Potential risk of underdosing with calcium gluconate in severe hyperkalaemia

Why is this action required?

Severe hyperkalaemia (≥ 6.5 mmol/L of potassium) is a life-threatening emergency. The risk of associated arrhythmias and cardiac arrest increases in proportion to the severity of elevated potassium and can be unpredictable. Calcium salts do not reduce serum potassium but are given to stabilise the myocardium and prevent cardiac arrhythmias.

Measures to lower potassium levels must also be instituted immediately. ECG changes provide evidence of toxicity but may take time to develop and may not be present initially. Calcium salts are effective within 3 minutes at improving adverse ECG appearances (e.g. narrowing of the QRS complex). The dose should be repeated if there is no effect within 5-10 minutes. The duration of action is only 30-60 minutes, so further doses may be necessary if hyperkalaemia remains uncontrolled (1).

Local guidelines should reflect that:

• A 30ml IV dose of calcium gluconate 10% should be given over 10 minutes or a 10ml IV dose of calcium chloride 10% should be given over 10 minutes in patients with ECG changes to stabilise the myocardium and prevent/treat reversible cardiac arrhythmias.
• The effect of calcium salts is temporary. Repeat calcium doses if adverse ECG changes remain after 5 to 10 minutes.
• Urgent expert advice should be sought about administering calcium in patients with severe hyperkalaemia without ECG changes.
• ECG monitoring is advised for potassium levels above 6.0mmol/L. Continue to monitor ECG and serum potassium while severe hyperkalaemia is being treated.
• Involvement from critical care and advanced life support / outreach teams may facilitate more rapid and co-ordinated treatment.

What evidence supports the issuing of this HSE NPSA?

Analysis of UK patient safety incident data included a fatal outcome and serious harm following underdosing of calcium gluconate in severe hyperkalaemia (2). There is also evidence that there has been underdosing in the Irish context following a review of HSE incident data. No direct link from potential underdosing issues to poor patient outcomes were highlighted. However, some incidents that reported the deterioration of patients referenced the administration of low doses of calcium gluconate. There is also evidence that the incorrect lower dose of calcium gluconate has been referenced in some local Irish hospital guidelines.

Irish reference resources are currently limited and no national guidelines are available at this time. The correct dosing of calcium gluconate for the treatment of severe hyperkalaemia is referenced in a number of international resources (1,3,4)

Note: Product information, including the ‘Summary of Product Characteristics’ is available via www.hpra.ie for authorised medicines, including calcium chloride. Currently there are no intravenous calcium gluconate products with a marketing authorisation in Ireland.

Please note:

• Tissue necrosis is a serious adverse event if extravasation occurs during administration of both IV calcium salts. Ensure reliable intravenous access and test with flush prior to administration.

What stakeholders were involved in issuing this HSE National Patient Safety Alert?

This alert was adapted from a UK National Patient Safety Alert (2). It has been adapted for the Irish Healthcare setting collaboratively by the following:

• National Clinical Lead for Renal Services
• HSE National Clinical Lead for Emergency Medicine
• HSE Nurse Lead Emergency Medicine Programme
• HSE National Clinical Lead for Anaesthesiology & Critical Care
• HSE National Clinical Lead for Cardiology
• National Quality & Patient Safety Directorate -Incident Management Team
• National Quality & Patient Safety Directorate -Medication Safety Team
• Irish Medication Safety Network
• Input from Health Products Regulatory Authority
• HSE National Patient Safety Alerts Committee

References

Please note that the non-Irish references are used to highlight the dosing requirements of calcium gluconate only, and have not formally been endorsed in full in Ireland.

(1) UK Adult Renal Association Clinical Practice Guidelines (2020) for the treatment of severe hyperkalaemia

(2) NatPSA June 2023 007 MHRA

(3) BNF – Medicines complete

(4) European Resuscitation Council Guidelines for emergency treatment of hyperkalaemia

is a HSE NPSA supporting infographic that uses non-technical language in plain English to explain; what a HSE NPSA is, why it is being issued and what it means for patients, service users or their families.

It also outlines what (if anything) the patient, service user or their family may need to do if the alert is relevant to their care.