Monday, September 30, 2013

Optimal Treatment for Post-Cardiac Arrest Patient

OK... it's been 2 weeks and it is time for another post.

Few days ago I had an interesting conversation with one of the cardiologist at one of the hospitals I'm working. The case was a 46-year-old post cardiac arrest patient. He had a witnessed collapse at home.  Paramedics arrived shortly after and began ACLS protocols. He was shocked seven times because of persistent VF and received five rounds of epinephrine with ROSC during transfer. Upon arrival his vitals were not terribly bad he was slightly hypotensive and tachycardic, but he's electrocardiogram didn't have ST elevation, but mild ST depressions in the inferior and lateral leads, so he didn't meet criteria to activate the cath lab as a code STEMI. However, this was a post arrest case and based on what I have seen in current literature, he has the best chances of surviving neurologically intact by combining hypothermia and catheterization. So I called the cardiologist on call and presented the case, and suggested that he should start making his way in while we start hypothermia and prepare him for cath. This conversation didn't go well at all. The cardiologist almost had a stroke while talking to me on the phone. He argued that there was no indication to go to the Cath Lab in a post cardiac arrest case without ST elevation in the ECG, and if someone agreed to cath this patient, it was the wrong thing to do and yara yara yard. - OK... no problem, thanks so much doc. Next; I called 2 different cardiologists with the same request. "Would you please take this young, post arrest, ST depression patient to cath? - The third cardiologist finally agreed, so we started cooling the patient and rushed to the cath lab before the cardiologist could change his decision... He found a 90% occluded LMCA. 

Unfortunately this is not an uncommon scenario. The cardiologists tend not to cath post-cardiac arrest patients without STEMIs because this group tends to do worse and it looks bad for their numbers. However... there is support for the cool and cath approach for NSTEMI post cardiac arrest patient in their own literature. Check this out, this is from the Journal of the American College of Cardiology, probably the most influential cardiology journal in the world, right up there with European Society of Cardiology and American Heart Association.

These are the key points of this article
- The lack of ST elevation in the post arrest 12-lead ECG is not a reliable predictor for the absence of acute coronary disease. 
- The NNT with coronary angiography in a post-cardiac arrest patient after cardiac arrest to find an acute culprit lesion needing emergent revascularization among those without ST-segment elevation is, in fact, just 4 patients.
- "Resuscitated cardiac arrest victims without an obvious non- cardiac etiology should undergo emergency coronary angiography and, where indicated, percutaneous coronary intervention. If comatose, they should receive concurrent therapeutic hypothermia. Such an approach can double long-term survival rates among those successfully resuscitated after out-of-hospital cardiac arrest".

Therapeutic hypothermia and early catheterization with PCA when needed, is the best chance for a good outcome in post-cardiac arrest patients regardless of the initial ECG. If they argue otherwise, just refer them to their own journal. However, It will be wise to sit with the cardiologists at 3 pm, have a coffee and agree in a plan for these type of situations and have it all sorted out, so when the ambulance arrives at 3 am things are easier for everybody.

A nice review article with everything included:

Wednesday, September 18, 2013

I am allergic to Penicllin... - Oh, are you really?

You: Sir, are you allergic to anything?
Patient: Oh yeah, I am allergic to Penicillin.
You: What happens when you get Penicillin?
Patient: I don't know, my mom told me I am allergic to it.
You: Did she tell you why or what happened to you?
Patient: Uhhh. Not really, but I think I stopped breathing.
You: Really...?  o_0

Well, you get the idea...

How many patients do we see who say they are allergic to PNC but there is no convincing proof they really are? About 8% of the US population claim being PNC allergic; but skin testing to identify true IgE-mediated allergy is rarely done. Anaphylaxis, the one reaction we care about, is actually quite rare in these patients. In May of this year, in the Journal of Allergy and Immunology, a study was published about this issue ( From 2010 to 2012, 500 patients with histories of penicillin allergy (based on diagnoses recorded in their records) were skin tested in a California allergy department. Negative tests were followed by 1-hour observed oral challenges with amoxicillin. Only 4 patients reacted to one of the two skin-test agents, and another four exhibited positive objective symptoms after oral challenges but none of these reactions were life threatening or required epinephrine, NONE! Fewer than 1 in 50 patients with penicillin allergy histories were truly allergic. Note that this is an allergy clinic, which already selects a higher allergic risk population compared to the undifferentiated patient we see in the ED.

We should stop accepting penicillin allergy history as a reason for lifelong avoidance. All drug reactions should be documented carefully. Patients with severe delayed reactions such as Stevens Johnson syndrome, drug reaction with eosinophilia and systemic symptoms (DRESS), or hemolytic anemia should never be challenged or tested; those with mild delayed reactions probably can undergo oral challenges. For those with potential IgE-mediated reactions (i.e., hives, edema, or other symptoms of anaphylaxis occurring within 1–2 hours), penicillin testing followed by oral challenge is safe and effective. However, are we going to do this in the ED? Abso-freaking-lutely NO. But we can suggest they follow up with their PCP for testing.

I guess for us in the ED, the main issue I hear a lot of noise around, is the cross reactivity with Cephalosporins. In fact, many EHR's flag red lights and sirens when ordering Cephalosporins in patients reporting PNC allergy. Even with the assumption that the patient is truly allergic to PNC, is there a real risk? - The answer is yes, but it is sooooo very small that the meningitis is more likely to kill the patient than the shot of Ceftriaxone. Here is the evidence ( "It is safe to administer cephalosporin antibiotics to penicillin-allergic patients and penicillin skin tests do not identify potential reactors", ( "The widely quoted cross-allergy risk of 10% between penicillin and cephalosporins is a myth". And one more... ( Out of 3.3 million (yes, million) who received PNC, 506,000 received a cephalosporin. The risk of anaphylaxis for those who had a prior event with PNC was < 0.001% after receiving a Cephalosporin.

So, these are my 2 conclusions:

1.- Patients who claim being allergic to PNC, unless they have a good history for skin/airway/hematologic reaction, are probably not.
2.- Cephalosporins are generally safe in patient with history of PNC allergy.

Thank you very much, stay tuned for more myth busting reading.

Saturday, September 14, 2013

Fever is HOT !

As many of you (who have time to read my notes) know, I have a little fascination with pediatric fever. I like the topic, reading about the body's response to infections is very interesting and the more I read about it the more I believe that treating fever does more harm that good (in most cases anyway). The ability of the body to heal it self can not be undermined. Just think about coagulation homeostasis, what a complex and yet perfectly balanced system that keeps us from bleeding to death and not dying from clotting. In the same way, the generating of fever is part of the immune system's response to infections improving chemotaxis of white cells, killer T-cell action, antibody production and many other protective immune functions... could the body be wrong by increasing body temperature? - I don't think so.

Few days ago I was searching for some articles about pediatric fever and came across this blog ( talking about how fever was used to treat neurosyphilis in the 1910's and how a Nobel prize winner cured some patients from paralytic syphilis by infecting them with the high-fever illness, malaria! Gonorrhea was also treated in the hyperthermia chamber with high cure rates. Another clear example that treating fever may cause more harm than good is the post vaccination period in children. It is very common to have parents rushing their kids to the ED because of fever after getting vaccinated. There is a very well done study done in the Czech Republic that evaluated the effect of antipyretics on the immunogenicity of vaccines ( The conclusion was that antipyretic use was associated with lower antibody levels for many vaccines, decreasing the protective effect of the immunizations. Hmmm, maybe we should start telling parents not to treat fever!

These examples invariably lead to the question... How (and when) did fever become a cause of panic and the evil symptom modern medicine aims to treat?  As more and more bacterias develop effective ways of resistance to multiple antibiotics and less and less new effective antibiotics are developed, I just wonder... will the days when induced hyperthermia become an effective therapy be back anytime soon? I believe they will.. just as induced hypothermia has become standard of care in post-cardiac arrest patients, induced hyperthermia will take the medicine world by storm in a not-too-far distant future. Although too many questions remained unanswered on type of infections that will benefit, degree and length of hyperthermia, whole body vs partial, technique to increase body temperature, protocols, etc. Therapeutic hyperthermia will bring some heat to the traditional thinking of total fever control for infectious diseases. I just need to develop a machine that safely increase temperature to a level enough to kill the bugs and yet prevent the brain from cooking. Anyone wants to take this with me?

Thursday, September 12, 2013

Kayexalate, would you like it orally or rectally? - NO THANK YOU !

Few days ago during a night shift, I saw an elderly gentleman from the nursing home who had a potassium of 6.9 mEq/L, among other lab abnormalities. His EKG had some tall T waves, but otherwise, he was asymptomatic. We proceeded to do the usual stuff; calcium, insulin, glucose, albuterol, IVF and some furosemide. We called for a monitored bed and when the patient went up, shortly after I got a call from the floor nurse asking why we didn't give Kayexalate to the hyperkalemic patient. I saw this as an opportunity to educate about how uneffective Kayexalate is and the possible risks of using this ancient and mostly unproven therapy, so I gladly explained that to the nurse. Few minutes later I got a phone call from the hospitalist asking the same question, "why didn't you give Kayexalate to the hyperkalemic patient?" - Now I am thinking... The nurse not only didn't believe me, she called the hospitalist at 3 am to tell him about my terrible omission of therapy! Once again, I tried to explain my reasons for not giving the resin. Dr X, an internist, proceeded to give me a physiology lecture about potassium metabolism and elimination. I politely listened, thanked him for his time and at the end told him that he may want to read what the nephrology literature says about this topic.

I really thought this Kayexalate issue had been put to rest few years ago. Why are we so hard to break old habits? This wouldn't be the first time; after all, medical science has had many bloopers when it comes to therapies, things we thought were good for our patients that were later proven to cause harm. Remember Thalidomide, HRT, Xigris..? It is wise to keep an open mind and look for the evidence behind our practice. So, let's see what the literature says about Kayexalate.

Sodium polystyrene sulfonate, AKA Kayexalate, made its debut in 1957 for the treatment of hyperkalemia. This resin was initially used alone but it caused severe constipation and colonic necrosis, then sorbitol was added as a cathartic. Although less frequent, the combination still has reports of colonic necrosis, perforation and poor outcomes related to its use. That's the reason why in 2009 the FDA issued a black box warning for Kayexalate. I bet you didn't see that one coming, did you? But does it work to reduce potassium? The short answer is NOT really. However, I will go over the long answer. There are only 3 paper in the literature that support the use of Kayexalate: 1) Flinn RB et al. Treatment of the oliguric patient with a new sodium-exchange resin and sorbitol; a preliminary report. N Engl J Med. 1961 Jan 19;264:111-5. This included 10 patients who received potassium free diet + resin/sorbitol. The potassium decreased 0.5 mEq in 24 hrs, and no control group.  2) Scherr L et al. Management of hyperkalemia with a cation-exchange resin. N Engl J Med. 1961 Jan 19;264:115-9. This one had 32 patients with renal failure, all received potassium free diet and Kayexalate oral or rectally. The average reduction in serum potassium was 1 mEq in 24 hr. Again, no control group.  3) Gruy-Kapral C et al. Effect of single dose resin-cathartic therapy on serum potassium concentration in patients with end-stage renal disease. J Am Soc Nephrol. 1998 Oct;9(10):1924-30. This one took 6 patient with renal failure and found no change in serum potassium levels at 12 hrs, and not surprising, this one had no control group either. Although this last study could be seen as a negative study, it is frequently cited as a reason to use the resin. But that's it…! The evidence to support the use of Kayexalate is based in 3 poorly done studies, with the grand total of 48 patients and no control group in any of them. Really… that's it!

And now for the grand finale…. In 2010 the nephrologists digged deep into this literature, which wasn't that hard b/c there is no much of it, and came to the same conclusion published in this paper: Sterns RH et al. Ion-exchange resins for the treatment of hyperkalemia: are they safe and effective? J Am Soc Nephrol. 2010 May;21(5):733-5. ( and If kayexalate and sorbitol were presented to the FDA today, they would likely not be approved. “It would be wise to exhaust other alternatives for managing hyperkalemia before turning to these largely unproven and potentially harmful therapies".

There you have it… From the Nephrologist's mouth; another myth debunked. Please please pleeeeeease…. forward this post to all your colleagues, and once you are at it, send it to your grandparents, soccer team and the neighbors. It is time to stop using this therapy and get on board with the current times.

Really... A Kayexalate coupon?!

Even the cartoons need to change!

In a side note: Thank you to all my friends at VBMC for treating me so well, to the folks in King Faisal University Hospital for putting such a great conference and letting me be part of it and to my buddies in London for making it my second home. You all know who you are...