Saturday, April 7, 2012

How Canada Does Chest Pain

Vancouver, Canada, to be specific.  The 37th most expensive city in the world to live in (ahead of New York and Los Angeles), a jewel on the coast of British Columbia, with breathtaking scenery, evergreens, rugged coasts, and mountains.

This is an observational series of their chest pain algorithm, and it falls into the category of "we do this and we like it" types of articles.  So, they do this, and they like it, and I can see why.

And the first thing you notice is that it is nothing like the United States.  Of the 1,116 patients they enrolled for this follow-up, they send home 25% of their potentially cardiac chest pain after an EKG and a single troponin.  These are patients whose mean age is 43 years old, and have TIMI scores of 0 or 1.  No outpatient stress test is arranged.  None of them had ACS within 30 days.

Another 20% had a negative 2-hour troponin and EKG and were sent home without outpatient stress testing, average age 49 years old and TIMI scores mostly 0 and 1.  None of them had ACS within 30 days.

Finally, at six hours, they were left with a group of 60 year old folks, 30% of their cohort, whose TIMI scores were >1.  They sent them all home, 25% of without an outpatient stress test and 75% with - and none of the no-stress cohort had ACS within 30 days.

Essentially, they send home over half their patients, aged 40 to 60 years old, and a couple cardiac risk factors - and they do fine.  We don't really know what sort of coronary disease the patients discharged without a follow-up stress test had, and it means they probably have some false negatives in their outcomes at 30 days simply because they don't receive any sort of additional diagnostic testing.  But, none of them had an unprovoked adverse coronary event, which counts for something.

About 20% of their patients referred for outpatient stress failed, and about half of those ultimately received a diagnosis of ACS - so, even then, in the patients they were most concerned about after negative ED testing, only 10% had ACS.  Seems like there's room to improve here, as well.

It's not crazy, it's Canada.

"Safety and Efficiency of a Chest Pain Diagnostic Algorithm With Selective Outpatient Stress Testing for Emergency Department Patients With Potential Ischemic Chest Pain"
www.ncbi.nlm.nih.gov/pubmed/22221842

Thursday, April 5, 2012

Rivaroxaban and Pulmonary Embolism

This is rivaroxaban, an oral Factor Xa inhibitor, part of the wave of potential warfarin replacements.  This is their phase III EINSTEIN-PE trial, which is a non-inferiority comparison against warfarin for the long-term outpatient management of pulmonary embolism.

Overall, it was slightly less effective at prevention of recurrent venous thromboembolism (2.1% vs 1.8%), but slightly safer with regards to bleeding episodes (10.3% vs. 11.4%).  Adherence to therapy was reasonable compared to other trials regarding the amount of time patients spent with therapeutic INR between 2.0 and 3.0.  So, really, it's pretty much a wash.

But, of course, when you have a new and expensive therapy that's essentially similar to the old, cheap option, the conclusion is: "Our findings in this study involving patients with pulmonary embolism, along with those of our previous evaluation involving patients with deep-vein thrombosis, support the use of rivaroxaban as a single oral agent for patients with venous thromboembolism."  

Of course, if you were expecting a different conclusion from an open-label, manufacturer-sponsored study, you are unfortunately mistaken.

So, make sure your hematology group is on board with PCCs, because there doesn't seem to be any other possible option for reversing life-threatening bleeding - and rivaroxaban is coming, whether it should be or not.

"Oral Rivaroxaban for the Treatment of Symptomatic Pulmonary Embolism"

Tuesday, April 3, 2012

Whole Blood Works For POC Pregnancy Tests

If there is such thing as a "cult favorite" article amongst Emergency Physicians, right now, this probably qualifies as the one receiving its 15 minutes of fame on Twitter.

If there is any singular agony known to all Emergency Physicians it is the inability to obtain urine samples in a timely manner.  Sometimes, this is for the urinalysis.  Other times, this is for the qualitative pregnancy test result.  If only there were a better way....

And, perhaps, there is.  This is a two year study of sensitivity/specificity of the POC pregnancy test using the Beckman Coulter ICON 25 - comparing the performance of using urine vs. whole blood, with laboratory quantitative bHCG >5 as the gold standard.  95.3% sensitivity for the urine test, 95.8% sensitivity for whole blood, with 100% specificity.  Most of the false negatives were due to beta hCG < 100.

Interesting alternative!

"Substituting whole blood for urine in a bedside pregnancy test"
http://www.ncbi.nlm.nih.gov/pubmed/21875776

Monday, April 2, 2012

One Year of EM Lit of Note!

Happy Birthday to my blog - one year old.  No longer neonatal, but still an infant.

Blogging has been interesting - it is, indeed, time-consuming to read all these articles.  However, I'd be reading them regardless - so the time commitment is mostly the part with the typing.  Luckily, in academics, your clinical time is scaled down specifically to encourage these sorts of activities (although, blogging has so far only been parlayed into an endowed chair by Michele Lin).  And operating a blog is nothing like the amazing podcasts other folks put together - I have no idea how they do it.

At the moment, we're on a schedule of a post every other day or so - and up to about 11,000 views per month.  In contrast, my article in JAMA from last summer has been downloaded 2,250 times.  Which has more value?  So far, the blog seems to be leading to more opportunities.  The traditional model of knowledge and opinion dissemination in medicine is certainly shifting.

Firefox and Safari are literally tied at 30% of my site traffic, as well as Macintosh vs. Windows at 30%.  Australia is in second place behind the U.S., and counts for about 10% of my traffic.

The top five most frequently viewed articles:
#1. Yet Another Highly Sensitive Troponin - In JAMA
#2. Too Many Traumatic Arrests Are Transported
#3. Cardiology Corner - More Brugada Tidbits
#4. C-Collars Cannot Stabilize Unstable Injuries
#5. Must We Use Paracetamol/Acetaminophen?

Thank for reading!

Sunday, April 1, 2012

Don't Hold It!

The hidden threat to patient safety in the Emergency Department - impaired cognitive performance secondary to suppressing the extreme urge to urinate!

Of course, this is only eight volunteers who consumed an average of 2.2 liters of water - and, by impaired cognitive performance, I mean to say they were slightly slower - but, it's certainly suitable for an April Fool's Day blog post.

This study shared the 2011 IgNobel Prize for Medicine.

"The Effect of Acute Increase in Urge to Void on Cognitive Function in Healthy Adults"
www.ncbi.nlm.nih.gov/pubmed/21058363