Month: April 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?”

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”

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”

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.”
http://www.ncbi.nlm.nih.gov/pubmed/22497929

“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”
http://www.ncbi.nlm.nih.gov/pubmed/22473364

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”
http://www.ncbi.nlm.nih.gov/pubmed/22474256

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?”
http://www.ncbi.nlm.nih.gov/pubmed/22488008

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.”
http://www.ncbi.nlm.nih.gov/pubmed/22313564

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”
http://www.ncbi.nlm.nih.gov/pubmed/22410507

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”
http://www.ncbi.nlm.nih.gov/pubmed/22442167