FCPS TOACS · ECG of Hyperkalemia Mock Test

❓ Q1. Describe the ECG findings.

✅ Model Answer:
• Peaked (tented) T waves (earliest) in V2-V4, prolonged PR, widened QRS, loss of P waves, sine wave pattern (severe), VT/VF.
• Progression: peaked T → prolonged PR → wide QRS → loss of P waves → sine wave → VF/asystole.

❓ Q2. What are the causes of hyperkalemia in children? How would you classify them?

✅ Model Answer:
• Pseudohyperkalemia (hemolysis, thrombocytosis).
• Increased intake (IV K+, blood transfusions).
• Transcellular shift (acidosis, rhabdomyolysis, tumor lysis, DKA).
• Decreased excretion (AKI/CKD, CAH, pseudohypoaldosteronism, drugs: ACE inhibitors, spironolactone).

❓ Q3. A child has serum K+ 6.5 mEq/L but a normal ECG and no symptoms. What is the most likely diagnosis and how do you confirm it?

✅ Model Answer:
• Diagnosis: Pseudohyperkalemia.
• Confirm: Repeat with heparinized plasma K+, check for hemolysis, check platelet/WBC count. Normal ECG supports pseudohyperkalemia.

❓ Q4. This patient has K+ 7.2 mEq/L and ECG changes. What is your emergency management plan?

✅ Model Answer:
• Step 1: Calcium gluconate 100-200 mg/kg IV (membrane stabilization).
• Step 2: Insulin 0.1 U/kg + glucose 0.5 g/kg IV (shifts K+ intracellularly).
• Step 3: Albuterol nebulization (2.5-5 mg).
• Step 4: Sodium bicarbonate if acidotic.
• Step 5: Kayexalate 1 g/kg PO/PR (remove K+).
• Step 6: Hemodialysis for severe/refractory cases.

❓ Q5. Why is calcium gluconate given first in hyperkalemia? What is the mechanism and when is it contraindicated?

✅ Model Answer:
• Mechanism: Stabilizes cardiac membrane, raises threshold potential, reduces arrhythmia risk. Does NOT lower K+.
• Contraindication: Digoxin toxicity (may precipitate arrhythmias).
• Dose: Calcium gluconate 100-200 mg/kg IV over 2-5 min.

❓ Q6. How does insulin and glucose lower potassium? What is the dose and how quickly does it work?

✅ Model Answer:
• Mechanism: Insulin stimulates Na-K-ATPase → shifts K+ into cells.
• Dose: Regular insulin 0.1 U/kg IV + glucose 0.5 g/kg IV (D25 2 mL/kg).
• Onset: 10-20 min, peak 30-60 min, duration 4-6 hours.
• Monitor glucose q30-60 min for 4-6 hours.

❓ Q7. What is the role of albuterol in hyperkalemia? How does it work and what is the dose?

✅ Model Answer:
• Mechanism: Beta-2 agonist → stimulates Na-K-ATPase → shifts K+ into cells.
• Dose: Nebulized albuterol 2.5-5 mg (10-15 mg for older children).
• Onset: 15-30 min, peak 30-60 min, duration 2-4 hours.

❓ Q8. When would you use sodium bicarbonate in hyperkalemia? Is it always effective?

✅ Model Answer:
• Indicated in metabolic acidosis (DKA, renal failure).
• Dose: 1-2 mEq/kg IV over 15-30 min.
• Not always effective (less predictable than insulin/albuterol).
• Avoid mixing with calcium (precipitates).

❓ Q9. What is the role of Kayexalate in hyperkalemia? What are the risks?

✅ Model Answer:
• Mechanism: Cation-exchange resin binds K+ in gut → excreted in stool.
• Dose: 1 g/kg PO or PR.
• Risks: Intestinal necrosis (especially with sorbitol), bowel obstruction, hypocalcemia.
• Not first-line emergency treatment.

❓ Q10. When is hemodialysis indicated in hyperkalemia?

✅ Model Answer:
• K+ >7.0 with ECG changes/arrhythmias.
• Refractory hyperkalemia despite medical therapy.
• Hyperkalemia in renal failure (anuria).
• Tumor lysis syndrome with massive K+ release.
• Life-threatening arrhythmias.

❓ Q11. A neonate with ambiguous genitalia, hyponatremia, and hyperkalemia (K+ 7.0). What is the diagnosis and treatment?

✅ Model Answer:
• Diagnosis: 21-hydroxylase deficiency (CAH, salt-wasting).
• Treatment: IV hydrocortisone, fludrocortisone, NS bolus, hyperkalemia management (calcium, insulin/glucose, albuterol).

❓ Q12. A neonate with hyperkalemia, hyponatremia, metabolic acidosis, normal BP, and high aldosterone. What is the diagnosis?

✅ Model Answer:
• Diagnosis: Pseudohypoaldosteronism type 1 (renal resistance to aldosterone).
• Features: Hyperkalemia, hyponatremia, acidosis, normal BP, high aldosterone, normal cortisol.
• Treatment: Sodium supplementation, kayexalate/dialysis; fludrocortisone NOT effective.

❓ Q13. Which drugs commonly cause hyperkalemia in children?

✅ Model Answer:
• ACE inhibitors, ARBs, potassium-sparing diuretics (spironolactone, amiloride), TMP-SMX, NSAIDs, beta-blockers, heparin, calcineurin inhibitors, succinylcholine.

⚕️ FCPS MCPS IMM MD Paediatrics TOACS · Mock Test