Sunday, April 29, 2012

Hopping To Rule Out Appendicitis

The "Best Evidence Topic" reports from the Manchester Royal Infirmary are published in the Journal of Emergency Medicine.  Overall, they are meant to summarize evidence regarding more practical, clinical applications.  One of the recent summaries focuses on appendicitis, and whether eliciting pain during coughing, percussion, or hopping is useful in ruling in or out disease.

For this topic, they summarize a few articles - mostly following a prospective derivation study in which hopping/percussion/coughing was 93% sensitive and 100% specific for appendicitis.  Unfortunately, the test performance didn't quite hold up - sensitivity ranging from 72% to 89%, depending on age group, and highly variable specificities.

So, unfortunately, somewhat like the "hamburger test," you won't be able to base the entirety of your clinical disposition on this, but it's not an irrelevant input into your general clinical gestalt.

"BET 1: Is abdominal pain when asked to hop suggestive of appendicitis in children?"

Friday, April 27, 2012

Lactate Clearance and ScvO2 Goals in Sepsis

Early goal-directed sepsis care is successful - but no one can say precisely what makes it successful.  Hawthorne effect?  Early antibiotics appear to have uncertain association with better outcomes.  Is it the blood?  Is it meeting the central venous oxygenation goal of >70%?

Other studies have shown equivalency in outcomes while performing serial lactic acid measurements, and this is another study in the same vein.  203 patients form the analysis cohort, in which 93 received management decisions based on lactate clearance and 110 which received management decisions based on the ScvO2.  All included patients had both values measured simultaneously, but were blinded to the opposition.

And, this is another study where the two measures are different but similar - which is probably why the analysis is so convoluted.  Of the 203 enrolled, 175 either fortuitously or by design met the ScvO2 goal, while 178 met the lactate clearance goal.  Meeting the ScvO2 goal led to a death rate of 21% and meeting the lactate clearance goal led to a death rate of 17%.  There was no difference in therapeutic interventions between the ScvO2 goal group and the lactate clearance group.

However, if you met the lactate clearance without meeting the ScvO2 goal, you had an 8% (2/25) mortality, while the ScvO2 group that didn't clear lactate had a 41% mortality (9/22).  Unfortunately, there were a number of baseline differences between the groups, and it's hard to draw any conclusions or hypotheses from this finding.  It's also clear they didn't identify any specific interventions that improved survival in their cohort - and, more appropriately, simply observed that poor lactate clearance simply portends a worse outcome, without any specific recommendation on how to address it.

"Prognostic Value and Agreement of Achieving Lactate Clearance or Central Venous Oxygen Saturation Goals During Early Sepsis Resuscitation"

Wednesday, April 25, 2012

Most Severe Mechanism Children Don't Need Head CTs

The PECARN group has published a set of criteria that identify children at very low risk for significant traumatic injury.  This is publicly available and an excellent decision instrument to enhance your clinical judgement.  But, the problem is, with excellent sensitivity, the specificity is weak - such that a great number of patients who fail to meet low-risk criteria will still have good outcomes.

So, this is a follow-on study attempting to determine whether the severe mechanism portion of the decision instrument was predictive of significant TBI, or whether scans could be avoided if mechanism was the only positive feature in their decision instrument.  And, yes, a severe injury mechanism in isolation - at least in the 35% of their cohort who received a head CT - had only a 0.3% chance of significant injury in age <2 years and 0.6% chance of significant injury in age >2 years.  Severe injury mechanisms associated with additional PECARN criteria, however, had 4% and 6% incidence of TBI, depending on age.

Probably the most important aspect of these numbers is they allow for a better discussion of risks with parents and families.  While 1 in 150 or 1 in 300 sound like pretty good odds, when you practice long enough, those odds will catch up with you.  Even with severe mechanism and additional features, 19 of 20 CTs will be negative - you can still make a reasonable case for observation rather than knee-jerk scanning.

"Prevalence of Clinically Important Traumatic Brain Injuries in Children With Minor Blunt Head Trauma and Isolated Severe Injury Mechanisms"

Monday, April 23, 2012

Mobile Stroke Units - Probably Not Helpful

Door to needle times too long?  Well, take the needle to the patient, then.

This is an interesting idea that, unfortunately, probably isn't a good idea.  They loaded a CT scanner, a stroke physician, a paramedic, and a mobile laboratory into a truck, and sent it out to meet acute stroke patients in the field.  The primary endpoint of the study - alarm to thrombolysis time - was great, with a mean time from alarm to therapy decision of 35 minutes.

The authors are very excited about the concept - as they feel the accelerated time scale in terms of acute stroke thrombolysis represents a paradigm shift in management.  Unfortunately, the patient-oriented outcomes - which were not part of the primary endpoint - don't support their enthusiasm.

All their safety and therapeutic outcomes are underpowered, but, out of their 47 intervention patients and 53 control (in-hospital thrombolysis) patients, 12 vs. 6 were treated stroke mimics and 3 vs. 0 were dead within 7 days.  Comorbidities and stroke severity should have favored the intervention group, so, these outcomes are surprising.  But, it is underpowered, so more data is needed.

"Diagnosis and treatment of patients with stroke in a mobile stroke unit versus in hospital: a randomised controlled trial."

Saturday, April 21, 2012

"Malodorous" Urine Isn't Necessarily a UTI

Which is to say, when a parent brings in a child with a fever and the urine "smells bad", plenty of those kids have normal urine cultures and plenty of children with Febreeze for urine have a urinary tract infection, regardless.

This is a prospective cohort study enrolling children receiving a urine culture as part of an evaluation for fever without a source in the Emergency Department - and then they went back and data mined for associations between the group diagnosed with UTI and not.  The overall incidence of UTI was 15%.  The overall incidence of UTI in those with "malodorous" urine was 24%.  It was the most significant contributing factor they found, but it's still not sensitive or specific enough to use in isolation to change management.

Other interesting tidbits:  no circumcised male had a UTI, known high-grade vesicoureteral reflux predicted UTI.

"Association of Malodorous Urine With Urinary Tract Infection in Children Aged 1 to 36 Months"

Thursday, April 19, 2012

Uninterrupted CPR is Better Than Interrupted

This is from King County, which has been publishing retrospective pre- and post- intervention outcomes related to out-of-hospital cardiac arrest for several years now.  This article focuses on the AHA guidelines for PEA and asystole, and the changes that were made in 2004 and 2005.  Those changes, if you recall, involve fewer pauses for pulse and rhythm checks and decreasing the number of ventilations.

Good news!  You were 1.5 times more likely to survive neurologically intact to hospital discharge after the introduction of the new guidelines.  Bad news: good neurological outcome was still only 5.1%, up from 3.4%.  So, yes, this is another piece of evidence supporting the "uninterrupted, high-quality CPR" concept, but perhaps the other important question that need be asked at the same time is:  how can we reduce the unnecessary resource expenditure associated with attempted resuscitation for the 95% that doesn't benefit?

"Impact of Changes in Resuscitation Practice on Survival and Neurological Outcome After Out-of-Hospital Cardiac Arrest Resulting From Nonshockable Arrhythmias"

Tuesday, April 17, 2012

Post-Arrest Troponin Measurements Predict Little

Taking post-arrest patients to cardiac catheterization improves outcomes - as long as they have a cardiac occlusion as the underlying etiology of their arrest.  Otherwise, you're simply delaying the diagnosis and treatment of alternative causes, as well as post-arrest ICU-level care.  Therefore, if there is some clinical feature that can be identified on initial Emergency Department evaluation that predicts a coronary occlusion, that would be of great value.

So, this is a retrospective analysis of a prospective registry of out-of-hospital arrests from Paris, where much of the post-arrest catheterization work has been done.  And, unfortunately, there isn't any useful association - 92% of their patients had elevated troponin on initial evaluation.  There was a nonsignificant trend towards higher troponin levels in patients with coronary occlusion, but even at their "optimum" cut-off of 4.66ng/mL, the sensitivity and specificity were nearly coin-flip at 66% each.  A troponin of 31ng/mL was required for 95% specificity.

ST-segment elevation, incidentally, was more predictive of a coronary occlusion - OR 10.19 (CI 5.39 to 19.26).

"Can early cardiac troponin I measurement help to predict recent coronary occlusion in out-of-hospital cardiac arrest survivors?"

Sunday, April 15, 2012

The Dexamethasone Dose for Croup is 0.15mg/kg

Unfortunately, this is still probably not the trial that convinces everyone.  In fact, it's been over 15 years since the original single-center trials/reports showing that 0.15mg/kg of dexamethasone was every bit as effective as 0.6mg/kg of dexamethasone.  This makes intuitive sense, considering the steroid equivalencies, and the doses used in studies that have established prednisolone as an adequate treatment for croup, as well.

Regardless, this is a very small - 30-odd patients - with mild croup, randomized to dexamethasone at 0.15mg/kg vs. placebo.  The point of this study was not to test the efficacy of dexamethasone, but rather to show that, despite it's long half-life, it had immediate effects.  And, I think it's fair to say this study demonstrates those significant effects in reduction in croup score, gaining statistical significance by 30 minutes.

I don't know where the attachment came from in terms of the 0.6mg/kg dose of dexamethasone, but it's just preposterously high.

"How fast does oral dexamethasone work in mild to moderately severe croup? A randomized double-blinded clinical trial."

Friday, April 13, 2012

Early Steroids Probably Better for Asthma

Not sure if this is the study that proves it - since due to ethical considerations it's simply observational, and doesn't control for confounders and introduces a lot of bias - but, it's a small piece of the puzzle.

This is a cohort in a Montreal pediatric emergency department in which they prospectively collected data on moderate and severe asthma exacerbations as patients progressed through their care pathway.  They see, essentially, a nonsignificant trend in increased odds of hospital admission for patients in whom administration of systemic steroids was delayed.  This is mostly a data mining exercise, so any significant associations should be considered hypothesis generating.  However, considering the patients who received delayed steroids had milder exacerbations overall - yet still seemed to go on to have higher admission rates - it might be tempting to interpret these findings as appropriately confirmatory of physiologic foundations of treatment.

At least, there's no suggestion of harm from early steroid administration in asthma with exacerbation in children.  Perhaps some prospective interventional data with patient-oriented outcomes will surface in response.

"Early Administration of Systemic Corticosteroids Reduces Hospital Admission Rates for Children With Moderate and Severe Asthma Exacerbation"

Wednesday, April 11, 2012

ABCD2 For Cerebrovascular Dizziness

This is a bit of an interesting idea - a repurposing of the ABCD2 prediction instrument for TIAs as a risk-stratification instrument for cerebrovascular causes of "dizziness."

Every ED physician loves the complaint of "dizziness."  It's either giddiness, unsteadiness, lightheadedness, vertigo, and it's frequently difficult to elicit any pertinent neurologic symptoms to clarify one of the benign causes of vertigo or a cerebrovascular cause.

This is a retrospective chart review in which they evaluated the charts of 907 "dizzy patients", 37 of which had a cerebrovascular cause - 4.1%.  It's a small sample size - so the confidence intervals for their odds ratios are very wide - but for multivariable adjusted odds, age > 60 had an increased OR of 5.1, BP >140/90 had an increased OR of 2.9, speech disturbance had an OR of 6.2, and unilateral weakness had an OR of 10.9.  Essentially, it's interesting to see - and it makes sense - that the same features that generally portend stroke after TIA also might help predict which of your dizzy patients will be higher yield for a more intensive evaluation.

"Application of the ABCD2 Score to Identify Cerebrovascular Causes of Dizziness in the Emergency Department"

Monday, April 9, 2012

You Should Behave on the Internet

This is an interesting little research letter in JAMA regarding the incidence of state medical board review of unprofessional online behavior.  Of the 48 boards responding, 44 indicated that at least one complaint had been reviewed secondary to inappropriate online behavior.

The most commonly reviewed instances were inappropriate patient communication, online misrepresentation of credentials, and "inappropriate practice."  The most common responses noted by the survey were disciplinary proceedings, sanctions, and informal warnings - and half of medical boards reported license restriction, suspension, or revocation in response to proceedings.

Behave on the internet!

"Physician Violations of Online Professionalism and Disciplinary Actions: A National Survey of State Medical Boards"

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"

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"

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"