Intravenous Calcium in Severe Hyperkalemia
IV calcium is indicated when severe hyperkalemia is accompanied by electrocardiographic changes or when rapid cardiac membrane stabilization is required [1][2][3]. Calcium gluconate is the preferred formulation for peripheral administration; calcium chloride may be used via a central line when a more concentrated calcium load is desired [1]. The standard dose is 1 g of calcium gluconate administered as an IV push, with the option to repeat once if ECG abnormalities persist [1]. ECG should be reassessed 5 minutes after administration, and patients should be monitored for signs of hypercalcemia, extravasation, and arrhythmia recurrence [1].
Indications for Calcium Administration
- Documented ECG changes (e.g., peaked T waves, widened QRS, sine wave) attributable to hyperkalemia [1][2].
- Serum potassium ≥6.5 mEq/L with high risk for cardiac toxicity, even in the absence of ECG changes [3].
- Need for immediate cardiac membrane stabilization before other potassium‑lowering therapies [2].
Formulation Choice
- Calcium gluconate (10 % solution): Preferred for peripheral IV access due to lower risk of tissue injury [1].
- Calcium chloride (10 % solution): Considered when central venous access is available and a higher elemental calcium dose is desired [1].
Dosing and Administration
| Formulation | Dose | Route | Administration |
|---|---|---|---|
| Calcium gluconate | 1 g (10 mL of 10 % solution) | IV push | Over 2–5 minutes; repeat once if ECG abnormalities persist [1] |
| Calcium chloride | 0.5–1 g (5–10 mL of 10 % solution) | IV push via central line | Over 2–5 minutes; repeat as above [1] |
Monitoring and Precautions
- Obtain baseline ECG before calcium administration [1].
- Repeat ECG 5 minutes after the initial dose; repeat calcium if ECG changes remain [1].
- Monitor serum calcium and ionized calcium levels after repeated dosing [2].
- Observe IV site for signs of infiltration or extravasation, especially with calcium chloride [1].
- Avoid concurrent administration of calcium with other vesicants; ensure patency of line [2].
- Consider contraindications such as hypercalcemia, digitalis toxicity, or severe renal impairment; proceed with caution [2].
Practical Considerations
- Prepare calcium gluconate in a separate syringe to avoid mixing with other IV drugs [1].
- Document timing of dose and ECG findings in the medical record [2].
- Educate staff on the difference between calcium gluconate and calcium chloride to prevent dosing errors [2].