hyperkalemia - EMCrit Blog - Emergency Department Critical Care

Bonus – Is Kayexalate Useless?

In EMCrit Podcast 32, we discussed the management of hyperkalemia. Of course, I recommended kayexalate in the treatment regimen. It is standard of care, right? So I thought, until I heard a brilliant piece by Dr. Siamak (Mak) Moayedi, MD. Dr. Moayedi reviewed the evidence and he found nothing to indicate that kayexalate is effective for the acute management of elevated potassium.

This was too good not to share with you folks, so first I got permission from Amal Mattu (EKG deity). Dr. Mattu had interviewed Dr. Moayedi for this piece and had placed it on the February episode of his excellent EMcast podcast. I also got permission from Rick Nunez, MD who runs the incredible educational resource, EMEDhome.

For more from Dr. Moayedi, listen to his fantastic piece on how to teach procedures from Rob Roger’s, EM:RAP Educators Edition.

References Mentioned in the Piece:

Levine M, Nikkanen H, Palin DJ. The effects of intravenous calcium in patients with digoxin toxicity. J Emerg Med 2011;40:41-46.
Sterns RH, Rojas M, Bernstein P, Chennupati S. Ion-exchange resins for the treatment of hyperkalemia: Are they safe and effective? J Am Soc Nephrol 21: 733-5, 2010.
Scherr L, Ogden DA, Mead AW, et al. Management of hyperkalemia with a cation-exchange resin. N Engl J Med 264: 115-9, 1961.
Flinn RB, Merrill JP, Welzan WR. Treatment of the oliguric patient with a new sodium ion exchange resin and sorbitol: A preliminary report. N Engl J Med 264: 111-5, 1961.
Gruy-Kapral C, Emmett M, Santa Ana CA, et al. Effect of single dose resin-cathartic therapy on serum potassium concentration in patients with end-stage renal disease. J Am Soc Nephrol 9: 1924–30, 1998.
Mahoney BA, Smith WAD, Lo D, et al. Emergency interventions for hyperkalaemia (review).
Cochcran Database of Systematic Reviews 2005, issue 3, 2009.
Kamel K, Wei C. Controversial issues in the treatment of hyperkalaemia. Nephrol Dial Transplant 18: 2215-8, 2003.
Rogers BR, LI SC. Acute colonic necrosis associated with sodium polystyrene sulfonate (kayexalate) enemas in a critically ill patient: Case report and review of the literature. J Trauma 51: 395-7, 2001.
Nyirenda MJ, Tang JI, Padfield PL, Seckl JR. Hyperkalaemia. BMJ 339: 1019-24, 2009.
Bomback A, Woosley JT, Kshirsagar AV. Colonic necrosis due to sodium polystyrene sulfate (kayexalate). Am J of EM 27: 753.e1-753.e2, 2009.
Welsberg LS. Management of severe hyperkalemia. Crit Care Med 36: 3246-51, 2008.
Sood MM, Sood AR, Richardson R. Emergency management and commonly encountered outpatient scenarios in patients with hyperkalemia. Mayo Clin Proc 82: 1553-61, 2007.

Review

J Am Soc Nephrol. 2010 May;21(5):733-5. Ion-exchange resins for the treatment of hyperkalemia: are they safe and effective?

If you want to just hand the Gen Med Residents a Single Article:

Then I think this one by Sterns et al. is the one.

Here is the Audio:

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EMCrit Podcast 42: A phD in EKG with Steve Smith

Today, I got to interview Dr. Stephen Smith. Dr. Smith is faculty at the Hennepin Program and author of one of the best books on EKGs in the ED, The ECG in Acute MI.

Dr. Smith’s EKG Blog is probably the best free EKG site out there for Emergency Physicians and Intensivists.

Here are the points we covered:

1. Ischemia Doesn’t Localize

If you see depressions in just one anatomic area, think reciprocal changes to subtle ST-elevations elsewhere

2. If you see Inferior Depressions, think High Lateral Wall STEMI

here are two good cases from Dr. Smith’s Blog:

Case: This is a 35 yo woman who had LAD occlusion that was very subtle on ECG, but easily seen with inferior ST depression
Case: This is one of a high lateral MI due to OM-2 occlusion that shows up mostly with inferior ST depression.

3. Lateral Wall STEMIs are often Subtle

Case: A patient had chest pain, went to his doctor who did an EKG, said it was fine, and sent my friend home. He had a cardiac arrest at home and was resuscitated because of good CPR by his wife. Later, I asked him to find the ECG. I told him I’m pretty sure it was not normal. And here it is: a very subtle high lateral MI detected by subtle ST depression in II and aVF
Another Case

4. Absolute millimeter criteria for STEMI will often fail you, it is the Pattern that Matters.

5. Benign Early Repolarization and LAD Occlusion can look very similar–You may need to do the math.

Dr. Smith derived this formula:

(1.196 x STE60 in V3 in mm) + (0.059 x computerized QTc in milliseconds) – (0.326 x RA in V4 in mm),

where RA is R-wave amplitude and STE60 is ST elevation at 60ms after the J-point relative to the PR interval.

If the value of the formula is greater than or equal to 23.4, it is MI (Sens, spec, accuracy all around 90%); if less, then it’s early repolarization.

Case: Here is a case that illustrates this, it shows a very subtle anterior STEMI, and how use of the complicated new rule that he developed. One need not use the complicated rule; among other features, it was the long QTc of 455ms that made it unlikely to be normal. The followup ECG is also very instructive.

You can also see a video of the concept

6. If you are calling it BER, there need to be R waves in the Precordial Leads

7. Q-waves can develop instantly after a STEMI

qR waves can develop instantly and are not indicative of poor response to lytics or PCI (J Am Coll Cardiol 1995;25:1084); this concept is not applicable to a QS pattern.

8. If you see a wide (>190 ms) QRS, think Hyperkalemia

9. The treatment for VT with hyper-K is Calcium, Calcium, Calcium

Check out this Case, it says it all

10. Check Out these Two Other Great Sites

HQMEDED: High Quality Medical Education and Ultrasound

The Prehospital 12-lead ECG Blog which despite the name, is great for all levels

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EMCrit Podcast 32 – Treatment of Severe Hyperkalemia

>>> Update: For a new take on kayexalate, see Mak Moayedi’s Lecture

Hey folks. As I get ready for ACEP, I just wanted to get a quick podcast put up. One of the listeners requested an episode on the treatment of hyperkalemia in the ED.

There was a fantastic article published in Critical Care Medicine on the topic by a Dr. Weisberg. I go through my management and discuss some of the pearls from the article.

Weisberg LS. Management of severe hyperkalemia. Crit Care Med. 2008 Dec;36(12):3246-51.

Additional References added Feb 2012

ECG is insensitive and non-specific for severe hyperkalemia issues; essentially is crap (Clin J Am Soc Nephrol 3: 324-330, 2008). ECG peaked T waves, that resolved after K normalized were noted in only 1 of the 14 hyperkalemic patients who went on to have arrhythmia or cardiac arrest. Only half of them had any T-wave changes.