CRNA CRNA Pharmacology and Anesthesia Agents 1 — Questions and Answers
Question 1: Which inhalational anesthetic agent has the lowest blood-gas partition coefficient, resulting in the fastest induction and emergence?
- Desflurane (Correct answer)
- Isoflurane
- Sevoflurane
- Halothane
Correct answer: Desflurane
Desflurane has the lowest blood-gas partition coefficient (0.45), allowing the fastest induction and emergence among commonly used inhalational agents.
Question 2: A patient receives succinylcholine and develops masseter muscle rigidity followed by rapidly rising temperature. What is the most likely diagnosis?
- Malignant hyperthermia (Correct answer)
- Neuroleptic malignant syndrome
- Serotonin syndrome
- Thyroid storm
Correct answer: Malignant hyperthermia
Masseter muscle rigidity after succinylcholine is a hallmark early sign of malignant hyperthermia, a life-threatening hypermetabolic crisis triggered by volatile agents and succinylcholine.
Question 3: Which opioid is most appropriate for a patient with renal failure requiring intraoperative analgesia due to its lack of active metabolites?
- Remifentanil (Correct answer)
- Morphine
- Meperidine
- Hydromorphone
Correct answer: Remifentanil
Remifentanil is metabolized by nonspecific plasma esterases and has no active metabolites, making it safe in renal failure.
Question 4: What is the mechanism of action of neostigmine used for reversal of neuromuscular blockade?
- Acetylcholinesterase inhibition (Correct answer)
- Nicotinic receptor agonism
- Muscarinic receptor antagonism
- Competitive antagonism at the neuromuscular junction
Correct answer: Acetylcholinesterase inhibition
Neostigmine inhibits acetylcholinesterase, increasing acetylcholine concentration at the neuromuscular junction to displace and overcome non-depolarizing blockers.
Question 5: Which benzodiazepine is preferred for IV sedation due to its water solubility and lack of pain on injection?
- Midazolam (Correct answer)
- Diazepam
- Lorazepam
- Triazolam
Correct answer: Midazolam
Midazolam is water-soluble at low pH, becoming lipophilic at physiologic pH, making it painless on injection and suitable for IV sedation.
Question 6: A patient on a MAO inhibitor requires opioid analgesia. Which opioid should be strictly avoided due to risk of serotonin syndrome?
- Meperidine (Correct answer)
- Fentanyl
- Morphine
- Hydromorphone
Correct answer: Meperidine
Meperidine inhibits serotonin reuptake and combined with MAO inhibitors can precipitate a fatal serotonin syndrome; it is absolutely contraindicated.
CRNA CRNA Pharmacology and Anesthesia Agents 1
Which inhalational anesthetic agent has the lowest blood-gas partition coefficient, resulting in the fastest induction and emergence?