FMGE 2025 - General Medicine PYQs Practice Questions

Q: A young female has episodes of binge eating followed by self-induced vomiting. Which of the following acid- base disturbance is she likely to have?

Metabolic alkalosis. ***Metabolic alkalosis***- Self-induced vomiting results in the significant loss of **gastric hydrochloric acid (HCl)**, leading to a net gain of bicarbonate (HCO3-) in the blood, causing metabolic alkalosis [1, 2].- This condition is often exacerbated by **volume depletion** (due to fluid loss), leading to a state known as "**contraction alkalosis**," where the kidneys attempt to conserve volume even at the expense of excreting bicarbonate [1].*Respiratory acidosis*- This condition is characterized by **hypoventilation** leading to the retention of **carbon dioxide (CO2)** and an increase in carbonic acid, lowering the pH [2].- It is typically seen in conditions compromising respiratory drive or function, such as COPD exacerbations, narcotic overdose, or severe pneumonia.*Respiratory alkalosis*- This disturbance is caused by **hyperventilation**, which results in excessive loss of **carbon dioxide (CO2)**, leading to low PCO2 and elevated pH [3].- While anxiety may be a component of eating disorders, the primary physiologic effect of vomiting is related to acid loss, not sustained hyperventilation causing respiratory alkalosis.*Metabolic acidosis*- This is caused by either the **addition of fixed acids** (e.g., lactic acidosis, diabetic ketoacidosis) or the **loss of bicarbonate** (e.g., severe diarrhea or renal tubular dysfunction) [2].- Vomiting directly causes loss of acid, which is the opposite mechanism needed to induce metabolic acidosis [2]. [Practice more General Medicine PYQs on OnCourse]

Q: A child was brought to the casualty with complaints of vomiting and loose stools with a history of laxative use. On examination, arrhythmia is present. What will be the abnormality present?

Hypokalemia. ***Hypokalemia*** - **Laxative abuse** leads to significant gastrointestinal losses of fluid and electrolytes, particularly **potassium** - Combined with **vomiting and loose stools**, potassium depletion is further aggravated - **Hypokalemia causes cardiac arrhythmias** through altered myocardial excitability - **ECG changes** include: U waves, T wave flattening, ST segment depression, prolonged QT interval, and risk of ventricular arrhythmias - This is a classic presentation requiring **urgent potassium replacement** *Hypocalcemia* - Presents with **tetany, carpopedal spasm**, and perioral numbness - ECG shows **prolonged QT interval** but not typical arrhythmias seen here - Not primarily associated with laxative abuse *Hyperkalemia* - Causes **peaked T waves, widened QRS**, and bradyarrhythmias - Occurs with **renal failure or potassium retention**, not GI losses - Opposite of what occurs with laxative abuse and diarrhea *Hyponatremia* - Primarily causes **CNS symptoms**: confusion, seizures, altered sensorium - Cardiac arrhythmias are **not a typical feature** - Can occur with fluid losses but doesn't explain the arrhythmia [Practice more General Medicine PYQs on OnCourse]

Question 1

A young female has episodes of binge eating followed by self-induced vomiting. Which of the following acid- base disturbance is she likely to have?

Accepted Answer

Metabolic alkalosis

Answer

Respiratory acidosis

Answer

Metabolic acidosis

Answer

Respiratory alkalosis

Question 2

A child was brought to the casualty with complaints of vomiting and loose stools with a history of laxative use. On examination, arrhythmia is present. What will be the abnormality present?

Accepted Answer

Hypokalemia

Answer

Hypocalcemia

Answer

Hyperkalemia

Answer

Hyponatremia

FMGE 2025 — General Medicine