NEET-PG 2013 - Anesthesiology Practice Questions

Q: Which anaesthetic is contraindicated in renal failure?

Methoxyflurane. ***Methoxyflurane*** - Methoxyflurane undergoes significant **metabolism** to produce inorganic **fluoride ions**, which are directly **nephrotoxic**. - This nephrotoxicity can cause **high-output renal failure** with reduced concentrating ability, making it contraindicated in patients with pre-existing renal impairment. *Isoflurane* - Isoflurane is minimally metabolized and produces very low levels of **fluoride ions**, making it generally **safe** for use in patients with renal failure. - Its elimination is primarily via the **lungs**, with very little hepatic metabolism or renal excretion of active compounds. *Desflurane* - Desflurane is also minimally metabolized, similar to isoflurane, and therefore produces negligible amounts of **fluoride ions**. - It is considered a **safe option** for patients with renal impairment due to its predominantly pulmonary elimination and lack of nephrotoxic metabolites. *Halothane* - While halothane can cause **hepatotoxicity**, it is generally **not directly nephrotoxic** in the way methoxyflurane is. - Its metabolism, though more extensive than isoflurane or desflurane, does not produce clinically significant levels of nephrotoxic fluoride ions to contraindicate its use in renal failure.

Q: Which of the following statements is NOT true regarding rapid induction of anesthesia?

Sellick's maneuver is always required.. ***Sellick's maneuver is always required.*** - **Sellick's maneuver**, or cricoid pressure, is applied to compress the esophagus against the vertebrae, aiming to prevent **gastric regurgitation** and aspiration during rapid sequence intubation (RSI). - While historically considered a standard component of RSI, its routine use has been increasingly questioned due to a lack of strong evidence supporting its efficacy and potential to impede glottic visualization and intubation. It is not "always" required; its application is often at the discretion of the anesthetist based on patient factors and risk assessment. *Pre-oxygenation is mandatory* - **Pre-oxygenation** is a critical step in rapid sequence induction, involving administering 100% oxygen for several minutes prior to induction. - This denitrogenates the functional residual capacity (FRC), creating an oxygen reservoir that extends the safe apnea time, thus preventing **hypoxemia** during the intubation attempt. *Suxamethonium is often used.* - **Suxamethonium** (succinylcholine) is a depolarizing neuromuscular blocker primarily used in rapid sequence intubation due to its **ultra-rapid onset** (30-60 seconds) and short duration of action (5-10 minutes). - Its rapid action facilitates quick muscle relaxation for tracheal intubation, which is crucial for minimizing the risk of aspiration in patients with a full stomach or other risk factors. *Mechanical ventilation is typically avoided before intubation.* - During rapid sequence induction, **positive pressure ventilation** with a bag-valve mask is typically avoided before intubation to prevent gastric insufflation. - Gastric insufflation can increase the risk of **regurgitation** and pulmonary aspiration of gastric contents, which is a major concern in patients undergoing RSI.

Q: Which drug is commonly used for emergency intubation?

Etomidate. ***Etomidate*** - Etomidate is a **short-acting nonbenzodiazepine hypnotic** often preferred for rapid sequence intubation (RSI) due to its minimal impact on **hemodynamic stability**. - It induces **rapid unconsciousness** with a quick onset and offset, making it suitable for emergency airway management in patients who are hemodynamically compromised. *Propofol* - Propofol is a **potent intravenous anesthetic** that can cause significant **hypotension** due to vasodilation and myocardial depression. - While it provides rapid onset of sedation and amnesia, its cardiovascular side effects make it less ideal for patients with **unstable hemodynamics** during emergency intubation. *Ketamine* - Ketamine is a **dissociative anesthetic** that causes a cataleptic state, amnesia, and analgesia, often leading to **bronchodilation** and cardiovascular stimulation. - While useful in patients with **reactive airway disease** or hypotension, it can increase intracranial pressure and may induce sympathetic stimulation, which might not be ideal for all emergency intubation scenarios. *None of the options* - This option is incorrect because **Etomidate is a commonly used drug** for emergency intubation, particularly where hemodynamic stability is a concern. - Other agents are also used but Etomidate is a clear clinical choice in many situations.

Q: Who coined the term "balanced anaesthesia"?

Lundy (John S. Lundy). ***Lundy (John S. Lundy)*** - **John S. Lundy** is credited with coining the term "**balanced anaesthesia**" in the early 20th century. - This concept describes the use of **multiple anesthetic agents** in combination, each contributing to different aspects of anesthesia (e.g., hypnosis, analgesia, muscle relaxation). *Simpson* - **Sir James Young Simpson** was a Scottish physician who pioneered the use of **chloroform** and ether as anesthetics in the mid-19th century. - While he significantly advanced the field of anesthesia, he did not coin the term "balanced anaesthesia." *Fischer* - **Emil Fischer** was a German chemist who won the Nobel Prize in Chemistry for his work on sugar and purine syntheses. - His contributions were primarily in organic chemistry and biochemistry, not directly in the field of clinical anesthesia terminology. *Morton* - **William T.G. Morton** was an American dentist who famously demonstrated the first public use of **ether** for surgical anesthesia in 1846. - He is known for popularizing ether as a surgical anesthetic but did not coin the term "balanced anaesthesia."

Q: Dissociative anaesthesia is produced by?

Ketamine. ***Ketamine*** - **Ketamine** is a unique anesthetic that produces a state of **dissociative anesthesia**, characterized by a trance-like state, analgesia, amnesia, and catalepsy. - This effect is primarily due to its antagonism of the **N-methyl-D-aspartate (NMDA) receptor**. *Etomidate* - **Etomidate** is an intravenous anesthetic characterized by its **cardiovascular stability**, making it suitable for patients with heart conditions. - It works primarily by modulating **GABA-A receptors** but does not produce dissociative anesthesia. *Propofol* - **Propofol** is a widely used intravenous anesthetic known for its **rapid onset and recovery**, and it is often used for induction and maintenance of general anesthesia. - Its primary mechanism of action involves enhancing the effects of **GABA-A receptors**, leading to central nervous system depression, but not dissociative anesthesia. *Thiopentone* - **Thiopentone** (Thiopental) is a barbiturate anesthetic that causes rapid loss of consciousness and has been historically used for inducing general anesthesia. - It acts as a **GABA-A receptor agonist**, depressing the central nervous system, but it does not produce the distinct dissociative state seen with ketamine.

Q: Which of the following anesthetics is known to increase intraocular pressure?

Ketamine. ***Ketamine*** - **Ketamine** is known to increase **intraocular pressure (IOP)**, making it generally avoided in patients with **glaucoma** or those undergoing ocular surgery. - This effect is due to its influence on sympathetic nervous system activity and extraocular muscle tone. *Thiopental* - **Thiopental**, a barbiturate, typically causes a **reduction in intraocular pressure**, which can be beneficial in certain ocular procedures. - Its mechanism involves decreasing cerebral blood flow and metabolic rate, indirectly leading to a decrease in IOP. *Alfentanil* - **Alfentanil**, an opioid, generally has **minimal to no significant effect on intraocular pressure**. - Its primary actions are analgesia and sedation, without direct impact on oculomotor tone or fluid dynamics. *Propofol* - **Propofol** is known to **decrease intraocular pressure**, making it a favorable agent for ophthalmic surgery. - This effect is attributed to a reduction in cerebral blood flow and an inhibition of aqueous humor production.

Q: Circuit of choice for controlled ventilation ?

Type D. **Type D** - The **Type D circuit** (also known as the **Bain circuit** or a modified Mapleson D circuit) is highly efficient for **controlled ventilation** due to its fresh gas flow entering near the patient, effectively sweeping away exhaled gases. - Its design maintains a relatively constant **expiratory resistance**, making it suitable for precise control of ventilation parameters. *Magill circuit* - The **Magill circuit** (Mapleson A) is efficient for **spontaneous ventilation** but requires a high fresh gas flow to prevent rebreathing during controlled ventilation. - During controlled ventilation, a high minute volume is required to flush out expired gases efficiently, which can be wasteful of anesthetic agents. *Type C* - The **Type C circuit** (Mapleson C circuit) is a simple system useful for **resuscitation** and short procedures but is inefficient for prolonged controlled ventilation. - It has a high resistance to gas flow and a tendency for significant rebreathing during both spontaneous and controlled breathing, leading to high CO2 levels. *Type E* - The **Type E circuit** (Mapleson E circuit) is a basic T-piece system, primarily used for **spontaneous breathing in infants and children**. - It lacks a reservoir bag and adjustable pressure limiting valve, making it unsuitable for controlling ventilation effectively in adults.

Q: What is the PRIMARY application of capnography during patient monitoring?

Correct intubation. ***Correct intubation*** - Capnography is the **gold standard** for confirming **endotracheal tube (ETT) placement** by detecting carbon dioxide in exhaled breath. - A persistent waveform indicates the ETT is in the **trachea**, while absence suggests esophageal intubation. *Pulmonary embolism* - While capnography can show a **decrease in end-tidal CO2 (ETCO2)** due to increased dead space in pulmonary embolism, it is not its primary or most definitive diagnostic application. - Other diagnostic methods like CT pulmonary angiogram are preferred for confirming pulmonary embolism. *Adequate ventilation* - Capnography provides information about **ETCO2 levels**, which can indirectly reflect adequate ventilation by showing CO2 elimination. - However, it's more direct application is intubation confirmation, and other measures like **tidal volume** and **respiratory rate** are also crucial for assessing overall ventilation. *Significant metabolic change* - Capnography can show changes in CO2 production reflecting metabolic rate, such as in **hypermetabolic states** (e.g., fever, sepsis) or hypometabolic states. - While useful for monitoring trends, its primary role is not for diagnosing such changes but rather intubation confirmation.

Q: Which of the following is a characteristic of the Supreme Laryngeal Mask Airway (LMA)?

Includes a built-in drain tube. ***Includes a built-in drain tube*** - The **Supreme Laryngeal Mask Airway (LMA)** features an integrated **drain tube** to facilitate gastric decompression and reduce the risk of aspiration. - This design allows for the passage of a gastric tube, which can be useful during longer procedures or in patients with a higher risk of gastric content regurgitation. *Designed specifically for infants* - While LMAs are available in various sizes for all age groups, the **Supreme LMA** is not designed *specifically* for infants; it is a general-purpose LMA available in multiple sizes for different patient populations. - Other LMA types, such as the LMA Unique, are more commonly associated with a broader pediatric application. *Utilizes high pressure, low volume cuff design* - The **Supreme LMA** actually utilizes a **low pressure, high volume cuff** design, which helps contour to the perilaryngeal anatomy and minimizes pressure on mucosal tissues. - A high pressure, low volume cuff is associated with traditional endotracheal tubes and could lead to increased tissue ischemia if used with an LMA. *Does not have a bite block* - The **Supreme LMA** incorporates an **integrated bite block** within its design to prevent occlusion of the airway tube from patient biting. - This feature helps maintain airway patency and protects the LMA from damage, making it a key characteristic.

Q: Critical temperature of oxygen is?

-118°C. ***-118°C*** - The **critical temperature** is the temperature above which a gas cannot be liquefied, no matter how much pressure is applied. - For oxygen, its critical temperature is approximately **-118°C**, meaning it can only exist as a gas above this temperature, regardless of pressure. *400°C* - This temperature is significantly **above** the critical temperature of oxygen, so oxygen would always be a gas at this temperature. - It does not represent any specific physical property of oxygen in relation to its phase changes. *20°C* - This temperature is also well **above** oxygen's critical temperature, so oxygen would remain in its gaseous state. - This is approximately room temperature, where oxygen is commonly found as a gas. *36.5°C* - This is close to typical human body temperature and is far **above** the critical temperature of oxygen. - At this temperature, oxygen exists only as a gas.

Question 1

Which anaesthetic is contraindicated in renal failure?

Accepted Answer

Methoxyflurane

Answer

Isoflurane

Answer

Desflurane

Answer

Halothane

Question 2

Which of the following statements is NOT true regarding rapid induction of anesthesia?

Accepted Answer

Sellick's maneuver is always required.

Answer

Suxamethonium is often used.

Answer

Mechanical ventilation is typically avoided before intubation.

Answer

Pre-oxygenation is mandatory

Question 3

Which drug is commonly used for emergency intubation?

Accepted Answer

Etomidate

Answer

None of the options

Answer

Propofol

Answer

Ketamine

Question 4

Who coined the term "balanced anaesthesia"?

Accepted Answer

Lundy (John S. Lundy)

Answer

Simpson

Answer

Fischer

Answer

Morton

Question 5

Dissociative anaesthesia is produced by?

Accepted Answer

Ketamine

Answer

Etomidate

Answer

Propofol

Answer

Thiopentone

Question 6

Which of the following anesthetics is known to increase intraocular pressure?

Accepted Answer

Ketamine

Answer

Thiopental

Answer

Alfentanil

Answer

Propofol

Question 7

Circuit of choice for controlled ventilation ?

Accepted Answer

Type D

Answer

Magill circuit

Answer

Type C

Answer

Type E

Question 8

What is the PRIMARY application of capnography during patient monitoring?

Accepted Answer

Correct intubation

Answer

Pulmonary embolism

Answer

Adequate ventilation

Answer

Significant metabolic change

Question 9

Which of the following is a characteristic of the Supreme Laryngeal Mask Airway (LMA)?

Accepted Answer

Includes a built-in drain tube

Answer

Designed specifically for infants

Answer

Utilizes high pressure, low volume cuff design

Answer

Does not have a bite block

Question 10

Critical temperature of oxygen is?

Accepted Answer

-118°C

Answer

400°C

Answer

20°C

Answer

36.5°C

NEET-PG 2013 — Anesthesiology