Before administering a Kayexalate enema for hyperkalemia, which statement reflects correct administration and expected effect?

• A. Retain the enema for 30 minutes to allow sodium exchange; afterwards, diarrhea occurs
• B. Immediately evacuate the enema and reassess potassium levels
• C. Administer with a laxative to speed the process
• D. Use as a nightly enema for several days to gradually reduce potassium

Answer: (A)

Kayexalate works by exchanging sodium ions for potassium ions in the colon, so it’s the contact time in the bowel that drives potassium removal. Retaining the enema for about 30 minutes allows the resin to bind potassium in the intestinal lumen effectively; if you evacuate immediately, you shortchange that contact time and the resin won’t remove as much potassium as it could. After a proper retention period, the resin and the increased water in the stool typically produce looser stools or diarrhea, reflecting that potassium is being excreted in the stool.

This approach aims to lower serum potassium gradually as it is eliminated through the GI tract, not to produce an immediate drop. It isn’t appropriate to give with a laxative to speed the process, nor to use nightly for several days—the regimen is based on achieving adequate contact time and monitoring response and electrolytes. Also, be mindful of potential risks, such as electrolyte shifts (including possible hypokalemia or hypernatremia) and GI complications, especially if bowel motility is compromised.