Hyperkalemia

Last week, a patient with hyperkalemia was discussed in morning report.

Causes of hyperkalemia always come down to renal handling of potassium. Dietary (or iatrogenic!) intake of potassium may play a role, but most clinical scenarios revolve around limitations in excretion.

Management options include:
1) Stop the exogenous potassium - this seems simple but is embarassing when missed.

2) Stop offending drugs - this is not the right time for any potassium sparing diuretics or ACE inhibitors

3) Shift the Potassium - This does not equal excretion and is only a temporary fix. Classically, a high glucose load (1 amp of D50W) with an intravenous insulin chaser (1o units iv) is the mainstay cocktail. Other options include intravenous sodium bicarbonate and inhaled beta agonists (8 puffs with aerochamber). Interestingly, beta agonists may be more efficacious than previously believed (see the article below).

4) Dump the Potassium - at the end of the day, you need to rid the body of the excess. A number of options exist. High dose furosemide (assuming this is not oliguric renal failure) is an effective way to mobilize potassium. Potassium binders are often used (kayexalate) but are slow and have other side effects (colonic necrosis!). Finally, hyperkalemia refractory to medical management is an indication for hemodialysis.

Check out CMAJ for a very recent review.