Pharm - General Anesthetics
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Questions and Answers
- 1.
A halogenated anesthetic that causes fast induction and recovery
- A.
Halothane
- B.
Sevoflurane
- C.
Nitrous oxide
- D.
Thiopental
- E.
Propofol
- F.
Etomidate
- G.
Ketamine
- H.
Midazolam
- I.
Fentanyl
Correct Answer
B. SevofluraneExplanation
Sevoflurane is a halogenated anesthetic that is known for its fast induction and recovery properties. It is commonly used in anesthesia due to its rapid onset of action and quick elimination from the body, allowing patients to wake up quickly after surgery. Sevoflurane is also considered to have a lower risk of side effects compared to other halogenated anesthetics, making it a preferred choice in many clinical settings.Rate this question:
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- 2.
This drug can trigger an attack of acute porphyria in risk patients.
- A.
Halothane
- B.
Sevoflurane
- C.
Nitrous oxide
- D.
Thiopental
- E.
Propofol
- F.
Etomidate
- G.
Ketamine
- H.
Midazolam
- I.
Fentanyl
Correct Answer
D. ThiopentalExplanation
Thiopental is a drug that can trigger an attack of acute porphyria in risk patients. Acute porphyria is a group of rare genetic disorders that affect the production of heme, a component of hemoglobin. Certain drugs, including thiopental, can induce an attack in individuals with a predisposition to porphyria. These attacks can cause severe abdominal pain, neurological symptoms, and potentially life-threatening complications. Therefore, it is important to avoid thiopental in patients with a history of porphyria or those at risk for the condition.Rate this question:
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- 3.
This drug has the highest incidence of postanesthetic nausea and vomiting.
- A.
Halothane
- B.
Sevoflurane
- C.
Nitrous oxide
- D.
Thiopental
- E.
Propofol
- F.
Etomidate
- G.
Ketamine
- H.
Midazolam
- I.
Fentanyl
Correct Answer
F. EtomidateExplanation
Etomidate is known to have the highest incidence of postanesthetic nausea and vomiting among the given options.Rate this question:
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- 4.
This inhaled anesthetic substantially reduced the needed concentration of other inhaled anesthetics given concomitantly
- A.
Halothane
- B.
Sevoflurane
- C.
Nitrous oxide
- D.
Thiopental
- E.
Propofol
- F.
Etomidate
- G.
Ketamine
- H.
Midazolam
- I.
Fentanyl
Correct Answer
C. Nitrous oxideExplanation
Nitrous oxide is the correct answer because it is known to have a synergistic effect with other inhaled anesthetics. This means that when nitrous oxide is used in combination with other inhaled anesthetics, it can significantly reduce the concentration of the other anesthetics needed to achieve the desired effect. This can be beneficial as it can help to minimize the potential side effects and risks associated with higher concentrations of other anesthetics.Rate this question:
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- 5.
This drug causes a cataleptic state called dissociative anesthesia
- A.
Halothane
- B.
Sevoflurane
- C.
Nitrous oxide
- D.
Thiopental
- E.
Propofol
- F.
Etomidate
- G.
Ketamine
- H.
Midazolam
- I.
Fentanyl
Correct Answer
G. KetamineExplanation
Ketamine is known to cause a cataleptic state called dissociative anesthesia. This means that it induces a state where the patient is detached from their surroundings and experiences a sense of dissociation. Ketamine is a commonly used anesthetic for procedures such as surgeries and is also used for sedation in emergency medicine. It works by blocking certain receptors in the brain, leading to its dissociative effects.Rate this question:
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- 6.
New potential general anesthetics were tested in laboratory animals. The minimum alveolar concentration (MAC) of each drug is reported in the table below: Which of the following drug has the highest potency?
- A.
Drug A
- B.
Drug B
- C.
Drug C
- D.
Drug D
- E.
Drug E
Correct Answer
D. Drug DExplanation
Learning objective: explain the meaning of the minimum alveolar concentration (MAC) of
inhalational anesthetics
Answer: D
During general anesthesia the partial pressure of an anesthetic in the brain equal that in the lung
when equilibrium is reached. Therefore the measurement of the steady state alveolar concentration
of different anesthetic provides a measure of their relative potencies. The Minimum Alveolar
Anesthetic Concentration (MAC) is defined as the concentration of the anesthetic that results in the
immobility of 50% of patients when exposed to a noxious stimulus. Thus MAC represent the ED50
on a conventional quantal dose-response curve, and is therefore a measure of the potency of the
inhaled anesthetic. The lower the MAC, the higher the potency.
A, B, C, E) (see explanation above)Rate this question:
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- 7.
A 43-year-old man underwent surgery to remove a prostatic cancer. Sevoflurane was used for general anesthesia. The drug has a minimum alveolar concentration (MAC) of 2.0. Which of the following phrases best describes the MAC of an inhalational anesthetic?
- A.
The blood/gas partition coefficient of the anesthetic
- B.
The concentration of anesthetic needed for short surgery
- C.
The ED50 on a conventional quantal dose-response curve
- D.
The maximal efficacy of the anesthetic
- E.
The concentration of anesthetic in the inspired air
Correct Answer
C. The ED50 on a conventional quantal dose-response curveExplanation
Learning objective: explain the meaning of the minimum alveolar concentration (MAC) of
inhalational anesthetics
Answer: C
The Minimum Alveolar Anesthetic Concentration (MAC) is defined as the concentration of the
anesthetic that results in the immobility of 50% of patients when exposed to a noxious stimulus.
Thus MAC represent the ED50 on a conventional quantal dose-response curve, and is therefore a
measure of the potency of the inhaled anesthetic.Rate this question:
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- 8.
A 48-year-old woman underwent surgery to remove an uterine myoma. General anesthesia was induced with propofol and maintained by sevoflurane and nitrous oxide. The blockade of which of the following receptors most likely mediated the effectiveness of nitrous oxide in this patient?
- A.
Nm cholinergic
- B.
Alpha-1 adrenergic
- C.
NMDA glutamatergic
- D.
GABAergic
- E.
5-HT3 serotonergic
Correct Answer
C. NMDA glutamatergicExplanation
Learning objective: explain the mechanism of action of nitrous oxide
Answer: C
Nitrous oxide is a potent and selective inhibitor of NMDA activated current, suggesting that its CNS
depressants effects are produced via a non competitive antagonistic activity at NMDA receptors
A, B, D, E) (see explanation above)Rate this question:
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- 9.
A 44-year-old man underwent surgery because of a prolapsed intervertebral disk. General anesthesia was induced with propofol and maintained with sevoflurane. When administration of sevoflurane was discontinued the patient regained consciousness in few minutes. Which of the following statements best explains why sevoflurane caused a rapid anesthetic recovery?
- A.
It redistributed rapidly to the lipid tissue
- B.
It is rapidly metabolized
- C.
It has a low MAC value
- D.
It has a low blood/gas partition coefficient
- E.
It concentrates mainly into the cerebral cortex
Correct Answer
D. It has a low blood/gas partition coefficientExplanation
Learning objective: describe the relationship between blood/gas partition coefficient and speed
of induction and recovery from general anesthesia.
Answer: D
Sevoflurane has a blood/gas partition coefficient of 0.69. Since the speed of induction and
recovery of anesthesia is inversely proportional to the blood/gas partition coefficient, sevoflurane
causes a rapid anesthetic induction and recovery.
A) Redistribution can be a factor that speed up the recovery from anesthesia but sevoflurane has
low lipid solubility and therefore redistribution into lipid tissue is minimal.
B) Metabolism of sevoflurane is very low (about 3%).
C) The MAC of an inhalational anesthetic is a measure of the potency of the drug i.e. it is a
pharmacodynamic variable. The speed of induction is dependent upon pharmacokinetic variables.
E) Inhalational anesthetics distribute uniformly into the brain. They are not concentrated in a
specific region of the brain.Rate this question:
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- 10.
A 63-year-old woman underwent surgery to remove a vulvar cancer. The patient was a heavy smoker and had been suffering from chronic obstructive pulmonary disease for 20 years. General Anesthesia was induced with propofol and maintained with sevoflurane. Which of the following sevoflurane effects most likely occurred during surgery?
- A.
Decreased cardiac output
- B.
Increased ventilatory response to carbon dioxide
- C.
Bronchodilation
- D.
Increased skeletal muscle tone
- E.
Increased uterine tone
Correct Answer
C. BronchodilationExplanation
Learning objective: describe the pharmacological effects of isoflurane.
Answer: C
All halogenated anesthetics have bronchodilating properties, an effect of value in patients with
underlying airway problems, like in the present case.
A) Cardiac output is minimally affected by sevoflurane.
B, D, E) In fact sevoflurane has effects opposite to those listed.Rate this question:
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- 11.
A 52-year-old woman underwent hysterectomy to remove an endometrial carcinoma. Anesthesia was induced with thiopental and maintained with nitrous oxide and halothane. Which of the following statements best explains why another anesthetic like halothane was added to nitrous oxide ?
- A.
To achieve a more complete analgesia
- B.
To maintain unconsciousness and muscle relaxation
- C.
To prevent sensitization of the myocardium to catecholamines
- D.
To prevent anesthesia induced respiratory depression
- E.
To prevent post anesthetic nausea and vomiting
Correct Answer
B. To maintain unconsciousness and muscle relaxationExplanation
Answer: B
Unconsciousness, which is usually achieved with thiopental, cannot be maintained with nitrous
oxide alone (the drug has a MAC higher than 100%) and therefore another potent anesthetic is
needed. Moreover nitrous oxide nas negligible effects on skeletal muscle tone and therefore an
halogenated anesthetic is given together, most of the time (all halogenated anesthetics cause
relaxation of skeletal muscle and enhance the effects of neuromuscular blocking agents).
A) Actually the nitrous oxide induced analgesia is excellent, even at low concentration of the gas.
C, D, E) Actually halothane can cause, not prevent, all these listed effects.Rate this question:
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- 12.
A 12-year-old was admitted to the hospital with the admitting diagnosis of acute appendicitis. Family history of the patient indicated that his father underwent surgery few years ago ad suffered a serious disorder just after the beginning of general anesthesia. Further analysis indicated that the disorder was an inherited autosomal dominant disease. Because of this the anesthesiologist avoided the use of halogenated anaesthetics in this boy. Which of the following was most likely the disorder suffered by the patient’s father?
- A.
Acute intermittent porphyria
- B.
Malignant hyperthermia
- C.
Acute hepatitis
- D.
Hemolytic anemia
- E.
Myasthenia gravis
Correct Answer
B. Malignant hyperthermiaExplanation
Learning objective: describe the anesthetic-induced malignant hypertermia.
Answer: B
In genetically susceptible patients, all halogenated anesthetics can trigger malignant hyperthermia,
a autosomal dominant disorder characterized by severe muscle contraction, rapid development of
hyperthermia and a massive increase in metabolic rate. The syndrome is frequently fatal.
A) Acute intermittent porphyria is an idiosyncratic disorder that can be triggered by barbiturates,
not by halogenated anesthetics.
C) Acute hepatitis is a rare disease that can be induced by halothane but not by other halogenated
anesthetics. Moreover it is not a genetic disorder.
D, E) These diseases are not genetically determined and are not induced by halogenated
anestheticsRate this question:
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- 13.
A 43-year-old woman underwent dilation and curettage because of an abnormal vaginal bleeding. General anesthesia was performed with thiopental. The patient lost consciousness in about 10 seconds and regained it 15 minutes later. Which of the following phrases best explains why general anesthesia induced by a standard dose of thiopental lasts 5-15 minutes?
- A.
Slow distribution of the drug into the CNS
- B.
Fast elimination of the drug from the body
- C.
Redistribution of the drug into peripheral tissues
- D.
Rapid biotransformation of the drug by the brain
- E.
Poor diffusion of the drug into the central neurons
Correct Answer
C. Redistribution of the drug into peripHeral tissuesExplanation
Learning objective: explain the reason of the short duration of anesthesia induced by
thiopental.
Answer: C
Thiopental rapidly diffuses out of the brain and other highly vascularized tissues and is
redistributed to muscle, fat and eventually to all body tissues. This is the principal mechanism
limiting anesthetic duration after a single anesthetic dose.
A, E) Actually thiopental distributes very rapidly into the CNS. Since it is very lipid soluble, diffusion
into the CNS neurons is very good.
B, D) Thiopental half life is about 12 hours, which indicates that the elimination of the drug from the
body is very slow.Rate this question:
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- 14.
A 61-year-old man underwent surgery to remove a prostate cancer. An IV injection of thiopental was performed and the patient lost consciousness in 10 seconds. Which of the following mechanism of action most likely mediated the anesthetic effect of the drug?
- A.
Increased affinity of GABA for its GABA-A receptor
- B.
Enhancement of beta-carboline affinity for GABA-A receptor
- C.
Blockade of NMDA glutamate receptors in the CNS
- D.
Enhancement of Cl- channel opening in the absence of GABA
- E.
Activation of GABA-B receptors on presynaptic terminals
Correct Answer
D. Enhancement of Cl- channel opening in the absence of GABAExplanation
Learning objective: describe the mechanism of action of barbiturates.
Answer: D
All barbiturates increase the affinity of GABA for its GABA-A receptor but, unlike benzodiazepines,
they can enhance Cl- channel opening in the absence of GABA, when given at high doses. Since
the dose of thiopental was high enough to lose consciousness the mechanism of this action was
most likely an Enhancement of Cl- channel opening in the absence of GABA.
A, B, C, E) (see explanation above)Rate this question:
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- 15.
A 61-year-old woman underwent colonoscopy because of rectal bleeding. The woman was very afraid of the procedure and asked for a general anesthesia. Since she had been suffering from coronary artery disease for seven years, etomidate was chosen for anesthesia. Which of the following effects most likely occurred in this patient during the postanesthetic period?
- A.
Nausea and vomiting
- B.
Delusions
- C.
Respiratory depression
- D.
Increased blood pressure
- E.
Decreased heart rate
Correct Answer
A. Nausea and vomitingExplanation
Learning objective: describe the pharmacological effects of etomidate.
Answer: A
Among general anesthetics etomidate is the drug with the highest incidence of postoperative
nausea and vomiting (>30% of cases).
B, C, D, E) Actually etomidate doesn’t cause delusion and provokes minimal cardiovascular and
respiratory depression.Rate this question:
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- 16.
A 4-year-old girl, who had been suffering from asthma for six months, was scheduled for a short suture procedure that was anticipated to take approximately 10 minutes. She was brought to the operation room by her parents and was in distress over parting from them and afraid of the doctors. Which of the following drugs would be appropriate for providing sedation and analgesia to this girl?
- A.
Ketamine
- B.
Thiopental
- C.
Fentanyl
- D.
Halothane
- E.
Sevoflurane
Correct Answer
A. KetamineExplanation
Learning objective: outline the therapeutic uses of ketamine.
Answer: A
Ketamine is a general anesthetic that induces a state of sedation, characterized by immobility,
profound analgesia, anterograde amnesia and a strong feeling of dissociation from the
environment without complete loss of consciousness. This state has been termed dissociative
anesthesia. Since it can provoke postoperative disorientation, perceptual illusions and vivid
dreams, it is not commonly used in general surgery. The drug causes negligible respiratory
depression and significant sympathetic stimulation. It is used in case of short, painful procedures in
children (who are less involved in the mental effect of the drug) especially when they have
respiratory problems, like in the present case.
B, C) These drugs can cause significant respiratory depression
D, E) Halogenated anesthetics are not suitable for minor surgical procedures.Rate this question:
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- 17.
A 49-year-old woman underwent abdominal surgery to remove a colon cancer. The anesthesia was performed with thiopental, fentanyl and nitrous oxide. Which of the following adverse effects was most likely to occur shortly after the recovery from anesthesia?
- A.
Watery diarrhea
- B.
Malignant hyperthermia
- C.
Hallucinations
- D.
Nausea and vomiting
- E.
Strong pain
Correct Answer
D. Nausea and vomitingExplanation
Learning objective: describe the adverse effects of general anesthesia
Answer: D
All the drugs used in the patient’s anesthetic protocol can cause postoperative nausea and
vomiting by an action on the chemoreceptor trigger zone and on the brainstem vomiting center. The
incidence of vomiting in the postoperative period with these drugs is about 15%.
A) Opioids actually tend to cause constipation
B) Halogenated anesthetic can very rarely cause malignant hyperthermia
C) Ketamine is the only anesthetic agent that has been associated with postoperative perceptual
illusion and hallucinations.
E) Postoperative strong pain is quite unlikely when a strong opioid like fentanyl has been used in
the anesthetic protocol.Rate this question:
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- 18.
A 52-year-old man underwent liver biopsy for a suspected liver cancer. Conscious sedation was induced with a drug combination that has the advantage of being reversible by the administration of specific receptor antagonists. Which of the following pairs of drugs was most likely administered ?
- A.
Fentanyl and thiopental
- B.
Fentanyl and midazolam
- C.
Fentanyl and ketamine
- D.
Thiopental and midazolam
- E.
Thiopental and ketamine
Correct Answer
B. Fentanyl and midazolamExplanation
Learning objective: describe the drug used for conscious sedation that have the advantage of
being reversible by the administration of specific receptor antagonists.
Answer: B
Conscious sedation refers to a drug-induced state of altered consciousness with the following
features:
-Consciousness is not lost (patient can respond to verbal commands)
-A patent airway is maintained (patient do not have to be ventilated)
-Cardiovascular effects are generally not marked.
-Anxiety is alleviated
-Pain is relieved.
-Some degree of anterograde amnesia is present.
A wide variety of IV anesthetic agents (benzodiazepines, propofol, opioids) have been used.
Benzodiazepines and opioids have the advantage that their effects can be easily reversed by the
use of specific receptor antagonists (flumazenil and naloxone).
A, C, D, E) There are not specific antagonists for thiopental and ketamineRate this question:
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- 19.
A 57-year-old man was undergoing surgery to remove a kidney carcinoma. The anesthesia was induced withy propofol, maintained with halothane, and supplemented by succinylcholine. A few minutes into the operation the patient exhibited fever of 104° F, skeletal muscle contracture, and profuse diaphoresis. His blood pressure dropped to 80/50 mm Hg and the heart rate was 125 bpm. Which of the following molecular actions best explains the signs and symptoms of the patient?
- A.
Excessive release of acetylcholine from motor neuron terminals
- B.
Opening of K+ channels in skeletal muscle membrane
- C.
Excessive release of Ca++ from sarcoplasmic reticulum
- D.
Blockade of Ca++ channel in skeletal muscle membrane
- E.
Opening of Cl- channels in motor end plate
Correct Answer
C. Excessive release of Ca++ from sarcoplasmic reticulumExplanation
Learning objective: describe the pathophysiology of malignant hyperthermia.
Answer: C
The signs of the patient strongly suggest that he was suffering from malignant hyperthermia, a rare
autosomal dominant disorder that can be triggered by the administration of halogenated
anesthetics and/or succinylcholine. The pathogenesis of the disease is thought to involve a
mutation in the gene encoding the skeletal muscle ryanodine receptor, a channel responsible for
the regulation of Ca++ release from the sarcoplasmic reticulum. This mutation would result in an
excessive release of CA++ which would be the main cause of the symptoms and signs of malignant
hyperthermia.
A, B, D, E) All these actions do not cause the syndrome exhibited by the patient.Rate this question:
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- 20.
A 63-year-old man underwent surgery to remove a laringeal carcinoma. The man was an heavy smoker and had been suffering from COPD for 15 years. General anesthesia was induced by propofol and maintained by sevoflurane and nitrous oxide. A low dose of ketamine was added to provide additional analgesia. The blockade of which of the following receptors most likely mediated the therapeutic efficacy of ketamine in this patient?
- A.
Nm cholinergic
- B.
Alpha-1 adrenergic
- C.
NMDA glutamatergic
- D.
GABAergic
- E.
Endorphinergic
Correct Answer
C. NMDA glutamatergicExplanation
Learning objective: explain the mechanism of action of ketamine
Answer: C
The mechanism of action of ketamine most likely involves a blockade of NMDA-type glutamate
receptors, a mechanism quite close to that of the psychedelic drug phencyclidine. In fact ketamine
itself has gained popularity as a drug of abuse (it is commonly known as “special K” or “K”).
A, B, D, E) (see explanation above)Rate this question:
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Mar 21, 2023Quiz Edited by
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Sep 04, 2012Quiz Created by
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