Flipped Classroom Flashcards
Which evoked potential is most resistant to anesthetic suppression?
A) Somatosensory Evoked Potentials (SSEPs)
B) Motor Evoked Potentials (MEPs)
C) Brainstem Auditory Evoked Potentials (BAEPs) D) Visual Evoked Potentials (VEPs)
Answer: C
Rationale: BAEPs originate in the brainstem, which is more resistant to anesthetic suppression
than cortical pathways.
Which of the following best describes evoked potentials?
A) Spontaneous electrical activity monitoring of the brain
B) Electrical responses recorded from the nervous system after a stimulus
C) Continuous monitoring of heart rate variability
D) A method to measure cerebrospinal fluid pressure
Answer: B
Rationale: Evoked potentials (EPs) measure the nervous system’s response to external stimuli, such as electrical, auditory, or visual inputs. They differ from spontaneous brain activity, which is measured by EEG.
During neurosurgical procedures, a sudden loss of Somatosensory Evoked Potentials (SSEPs) may indicate:
A) Adequate depth of anesthesia
B) Ischemic injury to the spinal cord or brain
C) An increase in muscle activity
D) A decrease in cerebrospinal fluid (CSF) pressure
Answer: B
Rationale: A sudden loss or significant decrease in SSEP amplitude suggests reduced blood
flow or neural damage, requiring immediate surgical intervention.
Which type of evoked potential evaluates the integrity of the sensory pathways from the periphery to the brain?
A) Brainstem Auditory Evoked Potentials (BAEPs)
B) Visual Evoked Potentials (VEPs)
C) Somatosensory Evoked Potentials (SSEPs)
D) Motor Evoked Potentials (MEPs)
Answer: C
Rationale: SSEPs evaluate the function of the sensory pathways by stimulating peripheral nerves and recording the response at the brain and spinal cord.
Which anesthetic management strategy is preferred when using Motor Evoked Potentials (MEPs)?
A) High-dose volatile agents with deep neuromuscular blockade
B) Total intravenous anesthesia (TIVA) with minimal neuromuscular blockade
C) Only spinal anesthesia
D) No anesthesia to allow patient movement
Answer: B
Rationale: MEPs require intact motor pathways, so neuromuscular blockade should be minimized. TIVA (propofol and remifentanil) preserves MEP signals better than volatile agents.
What is the primary reason Visual Evoked Potentials (VEPs) are not commonly used to assess depth of anesthesia?
A) They are too resistant to anesthetic effects
B) They are highly sensitive to anesthetics and easily suppressed
C) They do not measure brain activity
D) They require invasive procedures to record
Answer: B
Rationale: VEPs are extremely sensitive to anesthetics, making them unreliable for routine intraoperative monitoring.
Which of the following is the primary determinant of cerebral perfusion pressure (CPP)?
A) Intracranial pressure (ICP) alone
B) Mean arterial pressure (MAP) alone
C) The sum of ICP and MAP
D) The difference between MAP and ICP
Answer: D) The difference between MAP and ICP
Rationale: Cerebral perfusion pressure (CPP) is the difference between MAP and intracranial pressure (ICP)
(or central venous pressure [CVP], if it is greater than ICP). MAP – ICP (or CVP) = CPP. CPP is normally 80
to 100 mm Hg. Moreover, because ICP is normally less than 10 mm Hg, CPP is primarily dependent on MAP.
(Butterworth et al., 2022, p. 587)
Which anesthetic agent is preferred for neuroanesthesia due to its ability to reduce ICP, cerebral blood flow,
and cerebral metabolic rate of oxygen (CMRO₂)?
A) Isoflurane
B) Nitrous Oxide (N₂O)
C) Propofol
D) Ketamine
Answer: C) Propofol
Rationale: Propofol is a popular induction and maintenance agent for neurosurgical patients. It is very useful
in patients with intracranial pathologic conditions, provided that hypotension is prevented. The cerebral effects
are a dose-dependent reduction in CBF and CMRO2. The reductions are approximately 40% to 50%. CPP may
decrease because of reductions in blood pressure after bolus induction doses; however, the reduction in CBF
appears to be independent of systemic hemodynamic changes. They are most likely due to the metabolic
depressant effect and cerebral vasoconstriction. Reductions in systemic blood pressure produce corresponding
reductions in CPP. (Nagelhout et al., 2023. pp 718)
Which of the following is a contraindication for the use of succinylcholine in neurosurgical patients?
A) History of difficult intubation
B) Severe traumatic brain injury (TBI)
C) Need for rapid sequence induction
D) Refractory intracranial hypertension
Answer: B) Severe traumatic brain injury (TBI)
Rationale: As mentioned previously, succinylcholine is contraindicated in patients with neurologic or
denervated muscle because of the potential for life-threatening hyperkalemia. Succinylcholine should be
avoided in patients with cerebrovascular accident, upper and lower motor neuron lesions, coma, encephalitis,
closed head injury, and after severe burns and prolonged bed rest. (Nagelhout et al., 2023. pp 720).
Which intravenous anesthetic agent is known to cause adrenal suppression and is therefore avoided in
patients with traumatic brain injury (TBI) and sepsis?
A) Propofol
B) Dexmedetomidine
C) Etomidate
D) Ketamine
Answer: C) Etomidate
Rationale: Many clinicians feel that etomidate should be avoided in brain-injured patients. Although it is
considered an induction drug of choice in situations of hemodynamic compromise, prolonged adrenal
insufficiency is a major concern. Adrenal insufficiency is of special concern in critically ill patients with sepsis
and traumatic brain injury (TBI). For these reasons, it may be prudent to replace etomidate with an amnestic
dose of a benzodiazepine in combination with an opioid or ketamine to facilitate endotracheal intubation. If
etomidate is used, empirical adrenal replacement therapy for 24 hours should be considered. (Nagelhout et al.,
2023. P. 719).
Which of the following describes the pathophysiology of plateau waves (A waves of Lundberg) seen in
intracranial pressure monitoring?
A) Slow oscillations in ICP due to venous congestion
B) Persistent ICP elevation (40-100 mmHg) lasting 5-20 minutes, indicating critically low intracranial
compliance
C) Fluctuations in ICP due to transient vasodilation
D) Rapid ICP decline following CSF drainage
Answer: B) Persistent ICP elevation (40-100 mmHg) lasting 5-20 minutes, indicating critically low
intracranial compliance.
Rationale: Intracranial pathology leading to sustained elevations of ICP may produce plateau waves, also
known as A waves of Lundberg. These waves reflect a sudden dramatic rise in ICP to levels of40 to 100 mm
Hg, often lasting 5 to 20 minutes. Plateau waves indicate critically low intracranial compliance, leading to
marked changes in ICP, even with very small variations in intracranial volume. (Nagelhout et al., 2023. p.
722).
In patients with elevated ICP, which of the following ventilatory strategies optimally balances ICP
reduction while avoiding the risk of cerebral ischemia?
A) Permissive hypercapnia with a PaCO₂ target of 45–50 mmHg to promote cerebral vasodilation and oxygen
delivery
B) Tight PaCO₂ control (30–35 mmHg) to induce mild vasoconstriction and reduce cerebral blood volume
while preserving perfusion
C) Aggressive hyperventilation with PaCO₂ < 25 mmHg to maximize cerebral vasoconstriction and ICP
reduction
D) Maintaining tidal volumes > 10 mL/kg and PEEP > 10 cmH₂O to improve oxygenation and limit secondary
injury
Answer: B) Tight PaCO₂ control (30–35 mmHg) to induce mild vasoconstriction and reduce cerebral
blood volume while preserving perfusion.
Rationale: When the physiologic control is intact, hyperventilation lowers PaC02, resulting in respiratory
alkalosis and subsequent vasoconstriction. When vasoconstriction is pronounced, intracranial blood volume
will decrease and lower ICP. This is particularly important in known low-CBF conditions, such as severe TBI
or vasospasm. To avoid cerebral ischemia, Paco2 should be lowered to approximately 30 to 35 mm Hg.
(Nagelhout et al., 2023. pp. 723).
The nurse anesthetist is aware that the following patients are not ideal to use the BIS
monitor on as readings may not be reliable or fully accurate: (select all that apply)
A) Infants and children < 18 years old
B) Patients receiving Ketamine as the induction agent
C) Patients > 60 years old
D) Patients receiving Fospropofol as the induction agent
E) Patients receiving Nitrous Oxide with other inhalation agents
Correct Answer: A) Infants and children < 18 years old, B) Patients receiving Ketamine
as induction agent, C) Patients >60 years old, E) Patients receiving Nitrous Oxide with
other inhalation agents
• Rationale: Patients receiving Ketamine as an induction agent or Nitrous Oxide with
other inhalation agents will have altered waveforms from what is expected. The BIS
monitor can interpret the waveforms to an incorrect value that is not true to the patient’s
depth of anesthesia. Additionally, patients <18 and >60 years old have age-related EEG
waveform differences that can skew the BIS monitor’s readings. (Gropper et al., 2020)
What is the primary purpose of BIS monitoring?
A) To measure cerebral oxygen levels
B) To assess the depth of anesthesia using EEG signals
C) To correlate with heart rate during surgery
D) To monitor anesthesia concentration
• Correct Answer: B) To assess the depth of anesthesia using EEG signals
• Rationale: BIS monitoring provides near real-time data on patient consciousness levels,
helping anesthesia providers decrease risk for intraoperative awareness (Butterworth,
2022)
What BIS range is recommended for general anesthesia?
A) 80-100
B) 65-80
C) 40-65
D) 20-40
• Correct Answer: C) 40-60
• Rationale: A BIS value between 40 and 65 is considered an appropriate depth for general
anesthesia, reducing the risk of awareness. (Butterworth, 2022)
Why is BIS monitoring not always reliable?
A) It cannot be used with inhaled anesthetics
B) It is affected by environmental noise
C) Some patients report awareness despite BIS values below 65
D) It does not work with intravenous anesthesia
• Correct Answer: C) Some patients report awareness despite BIS values below 65
• Rationale: EEG responsiveness varies among individuals, affecting BIS accuracy
(Butterworth, 2022) & (Gropper et al., 2020)
Which EEG components are analyzed by BIS monitoring?
A) Low-frequency waves and high-frequency beta waves
B) Alpha waves and delta waves
C) Muscle contractions and oxygen saturation
D) Blood pressure and heart rate
• Correct Answer: A) Low-frequency waves and high-frequency beta waves
• Rationale: These components help determine if a patient is in deep anesthesia or light
sedation. (Elisha, 2023)
What is a recommended best practice for preventing intraoperative awareness?
A) Relying on BIS for primary monitoring
B) Using multimodal monitoring with BIS and ETAC
C) Avoiding Ketamine when using BIS
D) Keeping BIS values below 80
• Correct Answer: B) Using multimodal monitoring with BIS and ETAC
• Rationale: Combining different monitoring methods (such as End-Tidal Anesthetic
Concentration monitoring and vital signs) improves anesthesia depth assessment and
minimizes the risk of awareness. While readings would be altered when using Ketamine
and BIS values should be kept well below 80 to provide general anesthesia, these are not
BEST practice for preventing intraoperative awareness (Elisha, 2023) (Gropper et al.,
2020).
