FMGE 2018 — Anesthesiology

Q: In status asthmaticus, which anesthetic agent is used as a bronchodilator?

Ketamine. ***Ketamine*** - Possesses **bronchodilatory** properties due to its sympathomimetic effects, making it useful in severe asthma or **status asthmaticus**. - It can cause **catecholamine release**, leading to relaxation of bronchial smooth muscle and improved airflow. *Morphine* - Can cause **histamine release**, which may lead to **bronchoconstriction** and worsen an asthmatic patient's condition. - It is a respiratory depressant that can further compromise breathing in a patient with severe airway obstruction. *Thiopentone sodium* - May induce **histamine release** and cause **bronchospasm**, which is contraindicated in asthma. - It is a potent depressant of the central nervous system and can cause respiratory depression, worsening the clinical picture of status asthmaticus. *Halothane* - Although it has some **bronchodilatory** properties, its use has largely been replaced by newer inhalational anesthetics due to concerns about myocardial sensitization to catecholamines and potential **hepatotoxicity**. - It is a potent inhalational agent but is less favored in modern anesthesia for asthma due to side effect profiles compared to other agents. [Practice more Anesthesiology PYQs on OnCourse]

Q: Which of the following is the most suitable anesthetic agent for use in dogs?

Propofol. ***Propofol*** - **Propofol** is a widely used and highly effective intravenous anesthetic in dogs due to its **rapid induction** and **rapid recovery**. - It produces minimal cumulative effects when administered as a constant rate infusion, making it suitable for both short procedures and maintenance of anesthesia. *Medetomidine hydrochloride* - **Medetomidine** is an **alpha-2 agonist** primarily used as a sedative and analgesic in dogs, not typically as the sole anesthetic agent for general anesthesia. - While it provides profound sedation, it is usually combined with other drugs (e.g., ketamine) to achieve surgical planes of anesthesia, and its effects on reducing heart rate and blood pressure can be significant. *Ketamine* - **Ketamine** is a **dissociative anesthetic** that provides good analgesia and somatic anesthesia but often causes muscle rigidity and can increase sympathetic tone. - It is typically used in combination with other sedatives or tranquilizers (e.g., diazepam, midazolam) to ensure smooth induction and recovery and prevent adverse effects like seizures. *Midazolam* - **Midazolam** is a **benzodiazepine** primarily used as a sedative, anxiolytic, and muscle relaxant, often as a premedicant or co-induction agent, not as a primary anesthetic for general anesthesia in dogs. - It offers minimal cardiovascular and respiratory depression when used alone, but it does not produce sufficient anesthetic depth for surgical procedures. [Practice more Anesthesiology PYQs on OnCourse]

Q: False statement about post-dural puncture headache (PDPH):

Headache is relieved in sitting standing position. ***Headache is relieved in sitting standing position*** - This statement is **false** because a cardinal feature of PDPH is that the headache is **worse in the upright position** (sitting or standing) and **relieved by lying flat**. - The postural nature of the headache is due to the continued leakage of CSF, leading to reduced intracranial pressure, which is exacerbated by gravity when upright. *Commonly occipito-frontal in location* - PDPH typically presents as a headache that can be **holocranial**, **occipital**, or **frontal**, often radiating to the neck. - The location is due to changes in **intracranial pressure** affecting pain-sensitive structures like blood vessels and meninges. *Onset of headache is usually 12-72 hours following procedure* - The onset of PDPH is typically **delayed**, occurring in the vast majority of cases between **12 to 72 hours** after the dural puncture. - Although it can occur immediately or up to five days later, this delayed presentation is characteristic. *Breach of dura* - PDPH is a direct consequence of the intentional or accidental **breach of the dura mater** during procedures like spinal anesthesia or lumbar puncture. - This breach allows for continuous leakage of **cerebrospinal fluid (CSF)**, leading to a reduction in intracranial pressure, which causes the headache. [Practice more Anesthesiology PYQs on OnCourse]

Q: Which of the following drugs is used for hypotensive anesthesia:

Both Isoflurane and Nitroglycerin. ***Both Isoflurane and Nitroglycerin*** - **Isoflurane** is a volatile anesthetic that can induce **hypotension** by decreasing systemic vascular resistance and myocardial contractility. - **Nitroglycerin** is a potent vasodilator that primarily acts on veins, but also on arteries, to reduce preload and afterload, thereby lowering blood pressure. *Isoflurane* - While **Isoflurane** can be used as part of a hypotensive anesthesia strategy, it is not the sole drug capable of achieving this effect. - Its hypotensive action is dose-dependent and results from **vasodilation** and direct **myocardial depression**. *Nitroglycerin* - **Nitroglycerin** is effective in inducing controlled **hypotension** due to its rapid onset and short duration of action as a vasodilator. - It is frequently used in anesthesia for its ability to reduce blood pressure, particularly in situations requiring a **dry surgical field**. *Dantrolene* - **Dantrolene** is a skeletal muscle relaxant primarily used to treat and prevent **malignant hyperthermia**. - It does not directly induce **hypotension** and is not indicated for hypotensive anesthesia. [Practice more Anesthesiology PYQs on OnCourse]

4 Previous Year Questions with Answers & Explanations

Questions

In status asthmaticus, which anesthetic agent is used as a bronchodilator?

Which of the following is the most suitable anesthetic agent for use in dogs?

False statement about post-dural puncture headache (PDPH):

Which of the following drugs is used for hypotensive anesthesia:

FMGE 2018 - Anesthesiology FMGE Practice Questions and MCQs

Question 1: In status asthmaticus, which anesthetic agent is used as a bronchodilator?

A. Morphine
B. Thiopentone sodium
C. Halothane
D. Ketamine (Correct Answer)

Explanation: ***Ketamine*** - Possesses **bronchodilatory** properties due to its sympathomimetic effects, making it useful in severe asthma or **status asthmaticus**. - It can cause **catecholamine release**, leading to relaxation of bronchial smooth muscle and improved airflow. *Morphine* - Can cause **histamine release**, which may lead to **bronchoconstriction** and worsen an asthmatic patient's condition. - It is a respiratory depressant that can further compromise breathing in a patient with severe airway obstruction. *Thiopentone sodium* - May induce **histamine release** and cause **bronchospasm**, which is contraindicated in asthma. - It is a potent depressant of the central nervous system and can cause respiratory depression, worsening the clinical picture of status asthmaticus. *Halothane* - Although it has some **bronchodilatory** properties, its use has largely been replaced by newer inhalational anesthetics due to concerns about myocardial sensitization to catecholamines and potential **hepatotoxicity**. - It is a potent inhalational agent but is less favored in modern anesthesia for asthma due to side effect profiles compared to other agents.

Question 2: Which of the following is the most suitable anesthetic agent for use in dogs?

A. Propofol (Correct Answer)
B. Medetomidine hydrochloride
C. Ketamine
D. Midazolam

Explanation: ***Propofol*** - **Propofol** is a widely used and highly effective intravenous anesthetic in dogs due to its **rapid induction** and **rapid recovery**. - It produces minimal cumulative effects when administered as a constant rate infusion, making it suitable for both short procedures and maintenance of anesthesia. *Medetomidine hydrochloride* - **Medetomidine** is an **alpha-2 agonist** primarily used as a sedative and analgesic in dogs, not typically as the sole anesthetic agent for general anesthesia. - While it provides profound sedation, it is usually combined with other drugs (e.g., ketamine) to achieve surgical planes of anesthesia, and its effects on reducing heart rate and blood pressure can be significant. *Ketamine* - **Ketamine** is a **dissociative anesthetic** that provides good analgesia and somatic anesthesia but often causes muscle rigidity and can increase sympathetic tone. - It is typically used in combination with other sedatives or tranquilizers (e.g., diazepam, midazolam) to ensure smooth induction and recovery and prevent adverse effects like seizures. *Midazolam* - **Midazolam** is a **benzodiazepine** primarily used as a sedative, anxiolytic, and muscle relaxant, often as a premedicant or co-induction agent, not as a primary anesthetic for general anesthesia in dogs. - It offers minimal cardiovascular and respiratory depression when used alone, but it does not produce sufficient anesthetic depth for surgical procedures.

Question 3: False statement about post-dural puncture headache (PDPH):

A. Commonly occipito-frontal in location
B. Onset of headache is usually 12-72 hours following procedure
C. Breach of dura
D. Headache is relieved in sitting standing position (Correct Answer)

Explanation: ***Headache is relieved in sitting standing position*** - This statement is **false** because a cardinal feature of PDPH is that the headache is **worse in the upright position** (sitting or standing) and **relieved by lying flat**. - The postural nature of the headache is due to the continued leakage of CSF, leading to reduced intracranial pressure, which is exacerbated by gravity when upright. *Commonly occipito-frontal in location* - PDPH typically presents as a headache that can be **holocranial**, **occipital**, or **frontal**, often radiating to the neck. - The location is due to changes in **intracranial pressure** affecting pain-sensitive structures like blood vessels and meninges. *Onset of headache is usually 12-72 hours following procedure* - The onset of PDPH is typically **delayed**, occurring in the vast majority of cases between **12 to 72 hours** after the dural puncture. - Although it can occur immediately or up to five days later, this delayed presentation is characteristic. *Breach of dura* - PDPH is a direct consequence of the intentional or accidental **breach of the dura mater** during procedures like spinal anesthesia or lumbar puncture. - This breach allows for continuous leakage of **cerebrospinal fluid (CSF)**, leading to a reduction in intracranial pressure, which causes the headache.

Question 4: Which of the following drugs is used for hypotensive anesthesia:

A. Both Isoflurane and Nitroglycerin (Correct Answer)
B. Isoflurane
C. Nitroglycerin
D. Dantrolene

Explanation: ***Both Isoflurane and Nitroglycerin*** - **Isoflurane** is a volatile anesthetic that can induce **hypotension** by decreasing systemic vascular resistance and myocardial contractility. - **Nitroglycerin** is a potent vasodilator that primarily acts on veins, but also on arteries, to reduce preload and afterload, thereby lowering blood pressure. *Isoflurane* - While **Isoflurane** can be used as part of a hypotensive anesthesia strategy, it is not the sole drug capable of achieving this effect. - Its hypotensive action is dose-dependent and results from **vasodilation** and direct **myocardial depression**. *Nitroglycerin* - **Nitroglycerin** is effective in inducing controlled **hypotension** due to its rapid onset and short duration of action as a vasodilator. - It is frequently used in anesthesia for its ability to reduce blood pressure, particularly in situations requiring a **dry surgical field**. *Dantrolene* - **Dantrolene** is a skeletal muscle relaxant primarily used to treat and prevent **malignant hyperthermia**. - It does not directly induce **hypotension** and is not indicated for hypotensive anesthesia.