure would the nurse document for this patient?
1. 50 mm Hg
2. 90 mm Hg
3. 70/40 mm Hg
4. 40/70 mm Hg
Answer: 1
Explanation: 1. The cerebral perfusion pressure is calculated as the mean arterial pressure minus the intracranial pressure. In this patient, the cerebral perfusion pressure would be inadequate and intervention is needed.
2. This calculation is incorrect for the values given.
3. This calculation is incorrect for the values given.
4. This calculation is incorrect for the values given.
8) A nurse is monitoring a patient who sustained a head injury. The nurse recognizes which finding as the earliest sign of change in neurologic status?
1. The patient cannot remember where he is.
2. The patient’s pupil size is increased.
3. The patient’s blood pressure has increased.
4. The patient exhibits decorticate posturing when stimulated.
Answer: 1
Explanation: 1. The level of consciousness is the most important indicator of neurological function in the high-acuity patient.
2. Pupillary changes do occur with neurological damage but are not the earliest signs.
3. Changes in vital sign can indicate neurological damage, but are not the earliest signs.
4. Posturing is an important finding associated with neurologic damage, but is not the earliest sign.
9) A nurse is monitoring a patient’s Glasgow Coma Scale (GCS). At which point would the nurse document that the patient is comatose?
1. 11
2. 15
3. 7
4. 9
Answer: 3
Explanation: 1. A score of 11 indicates some impairment, but does not indicate coma.
2. A GCS of 15 is normal.
3. A score less than 8 indicates a significant alteration in the level of consciousness and the development of coma.
4. A GCS score of 9 indicates significant neurological changes, but does not indicate coma.
10) The nurse, assessing a patient with a Glasgow Coma Score of 4, finds the patient’s pupils to be pinpoint and nonreactive to light. The nurse takes into consideration that this finding can be due to which situations?
Note: Credit will be given only if all correct choices and no incorrect choices are selected.
Select all that apply.
1. The patient was given atropine sulfate for bradycardia.
2. The patient has increased blood glucose.
3. The patient may have taken an opioid drug overdose.
4. The patient has sustained compression of the oculomotor nerve.
5. The patient has sustained damage to the pons.
Answer: 3, 5
Explanation: 1. Recent administration of atropine sulfate leads to dilated pupils.
2. Metabolic disorders cause small but reactive pupils.
3. Opioid drug overdose will result in pinpoint, nonreactive pupils.
4. Compression of the oculomotor nerve causes a unilateral fixed and dilated pupil.
5. Damage to the pons will result in fixed and pinpoint pupils.
11) A nurse is assisting with a patient’s oculocephalic and oculovestibular reflex assessment. How should the nurse prepare for this testing?
Note: Credit will be given only if all correct choices and no incorrect choices are selected.
Select all that apply.
1. Prepare for oculocephalic testing to be done after oculovestibular testing.
2. Ensure that cervical spine injury has been ruled out.
3. Obtain cold water and a syringe.
4. Be certain there is no perforation of the tympanic membrane in the side being tested.
5. Tell the patient she will be asked to report any feeling of numbness or vertigo.
Answer: 2, 3, 4
Explanation: 1. Patients with an absent oculocephalic reflex may have a normal oculovestibular reflex, so testing for oculovestibular reflex should follow oculocephalic reflex testing.
2. Oculocephalic testing requires moving the patient’s head from side to side, so it should not be performed until the cervical spine is cleared of injury.
3. Oculovestibular reflex testing includes injecting cold water into the patient’s ear.
4. Since oculovestibular testing includes placing water in the ear, it is contraindicated if there is a perforation or tear in the tympanic membrane.
5. Oculovestibular and oculocephalic testing is done on patients with suspected brainstem depression. The patients are not conscious.
12) A patient with a head injury is being monitored with an intraventricular catheter. The nurse would design interventions based on which priority patient problem?
1. There is a risk the patient’s brain will be injured by the catheter.
2. Presence of the catheter alters the patient’s intracranial adaptation capacity.
3. The catheter is painful for the patient.
4. There is a high risk for infection related to this catheter.
Answer: 4
Explanation: 1. There is a risk of neuronal destruction from catheter insertion and presence, but this is not the most significant problem. Injury would likely be limited in nature.
2. The patient probably does have a decrease in intracranial adaptive capacity, but this is not specifically related to the presence of the catheter. It is probably the reason the catheter is required.
3. The pain this patient may be experiencing is likely due to injury, other procedures, or positioning. It is not the priority patient problem related to the presence of the catheter.
4. The placement of an intraventricular catheter to monitor intracranial pressure is very invasive and places the patient at risk for infection. Development of infection could be devastating. The nurse must practice meticulous infection control measures while caring for these patients.
13) A patient with an intraventricular catheter for the assessment of increased intracranial pressure (ICP) is demonstrating A waves. The nurse would assess for which other findings?
Note: Credit will be given only if all correct choices and no incorrect choices are selected.
Select all that apply.
1. Decreasing level of consciousness
2. Pupillary changes
3. Posturing
4. Variations in blood pressure
5. Changes in the wave associated with respiration
Answer: 1, 2, 3
Explanation: 1. A waves are clinically significant and typically occur when ICP is elevated. A decreasing level of consciousness may occur with this elevation.
2. A waves are clinically significant and typically occur when ICP is elevated. Pupillary changes may occur with this elevation.
3. A waves are clinically significant and typically occur when ICP is elevated. Posturing may occur with this elevation.
4. C waves occur with variations in blood pressure.
5. C waves vary according to respiration.
14) A patient who sustained a traumatic brain injury is being sent for a CT scan. Which nursing statements would help the patient’s spouse understand the rationale for a CT scan rather than an MRI?
Note: Credit will be given only if all correct choices and no incorrect choices are selected.
Select all that apply.
1. “CT scans are easier for patients with head injuries because movement is allowed.”
2. “We can get results from a CT scan quicker than from an MRI.”
3. “MRIs are more costly so the least expensive test is always done first.”
4. “CT scans are generally safer.”
5. “CT scans show more detail than an MRI.”
Answer: 2, 4
Explanation: 1. CT scans do not necessarily provide more patient movement while the test is being conducted.
2. The CT scan is the test of choice with head injury patients because MRIs take longer.
3. MRIs are typically more expensive, but the nurse should not use this as a rationale for the choice when talking with the family.
4. CT scans do not require concern for presence of metal and are generally considered safer.
5. MRIs show more tissue detail than do CT scans.
15) The family of a comatose patient asks the nurse if there is any way to know if their loved one will ever “wake up.” The nurse should consider which test when formulating a response to this concern?
1. Evoked potentials
2. CT scan
3. Electroencephalogram
4. Lumbar puncture
Answer: 1
Explanation: 1. Evoked potentials are recordings of cerebral electrical impulses generated in response to visual, auditory, or somatosensory stimuli. They are used to assist in the evaluation of the location and extent of brain dysfunction after head injury. Evoked potentials may be useful in predicting coma outcome.
2. A CT scan can help diagnose structural changes, but does not help predict outcome of a coma.
3. Electroencephalography allows recording of the electrical activity of the brain using electrodes attached to the scalp but is not the most useful test to help predict the outcome of a coma.
4. Lumbar puncture can help determine cause of coma but does not help predict outcome of coma.
