A patient presents with a history of vomiting. Arterial blood gas analysis reveals the following: - pH: 7.5 - pCO₂: 48 mm Hg - HCO₃⁻: 30 mEq/L What is the most likely acid-base abnormality?
A patient with a history of breast cancer underwent Cobalt-60 radiotherapy. She now presents with respiratory distress, and imaging shows haziness in the left lung. What is the most likely diagnosis?
A patient with a history of Graves' disease underwent I-131 ablation therapy. Which of the following is the most likely long-term side effect of this treatment?
In the context of mitral stenosis, which clinical feature is typically observed?
Which factor is most useful for distinguishing Acute Kidney Injury (AKI) from Chronic Kidney Disease (CKD)?
Which of the following is associated with a Graham-Steel murmur?
A patient with a history of throat infection presents with a water hammer pulse. What is the most likely diagnosis?
Which of the following is the management of a HIV positive patient with multiple dog bites?
A patient is diagnosed with Cryptococcal meningitis. What is the treatment?
A 23-year-old female visited the clinician with a solitary thyroid nodule and was advised for thyroid function tests where TSH level is 27.3 mU/L, T3 is 1.24 ng/mL, and T4 is 4.87 μg/dL. Which of the following manifestations is true regarding the condition?
FMGE 2025 - Internal Medicine FMGE Practice Questions and MCQs
Question 21: A patient presents with a history of vomiting. Arterial blood gas analysis reveals the following: - pH: 7.5 - pCO₂: 48 mm Hg - HCO₃⁻: 30 mEq/L What is the most likely acid-base abnormality?
- A. Metabolic alkalosis (Correct Answer)
- B. Respiratory acidosis
- C. Respiratory alkalosis
- D. Metabolic acidosis
Explanation: ***Metabolic alkalosis***- The high pH (7.5) indicates **alkalemia**, while the elevated **bicarbonate (HCO₃⁻)** of 30 mEq/L identifies the primary metabolic cause [3].- The mild elevation in **pCO₂ (48 mm Hg)** shows appropriate respiratory compensation via **hypoventilation**, attempting to normalize the pH [1, 2]. *Metabolic acidosis*- Requires a low **HCO₃⁻** level (< 22 mEq/L) and a low pH (< 7.35), directly contradicting the observed **high pH** (7.5) and high HCO₃⁻.- This state often arises from conditions like **lactic acidosis** or **diabetic ketoacidosis**, which are not supported by these blood gas results [4]. *Respiratory acidosis*- While the **pCO₂ is elevated (48 mm Hg)**, if this were the primary disorder, it would drive the pH toward an **acidemic** state (< 7.35), which is inconsistent with the pH of 7.5 [3].- Elevated pCO₂ in the context of alkalemia indicates that the respiratory change is a secondary, **compensatory response** to the primary metabolic alkalosis [1]. *Respiratory alkalosis*- This condition is characterized by a low **pCO₂** (< 35 mm Hg) leading to alkalemia, typically due to **hyperventilation** [1].- This diagnosis is ruled out because the patient’s pCO₂ is significantly elevated (48 mm Hg), not low.
Question 22: A patient with a history of breast cancer underwent Cobalt-60 radiotherapy. She now presents with respiratory distress, and imaging shows haziness in the left lung. What is the most likely diagnosis?
- A. Radiation Pneumonitis (Correct Answer)
- B. Infective Pneumonia
- C. Pulmonary Embolism
- D. Recurrence of Breast Cancer
Explanation: ***Radiation Pneumonitis*** - This is a non-infectious inflammatory response of the lung parenchyma following radiotherapy, typically occurring **1-6 months** after treatment, which fits the patient's timeline after **Cobalt-60 therapy**. - Imaging findings classically show **diffuse haziness**, consolidation, or ground-glass opacities that are sharply demarcated and conform to the **radiation port**, as seen in the provided chest X-ray. *Recurrence of Breast Cancer* - **Pulmonary metastases** from breast cancer usually present as discrete **nodules**, masses, or lymphangitic carcinomatosis on imaging, not a diffuse haziness confined to a prior radiation field. - The onset of symptoms in this case is more acute and temporally related to radiation therapy, making an inflammatory process like pneumonitis more likely than metastatic recurrence. *Pulmonary Embolism* - While cancer is a risk factor for **pulmonary embolism (PE)**, a chest X-ray is often normal or shows non-specific findings like atelectasis or a **Hampton's hump**; the diffuse haziness seen here is not a typical feature of PE. - Diagnosis of PE requires a **CT pulmonary angiogram (CTPA)** or V/Q scan, as the clinical signs can overlap but the radiographic evidence points elsewhere. *Infective Pneumonia* - **Infective pneumonia** typically presents with symptoms like **fever**, chills, and a productive cough, which are not described in the clinical vignette. - The radiographic opacities in bacterial pneumonia are usually lobar or segmental and do not have the sharp, straight borders that correspond to a radiation field.
Question 23: A patient with a history of Graves' disease underwent I-131 ablation therapy. Which of the following is the most likely long-term side effect of this treatment?
- A. Hypothyroidism (Correct Answer)
- B. Thyroid Storm
- C. Hyperthyroidism
- D. Acute Thyroiditis
Explanation: ***Hypothyroidism*** - The primary mechanism of **I-131 ablation** is the destruction of functional thyroid tissue by radiation, leading to a permanent reduction in hormone production. - **Hypothyroidism** is the most common and often inevitable long-term complication following successful **radioiodine ablation** for conditions like Graves' disease or thyroid cancer, occurring in 80-90% of patients within the first year [1]. - Requires lifelong thyroid hormone replacement therapy. *Acute Thyroiditis* - This is a possible immediate side effect, known as **radiation thyroiditis**, causing transient local pain and tenderness within days to weeks of treatment. - It is a short-term inflammatory response due to radiation-induced thyroid cell damage, not the defining long-term side effect [1]. - Usually self-limiting and managed with NSAIDs or corticosteroids. *Hyperthyroidism* - Although an initial transient surge of thyroid hormones (due to tissue destruction releasing stored hormone) can occur within the first 1-2 weeks after I-131, this is temporary [2]. - The treatment's primary purpose is to permanently cure hyperthyroidism by destroying thyroid tissue. - Persistent or recurrent hyperthyroidism would indicate treatment failure, not a side effect. *Thyroid Storm* - A **thyroid storm** is an acute, life-threatening exacerbation of hyperthyroidism usually precipitated by factors like infection, surgery, or trauma [2]. - While extremely rare, radioiodine therapy can theoretically precipitate a storm in inadequately prepared, severely hyperthyroid patients [2]. - This is **not a likely or common side effect** compared to permanent hypothyroidism, and proper pre-treatment with antithyroid drugs minimizes this risk.
Question 24: In the context of mitral stenosis, which clinical feature is typically observed?
- A. S3 gallop
- B. Loud S1 (Correct Answer)
- C. Muffled heart sounds
- D. Absent S1
Explanation: ***Loud S1*** - Mitral stenosis keeps the mitral leaflets in an open position until late diastole, resulting in an **abrupt and forceful closure** at the onset of systole, producing an abnormally loud S1. - This loud, snapping S1 is one of the **classic auscultatory findings** in non-calcific, mobile mitral stenosis. - The intensity of S1 correlates with valve mobility; as the valve becomes more calcified and immobile, S1 becomes softer. *Absent S1* - An absent or soft S1 indicates a **severely calcified, immobile mitral valve** (very advanced stenosis) or significant mitral regurgitation. - In early to moderate mitral stenosis, the valve leaflets remain mobile enough to generate a loud closure sound. - Loss of S1 intensity suggests progression to severe, end-stage valvular disease. *S3 gallop* - An S3 gallop is a sign of **rapid ventricular filling** caused by volume overload, typically heard in left ventricular systolic heart failure or significant mitral regurgitation. - Since mitral stenosis **restricts diastolic filling** into the left ventricle, an S3 is generally not heard in pure, isolated mitral stenosis. - The presence of S3 in a patient with MS should raise suspicion for coexistent left ventricular dysfunction or mixed valvular disease. *Muffled heart sounds* - Muffled or distant heart sounds suggest pathologies that dampen sound conduction, such as **pericardial effusion**, severe obesity, or emphysema. - Mitral stenosis characteristically produces **accentuated sounds** (loud S1, opening snap, diastolic rumble) rather than muffled sounds. - The presence of muffled sounds should prompt evaluation for alternative or additional cardiac pathology.
Question 25: Which factor is most useful for distinguishing Acute Kidney Injury (AKI) from Chronic Kidney Disease (CKD)?
- A. Blood urea nitrogen (BUN)
- B. Albumin levels (Correct Answer)
- C. Urinary output
- D. Creatinine levels
Explanation: ***Albumin levels (Persistent Albuminuria)*** - The presence of **persistent albuminuria** (albumin excretion in urine >30 mg/24 hours for ≥3 months) is one of the **defining criteria for Chronic Kidney Disease (CKD)** according to KDIGO guidelines [2]. - CKD is diagnosed when either **GFR <60 mL/min/1.73m²** OR **markers of kidney damage** (including albuminuria) persist for **≥3 months** [2]. - AKI typically involves acute tubular necrosis or prerenal azotemia without sustained, chronic albuminuria. While AKI may have transient proteinuria, it does not meet the chronicity criterion. - **Note:** In clinical practice, the **most useful distinguishing factors** are actually **kidney size on ultrasound** (small kidneys in CKD), **duration of elevated creatinine**, and **presence of complications of chronicity** (anemia, renal bone disease). Among the given laboratory markers, persistent albuminuria best indicates chronicity. *Creatinine levels* - Elevated serum **creatinine** reflects reduced GFR and is seen in **both AKI and CKD**. - A **single creatinine value** cannot distinguish between acute and chronic disease [1]. - **Serial measurements** showing trajectory (rapidly rising in AKI vs. chronically stable but elevated in CKD) are helpful, but a single level is not diagnostic [1]. *Urinary output* - Both severe AKI and advanced CKD can present with **oliguria** (<400 mL/day) or **anuria**. - Urinary output reflects current kidney function severity but does not indicate acuity versus chronicity. - **Non-oliguric AKI** is actually common, making urine output an unreliable distinguisher. *Blood urea nitrogen (BUN)* - **BUN** accumulates when GFR decreases and is elevated in **both AKI and CKD**. - A very high **BUN:Creatinine ratio (>20:1)** may suggest **prerenal AKI**, but this is not a reliable distinguisher between acute and chronic kidney disease. - BUN is also affected by non-renal factors (GI bleeding, catabolic states, protein intake).
Question 26: Which of the following is associated with a Graham-Steel murmur?
- A. Pulmonary regurgitation (Correct Answer)
- B. Aortic regurgitation
- C. Hypertrophic obstructive cardiomyopathy (HOCM)
- D. Ventricular septal defect (VSD)
Explanation: Detailed heart murmur assessment is necessary for diagnosis. While early diastolic murmurs are typically associated with valvular regurgitation, the specific Graham-Steel murmur is a high-pitched, early diastolic decrescendo murmur heard best over the pulmonary area [1]. It is specifically caused by pulmonary regurgitation that develops secondary to severe pulmonary hypertension. Ventricular septal defect (VSD) typically causes a pansystolic (holosystolic) murmur heard at the left sternal border. While VSD can lead to severe pulmonary hypertension, the primary associated murmur related to the defect itself is holosystolic. Hypertrophic obstructive cardiomyopathy (HOCM) is characterized by a harsh, mid-systolic ejection murmur heard at the left sternal border or apex [1]. Aortic regurgitation also produces an early diastolic decrescendo murmur, often heard at the left sternal edge [2]. It is due to failure of the aortic valve and is distinct from the Graham-Steel murmur, which is tied to pulmonary hypertension.
Question 27: A patient with a history of throat infection presents with a water hammer pulse. What is the most likely diagnosis?
- A. Rheumatic fever with aortic regurgitation (Correct Answer)
- B. Infective endocarditis
- C. Aortic stenosis
- D. Mitral stenosis
Explanation: ***Rheumatic fever with aortic regurgitation***- The history of a preceding **streptococcal throat infection** suggests **Acute Rheumatic Fever (ARF)**, which is the leading cause of acquired valvular heart disease globally.- **Aortic Regurgitation (AR)** is a common manifestation of rheumatic carditis [1] and characteristically presents with physical signs of high pulse pressure, such as the bounding, rapidly collapsing pulse known as the **water hammer pulse** (Corrigan's pulse) [2].*Infective endocarditis*- Although **infective endocarditis (IE)** can cause acute **Aortic Regurgitation (AR)** due to cusp destruction [3], the history of a preceding **throat infection** is a classic antecedent for **rheumatic fever**, not typical IE.- IE usually presents with fever, new murmur, and systemic emboli, often in patients with pre-existing valve disease or intravenous drug use.*Mitral stenosis*- **Mitral stenosis (MS)** results in decreased flow from the left atrium to the left ventricle, which *does not* lead to wide pulse pressure.- It is characterized by a **loud S1**, **opening snap**, and **mid-diastolic rumble**; MS does not cause a water hammer pulse, which is specific to **Aortic Regurgitation**.*Aortic stenosis*- **Aortic stenosis (AS)** causes mechanical obstruction to left ventricular outflow, resulting in low pulse pressure and a small, slow-rising pulse (**pulsus parvus et tardus**) [4].- AS is hemodynamically the opposite of **Aortic Regurgitation**, and therefore highly unlikely to present with a wide pulse pressure or a **water hammer pulse**.
Question 28: Which of the following is the management of a HIV positive patient with multiple dog bites?
- A. Immunoglobulin only
- B. Rabies vaccine + Immunoglobulin + Wound management (Correct Answer)
- C. Wound management
- D. Rabies vaccine + wound management
Explanation: ***Rabies vaccine + Immunoglobulin + Wound management***- **Category III exposure** (multiple/deep transmural bites) mandates both **Passive Immunization** (Human Rabies Immune Globulin - **HRIG**) and **Active Immunization** (**Rabies Vaccine**) for immediate and long-term protection [1].- Given the patient's **HIV-positive status**, they are considered **immunocompromised**; therefore, the highest level of post-exposure prophylaxis (PEP) is required to ensure adequate viral neutralization and immune response.*Rabies vaccine + wound management*- This regimen is inadequate for **Category III exposure** because it omits **Rabies Immunoglobulin (RIG)**, which provides immediate, neutralizing antibodies before the vaccine takes effect [1].- Omitting RIG is particularly dangerous in an **immunocompromised patient** as the onset of antibody production from the vaccine may be delayed or suboptimal.*Immunoglobulin only*- **Rabies Immunoglobulin (RIG)** provides vital passive immunity but its effects are short-lived, offering only temporary protection.- Effective rabies prevention requires the simultaneous administration of the **active vaccine** series to stimulate sustained, long-term protective antibody production [1].*Wound management*- While essential for reducing local bacterial infections and viral load, **wound management alone** is never sufficient for managing **Category III rabies exposure**.- This option neglects both the immediate (RIG) and subsequent (Vaccine) specific measures required to prevent the invariably fatal neurological disease caused by the **Rabies virus**.
Question 29: A patient is diagnosed with Cryptococcal meningitis. What is the treatment?
- A. L.Amp
- B. Fluconazole
- C. Flucytosine
- D. Flucytosine + L.Amp (Correct Answer)
Explanation: ***Correct: Flucytosine + L.Amp (Liposomal Amphotericin B)*** - This is the **standard induction therapy** for Cryptococcal meningitis as per WHO and CDC guidelines [1] - **Combination therapy** is superior to monotherapy, reducing mortality and improving outcomes [1] - The induction phase lasts **2 weeks**, followed by consolidation with fluconazole [1] - Liposomal Amphotericin B has **better CNS penetration** and fewer nephrotoxic effects compared to conventional Amphotericin B - Flucytosine enhances fungicidal activity and reduces the risk of resistance [1] *Incorrect: L.Amp alone* - Monotherapy with Amphotericin B is **less effective** than combination therapy [1] - Higher rates of treatment failure and relapse when used alone - Should always be combined with flucytosine when available [1] *Incorrect: Fluconazole alone* - Fluconazole is used in **consolidation phase** (after induction) and maintenance therapy - **Not recommended for induction** due to its fungistatic (not fungicidal) action - Slower CSF sterilization compared to combination therapy *Incorrect: Flucytosine alone* - **Never used as monotherapy** due to rapid development of resistance - Must always be combined with Amphotericin B or Azoles - Has good CSF penetration but inadequate as sole agent
Question 30: A 23-year-old female visited the clinician with a solitary thyroid nodule and was advised for thyroid function tests where TSH level is 27.3 mU/L, T3 is 1.24 ng/mL, and T4 is 4.87 μg/dL. Which of the following manifestations is true regarding the condition?
- A. Weight gain (Correct Answer)
- B. Diarrhea
- C. Tachycardia
- D. Heat intolerance
Explanation: ***Weight gain***- The patient's thyroid function tests (TFTs), showing a **highly elevated TSH** (27.3 mU/L) and **low T4** (4.87 μg/dL), confirm a diagnosis of **Primary Hypothyroidism** [1].- Weight gain is a classic symptom of hypothyroidism, resulting from reduced **basal metabolic rate** and frequently accompanied by **fluid retention** leading to *myxedema* [2]. *Heat intolerance*- Heat intolerance is a characteristic feature of **Hyperthyroidism**, where excess thyroid hormone increases heat production.- Patients with hypothyroidism typically experience **cold intolerance** due to decreased thermogenesis [2]. *Tachycardia*- **Tachycardia** (increased heart rate) is a common cardiovascular manifestation of **Hyperthyroidism** due to enhanced adrenergic effects [2].- Hypothyroidism generally leads to **bradycardia** (slow heart rate) and reduced cardiac contractility [2]. *Diarrhea*- Diarrhea is associated with **Hyperthyroidism** because of increased gastrointestinal motility.- Patients suffering from hypothyroidism commonly present with decreased bowel motility, leading to **constipation** [2].