The physiological marker of the last stage of acute asthma is
Which of the following is a characteristic finding in distal RTA?
The common cause of subarachnoid hemorrhage is:
Hyperkalemia aciduria is seen in
A diabetic patient presents with hyperkalemia and urinary pH < 5.5. What is the MOST likely underlying cause?
Calciphylaxis is a severe life-threatening condition. Which of the following is most commonly associated with it?
What is the primary clinical feature of Henoch-Schonlein purpura?
Interstitial nephritis is common with
All are seen in Samters triad except?
Isolated painful third nerve palsy is a feature of aneurysms of:
NEET-PG 2013 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 101: The physiological marker of the last stage of acute asthma is
- A. Hypocapnia
- B. Hyperoxia
- C. Alkalosis
- D. Increased carbon dioxide levels (Hypercapnia) (Correct Answer)
Explanation: ***Increased carbon dioxide levels (Hypercapnia)*** - In severe, acute asthma, **air trapping** and **muscle fatigue** lead to inadequate ventilation and impaired gas exchange [1]. - This results in a buildup of carbon dioxide in the blood, indicating impending **respiratory failure** and a critical stage of the asthma exacerbation [3]. *Hypocapnia* - **Hypocapnia**, or low blood CO2, is common in the **early stages** of an asthma attack due to **tachypnea** (rapid breathing) in an effort to compensate [1]. - As the condition worsens, the ability to ventilate adequately diminishes, leading to CO2 retention [3]. *Hyperoxia* - **Hyperoxia** means abnormally high levels of oxygen in the blood, which is generally not a physiological marker of acute asthma. - Patients with acute asthma typically experience **hypoxemia** (low oxygen levels) due to ventilation-perfusion mismatch [1]. *Alkalosis* - **Respiratory alkalosis** (high pH due to low CO2) can occur in the early stages as patients **hyperventilate**. - However, in the late stages, as CO2 builds up (**hypercapnia**), the patient shifts towards **respiratory acidosis** (low pH), which is a sign of severe compromise [2], [3].
Question 102: Which of the following is a characteristic finding in distal RTA?
- A. Urine pH < 5.5
- B. Hypokalemia
- C. Hypercalciuria (Correct Answer)
- D. Nephrolithiasis
Explanation: ***Hypercalciuria*** - **Hypercalciuria** is a characteristic finding in distal RTA (Type 1), leading to increased calcium in the urine. - This occurs due to reduced **distal tubular reabsorption of calcium** and increased bone resorption from chronic acidosis. *Urine pH < 5.5* - In distal RTA, the kidneys are unable to acidify the urine properly, leading to a **urine pH > 5.5** [1]. - A urine pH < 5.5 would suggest a normal kidney response to systemic acidosis, ruling out distal RTA. *Hypokalemia* - While hypokalemia can occur in distal RTA, it is not always present and is not the most definitive characteristic finding. - **Hypokalemia** is more characteristic of Type 1 RTA due to increased potassium excretion in an attempt to excrete H+ ions. *Nephrolithiasis* - **Nephrolithiasis** (kidney stones) is a common complication of distal RTA due to hypercalciuria and alkaline urine [2]. - However, hypercalciuria is the *reason* for the increased risk of nephrolithiasis, making it a more fundamental characteristic finding.
Question 103: The common cause of subarachnoid hemorrhage is:
- A. Arterio-venous malformation
- B. Cavernous angioma
- C. Aneurysm (Correct Answer)
- D. Hypertension
Explanation: ***Aneurysm*** - Aneurysms, particularly **saccular** or **berry aneurysms**, are the most frequent cause of **spontaneous subarachnoid hemorrhage (SAH)**, accounting for about 80-85% of cases [2]. - The sudden rupture of an intracranial aneurysm leads to blood spilling into the **subarachnoid space**, causing characteristic symptoms like a "thunderclap headache" [1]. *Arterio-venous malformation* - While AV malformations (AVMs) can cause SAH, they are a less common cause than aneurysms, accounting for approximately 5-10% of cases. - AVMs are abnormal direct connections between arteries and veins that bypass the capillary system and can rupture, leading to SAH or intraparenchymal hemorrhage. *Cavernous angioma* - Cavernous angiomas are abnormal clusters of dilated, thin-walled capillaries that can lead to hemorrhage, but they primarily cause **intraparenchymal hemorrhage** rather than SAH. - They are much less likely to result in diffuse bleeding into the subarachnoid space compared to ruptured aneurysms. *Hypertension* - Hypertension is a significant risk factor for the formation and rupture of aneurysms [1], but it is not a direct cause of SAH itself in the same way an aneurysm rupture is. - While uncontrolled hypertension is often associated with **intracerebral hemorrhage** (bleeding within the brain tissue), its direct role in causing SAH is usually secondary to an underlying vascular abnormality like an aneurysm.
Question 104: Hyperkalemia aciduria is seen in
- A. Type I Renal Tubular Acidosis
- B. Type IV Renal Tubular Acidosis (Correct Answer)
- C. Sigmoidocolostomy procedure
- D. Type II Renal Tubular Acidosis
Explanation: Type IV Renal Tubular Acidosis - This condition is characterized by **hyperkalemia** and **aciduria**, often due to a deficiency in aldosterone or a renal tubular insensitivity to aldosterone [1]. - The impaired aldosterone action leads to reduced potassium excretion and decreased ammonium production, both contributing to **hyperkalemia** and metabolic acidosis [1]. *Type I Renal Tubular Acidosis* - Type I RTA (distal RTA) is characterized by a defect in acid secretion in the distal tubule, leading to **hypokalemia** and metabolic acidosis with persistently high urine pH [2]. - Patients typically excrete an alkaline urine despite systemic acidosis, contrasting with the aciduria seen with hyperkalemia [2]. *Sigmoidocolostomy procedure* - A sigmoidocolostomy can lead to **hyperchloremic metabolic acidosis** due to the reabsorption of chloride and excretion of bicarbonate by the colonic mucosa. - However, it typically causes **hypokalemia** as potassium is secreted into the colonic lumen from the blood. *Type II Renal Tubular Acidosis* - Type II RTA (proximal RTA) involves a defect in bicarbonate reabsorption in the proximal tubule, resulting in **hypokalemia** and metabolic acidosis. - The kidney's ability to acidify urine is still largely intact in the distal nephron once the bicarbonate buffer system is overwhelmed.
Question 105: A diabetic patient presents with hyperkalemia and urinary pH < 5.5. What is the MOST likely underlying cause?
- A. Uremia
- B. Primary hyperaldosteronism
- C. Type IV RTA (Correct Answer)
- D. Type I Renal tubular acidosis
Explanation: ***Type IV RTA*** - Patients with **diabetes mellitus** frequently develop **hyporeninemic hypoaldosteronism**, leading to Type IV RTA [1]. - This condition is characterized by **hyperkalemia** and **acidosis** with a paradoxically low urinary pH (typically < 5.5). *Uremia* - **Uremia** can cause hyperkalemia and acidosis, but it is a broader term for severe kidney failure and not the most specific underlying cause for the given urinary findings. - While patients with uremia can have aciduria, the combination of **diabetic hyperkalemia** and acid urine points more directly to a specific tubular defect. *Primary hyperaldosteronism* - **Primary hyperaldosteronism** is characterized by **hypertension**, **hypokalemia**, and metabolic alkalosis, which is the opposite of the patient's presentation [1]. - This condition involves excessive aldosterone production, leading to increased potassium excretion [1]. *Type I Renal tubular acidosis* - **Type I RTA** (distal RTA) is characterized by the inability to acidify urine, resulting in a **urinary pH > 5.5** despite systemic acidosis [1]. - While it can cause hypokalemia (due to increased distal K+ secretion) and acidosis, the elevated urinary pH is a key differentiating factor from this patient's presentation [1].
Question 106: Calciphylaxis is a severe life-threatening condition. Which of the following is most commonly associated with it?
- A. Parathyroidectomy
- B. Medullary carcinoma thyroid
- C. Hyperthyroidism
- D. End stage Renal disease (Correct Answer)
Explanation: ***End stage Renal disease*** - Calciphylaxis frequently occurs in patients with **end-stage renal disease**, primarily associated with **secondary hyperparathyroidism** [1] and **calcium-phosphate imbalance**. - It leads to **cutaneous ischemia** and necrosis, often requiring aggressive management due to its high **mortality rate**. *Parathyroidectomy* - While parathyroidectomy may affect calcium levels, it is not directly linked to calciphylaxis. - Calciphylaxis more commonly develops due to underlying **chronic renal failure** [1] rather than surgical interventions. *Hyperthyroidism* - Hyperthyroidism primarily causes symptoms related to metabolism, **thyroid hormone excess**, and does not lead to calciphylaxis. - There is no direct correlation between hyperthyroid states and the pathophysiology of calciphylaxis. *Medullary carcinoma thyroid* - This condition involves **medullary thyroid carcinoma**, associated with calcitonin production and does not cause calciphylaxis. - Patients typically experience **thyroid-related symptoms** rather than the vascular complications seen in calciphylaxis.
Question 107: What is the primary clinical feature of Henoch-Schonlein purpura?
- A. Abdominal pain due to vasculitis
- B. Joint pain associated with the condition
- C. Kidney involvement in the disease
- D. Skin rash characterized by palpable purpura (Correct Answer)
Explanation: ***Skin rash characterized by palpable purpura*** - **Palpable purpura** is the hallmark cutaneous manifestation of **Henoch-Schonlein purpura (HSP)**, a small-vessel vasculitis [1]. - This rash typically appears on the **lower extremities and buttocks**, reflecting the deposition of IgA in vessel walls [1]. *Abdominal pain due to vasculitis* - While **abdominal pain** is a common feature of HSP due to gastrointestinal vasculitis, it is not considered the primary clinical feature [1]. - Gastrointestinal involvement can manifest with pain, bleeding, and intussusception, but the **skin rash** is more consistently present and diagnostic. *Joint pain associated with the condition* - **Arthralgia** or **arthritis** (joint pain) is seen in a significant number of HSP patients, particularly in the knees and ankles. - However, it is a secondary manifestation, and not the **defining primary sign** of the disease. *Kidney involvement in the disease* - **Renal involvement**, presenting as hematuria and proteinuria, occurs in about one-third of HSP cases and can lead to serious long-term complications. - Despite its significance for prognosis, **kidney disease** is a later and not universally present feature, making the rash the most critical initial diagnostic clue.
Question 108: Interstitial nephritis is common with
- A. Black water fever
- B. Rhabdomyolysis
- C. Tumor lysis syndrome
- D. Nonsteroidal anti-inflammatory drugs (NSAIDs) (Correct Answer)
Explanation: ***Nonsteroidal anti-inflammatory drugs (NSAIDs)*** - **NSAIDs** are a known cause of **acute interstitial nephritis** (AIN), an inflammatory condition affecting the tubules and interstitium of the kidney [1]. - This adverse reaction often manifests as **fever**, **rash**, **eosinophilia**, and **acute kidney injury**, typically 7-10 days after drug exposure. *Black water fever* - **Blackwater fever** is a severe complication of **malaria**, characterized by massive hemolysis leading to **hemoglobinuria**, which darkens the urine. - It primarily causes **acute kidney injury** through **acute tubular necrosis** due to hemoglobin precipitation in the renal tubules, not interstitial nephritis. *Rhabdomyolysis* - **Rhabdomyolysis** involves the breakdown of muscle tissue, releasing myoglobin into the bloodstream, which is toxic to the kidneys. [1] - This condition leads to **acute kidney injury** predominantly through **acute tubular necrosis** due to myoglobin casts obstructing tubules and direct toxicity, not interstitial inflammation. *Tumor lysis syndrome* - **Tumor lysis syndrome** occurs when large numbers of cancer cells are rapidly destroyed, releasing intracellular contents like potassium, phosphate, and nucleic acids. - The high concentration of **uric acid** and **phosphate** in the renal tubules leads to crystal formation, causing **acute kidney injury** primarily through **acute uric acid nephropathy** and **phosphate nephropathy**, rather than interstitial nephritis [1].
Question 109: All are seen in Samters triad except?
- A. Nasal polyp
- B. Aspirin sensitivity
- C. Asthma
- D. Bacterial infection (Correct Answer)
Explanation: ***Bacterial infection*** - **Samter's triad**, also known as aspirin-exacerbated respiratory disease (AERD), consists of **asthma**, **nasal polyps**, and **aspirin sensitivity** (or NSAID sensitivity) [1]. - **Bacterial infection** is not a component of Samter's triad, although patients with nasal polyps may be more prone to secondary bacterial sinusitis. *Asthma* - **Asthma** is one of the three main components of Samter's triad, typically becoming more symptomatic after aspirin ingestion [1]. - Patients experience **bronchoconstriction** and worsening respiratory symptoms. *Nasal polyp* - **Nasal polyps** are a characteristic feature of Samter's triad, often extensive and recurrent [1]. - They contribute to nasal obstruction and chronic rhinosinusitis. *Aspirin sensitivity* - **Aspirin sensitivity** (or NSAID sensitivity) is the third key component, where ingestion of aspirin or other NSAIDs triggers severe respiratory reactions [1]. - This sensitivity is due to an abnormal arachidonic acid metabolism pathway involving **leukotrienes**.
Question 110: Isolated painful third nerve palsy is a feature of aneurysms of:
- A. Aneurysm of the posterior communicating artery (Correct Answer)
- B. Aneurysm of the anterior communicating artery
- C. Aneurysm of the vertebrobasillary artery
- D. Aneurysm of the ophthalmic artery
Explanation: ***Aneurysm of the posterior communicating artery*** - An aneurysm of the **posterior communicating artery (PCOM)** can compress the ipsilateral **oculomotor nerve (CN III)** as it exits the brainstem. - This compression typically affects the **superficial parasympathetic fibers** first, leading to a **dilated pupil** (mydriasis) along with ophthalmoplegia and ptosis, making the third nerve palsy "painful" and "isolated" without other focal neurological deficits. *Aneurysm of the anterior communicating artery* - Aneurysms of the **anterior communicating artery (ACoM)** are more commonly associated with **subarachnoid hemorrhage** and can cause **visual field defects** or **frontal lobe dysfunction**, but generally not isolated CN III palsy. - While rupture can lead to various neurological deficits, isolated painful third nerve palsy due to ACoM aneurysm is atypical. *Aneurysm of the vertebrobasillary artery* - Aneurysms in the **vertebrobasillar system** typically present with symptoms related to **brainstem compression** or ischemia, such as cranial nerve palsies beyond the third nerve, ataxia, or motor/sensory deficits. - Isolated third nerve palsy is an uncommon presentation for vertebrobasilar aneurysms compared to PCOM aneurysms. *Aneurysm of the ophthalmic artery* - **Ophthalmic artery aneurysms** are usually **intraorbital** and can cause **visual loss** due to direct compression of the **optic nerve (CN II)** or orbital structures. - They are less likely to cause isolated painful third nerve palsy, as the third nerve's course is generally not directly compromised by ophthalmic artery aneurysms.