Anesthesiology
3 questionsAll of the following cause myocardial depression except:
What does the Dibucaine number indicate in clinical practice?
Who is known for demonstrating the levels of ether anesthesia?
NEET-PG 2012 - Anesthesiology NEET-PG Practice Questions and MCQs
Question 851: All of the following cause myocardial depression except:
- A. Halothane
- B. Thiopentone
- C. Etomidate (Correct Answer)
- D. Ketamine
Explanation: ***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.
Question 852: What does the Dibucaine number indicate in clinical practice?
- A. Atypical acetylcholinesterase activity (Correct Answer)
- B. Potency of muscle relaxants
- C. Potency of general anesthetics
- D. None of the options
Explanation: ***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.
Question 853: Who is known for demonstrating the levels of ether anesthesia?
- A. Morton
- B. Guedel (Correct Answer)
- C. Thompson
- D. None of the options
Explanation: ***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.
Dermatology
1 questionsWhich of the following is NOT a characteristic of dermatophytosis?
NEET-PG 2012 - Dermatology NEET-PG Practice Questions and MCQs
Question 851: Which of the following is NOT a characteristic of dermatophytosis?
- A. Scaly skin
- B. Itchy skin
- C. Superficial infection
- D. Subdermal infection (Correct Answer)
Explanation: ***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.
Internal Medicine
1 questionsOculoorogenital ulcers are associated with which of the following conditions?
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 851: Oculoorogenital ulcers are associated with which of the following conditions?
- A. Lichen planus
- B. Behcet's disease (Correct Answer)
- C. Systemic lupus erythematosus (SLE)
- D. Psoriasis
Explanation: ***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.
Obstetrics and Gynecology
1 questionsNuchal translucency is used in
NEET-PG 2012 - Obstetrics and Gynecology NEET-PG Practice Questions and MCQs
Question 851: Nuchal translucency is used in
- A. Head scan
- B. MRI neck
- C. ANC USG (Correct Answer)
- D. Anthropometry
Explanation: ***ANC USG*** - **Nuchal translucency** measurement is a key component of the **first-trimester antenatal ultrasound** (ANC USG). - It helps in screening for chromosomal abnormalities like **Down syndrome (Trisomy 21)** and certain cardiac defects. *Head scan* - A head scan (e.g., CT or MRI of the head) is used to evaluate the **brain** and **skull** for conditions like tumors, strokes, or trauma. - It is not routinely used for fetal screening or nuchal translucency assessment. *MRI neck* - **MRI of the neck** is employed to visualize soft tissues, blood vessels, and bones in the neck region. - Its primary use is in diagnosing conditions like cervical disc herniations, spinal cord compression, or neck masses, not for fetal screening. *Anthropometry* - **Anthropometry** involves the measurement of the human body, such as height, weight, and limb circumference. - While general measurements are taken during pregnancy, anthropometry specifically does not refer to the assessment of nuchal translucency.
Pharmacology
2 questionsWhich local anesthetic is known for its vasoconstrictive properties?
Which anaesthetic agent is neither metabolised by liver nor by kidney?
NEET-PG 2012 - Pharmacology NEET-PG Practice Questions and MCQs
Question 851: Which local anesthetic is known for its vasoconstrictive properties?
- A. Lidocaine
- B. Chlorprocaine
- C. Procaine
- D. Cocaine (Correct Answer)
Explanation: ***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.
Question 852: Which anaesthetic agent is neither metabolised by liver nor by kidney?
- A. Vecuronium
- B. Pancuronium
- C. Rocuronium
- D. Atracurium (Correct Answer)
Explanation: ***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].
Radiology
2 questionsInvestigation of choice for multiple sclerosis
Which chamber enlargement shows a double right heart border with a wide subcarinal angle?
NEET-PG 2012 - Radiology NEET-PG Practice Questions and MCQs
Question 851: Investigation of choice for multiple sclerosis
- A. CT
- B. MRI (Correct Answer)
- C. USG
- D. PET
Explanation: ***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 852: Which chamber enlargement shows a double right heart border with a wide subcarinal angle?
- A. Left atrium (Correct Answer)
- B. Left ventricle
- C. Right atrium
- D. Right ventricle
Explanation: ***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.