Who's the dinosaur that taught you this?
There is no quality evidence that kayexalate works. The 2 original trials often cited from 1961 were completed without any controls, included multiple confounding variables, a lack of rigorous statistical analysis, and demonstrated minimal if any effect of Kayexalate on serum K levels (
Scherr, 1961 &
Flinn, 1961). Furthermore, a 1998 study also failed to show a statistically significant difference in serum K levels at 4, 8, and 12 hrs after administration of Kayexalate with sorbitol compared to placebo (
Gruy-Kapral, 1998).
In addition to the lack of evidence demonstrating any efficacy, there have been multiple case reports of intestinal necrosis, GI bleeding, and intestinal perforation secondary to Kayexalate (
Rogers, 2001 &
Rashid 1997).
http://emlyceum.com/2012/04/18/hyperkalemia-answers/
It doesn't do anything. EM lyceum did an excellent review on hyperK treatment a few yrs ago. See above.
The link between ECG changes and K level is also tenuous at best and highly unpredictable.
FWIW I'd personally start Ca gluconate on any patient with a K >6.5.