NEET-PG 2012 Practice Questions

Q: Who is known for demonstrating the levels of ether anesthesia?

Guedel. ***Guedel*** - Arthur Guedel developed and refined the **stages and planes of ether anesthesia** based on clinical observations of respiratory patterns, eye signs, and muscle tone. - His classification system, known as the **Guedel stages**, provided a systematic approach to monitoring anesthetic depth, especially useful before the advent of modern anesthetic agents and monitoring equipment. *Morton* - **William T.G. Morton** is credited with the first successful public demonstration of sulfuric ether as a surgical anesthetic in 1846 during a tooth extraction. - While he pioneered the use of ether for anesthesia, he did not develop the classic stages of anesthetic depth. *Thompson* - There is no widely recognized historical figure named Thompson who is primarily known for defining the **levels or stages of ether anesthesia**. - This name is not associated with the primary discovery or classification of anesthetic depth. *None of the options* - This option is incorrect because **Guedel** is specifically known for his work in defining the stages of ether anesthesia. - Guedel's contributions were significant in standardizing anesthetic practice for many years.

Q: What does the Dibucaine number indicate in clinical practice?

Atypical acetylcholinesterase activity. ***Atypical acetylcholinesterase activity*** - The **Dibucaine number** quantifies the inhibition of **pseudocholinesterase (butyrylcholinesterase)** by the local anesthetic dibucaine. - A low Dibucaine number (e.g., < 20-30) indicates a genetically determined **atypical variant** of pseudocholinesterase, leading to prolonged duration of action of drugs like succinylcholine. *Potency of muscle relaxants* - The potency of muscle relaxants is typically assessed by the **ED95**, which is the dose required to produce 95% suppression of twitch response. - While Dibucaine is a local anesthetic that can cause muscle relaxation, the **Dibucaine number** specifically evaluates an enzyme's activity, not the strength of the relaxant itself. *Potency of general anesthetics* - The potency of general anesthetics is primarily measured by the **Minimum Alveolar Concentration (MAC)** required to prevent movement in 50% of patients in response to a noxious stimulus. - The Dibucaine number is unrelated to the mechanism or potency of general anesthetic agents. *None of the options* - This option is incorrect because **Atypical acetylcholinesterase activity** accurately describes what the Dibucaine number indicates. - The Dibucaine number is a specific laboratory test used to identify genetic variations in butyrylcholinesterase, which has significant clinical implications for drug metabolism.

Q: All of the following cause myocardial depression except:

Etomidate. ***Etomidate*** - **Etomidate** is known for its **hemodynamic stability** and minimal effect on myocardial contractility, making it a suitable induction agent for patients with cardiovascular compromise. - While it can cause some decrease in systemic vascular resistance, it maintains **cardiac output** much better than other agents listed. *Halothane* - **Halothane** is a potent volatile anesthetic that directly depresses **myocardial contractility** and reduces cardiac output. - It sensitizes the myocardium to **catecholamines**, increasing the risk of arrhythmias. *Thiopentone* - **Thiopentone** (thiopental) is a barbiturate that causes significant **dose-dependent myocardial depression** and systemic vasodilation. - This can lead to a substantial decrease in **blood pressure** and cardiac output, especially with rapid administration. *Ketamine* - Although ketamine often causes an increase in heart rate and blood pressure due to **sympathetic stimulation**, it can also have a direct **myocardial depressant effect** when the sympathetic nervous system is exhausted or blocked. - Its indirect stimulant effects *can mask* a direct negative inotropic effect on the myocardium.

Q: Which of the following skin lesions is not classified as a nevus of melanocytes?

Becker nevus. ***Becker nevus*** - A **Becker nevus** is a **hamartoma** of the **epidermis, dermis, and hair follicles**, characterized by increased epidermal basal layer pigmentation and smooth muscle hyperplasia. - While it contains increased **melanin**, it does **not** involve a proliferation of **melanocytes** themselves, differentiating it from true melanocytic nevi. - It is an **organoid hamartoma** with epidermal and dermal components, not a melanocytic lesion. *Mongolian spot* - A **Mongolian spot** is a **dermal melanocytosis** where melanocytes are entrapped in the dermis during their migration from the neural crest to the epidermis. - While technically termed a "melanocytosis" rather than a "nevus," it represents an **ectopic collection of dermal melanocytes** and is classified among melanocytic lesions. - Unlike Becker nevus, it involves an actual abnormal distribution of melanocytes (not just increased melanin). *Congenital melanocytic nevus* - A **congenital melanocytic nevus** is a benign proliferation of **melanocytes** present at birth, involving the dermis and/or epidermis. - These are true **melanocytic nevi**, with a risk of malignant transformation, particularly in larger lesions (>20 cm). *Dysplastic nevus* - A **dysplastic nevus** (atypical nevus) is an atypical melanocytic nevus with architectural and cytological atypia, considered a potential precursor to melanoma. - It is classified as a **melanocytic nevus** due to the proliferation of atypical melanocytes with architectural disorder.

Q: Which of the following is NOT a characteristic of dermatophytosis?

Subdermal infection. ***Subdermal infection*** - Dermatophytosis, or **ringworm**, is characterized by infection of the **superficial keratinized tissues** (skin, hair, nails) and does not typically extend into the subdermal layers. - While fungal infections can be systemic or deep, dermatophytes specifically are restricted to the **stratum corneum** and other dead keratinized structures. *Scaly skin* - **Scaling** is a very common characteristic of dermatophyte infections due to the fungus proliferating within the **stratum corneum**, leading to increased epidermal turnover and shedding. - The scaling can be fine or coarse, often presenting in an **annular (ring-like)** pattern. *Itchy skin* - **Pruritus (itching)** is a prominent symptom of dermatophytosis, often leading patients to seek medical attention. - The itching can range from mild to severe, contributing to discomfort and potential secondary skin excoriations. *Superficial infection* - Dermatophytosis is by definition a **superficial fungal infection**, meaning it is confined to the outermost layers of the skin, hair, and nails. - These fungi produce enzymes such as **keratinases** that allow them to digest keratin, but they generally do not invade viable tissue below the epidermis.

Q: Oculoorogenital ulcers are associated with which of the following conditions?

Behcet's disease. ***Behcet's disease*** - This condition is characterized by **recurrent oral and genital ulcers**, along with **ocular inflammation** (e.g., uveitis), perfectly matching the "Oculoorogenital ulcers" description. - It is a **chronic, relapsing inflammatory disease** of unknown etiology involving vasculitis affecting various organ systems. *Lichen planus* - This is a chronic inflammatory condition affecting the **skin, hair, nails, and mucous membranes**. - While it can cause oral lesions, it typically presents as **purple, polygonal, pruritic papules** on the skin and does not cause genital ulcers or significant ocular involvement like Behcet's. *Systemic lupus erythematosus (SLE)* - SLE is a **systemic autoimmune disease** with diverse manifestations, including skin rashes, arthritis, and internal organ involvement. - Oral ulcers can occur, but **genital ulcers and severe ocular inflammation** as a prominent triad are not typical diagnostic features of SLE. *Psoriasis* - This is a common **chronic inflammatory skin disease** characterized by well-demarcated erythematous plaques with silvery scales. - Psoriasis primarily affects the skin and joints, and **does not typically present with oral, genital, or ocular ulcers** as described.

Q: Which anaesthetic agent is neither metabolised by liver nor by kidney?

Atracurium. ***Atracurium*** - **Atracurium** undergoes **Hofmann elimination**, a non-enzymatic chemical degradation in plasma, and also **ester hydrolysis** by non-specific plasma esterases [2]. - This unique metabolism makes its elimination largely independent of **liver** and **kidney function**, making it a good choice for patients with organ dysfunction [2]. *Vecuronium* - Primarily metabolized by the **liver** into active and inactive metabolites [1]. - Its elimination can be prolonged in patients with **hepatic impairment** [1]. *Pancuronium* - Undergoes significant **hepatic metabolism** and subsequent **renal excretion** of both parent drug and metabolites [1]. - Its duration of action is significantly affected by both **liver** and **kidney dysfunction** [1]. *Rocuronium* - Primarily eliminated unchanged via **biliary excretion** (liver) [1]. - Its duration of action is prolonged in patients with **hepatic impairment** [1].

Q: Which local anesthetic is known for its vasoconstrictive properties?

Cocaine. ***Cocaine*** - Cocaine is unique among local anesthetics for its inherent **sympathomimetic** properties, leading to **vasoconstriction**. - This vasoconstriction is due to its ability to block the reuptake of **norepinephrine** and other catecholamines at adrenergic nerve terminals. *Procaine* - Procaine is an **ester-type** local anesthetic that typically causes **vasodilation**, which can lead to rapid systemic absorption and a shorter duration of action. - It does not possess any inherent vasoconstrictive properties. *Lidocaine* - Lidocaine, an **amide-type** local anesthetic, generally causes **vasodilation** at clinical concentrations. - Due to this vasodilatory effect, **epinephrine** is often added to lidocaine preparations to prolong its action and reduce systemic absorption. *Chlorprocaine* - Chlorprocaine is another **ester-type** local anesthetic known for its rapid onset and short duration of action. - It primarily causes **vasodilation**, similar to procaine, and has no intrinsic vasoconstrictive effects.

Q: Which chamber enlargement shows a double right heart border with a wide subcarinal angle?

Left atrium. ***Left atrium*** - A **double right heart border** on a chest X-ray is a classic sign of **left atrial enlargement**, as the enlarged left atrium bulges into the right atrial silhouette. - The **wide subcarinal angle** (angle between the mainstem bronchi) also indicates left atrial enlargement, as the expanding left atrium pushes the bronchi apart. *Left ventricle* - **Left ventricular enlargement** primarily manifests as a **downward and leftward displacement of the apex** and increased cardiac silhouette on the left. - It does not typically cause a double right heart border or widening of the subcarinal angle. *Right atrium* - **Right atrial enlargement** usually presents as a **prominent right heart border** that extends further to the right than normal. - It does not result in a double right heart border or affect the subcarinal angle. *Right ventricle* - **Right ventricular enlargement** leads to an **anterior bowing of the sternum** (in severe cases) and an upward and leftward displacement of the cardiac apex. - It pushes the left ventricle posteriorly and does not produce a double right heart border or a wide subcarinal angle.

Q: Investigation of choice for multiple sclerosis

MRI. ***MRI*** - **Magnetic Resonance Imaging (MRI)** is the investigation of choice for **multiple sclerosis** due to its superior ability to visualize **demyelinating plaques** in the brain and spinal cord. - It can detect both **new and old lesions**, crucial for diagnosis and monitoring disease progression, according to the **McDonald criteria**. *CT* - **Computed Tomography (CT) scans** are generally less sensitive than MRI in detecting the subtle **demyelinating lesions** characteristic of multiple sclerosis. - While it can sometimes show larger lesions, it often misses smaller or early-stage plaques, making it less suitable for initial diagnosis. *USG* - **Ultrasound (USG)** is primarily used for visualizing soft tissues and vascular structures, not for detailed imaging of the brain or spinal cord parenchyma. - It has no role in the diagnosis or monitoring of **multiple sclerosis**. *PET* - **Positron Emission Tomography (PET) scans** are used to assess metabolic activity and perfusion, often in oncology or certain neurological disorders like Alzheimer's or Parkinson's disease. - It is not routinely used for the diagnosis of **multiple sclerosis**, as it does not clearly visualize the **demyelinating lesions**.

Question 1

Who is known for demonstrating the levels of ether anesthesia?

Accepted Answer

Guedel

Answer

Morton

Answer

Thompson

Answer

None of the options

Question 2

What does the Dibucaine number indicate in clinical practice?

Accepted Answer

Atypical acetylcholinesterase activity

Answer

Potency of muscle relaxants

Answer

Potency of general anesthetics

Answer

None of the options

Question 3

All of the following cause myocardial depression except:

Accepted Answer

Etomidate

Answer

Halothane

Answer

Thiopentone

Answer

Ketamine

Question 4

Which of the following skin lesions is not classified as a nevus of melanocytes?

Accepted Answer

Becker nevus

Answer

Dysplastic nevus

Answer

Congenital melanocytic nevus

Answer

Mongolian spot

Question 5

Which of the following is NOT a characteristic of dermatophytosis?

Accepted Answer

Subdermal infection

Answer

Scaly skin

Answer

Itchy skin

Answer

Superficial infection

Question 6

Oculoorogenital ulcers are associated with which of the following conditions?

Accepted Answer

Behcet's disease

Answer

Lichen planus

Answer

Systemic lupus erythematosus (SLE)

Answer

Psoriasis

Question 7

Which anaesthetic agent is neither metabolised by liver nor by kidney?

Accepted Answer

Atracurium

Answer

Vecuronium

Answer

Pancuronium

Answer

Rocuronium

Question 8

Which local anesthetic is known for its vasoconstrictive properties?

Accepted Answer

Cocaine

Answer

Lidocaine

Answer

Chlorprocaine

Answer

Procaine

Question 9

Which chamber enlargement shows a double right heart border with a wide subcarinal angle?

Accepted Answer

Left atrium

Answer

Left ventricle

Answer

Right atrium

Answer

Right ventricle

Question 10

Investigation of choice for multiple sclerosis

Accepted Answer

MRI

Answer

CT

Answer

USG

Answer

PET

NEET-PG 2012

Anesthesiology

Dermatology

Internal Medicine

Pharmacology

Radiology