Inhalational Anesthesia Questions

Question 1: What is the primary mechanism by which anesthetic gases render a patient unconscious?

A. Concentration of gas

B. Partial pressure in alveoli

C. Diffusion through blood

D. Direct action on neurons

Question 2: Which anesthetic property determines the speed of induction in inhaled anesthetics?

A. Solubility in blood

B. Solubility in tissues

C. Alveolar partial pressure

D. Concentration in CNS

Question 3: What factor is most responsible for achieving an adequate depth of anesthesia with inhaled agents?

A. Concentration of anesthetic

B. Partial pressure equilibrium

C. Type of anesthetic

D. Patient age

Question 4: How does a decrease in atmospheric pressure at high altitudes affect the partial pressure of an inhaled anesthetic in the alveoli?

A. Increases partial pressure

B. Has no effect on partial pressure

C. Reduces partial pressure

D. Concentration remains the same

Question 5: At higher altitudes, to achieve the same anesthetic effect as at sea level, the concentration of inhaled anesthetic should be:

A. Decreased

B. Increased

C. Unchanged

D. nan

Question 6: Which factor primarily determines the inspired concentration (FI) of an inhaled anesthetic?

A. Alveolar ventilation

B. Fresh gas flow rate

C. Type of anesthetic used

D. Patient’s metabolic rate

Question 7: Increasing which of the following will help inspired concentration (FI) approximate the delivered concentration?

A. Circuit absorption

B. Fresh gas flow rate

C. Uptake by the patient

D. Alveolar partial pressure

Question 8: The alveolar partial pressure (PA) of an inhaled anesthetic is determined by the balance between which two factors?

A. Input (delivery) and uptake (loss)

B. Inspired concentration and metabolism

C. Circuit volume and absorption

D. Fresh gas flow and patient’s cardiac output

Question 9: Which factor will lead to a faster induction of anesthesia by increasing the FA/FI ratio?

A. Increased blood solubility

B. Increased cardiac output

C. Decreased blood solubility

D. Increased alveolar-venous difference

Question 10: How does a high cardiac output affect the induction of anesthesia with inhaled agents?

A. Speeds up induction

B. Slows down induction

C. Has no effect on induction rate

D. Increases inspired concentration

Question 11: Which inhaled anesthetic property leads to the fastest rise in the FA/FI ratio, resulting in quicker induction?

A. High blood solubility

B. Low blood solubility

C. High alveolar-venous partial pressure

D. Low fresh gas flow rate

Question 12: Which of the following factors makes poorly soluble anesthetic gases less affected by changes in cardiac output?

A. High uptake into blood

B. Minimal uptake into blood

C. Faster elimination from the body

D. Increased concentration in alveoli

Question 13: How does a right-to-left shunt affect the induction of anesthesia with poorly soluble volatile agents?

A. Speeds up induction

B. Slows down induction

C. Has no effect on induction

D. Increases alveolar concentration

Question 14: Why do intravenous anesthetics have a faster onset in patients with a right-to-left shunt compared to volatile anesthetics?

A. They bypass the lungs and reach the CNS faster

B. They mix with volatile agents in alveoli

C. They have higher solubility in blood

D. They are metabolized in the CNS

Question 15: How does increasing the inspired concentration (FI) of an inhaled anesthetic affect the alveolar concentration (FA)?

A. Only increases FA

B. Only increases rate of FA/FI equilibrium

C. Increases both FA and the rate FA approaches FI

D. Has no effect on FA

Question 16: What is the primary outcome of the concentration effect in inhaled anesthetics?

A. Faster achievement of target blood levels

B. Faster rise of alveolar concentration (FA)

C. Reduced time to achieve CNS saturation

D. Lower required doses of anesthetic

Question 17: What is the primary mechanism by which the Second Gas Effect enhances the uptake of a secondary anesthetic gas?

A. Increased solubility of the second gas

B. Rapid uptake of the first gas (e.g., nitrous oxide)

C. Decreased blood flow to alveoli

D. Higher inspired concentration of the second gas

Question 18: Which gas is commonly used to demonstrate the Second Gas Effect in anesthesia, particularly to increase the concentration of a second gas?

A. Oxygen

B. Nitrous oxide

C. Carbon dioxide

D. Halothane

Question 19: Which anesthetic gas has the lowest blood partition coefficient, indicating the fastest induction and emergence?

A. Nitrous Oxide

B. Desflurane

C. Sevoflurane

D. Isoflurane

Question 20: Which anesthetic gas has the highest MAC value, making it the least potent?

A. Desflurane

B. Halothane

C. Nitrous Oxide

D. Sevoflurane

Question 21: Which inhaled anesthetic has the highest vapor pressure at 20°C, making it more volatile than others?

A. Isoflurane

B. Nitrous Oxide

C. Desflurane

D. Sevoflurane

Question 22: Which of the following gases would be expected to have the slowest onset of action based on its blood partition coefficient?

A. Nitrous

B. Des

C. Halo

D. Sevoflurane

Question 23: If a patient requires a very low MAC percentage to achieve adequate anesthesia, which gas might be most appropriate?

A. Nitrous Oxide

B. Enflurane

C. Desflurane

D. Halothane

Question 24: How does an increase in fat content in the blood, such as in postprandial lipidemia, affect the blood

A. Increases partition coefficient, slows induction

B. Increases partition coefficient, speeds induction

C. Decreases partition coefficient, slows induction

D. Decreases partition coefficient, speeds induction

Question 25: How does nitrous oxide (N₂O) affect cerebral metabolic rate of oxygen (CMRO₂) and cerebral blood flow (CBF)?

A. Decreases CMRO₂ and decreases CBF

B. Increases CMRO₂ and decreases CBF

C. Increases CMRO₂ and increases CBF

D. Decreases CMRO₂ and increases CBF

Question 26: At 0.5 MAC of volatile anesthetics like sevoflurane, desflurane, or isoflurane, how does CMRO₂ reduction affect cerebral blood flow (CBF)?

A. CBF remains unchanged

B. CBF decreases

C. CBF increases

D. CBF becomes unpredictable

Question 27: What happens to cerebral blood flow (CBF) at 1 MAC of volatile anesthetics like sevoflurane, desflurane, or isoflurane, where CMRO₂ reduction is maximal?

A. CBF decreases

B. CBF remains unchanged

C. Vasodilation increases CBF

D. CBF decreases due to reduced CMRO₂

Question 28: How do volatile anesthetics affect tidal volume (Vt) and respiratory rate (RR)?

A. ↑ Vt, ↓ RR

B. ↓ Vt, ↑ RR

C. ↑ Vt, ↑ RR

D. ↓ Vt, ↓ RR

Question 29: What effect do anesthetic gases have on the ventilatory response to hypercapnia and hypoxemia?

A. No effect

B. Dose-dependent increase

C. Dose-dependent decrease

D. Dose-independent decrease

Question 30: Which of the following is a pulmonary benefit of using volatile anesthetics during anesthesia?

A. Increased tidal volume

B. Bronchodilation

C. Enhanced hypoxic response

D. Increased respiratory rate

Question 31: How do volatile anesthetics generally affect renal function, specifically renal blood flow and glomerular filtration rate (GFR)?

A. Increase renal blood flow and GFR

B. Decrease renal blood flow and GFR

C. No effect on renal blood flow and GFR

D. Decrease renal blood flow, increase GFR

Question 32: Why is nitrous oxide (N₂O) often contraindicated in patients with air-filled cavities, such as those with a pneumothorax?

A. It causes muscle relaxation

B. It can cause expansion of air-filled cavities

C. It increases skeletal muscle tone

D. It reduces alveolar oxygen concentration

Question 33: Which of the following conditions may result from prolonged exposure to nitrous oxide?

A. Bone marrow depression and peripheral neuropathies

B. Pulmonary embolism

C. Hepatotoxicity

D. Renal toxicity

Question 34: What action should be taken when using nitrous oxide for prolonged procedures involving an endotracheal tube (ETT)?

A. Increase the inspired concentration of N₂O

B. Periodically let air out of the ETT cuff

C. Administer additional muscle relaxants

D. Decrease the inspired concentration of N₂O

Question 35: Which of the following is a characteristic of nitrous oxide that distinguishes it from volatile anesthetics like sevoflurane and isoflurane?

A. It produces skeletal muscle relaxation

B. It has no effect on myocardial depression

C. It is not a trigger for malignant hyperthermia

D. It increases the MAC of volatile agents

Question 36: Which inhaled anesthetic is highly pungent and known to be the least expensive among clinically used volatile agents?

A. Sevoflurane

B. Isoflurane

C. Desflurane

D. Halothane

Question 37: What is the primary mechanism previously implicated in isoflurane's "coronary steal" phenomenon?

A. Constriction of coronary arteries

B. Dilation of stenotic vessels

C. Dilation of “normal” coronary arteries

D. Reduction in cardiac output

Question 38: At what minimum MAC of isoflurane is an increase in cerebral blood flow (CBF) typically observed?

A. 0.5 MAC

B. 1.0 MAC

C. 1.6 MAC

D. 2.0 MAC

Question 39: What effect does isoflurane have on the electroencephalogram (EEG) at 2 MAC?

A. Increases EEG activity

B. Produces electrically silent EEG

C. Decreases CBF

D. Causes seizure-like activity

Question 40: Why is sevoflurane particularly popular for inhalational induction, especially in pediatric patients?

A. It is highly pungent

B. It has a sweet smell and is non-pungent

C. It has a high MAC

D. It has a very slow onset

Question 41: Which toxic byproduct can sevoflurane form when exposed to CO₂ absorbents containing alkali substances like soda lime?

A. Compound A

B. Compound B

C. Compound C

D. Compound D

Question 42: Some guidelines recommend keeping fresh gas flows above 2 L/min when using sevoflurane to prevent which of the following?

A. Increased MAC

B. Rebreathing of Compound A

C. Faster uptake

D. Accumulation of CO₂

Question 43: Why does desflurane require a special heated, pressurized vaporizer for administration?

A. It has a high potency

B. It has a low MAC

C. It has a high vapor pressure near atmospheric pressure

D. It has a low vapor pressure

Question 44: Which side effect is commonly associated with the administration of desflurane in an awake patient?

A. Muscle relaxation

B. Increased salivation and coughing

C. Decreased sympathetic response

D. Sedation

Question 45: What can occur if the inspired concentration of desflurane is increased rapidly in a patient?

A. Hypotension

B. Bradycardia

C. Increased sympathetic response (tachycardia, hypertension)

D. Bronchoconstriction

Question 46: Which anesthetic has the highest vapor pressure, requiring a special vaporizer to maintain a stable concentration?

A. Sevoflurane

B. Enflurane

C. Isoflurane

D. Desflurane

Question 47: Among the following volatile anesthetics, which has the lowest vapor pressure, making it less volatile compared to others?

A. Desflurane

B. Sevoflurane

C. Enflurane

D. Halothane

Question 48: Which factor determines the partial pressure of the anesthetic vapor in the carrier gas when using a modern vaporizer?

A. Total pressure of the system

B. Temperature and saturated vapor pressure (SVP) of the anesthetic

C. Carrier gas concentration

D. Flow rate of the anesthetic