Inhalation anesthetics – Sevoflurane MCQs With Answer

Inhalation anesthetics – Sevoflurane MCQs With Answer
Sevoflurane is a widely used volatile inhalation anesthetic, ideal for B. Pharm students learning pharmacology, pharmacokinetics, and clinical anesthesia practice. This introduction covers key concepts: mechanism of action (GABA-A potentiation), low blood:gas solubility for rapid induction and emergence, MAC values, hepatic metabolism producing inorganic fluoride, and Compound A formation with CO2 absorbents. Clinical aspects include pediatric mask induction, effects on hemodynamics, cerebral physiology, malignant hyperthermia risk, and safe low-flow anesthesia practices. These focused, exam-oriented MCQs will strengthen understanding of sevoflurane’s pharmacology, safety considerations, monitoring parameters, and interactions. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. What class of anesthetic does sevoflurane belong to?

• Intravenous anesthetic
• Barbiturate
• Volatile inhalation anesthetic
• Local anesthetic

Correct Answer: Volatile inhalation anesthetic

Q2. Which property of sevoflurane explains its rapid induction and emergence compared with isoflurane?

• Higher oil:gas partition coefficient
• Lower blood:gas solubility
• Greater potency (higher MAC)
• Higher vapor pressure

Correct Answer: Lower blood:gas solubility

Q3. Sevoflurane is particularly favored for inhalational induction in children because it is:

• Pungent and irritating to airways
• Nonpungent with a pleasant odor
• Highly metabolized producing strong smell
• Associated with severe coughing on induction

Correct Answer: Nonpungent with a pleasant odor

Q4. Which enzyme primarily metabolizes sevoflurane in the liver?

• CYP3A4
• CYP1A2
• CYP2E1
• Monoamine oxidase

Correct Answer: CYP2E1

Q5. Approximately what percentage of sevoflurane is metabolized by the body?

• Less than 0.1%
• Approximately 2–5%
• About 25–30%
• Nearly 50%

Correct Answer: Approximately 2–5%

Q6. Which metabolite of sevoflurane has been monitored because of potential renal concerns?

• Hexafluoroisopropanol and inorganic fluoride
• Chloroform
• Trifluoroacetic acid
• Acetaldehyde

Correct Answer: Hexafluoroisopropanol and inorganic fluoride

Q7. What is “Compound A” in relation to sevoflurane?

• An impurity added during manufacture
• A degradation product formed when sevoflurane reacts with CO2 absorbents
• A metabolite produced by CYP450 in kidneys
• An active analgesic metabolite

Correct Answer: A degradation product formed when sevoflurane reacts with CO2 absorbents

Q8. Which factor increases the formation of Compound A during sevoflurane anesthesia?

• High fresh gas flow
• Low fresh gas flow and dry, heated CO2 absorbent
• Use of modern carbon dioxide scavengers outside the circuit
• Administration via face mask only

Correct Answer: Low fresh gas flow and dry, heated CO2 absorbent

Q9. What fresh gas flow is commonly recommended to minimize Compound A exposure during prolonged sevoflurane use?

• Less than 0.5 L/min
• 1–2 L/min or higher depending on guideline
• Fresh gas flow has no impact on Compound A
• Zero flow (closed system) only

Correct Answer: 1–2 L/min or higher depending on guideline

Q10. Sevoflurane is a known trigger for which life-threatening pharmacogenetic disorder?

• Serotonin syndrome
• Neuroleptic malignant syndrome
• Malignant hyperthermia
• Jacksonian epilepsy

Correct Answer: Malignant hyperthermia

Q11. The primary molecular target contributing to the hypnotic effect of sevoflurane is believed to be:

• Voltage-gated sodium channels
• GABA-A receptor potentiation and other ligand-gated channels
• Dopamine D2 receptor blockade
• Peripheral nicotinic receptors

Correct Answer: GABA-A receptor potentiation and other ligand-gated channels

Q12. Minimum Alveolar Concentration (MAC) is best described as:

• The concentration preventing awareness in 50% of patients
• The concentration that causes apnea in 50% of patients
• The alveolar concentration preventing movement in response to surgical stimulus in 50% of patients
• The concentration producing maximal analgesia

Correct Answer: The alveolar concentration preventing movement in response to surgical stimulus in 50% of patients

Q13. What is the approximate MAC of sevoflurane in healthy adults?

• 0.5%
• 2% (approximately)
• 6% (approximately)
• 10% (approximately)

Correct Answer: 2% (approximately)

Q14. Which agent, when co-administered with sevoflurane, significantly reduces its MAC?

• Non-depolarizing neuromuscular blocker
• Opioids (e.g., fentanyl)
• Vasopressor (e.g., phenylephrine)
• Beta blocker (e.g., metoprolol)

Correct Answer: Opioids (e.g., fentanyl)

Q15. Compared with desflurane, sevoflurane has:

• Lower blood:gas solubility and faster onset than desflurane
• Higher blood:gas solubility and slower onset than desflurane
• Identical blood:gas solubility
• Significantly higher tendency to cause airway irritation than desflurane

Correct Answer: Higher blood:gas solubility and slower onset than desflurane

Q16. Sevoflurane’s effect on systemic blood pressure is primarily due to:

• Marked increase in cardiac output
• Dose-dependent reduction in systemic vascular resistance
• Severe vasoconstriction
• Direct stimulation of sympathetic nervous system

Correct Answer: Dose-dependent reduction in systemic vascular resistance

Q17. How does sevoflurane typically affect heart rate at clinical concentrations?

• Produces profound bradycardia in all patients
• Usually causes little change or a slight increase in heart rate
• Produces consistent tachyarrhythmias
• Completely abolishes autonomic control of heart rate

Correct Answer: Usually causes little change or a slight increase in heart rate

Q18. Regarding respiratory effects, sevoflurane is best described as:

• Stimulating ventilation and increasing tidal volume
• Causing dose-dependent respiratory depression and providing bronchodilation
• Having no effect on respiratory drive
• Causing bronchospasm in most asthmatic patients

Correct Answer: Causing dose-dependent respiratory depression and providing bronchodilation

Q19. Sevoflurane’s influence on cerebral physiology includes:

• Decreasing cerebral blood flow at all concentrations
• Increasing cerebral blood flow and potentially raising intracranial pressure at higher concentrations
• Being a potent cerebral vasoconstrictor
• Eliminating autoregulation permanently

Correct Answer: Increasing cerebral blood flow and potentially raising intracranial pressure at higher concentrations

Q20. Does sevoflurane potentiate the effects of neuromuscular blocking agents?

• No, it antagonizes them
• Yes, it potentiates neuromuscular blockade
• It has no interaction with them
• It converts non-depolarizing to depolarizing block

Correct Answer: Yes, it potentiates neuromuscular blockade

Q21. Which monitoring parameter correlates best with sevoflurane brain partial pressure and anesthetic depth?

• Inspired concentration only
• End-tidal alveolar concentration
• Blood pressure alone
• Heart rate variability

Correct Answer: End-tidal alveolar concentration

Q22. In the context of uptake and distribution, increasing cardiac output will typically cause what effect on induction with sevoflurane?

• Speed up induction for all agents
• Slow induction for agents with higher blood solubility more than for sevoflurane
• Have no effect on induction speed
• Cause immediate equilibration between alveolar and brain concentrations

Correct Answer: Slow induction for agents with higher blood solubility more than for sevoflurane

Q23. Sevoflurane’s oil:gas partition coefficient is an indicator of:

• Its blood solubility
• Its potency (higher oil:gas = higher potency)
• Its vapor pressure
• Its pungency

Correct Answer: Its potency (higher oil:gas = higher potency)

Q24. Which statement about sevoflurane and renal toxicity is most accurate?

• Sevoflurane invariably causes acute renal failure
• It can increase serum fluoride, but clinically significant renal damage is rare with recommended use
• It directly produces nephrotoxic halothane metabolites
• Renal toxicity is dose-independent and universal

Correct Answer: It can increase serum fluoride, but clinically significant renal damage is rare with recommended use

Q25. Which CO2 absorbent component is most associated with increased sevoflurane degradation leading to Compound A?

• Calcium hydroxide-based absorbents
• Soda lime containing strong bases (e.g., KOH/NaOH) when desiccated
• Pure silica gel absorbents
• Activated charcoal filters

Correct Answer: Soda lime containing strong bases (e.g., KOH/NaOH) when desiccated

Q26. During pregnancy, sevoflurane crosses the placenta. The clinical implication is:

• Fetus is completely protected from anesthetic effects
• Sevoflurane can affect the fetus and uterine tone—use with obstetric considerations
• It cannot be detected in maternal blood
• It is contraindicated at all stages of pregnancy

Correct Answer: Sevoflurane can affect the fetus and uterine tone—use with obstetric considerations

Q27. Which of the following best describes sevoflurane’s pungency and airway irritation compared with other volatile agents?

• Highly pungent and causes coughing
• Minimal pungency and well tolerated for mask induction
• Causes severe laryngospasm more than others
• Is irritant to all pediatric patients

Correct Answer: Minimal pungency and well tolerated for mask induction

Q28. Which of the following best explains why sevoflurane often causes rapid emergence after short procedures?

• It is metabolized extremely rapidly to inactive metabolites
• Its low blood solubility allows quick equilibration and elimination
• It binds irreversibly to brain receptors which promotes fast wake-up
• It is excreted primarily unchanged in urine within minutes

Correct Answer: Its low blood solubility allows quick equilibration and elimination

Q29. Which of the following statements about sevoflurane and malignant hyperthermia (MH) is correct?

• Sevoflurane is safe in MH-susceptible patients
• Sevoflurane can trigger MH and should be avoided in susceptible individuals
• Sevoflurane prevents MH if given with dantrolene
• Sevoflurane causes MH only when combined with succinylcholine

Correct Answer: Sevoflurane can trigger MH and should be avoided in susceptible individuals

Q30. Which clinical sign is NOT typically associated with malignant hyperthermia triggered intraoperatively?

• Rapid rise in end-tidal CO2
• Muscle rigidity
• Hypothermia
• Hyperkalemia

Correct Answer: Hypothermia

Q31. Which statement about sevoflurane-induced emergence delirium is true?

• It is most commonly seen in adults over 60
• It is more frequent in children and may present as agitation on awakening
• It indicates irreversible brain damage
• It never occurs after short procedures

Correct Answer: It is more frequent in children and may present as agitation on awakening

Q32. Which physiologic reflex relevant to anesthesia is inhibited by volatile agents like sevoflurane, potentially worsening ventilation-perfusion matching?

• Cough reflex
• Hypoxic pulmonary vasoconstriction (HPV)
• Blink reflex
• Baroreceptor reflex

Correct Answer: Hypoxic pulmonary vasoconstriction (HPV)

Q33. In a low-flow anesthesia circuit using sevoflurane, which practice reduces Compound A production?

• Use of desiccated CO2 absorbent
• Switching to higher fresh gas flows periodically
• Increasing circuit temperature
• Leaving the absorbent dry and unused

Correct Answer: Switching to higher fresh gas flows periodically

Q34. Sevoflurane produces EEG changes. With increasing concentrations, EEG typically shows:

• Progressive activation then depression leading to burst suppression at high doses
• Permanent EEG normalization
• No change in EEG patterns
• Isolated epileptiform discharges in all patients

Correct Answer: Progressive activation then depression leading to burst suppression at high doses

Q35. Which statement about sevoflurane and hepatic injury is most accurate?

• Sevoflurane commonly causes severe halothane-like hepatitis
• Sevoflurane has a low incidence of clinically significant hepatotoxicity compared with older agents
• Sevoflurane is entirely free from any hepatic metabolism
• Sevoflurane always causes transaminase elevations

Correct Answer: Sevoflurane has a low incidence of clinically significant hepatotoxicity compared with older agents

Q36. Which statement correctly describes the relationship between blood:gas solubility and speed of induction for inhalational agents?

• Higher blood:gas solubility results in faster induction
• Lower blood:gas solubility results in faster induction
• Blood:gas solubility has no effect on induction speed
• Only oil:gas solubility affects induction speed

Correct Answer: Lower blood:gas solubility results in faster induction

Q37. Which clinical scenario increases sevoflurane uptake into blood and delays rise of alveolar concentration?

• Low cardiac output and slow ventilation
• High cardiac output and large alveolar-capillary blood flow
• Using a face mask for a short time only
• Administration at very low inspired concentration

Correct Answer: High cardiac output and large alveolar-capillary blood flow

Q38. Sevoflurane’s vasodilatory effects on the uterus during cesarean section can lead to:

• Improved uterine contraction and reduced bleeding
• Uterine relaxation and potential increased blood loss if used in high concentrations
• No effect on uterine tone
• Complete uterine atony in all patients

Correct Answer: Uterine relaxation and potential increased blood loss if used in high concentrations

Q39. Which of the following statements about occupational exposure to sevoflurane is correct?

• No scavenging systems are necessary
• Scavenging systems reduce staff exposure and are recommended
• Sevoflurane exposure is harmless at any concentration
• Exposure monitoring is banned in operating rooms

Correct Answer: Scavenging systems reduce staff exposure and are recommended

Q40. Which of the following best describes sevoflurane’s analgesic properties?

• It provides potent analgesia equivalent to opioids
• Inhalational agents have modest intrinsic analgesia; MAC reduction reflects immobility not pure analgesia
• Sevoflurane has no effect on nociception
• It is a primary opioid agonist

Correct Answer: Inhalational agents have modest intrinsic analgesia; MAC reduction reflects immobility not pure analgesia

Q41. If prolonged high-concentration sevoflurane anesthesia is required, what monitoring or precaution is reasonable?

• Routine hourly serum fluoride levels for all patients
• Consider limiting low-flow techniques or use appropriate absorbents and monitor renal function as clinically indicated
• No special precautions are necessary for any duration
• Stop anesthesia every 30 minutes to prevent Compound A

Correct Answer: Consider limiting low-flow techniques or use appropriate absorbents and monitor renal function as clinically indicated

Q42. In which patient is sevoflurane induction by inhalation most often preferred?

• An adult with a full stomach at high risk of aspiration
• A cooperative adult electing awake fiberoptic intubation
• A pediatric patient requiring mask induction
• A patient with malignant hyperthermia susceptibility

Correct Answer: A pediatric patient requiring mask induction

Q43. Which inhalational agent comparison is true regarding airway irritation during induction?

• Sevoflurane is more irritating than desflurane
• Sevoflurane is less irritating than desflurane and suitable for mask induction
• Sevoflurane and desflurane have identical pungency
• Desflurane is nonpungent and ideal for children

Correct Answer: Sevoflurane is less irritating than desflurane and suitable for mask induction

Q44. Which statement best describes sevoflurane’s elimination from the body?

• Eliminated primarily by hepatic metabolism only
• Eliminated mainly via exhalation with a small percentage metabolized hepatically
• Stored permanently in fat and not eliminated
• Converted to water and excreted in urine immediately

Correct Answer: Eliminated mainly via exhalation with a small percentage metabolized hepatically

Q45. Which of the following is the most appropriate statement regarding sevoflurane use in patients with known renal insufficiency?

• Sevoflurane is absolutely contraindicated in renal failure
• Use with caution; monitor renal function and consider limiting low-flow anesthesia to reduce Compound A exposure
• No precaution is necessary; it improves renal function
• Switch to halothane which is safer

Correct Answer: Use with caution; monitor renal function and consider limiting low-flow anesthesia to reduce Compound A exposure

Q46. Which physiologic effect of sevoflurane can complicate neuroanesthesia by increasing intracranial pressure?

• Reduction in cerebral metabolic rate without vascular effects
• Cerebral vasodilation that increases cerebral blood flow at higher doses
• Complete abolition of cerebral autoregulation at sub-MAC doses only
• Decrease in mean arterial pressure only

Correct Answer: Cerebral vasodilation that increases cerebral blood flow at higher doses

Q47. Which of the following is an advantage of sevoflurane over older agents like halothane?

• Higher hepatotoxicity risk
• Faster recovery and lower incidence of arrhythmogenic effects
• Greater myocardial sensitization to catecholamines
• Produces more malignant hyperthermia than halothane

Correct Answer: Faster recovery and lower incidence of arrhythmogenic effects

Q48. How does nitrous oxide interaction affect sevoflurane MAC?

• Nitrous oxide increases sevoflurane MAC
• Nitrous oxide decreases sevoflurane MAC (MAC-sparing effect)
• Nitrous oxide has no effect on sevoflurane MAC
• Nitrous oxide converts sevoflurane to Compound A

Correct Answer: Nitrous oxide decreases sevoflurane MAC (MAC-sparing effect)

Q49. Which one of the following statements about sevoflurane and electroencephalographic monitoring (e.g., BIS) is correct?

• Volatile agents cannot be monitored by BIS
• Sevoflurane causes dose-dependent EEG depression; BIS may correspondingly decrease with higher concentrations
• Sevoflurane increases BIS values consistently
• BIS is only useful for intravenous anesthetics

Correct Answer: Sevoflurane causes dose-dependent EEG depression; BIS may correspondingly decrease with higher concentrations

Q50. Which safety practice is recommended when using sevoflurane in low-flow anesthesia to minimize risks?

• Use desiccated soda lime to bind sevoflurane
• Ensure appropriate fresh gas flows, maintain absorbent hydration, and use compatible CO2 absorbents
• Never use scavenging systems
• Keep circuit temperatures as high as possible

Correct Answer: Ensure appropriate fresh gas flows, maintain absorbent hydration, and use compatible CO2 absorbents

G S Sachin

I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.

Mail- Sachin@pharmacyfreak.com