FMGE 2019 — Anesthesiology

Q: Endotracheal tube in the esophagus is best assessed by:

CO2 Exhalation. ***CO2 Exhalation*** - Measuring **CO2 exhalation** (capnography) is the most reliable method to confirm endotracheal tube placement, as CO2 is present in the trachea but not in the esophagus. - A persistent **waveform on the capnograph** indicates proper tracheal intubation. *Direct laryngoscopy* - While helpful for initial visualization during intubation, **direct laryngoscopy** cannot confirm continuous tracheal placement after the tube is advanced. - It only confirms the tube passing through the vocal cords, not its final position in the trachea versus esophagus. *Auscultation* - **Auscultation** can be misleading because stomach sounds can be transmitted to the chest, and breath sounds can be heard in the epigastrium even with esophageal intubation. - It relies on subjective interpretation and is less definitive than capnography. *Chest wall movement* - Observing **chest wall movement** is not a definitive sign, as the chest can still rise with esophageal intubation due to air entering the stomach. - This method is unreliable and can be mistaken for proper ventilation, leading to dangerous delays in correcting tube misplacement. [Practice more Anesthesiology PYQs on OnCourse]

Q: Spinal anaesthesia in an adult is given at this level:

L3-L4. ***L3-L4*** - This intervertebral space is a **safe and common site** for spinal anaesthesia in adults because the **spinal cord typically terminates at L1-L2** in adults. - Inserting the needle at L3-L4 minimizes the risk of **spinal cord injury** while still allowing access to the cerebrospinal fluid. *T12-L1* - This level is **too high** for routine spinal anaesthesia in adults, as it is often at or very near the **conus medullaris** (the end of the spinal cord). - Puncture at this level carries a **significant risk of direct spinal cord injury**. *L1-L2* - While technically possible, this level is still considered **higher risk** as it is often the **terminal end of the spinal cord** in adults. - The **cauda equina** is present below L1-L2, but the L3-L4 space offers a greater margin of safety. *L5-S1* - This intervertebral space is generally **too low and difficult to access** for consistent and effective spinal anaesthesia. - The **iliac crests typically align with L4**, making the L3-L4 or L4-L5 spaces more accessible for spinal puncture. [Practice more Anesthesiology PYQs on OnCourse]

Q: Which of the following inhalational anaesthetic agent can cause hepatitis on repeated use?

Halothane. ***Halothane*** - Halothane is known to cause **halothane hepatitis** (also known as halothane-induced liver injury), a rare but severe form of liver damage, particularly on **repeated exposure**. - This is due to the **metabolism of halothane** in the liver, which can produce reactive intermediates that lead to immune-mediated liver cell necrosis. *Sevoflurane* - Sevoflurane is generally considered to have a **low incidence of liver toxicity** and is preferred in patients with pre-existing liver disease. - While it can be metabolized to fluoride ions, the clinical significance of this in terms of liver damage is considered to be minimal compared to halothane. *Ether* - **Diethlyl ether** is an older anesthetic agent that is no longer commonly used due to its flammability and slower induction/recovery times. - While it can cause some hepatic dysfunction, it is not primarily associated with the severe, immune-mediated hepatitis seen with halothane. *Isoflurane* - Isoflurane is an ether-based anesthetic with a much **lower metabolism** rate than halothane. - This reduced metabolism contributes to its **lower potential for liver toxicity** compared to halothane, making it a safer option for patients with liver concerns. [Practice more Anesthesiology PYQs on OnCourse]

Q: The duration of spinal anaesthesia is based directly on:

Dose. ***Dose*** - The **total mass** (dose) of the local anesthetic administered directly influences the number of nerve fibers blocked and the duration of block. - A higher dose of a given local anesthetic generally leads to a **longer duration** of action in spinal anesthesia. *Height* - While patient height can influence the **spread** of spinal anesthesia due to differences in spinal column length, it does not directly determine the **duration** of the block. - The **volume** of the injectate, rather than the patient's height alone, affects the cranial spread of the anesthetic. *Total body fat* - Total body fat has **minimal direct impact** on the duration of spinal anesthesia since local anesthetics are injected directly into the cerebrospinal fluid, largely bypassing systemic fat distribution initially. - **Lipid solubility** of the drug affects its potency and duration within the neuraxis, not external body fat. *Age* - **Age** can influence the **spread** and **onset** of spinal anesthesia due to changes in cerebrospinal fluid volume and spinal cord compliance, but it is not the primary determinant of **duration**. - Older patients may experience a greater spread for a given dose, but the primary factor for duration remains the total drug dose. [Practice more Anesthesiology PYQs on OnCourse]

Q: Which of the following is used for day care surgery?

Propofol. ***Propofol*** - **Propofol** is favored for **day care surgery** due to its **rapid onset** and **rapid recovery** profile, allowing patients to be discharged quickly. - It produces a **clear-headed recovery** with less postoperative nausea and vomiting compared to other agents. *Thiopentone* - **Thiopentone** has a **longer recovery time** and greater potential for **postoperative sedation** and **nausea**, making it less suitable for day care surgery. - Its use often leads to a **delayed discharge** from the recovery unit. *Ketamine* - **Ketamine** can cause **psychomimetic effects** (e.g., hallucinations, vivid dreams) and **delirium** during emergence, which are undesirable for day care procedures. - It also leads to **increased heart rate** and **blood pressure**, which may prolong recovery and observation time. *Etomidate* - **Etomidate** is known to cause **adrenocortical suppression** and can be associated with **pain on injection** and **myoclonus**, which are not ideal for routine day care use. - While it has a relatively **stable cardiovascular profile**, these side effects limit its widespread use in short procedures where rapid, smooth recovery is paramount. [Practice more Anesthesiology PYQs on OnCourse]

7 Previous Year Questions with Answers & Explanations

Questions

Endotracheal tube in the esophagus is best assessed by:

Spinal anaesthesia in an adult is given at this level:

Which of the following inhalational anaesthetic agent can cause hepatitis on repeated use?

The duration of spinal anaesthesia is based directly on:

Which of the following is used for day care surgery?

In CPR, number of chest compressions per minute in an adult:

What is the color of the nitrous oxide cylinder?

FMGE 2019 - Anesthesiology FMGE Practice Questions and MCQs

Question 1: Endotracheal tube in the esophagus is best assessed by:

A. Direct laryngoscopy
B. Auscultation
C. CO2 Exhalation (Correct Answer)
D. Chest wall movement

Explanation: ***CO2 Exhalation*** - Measuring **CO2 exhalation** (capnography) is the most reliable method to confirm endotracheal tube placement, as CO2 is present in the trachea but not in the esophagus. - A persistent **waveform on the capnograph** indicates proper tracheal intubation. *Direct laryngoscopy* - While helpful for initial visualization during intubation, **direct laryngoscopy** cannot confirm continuous tracheal placement after the tube is advanced. - It only confirms the tube passing through the vocal cords, not its final position in the trachea versus esophagus. *Auscultation* - **Auscultation** can be misleading because stomach sounds can be transmitted to the chest, and breath sounds can be heard in the epigastrium even with esophageal intubation. - It relies on subjective interpretation and is less definitive than capnography. *Chest wall movement* - Observing **chest wall movement** is not a definitive sign, as the chest can still rise with esophageal intubation due to air entering the stomach. - This method is unreliable and can be mistaken for proper ventilation, leading to dangerous delays in correcting tube misplacement.

Question 2: Spinal anaesthesia in an adult is given at this level:

A. L3-L4 (Correct Answer)
B. T12-L1
C. L1-L2
D. L5-S1

Explanation: ***L3-L4*** - This intervertebral space is a **safe and common site** for spinal anaesthesia in adults because the **spinal cord typically terminates at L1-L2** in adults. - Inserting the needle at L3-L4 minimizes the risk of **spinal cord injury** while still allowing access to the cerebrospinal fluid. *T12-L1* - This level is **too high** for routine spinal anaesthesia in adults, as it is often at or very near the **conus medullaris** (the end of the spinal cord). - Puncture at this level carries a **significant risk of direct spinal cord injury**. *L1-L2* - While technically possible, this level is still considered **higher risk** as it is often the **terminal end of the spinal cord** in adults. - The **cauda equina** is present below L1-L2, but the L3-L4 space offers a greater margin of safety. *L5-S1* - This intervertebral space is generally **too low and difficult to access** for consistent and effective spinal anaesthesia. - The **iliac crests typically align with L4**, making the L3-L4 or L4-L5 spaces more accessible for spinal puncture.

Question 3: Which of the following inhalational anaesthetic agent can cause hepatitis on repeated use?

A. Sevoflurane
B. Halothane (Correct Answer)
C. Ether
D. Isoflurane

Explanation: ***Halothane*** - Halothane is known to cause **halothane hepatitis** (also known as halothane-induced liver injury), a rare but severe form of liver damage, particularly on **repeated exposure**. - This is due to the **metabolism of halothane** in the liver, which can produce reactive intermediates that lead to immune-mediated liver cell necrosis. *Sevoflurane* - Sevoflurane is generally considered to have a **low incidence of liver toxicity** and is preferred in patients with pre-existing liver disease. - While it can be metabolized to fluoride ions, the clinical significance of this in terms of liver damage is considered to be minimal compared to halothane. *Ether* - **Diethlyl ether** is an older anesthetic agent that is no longer commonly used due to its flammability and slower induction/recovery times. - While it can cause some hepatic dysfunction, it is not primarily associated with the severe, immune-mediated hepatitis seen with halothane. *Isoflurane* - Isoflurane is an ether-based anesthetic with a much **lower metabolism** rate than halothane. - This reduced metabolism contributes to its **lower potential for liver toxicity** compared to halothane, making it a safer option for patients with liver concerns.

Question 4: The duration of spinal anaesthesia is based directly on:

A. Height
B. Total body fat
C. Dose (Correct Answer)
D. Age

Explanation: ***Dose*** - The **total mass** (dose) of the local anesthetic administered directly influences the number of nerve fibers blocked and the duration of block. - A higher dose of a given local anesthetic generally leads to a **longer duration** of action in spinal anesthesia. *Height* - While patient height can influence the **spread** of spinal anesthesia due to differences in spinal column length, it does not directly determine the **duration** of the block. - The **volume** of the injectate, rather than the patient's height alone, affects the cranial spread of the anesthetic. *Total body fat* - Total body fat has **minimal direct impact** on the duration of spinal anesthesia since local anesthetics are injected directly into the cerebrospinal fluid, largely bypassing systemic fat distribution initially. - **Lipid solubility** of the drug affects its potency and duration within the neuraxis, not external body fat. *Age* - **Age** can influence the **spread** and **onset** of spinal anesthesia due to changes in cerebrospinal fluid volume and spinal cord compliance, but it is not the primary determinant of **duration**. - Older patients may experience a greater spread for a given dose, but the primary factor for duration remains the total drug dose.

Question 5: Which of the following is used for day care surgery?

A. Thiopentone
B. Ketamine
C. Etomidate
D. Propofol (Correct Answer)

Explanation: ***Propofol*** - **Propofol** is favored for **day care surgery** due to its **rapid onset** and **rapid recovery** profile, allowing patients to be discharged quickly. - It produces a **clear-headed recovery** with less postoperative nausea and vomiting compared to other agents. *Thiopentone* - **Thiopentone** has a **longer recovery time** and greater potential for **postoperative sedation** and **nausea**, making it less suitable for day care surgery. - Its use often leads to a **delayed discharge** from the recovery unit. *Ketamine* - **Ketamine** can cause **psychomimetic effects** (e.g., hallucinations, vivid dreams) and **delirium** during emergence, which are undesirable for day care procedures. - It also leads to **increased heart rate** and **blood pressure**, which may prolong recovery and observation time. *Etomidate* - **Etomidate** is known to cause **adrenocortical suppression** and can be associated with **pain on injection** and **myoclonus**, which are not ideal for routine day care use. - While it has a relatively **stable cardiovascular profile**, these side effects limit its widespread use in short procedures where rapid, smooth recovery is paramount.

Question 6: In CPR, number of chest compressions per minute in an adult:

A. 30-50 per minute
B. 100-120 per minute (Correct Answer)
C. 50-72 per minute
D. 120-200 per minute

Explanation: ***100-120 per minute*** - The **American Heart Association (AHA)** and other international resuscitation guidelines recommend a compression rate of **100 to 120 beats per minute** for adults. - This rate ensures adequate blood flow to vital organs while minimizing rescuer fatigue. *30-50 per minute* - This rate is **too low** and would be ineffective in maintaining adequate cerebral and coronary perfusion during cardiac arrest. - Insufficient compressions per minute significantly **reduce the chances of survival** and positive neurological outcomes. *50-72 per minute* - While better than 30-50, this rate is still **below the recommended range** for effective CPR in adults. - It would likely result in **inadequate blood flow** to the brain and heart, diminishing the effectiveness of resuscitation. *120-200 per minute* - While aiming for higher compression rates might seem beneficial, rates **above 120 per minute** can be counterproductive. - Excessively fast compressions can **reduce chest recoil** and ventricular filling time, actually decreasing cardiac output and perfusion.

Question 7: What is the color of the nitrous oxide cylinder?

A. Blue (Correct Answer)
B. Black
C. Blue body with white shoulder
D. White

Explanation: ***Blue*** - According to international color coding for medical gas cylinders, **nitrous oxide (N2O)** cylinders are uniformly colored **blue**. - This color coding helps in distinguishing different medical gases to prevent errors in healthcare settings. *Black* - **Black** is generally the color code for **nitrogen** cylinders in medical gas systems. - This color is distinct from nitrous oxide to avoid confusion during gas administration. *Blue body with white shoulder* - While cylinders have specific body and shoulder colors, a **blue body with a white shoulder** is typically associated with **medical air** in some regions, not nitrous oxide. - Nitrous oxide cylinders are completely blue. *White* - **White** is the color code for **oxygen** cylinders in some international and regional standards, though green is also common, depending on the country. - This color is not used for nitrous oxide cylinders.