What does ristocetin testing indicate in von Willebrand disease?
Shrinking Lung Syndrome is seen in:
What is the significance of the absence of Vi-antibody in a patient with typhoid fever?
Most common route of infection in pasteurella cellulitis -
Most common complication of diphtheria is -
Eschar is seen in all the Rickettsial diseases except:
What is the causative agent of trench fever?
A patient with first-degree heart block presents with dizziness. What is the most appropriate management for this patient?
What is the most common arrhythmia in ICU patients?
In the context of ventricular tachycardia, what do extra systoles appear as on an electrocardiogram (ECG)?
NEET-PG 2015 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 31: What does ristocetin testing indicate in von Willebrand disease?
- A. Normal agglutination
- B. Increased agglutination
- C. No agglutination
- D. Decreased agglutination (Correct Answer)
Explanation: ***Decreased agglutination*** - In von Willebrand disease, **ristocetin induces less agglutination** due to a deficiency or dysfunction of von Willebrand factor. - This results in **impaired platelet adhesion** [1], crucial for effective hemostasis. *Increased agglutination* - Would suggest an increased platelet interaction, which is **not characteristic of von Willebrand disease**. - It can occur in conditions with enhanced von Willebrand factor, unlike in this case. *No agglutination* - Suggests complete lack of platelet interaction, which is **not typical** in von Willebrand disease. - There is often some level of interaction, albeit reduced, not a total absence of agglutination. *Normal agglutination* - Indicates no abnormalities, which **contradicts the known pathology** of von Willebrand disease. - Patients typically demonstrate decreased levels of agglutination, not normal findings in this test.
Question 32: Shrinking Lung Syndrome is seen in:
- A. SLE (Correct Answer)
- B. Rheumatoid Arthritis
- C. Scleroderma
- D. Sarcoidosis
Explanation: ***SLE*** - **Shrinking lung syndrome (SLS)** is a rare but recognized pulmonary manifestation of **systemic lupus erythematosus (SLE)** [1]. - It is characterized by **dyspnea**, **pleuritic chest pain**, and elevated diaphragms with reduced lung volumes, often without significant interstitial lung disease [1]. *Rheumatoid Arthritis* - While **rheumatoid arthritis** can cause various lung manifestations like **interstitial lung disease (ILD)**, pleural effusions, and rheumatoid nodules, **shrinking lung syndrome** is not typically associated with it [2]. - Lung disease in RA often involves **pulmonary fibrosis** or bronchiolitis, differing from the restrictive physiology of SLS. *Scleroderma* - **Scleroderma (Systemic Sclerosis)** commonly affects the lungs, primarily leading to **interstitial lung disease (ILD)** and **pulmonary hypertension** [1]. - **Shrinking lung syndrome**, with its characteristic restrictive pattern and elevated diaphragms, is not a typical presentation of lung involvement in scleroderma. *Sarcoidosis* - **Sarcoidosis** is characterized by the formation of **non-caseating granulomas**, primarily affecting the lungs and lymph nodes. - Lung involvement in sarcoidosis typically presents as **interstitial lung disease** or nodular infiltrates, not the distinct features of **shrinking lung syndrome** [3].
Question 33: What is the significance of the absence of Vi-antibody in a patient with typhoid fever?
- A. Indicates a poor prognosis
- B. Indicates a favorable prognosis (Correct Answer)
- C. No impact on prognosis
- D. Suggests a negative response to treatment
Explanation: ***Indicates a favorable prognosis*** - The **Vi (Virulence) antigen** is a **polysaccharide capsule** that helps *Salmonella typhi* evade the immune system and is associated with **virulence** and **carrier state development**. - **Absence of Vi-antibody** indicates infection with a **less virulent strain**, successful **immune clearance**, and **lower likelihood** of developing a chronic carrier state. *Indicates a poor prognosis* - The **absence of Vi-antibody** is actually associated with **better outcomes**, not worse prognosis. - **Poor prognosis** in typhoid fever is typically related to complications like **intestinal perforation** or **septic shock**, not Vi-antibody status [1]. *No impact on prognosis* - **Vi-antibody status** is a **recognized prognostic marker** in typhoid fever and does have clinical significance. - The **presence of Vi-antibodies** may indicate **persistent infection** or **carrier state development**, making it a relevant prognostic indicator. *Suggests a negative response to treatment* - **Absence of Vi-antibody** typically indicates **successful treatment response** and **effective clearance** of the organism. - **Negative treatment response** would be evidenced by **persistent fever**, **positive cultures**, or **clinical deterioration** despite appropriate antibiotic therapy.
Question 34: Most common route of infection in pasteurella cellulitis -
- A. Animal bites or scratches (Correct Answer)
- B. Aerosols or dust
- C. Contaminated tissue
- D. Human to human
Explanation: ***Animal bites or scratches*** - *Pasteurella multocida* is a common commensal bacterium in the oral flora of **cats and dogs**. - **Animal bites or scratches** are the primary mode of transmission for *Pasteurella* infections, particularly cellulitis, due to direct inoculation. *Aerosols or dust* - Transmission via **aerosols or dust** is rare for *Pasteurella* infections, which typically require direct contact or inoculation. - While other bacteria can spread this way, *Pasteurella* cellulitis is not commonly acquired through airborne routes. *Contaminated tissue* - While possible in some contexts, **contaminated tissue** is not the most common route of infection for *Pasteurella* cellulitis. - Direct inoculation from an **animal's oral flora** is far more frequent than contact with contaminated environmental tissues. *Human to human* - *Pasteurella* infections are generally **not transmissible from human to human**. - The organism is primarily associated with animals and their bites or scratches.
Question 35: Most common complication of diphtheria is -
- A. Myocarditis (Correct Answer)
- B. Pneumonia
- C. Meningitis
- D. Endocarditis
Explanation: ***Myocarditis*** - Diphtheria toxin can directly damage myocardial cells, leading to inflammation and dysfunction of the heart muscle, making **myocarditis** the most common and serious complication. - This can result in **heart failure**, arrhythmias, and even death, highlighting its significance in diphtheria. *Pneumonia* - While respiratory complications can occur in diphtheria, **pneumonia** is not the most common or life-threatening complication associated with the diphtheria toxin itself. - Secondary bacterial infections might lead to pneumonia, but it is not a direct toxic effect like myocarditis. *Meningitis* - **Meningitis**, an inflammation of the membranes surrounding the brain and spinal cord, is an extremely rare complication of diphtheria. - Diphtheria primarily affects the upper respiratory tract and heart [1], with neurological complications typically manifesting as neuropathies rather than meningitis. *Endocarditis* - Although diphtheria can cause cardiac complications, **endocarditis** (inflammation of the heart's inner lining, including the valves) is not a common complication. - Myocarditis, due to the direct toxic effect on heart muscle, is far more prevalent than endocarditis in diphtheria.
Question 36: Eschar is seen in all the Rickettsial diseases except:
- A. Scrub typhus
- B. Rickettsial pox
- C. Indian tick typhus
- D. Endemic typhus (Correct Answer)
Explanation: ***Endemic typhus*** - **Endemic typhus**, caused by *Rickettsia typhi*, is transmitted by **fleas** and typically presents without an eschar. - The disease is characterized by fever, headache, and a maculopapular rash, but the **inoculation site lesion (eschar) is rare or absent**. *Scrub typhus* - **Scrub typhus**, caused by *Orientia tsutsugamushi*, is known for causing a prominent **eschar** [1] at the site of the **chigger mite bite**. - This **painless black scab** is a classic diagnostic feature of the disease [1]. *Rickettsial pox* - **Rickettsial pox**, caused by *Rickettsia akari*, almost invariably presents with an **eschar**, often referred to as an **inoculation lesion**. - This lesion appears as a papule that vesiculates and then forms a scab, indicating the site of the **mite bite**. *Indian tick typhus* - **Indian tick typhus** (part of the **spotted fever group rickettsioses**), caused by *Rickettsia conorii*, frequently presents with a characteristic **eschar** at the site of the **tick bite**. - This eschar, known as a **tache noire**, is a valuable diagnostic clue in affected patients.
Question 37: What is the causative agent of trench fever?
- A. Q-fever
- B. Boutonneuse fever
- C. Indian tick typhus
- D. Bartonella quintana (Correct Answer)
Explanation: ***Bartonella quintana*** - **Trench fever** is a **rickettsial-like illness** primarily transmitted by the human body louse. - The causative agent is the bacterium **Bartonella quintana**, which causes recurrent fever, headache, and body pains. *Q-fever* - Q-fever is caused by the bacterium **Coxiella burnetii** and is typically transmitted through airborne exposure to contaminated aerosols from infected animals. - It presents with fever, headache, and atypical pneumonia, and is not associated with human body lice. *Boutonneuse fever* - This fever is caused by **Rickettsia conorii**, transmitted by the **brown dog tick**. - Characterized by a **maculopapular rash** and an **eschar (tache noire)** at the site of the tick bite. *Indian tick typhus* - This is a form of spotted fever group rickettsiosis caused by **Rickettsia conorii subspecies indica**, transmitted by ticks [1]. - It presents with fever, rash, and an eschar, similar to boutonneuse fever, but is specified for the Indian subcontinent [1].
Question 38: A patient with first-degree heart block presents with dizziness. What is the most appropriate management for this patient?
- A. Observation and investigation of other causes (Correct Answer)
- B. Pacemaker insertion
- C. Isoprenaline
- D. Atropine
Explanation: ***Observation and investigation of other causes*** - **First-degree heart block** is usually **asymptomatic** and benign, rarely causing dizziness or other symptoms. - The dizziness experienced by the patient is likely due to another underlying condition and warrants **further investigation** rather than direct intervention for the heart block [2], [3]. *Pacemaker insertion* - **Pacemaker insertion** is reserved for **symptomatic heart blocks** of higher degrees (e.g., Mobitz II or complete heart block) or those with significant hemodynamic compromise [1]. - Given that first-degree heart block is typically asymptomatic, inserting a pacemaker would be an **overtreatment** and unnecessary for this condition alone. *Isoprenaline* - **Isoprenaline** is a **beta-agonist** that increases heart rate and AV conduction, sometimes used in certain bradyarrhythmias. - However, for first-degree heart block, which is generally benign, pharmacologic intervention with agents like **isoprenaline** is not typically indicated and carries risks of adverse effects [2]. *Atropine* - **Atropine** is an anticholinergic drug used to **increase heart rate** by blocking vagal stimulation of the SA and AV nodes. - While it can improve AV conduction, it is not indicated for **asymptomatic first-degree heart block** or when symptoms like dizziness are unlikely to be directly caused by the block itself.
Question 39: What is the most common arrhythmia in ICU patients?
- A. Atrial flutter
- B. Atrial fibrillation (Correct Answer)
- C. Atrial Tachycardia
- D. Supraventricular Tachycardia
Explanation: ***Atrial fibrillation*** - **Atrial fibrillation (AF)** is the most prevalent arrhythmia in the general population [1], and its incidence is significantly higher in critically ill patients due to various stressors. - Factors like **sepsis**, **hypoxemia**, **electrolyte imbalances**, **myocardial ischemia**, and **inflammatory states** common in the ICU are known triggers for new-onset AF. *Atrial flutter* - While atrial flutter is a common arrhythmia, its overall incidence in the ICU setting is **less frequent than atrial fibrillation**. - It often involves a **re-entrant circuit** in the right atrium [2], leading to characteristic "sawtooth" waves on ECG. *Atrial Tachycardia* - Atrial tachycardia is a form of **supraventricular tachycardia (SVT)** that originates in the atria but is **less common** than AF in the ICU [2]. - It often presents as a **regular, narrow-complex tachycardia** with discrete P waves. *Supraventricular Tachycardia* - This is a broad term encompassing arrhythmias that originate **above the ventricles** [3], including AF, atrial flutter, and atrial tachycardia. - While SVT as a category is common, **atrial fibrillation is the single most frequent specific arrhythmia** within this group in the ICU.
Question 40: In the context of ventricular tachycardia, what do extra systoles appear as on an electrocardiogram (ECG)?
- A. P wave
- B. QRS complex (Correct Answer)
- C. T wave
- D. R wave
Explanation: ***QRS complex*** - Extra systoles, particularly **premature ventricular contractions (PVCs)**, originate in the ventricles and result in a **wide and bizarre QRS complex** on an ECG [2]. - The QRS complex represents **ventricular depolarization**, and in ventricular tachycardia, the *ventricular activity* dominates the ECG tracing [2]. *P wave* - The **P wave** represents **atrial depolarization** and is typically either absent or dissociated from the QRS complex in ventricular tachycardia [1], [2]. - Its presence or absence helps differentiate supraventricular from ventricular arrhythmias. *T wave* - The **T wave** represents **ventricular repolarization**, which typically follows the QRS complex [1]. - While it will be present, it often appears abnormal or discordant in ventricular tachycardia due to the altered ventricular depolarization. *R wave* - The **R wave** is part of the QRS complex, specifically the first positive deflection. - While an R wave is present within the QRS complex of an extrasystole, referring to the entire **QRS complex** is more accurate as it encompasses the complete ventricular depolarization in an abnormal morphology.