NEET-PG 2019 — Anesthesiology

Q: Which of the following intravenous agents is known to cause pain upon injection?

Propofol. ***Propofol*** - **Propofol** is notoriously known to cause significant **pain upon injection**, especially when administered into smaller veins. - This is attributed to its **lipid emulsion formulation** and activation of **TRPA1 receptors** on sensory neurons. *Methohexital* - While **methohexital** can cause localized pain and venous irritation, it is generally less pronounced and less frequent than with propofol. - It is known more for causing **hiccups** and **muscle twitching** upon induction, rather than severe injection pain. *Ketamine* - **Ketamine** typically causes minimal to no pain upon intravenous injection. - Its side effects are often related to its **dissociative anesthetic** properties, such as psychomimetic effects and increased sympathetic activity. *Etomidate* - **Etomidate** is generally considered to be low in causing injection site pain. - Its primary concern is the potential for **adrenocortical suppression** and a high incidence of **myoclonus**. [Practice more Anesthesiology PYQs on OnCourse]

Q: IV administration of which anesthetic drug is most painful among the following?

Propofol. ***Propofol*** - **Propofol** is notoriously known for causing **significant pain on injection** due to its formulation with **soybean oil emulsion** and its direct irritation of venous free nerve endings. - This pain is often described as a **burning sensation** and can be severe enough to require pre-treatment with lidocaine or administering it in a larger vein. *Methohexital* - While **methohexital** can cause localized pain and sometimes **thrombophlebitis** during intravenous administration, it is generally considered less painful than propofol. - It is a **barbiturate** and its discomfort is typically related to its alkaline pH and potential for venous irritation. *Ketamine* - **Ketamine** typically causes **minimal pain on injection** when administered intravenously. - Its mechanism of action as an **NMDA receptor antagonist** does not generally involve direct irritation of venous endothelium in the same way as propofol. *Etomidate* - **Etomidate**, like methohexital, can cause some **pain and irritation on injection**, and poses a risk of **thrombophlebitis**. - However, the severity of pain is generally **less pronounced** compared to the distinct and often intense burning sensation associated with propofol. [Practice more Anesthesiology PYQs on OnCourse]

Q: Which of the following is the most common method used to know depth of anaesthesia?

BIS. ***BIS*** - The **BIS (Bispectral Index) monitor** is the most common and widely utilized objective method for assessing the depth of anesthesia by analyzing brain electrical activity. - It provides a numerical value, typically from 0 to 100, where lower numbers indicate deeper anesthetic states, aiming for a range of 40-60 during general anesthesia. *Oesophageal contractility* - While esophageal motility can be affected by anesthetic depth, it is **not a standard or common method** for monitoring anesthesia during surgery. - Its measurement is invasive and not directly correlated with cortical brain activity, which is the primary target of most general anesthetics. *Depressed responses* - **Clinical signs of depressed responses** (e.g., lack of purposeful movement, stable vital signs) are important, but they are subjective and less reliable for accurately measuring anesthetic depth, especially in paralyzed patients. - These signs can be influenced by various factors unrelated to anesthetic depth, such as neuromuscular blockade or hypothermia. *Hypotension* - **Hypotension** is a common side effect of general anesthesia, but it is an indicator of the *hemodynamic effects* of anesthetics, not a direct or reliable measure of their depth. - Hypotension can be caused by many factors other than anesthetic depth, such as blood loss, hypovolemia, or cardiac dysfunction, making it a non-specific indicator. [Practice more Anesthesiology PYQs on OnCourse]

Q: Which IV anesthetic does not cause cardiac depression?

Etomidate. **Etomidate** - **Etomidate** is known for its **minimal cardiovascular effects**, making it a preferred choice in patients with **pre-existing cardiac disease** or hemodynamic instability. - Unlike other IV anesthetics, it causes very little change in **heart rate**, **blood pressure**, or **cardiac output**. *Propofol* - **Propofol** frequently causes **dose-dependent myocardial depression** and **vasodilation**, leading to significant decreases in blood pressure. - Its cardiovascular effects can be problematic in patients with compromised cardiac function. *Thiopentone* - **Thiopentone**, a barbiturate, typically causes **dose-dependent cardiovascular depression**, including reduced **myocardial contractility** and **vasodilation**. - This can result in a decrease in **blood pressure** and **cardiac output**. *Methohexital* - **Methohexital**, another barbiturate, also causes **cardiovascular depression** similar to thiopentone. - It can lead to decreased **blood pressure** due to both **myocardial depression** and **peripheral vasodilation**. [Practice more Anesthesiology PYQs on OnCourse]

Q: Depth of Anesthesia is best measured by:

BIS. ***BIS*** - The **BIS (Bispectral Index)** is an EEG-derived parameter that provides a quantitative measure of the patient's level of consciousness or depth of anesthesia. - A typical range for adequate surgical anesthesia is a BIS score between **40 and 60**, indicating a low probability of consciousness and recall. *TOF* - **TOF (Train-of-Four)** monitoring is used to assess the level of neuromuscular blockade, measuring the response of a muscle to a series of four electrical stimuli. - While important for managing **muscle relaxants**, it does not directly measure the depth of anesthesia or consciousness. *MAC* - **MAC (Minimum Alveolar Concentration)** is a measure of the potency of an inhaled anesthetic, defined as the concentration at which 50% of patients do not respond to a surgical stimulus. - It reflects the **ED50 of the anesthetic agent** itself rather than the patient's individual depth of anesthesia at a given moment. *Post Tetanic Potentiation* - **Post Tetanic Potentiation (PTP)** is a phenomenon observed during neuromuscular monitoring where a single twitch response is enhanced following a brief tetanus (rapid series of high-frequency stimuli). - PTP is used to assess **deep neuromuscular blockade** and recovery from paralytics, not the depth of anesthesia. [Practice more Anesthesiology PYQs on OnCourse]

9 Previous Year Questions with Answers & Explanations

Questions

Which of the following intravenous agents is known to cause pain upon injection?

IV administration of which anesthetic drug is most painful among the following?

Which of the following is the most common method used to know depth of anaesthesia?

Which IV anesthetic does not cause cardiac depression?

Depth of Anesthesia is best measured by:

Which of the following anesthetic agent is not painful on intravenous administration?

Drug that does not cause cardiac depression:

Maximum Airway Irritation caused by:-

Inhalational anesthetic with highest respiratory irritation is:-

NEET-PG 2019 - Anesthesiology NEET-PG Practice Questions and MCQs

Question 1: Which of the following intravenous agents is known to cause pain upon injection?

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

Explanation: ***Propofol*** - **Propofol** is notoriously known to cause significant **pain upon injection**, especially when administered into smaller veins. - This is attributed to its **lipid emulsion formulation** and activation of **TRPA1 receptors** on sensory neurons. *Methohexital* - While **methohexital** can cause localized pain and venous irritation, it is generally less pronounced and less frequent than with propofol. - It is known more for causing **hiccups** and **muscle twitching** upon induction, rather than severe injection pain. *Ketamine* - **Ketamine** typically causes minimal to no pain upon intravenous injection. - Its side effects are often related to its **dissociative anesthetic** properties, such as psychomimetic effects and increased sympathetic activity. *Etomidate* - **Etomidate** is generally considered to be low in causing injection site pain. - Its primary concern is the potential for **adrenocortical suppression** and a high incidence of **myoclonus**.

Question 2: IV administration of which anesthetic drug is most painful among the following?

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

Explanation: ***Propofol*** - **Propofol** is notoriously known for causing **significant pain on injection** due to its formulation with **soybean oil emulsion** and its direct irritation of venous free nerve endings. - This pain is often described as a **burning sensation** and can be severe enough to require pre-treatment with lidocaine or administering it in a larger vein. *Methohexital* - While **methohexital** can cause localized pain and sometimes **thrombophlebitis** during intravenous administration, it is generally considered less painful than propofol. - It is a **barbiturate** and its discomfort is typically related to its alkaline pH and potential for venous irritation. *Ketamine* - **Ketamine** typically causes **minimal pain on injection** when administered intravenously. - Its mechanism of action as an **NMDA receptor antagonist** does not generally involve direct irritation of venous endothelium in the same way as propofol. *Etomidate* - **Etomidate**, like methohexital, can cause some **pain and irritation on injection**, and poses a risk of **thrombophlebitis**. - However, the severity of pain is generally **less pronounced** compared to the distinct and often intense burning sensation associated with propofol.

Question 3: Which of the following is the most common method used to know depth of anaesthesia?

A. BIS (Correct Answer)
B. Oesophageal contractility
C. Depressed responses
D. Hypotension

Explanation: ***BIS*** - The **BIS (Bispectral Index) monitor** is the most common and widely utilized objective method for assessing the depth of anesthesia by analyzing brain electrical activity. - It provides a numerical value, typically from 0 to 100, where lower numbers indicate deeper anesthetic states, aiming for a range of 40-60 during general anesthesia. *Oesophageal contractility* - While esophageal motility can be affected by anesthetic depth, it is **not a standard or common method** for monitoring anesthesia during surgery. - Its measurement is invasive and not directly correlated with cortical brain activity, which is the primary target of most general anesthetics. *Depressed responses* - **Clinical signs of depressed responses** (e.g., lack of purposeful movement, stable vital signs) are important, but they are subjective and less reliable for accurately measuring anesthetic depth, especially in paralyzed patients. - These signs can be influenced by various factors unrelated to anesthetic depth, such as neuromuscular blockade or hypothermia. *Hypotension* - **Hypotension** is a common side effect of general anesthesia, but it is an indicator of the *hemodynamic effects* of anesthetics, not a direct or reliable measure of their depth. - Hypotension can be caused by many factors other than anesthetic depth, such as blood loss, hypovolemia, or cardiac dysfunction, making it a non-specific indicator.

Question 4: Which IV anesthetic does not cause cardiac depression?

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

Explanation: **Etomidate** - **Etomidate** is known for its **minimal cardiovascular effects**, making it a preferred choice in patients with **pre-existing cardiac disease** or hemodynamic instability. - Unlike other IV anesthetics, it causes very little change in **heart rate**, **blood pressure**, or **cardiac output**. *Propofol* - **Propofol** frequently causes **dose-dependent myocardial depression** and **vasodilation**, leading to significant decreases in blood pressure. - Its cardiovascular effects can be problematic in patients with compromised cardiac function. *Thiopentone* - **Thiopentone**, a barbiturate, typically causes **dose-dependent cardiovascular depression**, including reduced **myocardial contractility** and **vasodilation**. - This can result in a decrease in **blood pressure** and **cardiac output**. *Methohexital* - **Methohexital**, another barbiturate, also causes **cardiovascular depression** similar to thiopentone. - It can lead to decreased **blood pressure** due to both **myocardial depression** and **peripheral vasodilation**.

Question 5: Depth of Anesthesia is best measured by:

A. TOF
B. MAC
C. BIS (Correct Answer)
D. Post Tetanic Potentiation

Explanation: ***BIS*** - The **BIS (Bispectral Index)** is an EEG-derived parameter that provides a quantitative measure of the patient's level of consciousness or depth of anesthesia. - A typical range for adequate surgical anesthesia is a BIS score between **40 and 60**, indicating a low probability of consciousness and recall. *TOF* - **TOF (Train-of-Four)** monitoring is used to assess the level of neuromuscular blockade, measuring the response of a muscle to a series of four electrical stimuli. - While important for managing **muscle relaxants**, it does not directly measure the depth of anesthesia or consciousness. *MAC* - **MAC (Minimum Alveolar Concentration)** is a measure of the potency of an inhaled anesthetic, defined as the concentration at which 50% of patients do not respond to a surgical stimulus. - It reflects the **ED50 of the anesthetic agent** itself rather than the patient's individual depth of anesthesia at a given moment. *Post Tetanic Potentiation* - **Post Tetanic Potentiation (PTP)** is a phenomenon observed during neuromuscular monitoring where a single twitch response is enhanced following a brief tetanus (rapid series of high-frequency stimuli). - PTP is used to assess **deep neuromuscular blockade** and recovery from paralytics, not the depth of anesthesia.

Question 6: Which of the following anesthetic agent is not painful on intravenous administration?

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

Explanation: ***Ketamine*** - **Ketamine** is known for causing minimal pain on intravenous administration compared to other common induction agents. - Its mechanism of action as an **NMDA receptor antagonist** does not involve irritation of venous endothelium to the same extent as some other anesthetics. *Propofol* - **Propofol** is infamous for causing significant **injection pain** due to its formulation, which contains soybean oil, glycerol, and egg lecithin, acting as a direct irritant to the intima of veins. - The pain is often described as a **burning sensation** and can be severe enough to require pre-treatment with lidocaine. *Etomidate* - **Etomidate**, like propofol, can cause significant pain on injection, although generally less severe than propofol. - The pain is thought to be related to its **propylene glycol vehicle**, which can cause venous irritation. *Methohexital* - **Methohexital**, a barbiturate, is associated with a moderate incidence of **injection site pain and thrombophlebitis**. - Its alkaline pH and direct irritation of the **venous intima** are the primary reasons for patient discomfort during administration.

Question 7: Drug that does not cause cardiac depression:

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

Explanation: ***Etomidate*** - Etomidate is known for its **cardiovascular stability**, making it a preferred induction agent in patients with **compromised cardiac function**. - It maintains **myocardial contractility** and does not typically cause a significant drop in blood pressure. *Thiopentone* - Thiopentone causes **dose-dependent myocardial depression** and peripheral vasodilation. - This can lead to a significant **decrease in blood pressure** and cardiac output, especially in hypovolemic patients. *Propofol* - Propofol is a potent **vasodilator** and can cause significant **myocardial depression**, leading to hypotension. - Its cardiovascular effects are often more pronounced than those of other induction agents, necessitating careful titration. *Ketamine* - Ketamine causes indirect cardiovascular stimulation (due to **sympathetic nervous system activation**), but direct myocardial depression. - While it often increases heart rate and blood pressure, this is a compensatory mechanism and its direct effect on the myocardium is depressant.

Question 8: Maximum Airway Irritation caused by:-

A. Halothane
B. Enflurane
C. Desflurane (Correct Answer)
D. Sevoflurane
E. Isoflurane

Explanation: ***Desflurane*** - **Desflurane** has a pungent odor and is known to cause significant **airway irritation**, leading to coughing, breath-holding, laryngospasm, and secretions, especially during induction. - Its high volatility and low blood-gas solubility contribute to its rapid onset and offset, but also increase its propensity for airway irritation. *Halothane* - **Halothane** has a sweet, non-pungent odor and is generally well-tolerated during induction, causing minimal airway irritation. - Although it causes myocardial depression and is associated with hepatotoxicity, airway irritation is not a primary concern. *Enflurane* - **Enflurane** has a mild, sweet odor and causes less airway irritation than **desflurane**, but more than halothane or sevoflurane. - It can cause central nervous system excitation at high concentrations, but airway irritation is not its most prominent side effect. *Sevoflurane* - **Sevoflurane** has a pleasant, non-pungent odor and is known for its minimal airway irritation, making it an excellent choice for inhalational inductions, particularly in pediatric patients. - It is often preferred over other volatile anesthetics when airway reactivity is a concern. *Isoflurane* - **Isoflurane** has a pungent odor and can cause moderate airway irritation, but generally less than desflurane. - It is associated with a higher incidence of coughing and breath-holding during induction compared to sevoflurane.

Question 9: Inhalational anesthetic with highest respiratory irritation is:-

A. Desflurane (Correct Answer)
B. Halothane
C. Nitrous oxide
D. Sevoflurane

Explanation: ***Desflurane*** - **Desflurane** has the highest **pungency** among common inhalational anesthetics, leading to significant respiratory irritation. - This irritation can manifest as **coughing**, **laryngospasm**, and **bronchospasm**, particularly during induction. *Halothane* - **Halothane** is a less pungent anesthetic and is generally well-tolerated by the respiratory system. - It was historically known for its **bronchodilating properties**, making it less irritating than Desflurane. *Nitrous oxide* - **Nitrous oxide** is a gaseous anesthetic with a very low solubility and virtually no respiratory irritant properties. - It is often used as a carrier gas and is known for its quick onset and offset without causing airway reactivity. *Sevoflurane* - **Sevoflurane** is known for its sweet smell and is considered a non-pungent agent, making it suitable for inhalational induction, especially in children. - It causes minimal respiratory irritation and has **bronchodilating effects**, which are beneficial in patients with reactive airway disease.