Hypocalcemia vs Hypercalcemia
Both calcium imbalances cause cardiac dysrhythmias, but the QT interval moves in opposite directions and the neuromuscular signs are polar opposites. Picking the wrong one on NCLEX means choosing an intervention that worsens the imbalance — and the patient codes.
Side-by-side comparison
- Thyroid/parathyroidectomy; low vitamin D
- Pancreatitis; massive transfusion (citrate binds Ca)
- Hyperparathyroidism; malignancy (bone mets)
- Immobility; thiazides, excess vitamin D
- ★+ Trousseau / Chvostek; tetany
- Numbness, tingling; laryngospasm risk
- ★Stones, bones, groans, moans
- Muscle weakness, hyporeflexia, fatigue
- ★Ca²⁺ <8.5; prolonged QT, torsades risk
- Phosphorus HIGH (inverse to Ca²⁺)
- Ca²⁺ >10.5; shortened QT
- Phosphorus LOW
- Seizure precautions
- Trach tray at bedside post-thyroidectomy
- Telemetry during IV calcium
- Aggressive IV NS to promote calciuresis
- Encourage mobility; fall precautions
- Telemetry; strain urine for stones
- IV calcium gluconate, slow push 10–20 min
- Vitamin D replacement
- Calcitonin or bisphosphonates per order
- Loop diuretic only if fluid overloaded
- Increase calcium + vitamin D intake
- Report tingling, muscle spasms
- Increase fluids; stay mobile
- Avoid calcium/vitamin D supplements
- ★Laryngospasm → airway emergency
- Torsades de pointes; seizures
- Bradycardia, heart block, arrest
- Potentiated digoxin toxicity
- Decreased contractility; hypotension
- Tetany, respiratory compromise
- Renal calculi; bone pain
- Cardiac arrest; coma
Hypocalcemia (< 8.5 mg/dL)
- Thyroid/parathyroidectomy; low vitamin D
- Pancreatitis; massive transfusion (citrate binds Ca)
Hypercalcemia (> 10.5 mg/dL)
- Hyperparathyroidism; malignancy (bone mets)
- Immobility; thiazides, excess vitamin D
Hypocalcemia (< 8.5 mg/dL)
- ★+ Trousseau / Chvostek; tetany
- Numbness, tingling; laryngospasm risk
Hypercalcemia (> 10.5 mg/dL)
- ★Stones, bones, groans, moans
- Muscle weakness, hyporeflexia, fatigue
Hypocalcemia (< 8.5 mg/dL)
- ★Ca²⁺ <8.5; prolonged QT, torsades risk
- Phosphorus HIGH (inverse to Ca²⁺)
Hypercalcemia (> 10.5 mg/dL)
- Ca²⁺ >10.5; shortened QT
- Phosphorus LOW
Hypocalcemia (< 8.5 mg/dL)
- Seizure precautions
- Trach tray at bedside post-thyroidectomy
- Telemetry during IV calcium
Hypercalcemia (> 10.5 mg/dL)
- Aggressive IV NS to promote calciuresis
- Encourage mobility; fall precautions
- Telemetry; strain urine for stones
Hypocalcemia (< 8.5 mg/dL)
- IV calcium gluconate, slow push 10–20 min
- Vitamin D replacement
Hypercalcemia (> 10.5 mg/dL)
- Calcitonin or bisphosphonates per order
- Loop diuretic only if fluid overloaded
Hypocalcemia (< 8.5 mg/dL)
- Increase calcium + vitamin D intake
- Report tingling, muscle spasms
Hypercalcemia (> 10.5 mg/dL)
- Increase fluids; stay mobile
- Avoid calcium/vitamin D supplements
Hypocalcemia (< 8.5 mg/dL)
- ★Laryngospasm → airway emergency
- Torsades de pointes; seizures
Hypercalcemia (> 10.5 mg/dL)
- Bradycardia, heart block, arrest
- Potentiated digoxin toxicity
Hypocalcemia (< 8.5 mg/dL)
- Decreased contractility; hypotension
- Tetany, respiratory compromise
Hypercalcemia (> 10.5 mg/dL)
- Renal calculi; bone pain
- Cardiac arrest; coma
★ marks the fact that sets a column apart.
Clinical Pearl
Trousseau's and Chvostek's = nerves too excitable = LOW calcium; "bones, stones, groans, moans" = HIGH calcium.
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