Thread by @jamiekwillows

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Hyperkalaemia treatment

KDIGO have just published their conference conclusions on managing acute #hyperkalaemia so I run through some learning points, some criticisms and the bits I’m not sure about as a renal reg.

#medtwitter #nephpearls #meded

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Before we start - why do we care?

Because hyperkalaemia associates with a large increase in risk of death in the next 24 hours.

☠️ mortality not necessarily caused by the hyperkalaemia itself, but can indicate that something bad is happening

ncbi.nlm.nih.gov/m/pubmed/19546…

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So, the KDIGO conference paper.

Firstly, no one can even agree on the definition of hyperK. What’s up with the Swiss? 4.5mmol/l as the upper limit of normal? Compare this with some values used in research papers.....!

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A pearl in diagnosis - suspect pseudohyperkalaemia in patients with very high WCC or platelet counts. Prove it by taking a VBG straight to the gas machine (no time for K release from cells so you’ll get the true K value and avoid the harms of unnecessary treatment)

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In hyperkalaemia, bad ECGs do badly. How much more badly you ask?

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HyperK severity depends on absolute value & ECG appearance. In the text they rightly point out that normal ECGs are common even in severe hyperkalaemia, so don’t use ECGs diagnostically.

(however again the cut-offs for what deserves to be ‘mild’ or ‘moderate’ are debatable)

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KDIGO hyperkalaemia treatment algorithm

Key message #tipsfornewdocs

✅ Don’t use potassium-hiding therapies (iv insulin/dextrose and neb) but do nothing else as it’ll just rebound. You must address the underlying cause and consider potassium-eliminating treatments.

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Algorithm problems IMO

✅ default = iv insulin/dex AND salbutamol
✅ repeat ECG at 5 mins & re-bolus calcium if ECG changes persist (they do mention this in text)
✅ Sodium bicarb 8.4% doesn’t work (solute drag moving K out of cells cancels out benefit of improving pH?)

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Further #tipsfornewdocs that is often mismanaged; the dose of B2-agonist is really big compared to COPD/asthma dose

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I have zero experience of using 5 units of insulin instead of 10 but given how often hypoglycaemia complicates treatment this would be great if equal efficacy - anyone doing this routinely?

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And because I’m often asked - the iv isotonic sodium bicarb checklist for acute hyperkalaemia
✅ an adjunctive treatment, never by itself
✅ acidaemia due to AKI or normal anion gap metabolic acidosis
✅ room for volume
✅ patient can ⬆️RR to blow off CO2
✅ no hypocalcaemia

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Sigh. Don’t think most in UK renal would refer well CKD outpatient to ED because K 6.2 in clinic
- ⬇️ACEi
- K wasting diuretic
- discuss diet
- PO bicarb
- arrange repeat
- don’t send to ED at 11pm

Also don’t forget to r/v ACEi again asap.

If unwell, it’s a different story.

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If you’ve made it this far you may be the type of person to wonder if KDIGO had anything good in their supplementary material. Well, this is as thorough a list of hyperkalaemia risk factors as I’ve ever seen....

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Here’s the paper. Would love to hear other people’s opinions (or disagreements).

kidney-international.org/article/S0085-…