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"

Friday, March 30, 2012

Glucose-Insulin-Potassium For MI?

"Investigators, led by Dr Harry Selker (Tufts Medical Center, Boston, MA), are pleased with the results, believing that after years of futile study, they have finally found some clinical evidence to support the experimental data suggesting that GIK [glucose-insulin-potassium] myocardial metabolic support could protect the heart in the ACS setting."

...which lead to the press release tweet of "Intravenous GIK Slashes Death Risk in Acute Coronary Syndrome: CHICAGO – Glucose, insulin, and potassium given i..." by @ACEPNews.  That press release can be seen here.

There have been trials enrolling over 20,000 patients to date that have been negative.

Despite all these previous negative trials, the authors believed the problem was timeliness - the critical time in which to provide metabolic support to the infarcting myocardium was in the prehospital setting, upon the earliest recognition of ACS.  The original goal was to enroll 15,450 patients.  They ended up with 880.  Then, after data collection, they changed the primary endpoint from all-cause mortality to progression to myocardial infarction at 30 days and at 1 year.  And they only have the 30 day data right now, they'll get back to us with the 1 year outcomes.  How this made the cut for publication in JAMA is outside the scope of my speculative powers.

So, they enrolled folks prehospital with signs and symptoms of potential acute coronary syndrome whose prehospital EKG was read as STEMI or met the ACI-TIPI prediction instrument probability threshold of 75%.  They received the GIK solution with 90 minutes, on average.  And, the primary outcome measure was negative for progression to MI, trend favoring GIK with OR 0.88 (CI 0.66-1.13).  Negative for 30 day mortality, OR 0.72 (0.40-1.29).  For STEMI patients, negative for progression to MI, OR 0.74 (0.40-1.38), and negative for 30 day mortality, OR 0.63 (0.27-1.49).
So, yes, there is a trend.  And some subgroups even had significant trends in favor of GIK.  But for JAMA and the rest of the internet to be promoting this as practice-changing at this juncture is absolutely inappropriate.

"Out-of-Hospital Administration of Intravenous Glucose-Insulin-Potassium in Patients With Suspected Acute Coronary Syndromes:  The IMMEDIATE Randomized Controlled Trial"

Wednesday, March 28, 2012

CCTA Is A Bad Shortcut Around Bad Care

"Although an acute coronary syndrome is ultimately diagnosed in only 10 to 15% of patients who present with chest pain, the majority of these patients are admitted to hospitals, at an estimated cost of over $3 billion annually."

This is, essentially, the statement of problem from the NEJM article, sponsored by Siemens, regarding the use of coronary CT angiograms in the Emergency Department on low-to-intermediate risk chest pain.  They are clearly huge fans of CCTA up at the University of Pennsylvania, and I hate to think it has something to do with the parade of imaging technology companies and patent applications listed as disclosures by the authors.

In this study, the authors enrolled 1,392 patients with chest pain with the goal of testing the primary hypothesis that "patients without clinically significant coronary disease on CCTA (i.e., no coronary-artery stenosis ≥50%) would have a 30-day rate of cardiac death or myocardial infarction of less than 1%."

Good news!  They were right.  Bad news:  their entire enrolled cohort had a 30-day death or MI rate of only nearly 1%.  It's rather incredible, really, that they have this entire article in which they sing the praises of CCTA for identifying low-risk chest pain, when in reality, they gloss over the fact that they simply could have sent home every single patient in the study without doing a single additional test and only nearly 1% would have had death or MI within 30 days.

Going back to their essential statement of problem, it might be true that CCTA were valuable if they were looking to apply it in a population and practice environment in which we were actually hospitalizing patients with a 10-15% rule-in rate.  However, the opposite of what these authors propose is the real truth - clinically identify all the low-risk chest pain and stop doing all these expensive tests!  They claim it expedites discharge from the Emergency Department, which, in theory, saves money - but it isn't!  Despite 90% of their CCTA being negative for stenosis >50%, they still end up admitting half their CCTA cohort.  Even the negative CCTA cohort, while their length of stay is reduced to 12 hours, still means they're being placed in observation status and billed an additional separate observation code - which in many places is a protocolized chest pain observation unit run by the Emergency Department.

This is simply a bad solution to bad baseline practice patterns.  The measurable benefit here isn't to the patient, it's to the malpractice risk of the physician, to Siemens and other sponsors of the study, and likely to the Emergency Departments whose billing increases for these short stay observation patients.

"CT Angiography for Safe Discharge of Patients with Possible Acute Coronary Syndromes"

Monday, March 26, 2012

Pan-Scan & Zero-Miss

In an interesting contrast to a prior article regarding over-scanning in trauma, this article takes a different perspective.  While the authors do note that there is controversy regarding the impact of "pan scan" on survival, they are rather focused on the sensitivity/specificity of the "pan scan," rather than the appropriateness.

This is a review of 982 consecutive patients undergoing "pan scan" in Germany.  The indications for scanning were a set of "red flag" criteria, which included impaired patients, patients with obvious injuries, "suspicion of severe trauma" or "high risk mechanism".  The diagnostic reference standard was chart review by two reviewers of the electronic notes for any injuries missed on the initial scan.

The results are rather interesting in a couple ways:  the prevalence of injuries per organ system is not terribly high, and the sensitivity of scanning was rather low.  The highest prevalence of injuries for an organ system was 37%, for chest, followed by head and neck at 34%.  However, the sensitivities range from a high of only 86.7% for chest down to a low of 79.6% for face - likely because dedicated fine cuts of the face were not part of their protocol.  Regardless, with sensitivities in the mid-80s meant they missed almost one seventh of the total number of injuries.  Of these 70 missed injuries, almost half required surgery or a critical intervention as treatment.

So, pan-scanning: expensive, low yield, yet still misses important injuries.  The authors do not try to fully address whether their yield is reasonable or not, and wisely simply state further research is needed regarding triaging patients into groups likely to benefit from scanning.

"Accuracy of single-pass whole-body computed tomography for detection of injuries in patients with major blunt trauma."

Saturday, March 24, 2012

More Nails In the Coffin For Epinephrine

The news for epinephrine in cardiac arrest keeps getting worse - it restarts the heart, but at what cost, and with what outcomes?

This is a study, published in JAMA, of 417,188 out-of-hospital cardiac arrest patients in Japan - only 15,030 of which received epinephrine during prehospital transport - a far cry from the U.S., where the toolbox has typically already been emptied prior to the ED.  Nearly every baseline characteristic favored the epinephrine group - more witnessed arrests, more received bystander CPR, a physician was more frequently in the ambulance, more patients in ventricular fibrillation/PEA.  However, more of these patients also received an advanced airway, which has also been associated with worse outcomes.

In their unadjusted analysis, the epinephrine cohort was three times as likely to have ROSC, and had an OR of 1.15 to be alive at one month.  However, they were half as likely to be functional as the non-epinephrine survivors.  Then, when they do all their statistical adjustments for all the favorable baseline factors in the epinephrine cohort, all these numbers become less favorable for epinephrine.  They also do a propensity-matched cohort of 26,802 patients that has favorable ROSC with epinephrine, but dismal 1 month and functional outcomes.

This data is from before the era of routine hypothermia - which may be beneficial - but it certainly supports what we already expected regarding the damaging physiologic effects of epinephrine while senselessly flogging the heart back into action.

"Prehospital Epinephrine Use and Survival Among Patients With Out-of-Hospital Cardiac Arrest"

Thursday, March 22, 2012

TPA is Dead, Long Live TPA

I'm sure this saturating the medical airwaves this morning, but yesterday's NEJM published a study which they succinctly summarize on Twitter as "In trial of 75 pts w/ acute ischemic , tenecteplase assoc w/ better reperfusion, clin outcomes than alteplase."

Well, that's very exciting!  It's still smashing a teacup with a sledgehammer, but it does appear to be a more functional sledgehammer.  Particularly encouraging were the rates of sustained complete recanalization - which were 36% at 24 hours for alteplase and 58% for tenecteplase - and the rates of intracranial hemorrhage - which were 20% for alteplase and 6% for tenecteplase.

However, the enthusiasm promoted by NEJM, and likely the rest of the internet, should be tempered by the fact that there were only 25 patients in each arm, and there is enough clinical variability between groups that it is not yet practice changing.  This was a phase 2B trial, and it is certainly reasonable evidence to proceed with a phase III trial.

Unfortunately, in a replay of prior literature, the authors are all affiliated with Boehringer Ingelheim, the manufacturer of tenecteplase.

"A Randomized Trial of Tenecteplase versus Alteplase for Acute Ischemic Stroke"

Addendum:  As Andy Neil appropriately points out, tenecteplase has been studied before - 112 patients over several years, terminated early due to slow enrollment - without seeing a significant advantage.

Tuesday, March 20, 2012

Over-Prescribing of Antibiotics Happens Everywhere

On Twitter a couple weeks back, in response to my plea to reduce empiric macrolide use for benign clinical syndromes, there was an allusion suggesting Pediatricians were the culprits of a poor antibiotic stewardship.

Of course, that's clearly not the case.  And, while we all envision Urgent Cares and customer-service medicine contributing to the over-prescription of antibiotics, it's happening in our academic medical centers, as this article indicates.  This is a retrospective chart review from San Diego that evaluated 836 patients receiving a diagnosis of "acute bronchitis", a typically self-limited disease that evolves into pneumonia only in a minority of cases in elderly patients or patients with significant pulmonary comorbidities.

The average age was 46, 10% had comorbid COPD noted, 17% asthma, 8% diabetes, and 4% HIV/AIDS.  All told, 74% were prescribed antibiotics - 50% received a macrolide, 15% a tetracycline, 6% a fluoroquinolone, along with a few others.


And certainly not just the Pediatricians.

"Antibiotic and bronchodilator prescribing for acute bronchitis in the Emergency Department."

Sunday, March 18, 2012

Is It Reasonable to Keep Using Vasopressin in Shock?

The authors of this meta-analysis seem to think so.

Unfortunately, they identify a very heterogenous set of evidence for analysis, which reduces the statistical power of every comparison.  They identify only a couple studies of vasopressin vs. placebo, and most of their studies are vasopressin vs. an increased dose of norepinephrine.

It's hard to generate any unreasonable conclusion from this data - the error bars cross one, so you can either take this as permission to drop vasopressin from your usage patterns because its use has no measurable mortality benefit, or you can continue to use vasopressin because it doesn't seem to be harmful, and allows you to reduce the dose of norepinephrine.

I'd really like to see more vasopressin vs. control - there's only one reasonably sized vasopressin vs. placebo trial - and it heavily, but non-significantly, favors control with a risk ratio for mortality of 1.94 (0.74 to 5.10).

More to be done!

"Vasopressin for treatment of vasodilatory shock: an ESICM systematic review and meta-analysis"

Friday, March 16, 2012

Pharmaceutical Bias Article in EM News

Imagine my surprise to be paging through Emergency Medicine News this month and stumble upon an article about TPA in stroke - and find that it's a review of my Western Journal of Emergency Medicine article from last summer.

The EM News article is here:

And my West JEM article is open access, available here:

It Feels Good To Use an iPad

Recently, there has been a great deal of coverage on internet news sites with headlines such as "Study: iPads Increase Residency Efficency."  These headlines are pulled from a "Research Letter" in Archives of Internal Medicine, reporting from the University of Chicago, regarding the distribution of iPads capable of running Epic via Citrix.

Sounds good, but it's untrue.

What is true is that residents reported that they used the iPads for work.  The additionally thought that it saved them time, and thought it improved their efficiency on the wards.  This is to say, they liked using the iPad.

The part that isn't true is where the authors claim an increase in "actual resident efficiency."  By analyzing the hour of the day in which orders are placed, the authors attempt to extrapolate to a hypothetical reality in which this means iPads are helping their residents place orders more quickly on admitted patients, and to place additional orders while post-call, just before leaving the hospital.  There is, in fact, no specific data that using the iPad makes the residents more efficient, only data showing the hour of the day in which orders are placed has changed from one year to the next.  The iPad has, perhaps, changed their work habits - but without prospectively observing how these iPads are being used, it is impossible to conclude how or why.

But, at least they liked them!  And, considering how addictive Angry Birds is, I'm surprised their productivity isn't decreased.

"Impact of Mobile Tablet Computers on Internal Medicine Resident Efficiency"


Wednesday, March 14, 2012

Ketamine + Propofol = Ketofol

Combining propofol, a beloved agent for procedural sedation for its rapid onset, quick recovery times, and titratable levels of sedation with ketamine, the world's safest agent for unmonitored anesthesia, has been shown in case series to be as safe and effective as expected.

This small, randomized trial is a direct comparison between ketofol and propofol, with the primary outcome measure being the proportion of patients experiencing an adverse respiratory event using the standardized Quebec Criteria.  The authors are testing the hypothesis that use of ketofol will result in fewer adverse respiratory events, which they believe to be one of the weaknesses of propofol, and one of the strengths of ketamine.

With ~120 patients in each group, there is essentially no clinical or statistical difference between outcomes of the two groups.  Clinicians provided transient assisted ventilation for three ketofol patients and one propofol patient - which is not statistically different.  Secondary outcomes were similar, although a handful of ketofol patients experienced recovery agitation, some of which required treatment.

It seems odd to me that the authors would be testing the respiratory adverse events of ketofol - both ketamine and propofol are so profoundly safe, with already extremely low rates of assisted ventilation, and unplanned intubation rates of ~1 in 5,000 or more.  Ketofol has been similarly already shown to be extremely safe in terms of respiratory events, primarily in retrospective case series.  They've essentially set themselves up to test something that's almost already conclusively expected to generate insignificant differences.  What is more interesting to clinicians now, when considering agents for sedation, is the secondary effects - hypotension, hypersalivation, vomiting, myoclonus, agitation - and how that affects procedural success and time to disposition.  Ketofol is a great combination - but its value seems to be in the mitigation of the non-airway adverse events.

"Ketamine-Propofol Combination (Ketofol) Versus Propofol Alone for Emergency Department Procedural Sedation and Analgesia:  A Randomized Double-Blind Trial"

Monday, March 12, 2012

Mechanical Thrombectomy - Promising, But Still Unsafe

This article is just a retrospective, consecutive case series from Spain reporting outcomes and adverse events from mechanical thrombectomy in acute stroke.  Most of their patients are significantly disabled from their strokes, with NIHSS ranging from 12 to 20 - unlikely to have great outcomes - but 14% developed intraparenchymal hemorrhage and 25% were deceased at 90 days.  Six patients had vessel wall perforation from the thrombectomy device.

The key sentence is the last sentence:
"Clinical efficacy of this approach compared with standard medical therapy remains to be demonstrated in prospective, randomized controlled trials."

When mortality is 25% here, and 33% at 90 days in MERCI, multi-MERCI, and Penumbra trials, I'm still not sure this strategy is quite ready for prime time.  They do report that 54% had a "good outcome", but it's interesting to see that "good outcome" in stroke trials has progressed from Rankin Scores of 0 or 1 in NINDS etc. to ≤2 in these new trials.  They  also don't offer a lot of granularity in their outcomes data.

But, as usual, as long as there are authors out there who "receive consulting and speaker fees from Co-Axia, ev3, Concentric Medical, and Micrus," we'll keep seeing reports like this.

"Manual Aspiration Thrombectomy : Adjunctive Endovascular Recanalization Technique in Acute Stroke Interventions"

Saturday, March 10, 2012

Please Stop Using Azithromycin Indiscriminantly

There is a time and a place for a macrolide with a long half-life, and it is not empirically for pharyngitis.

And, it's even less appropriate empirically for pharyngitis now that it's been overused to the point where it's nearly in the drinking water - because it can no longer be considered second-line for group A streptococcus for your penicillin allergic patients.

This is a case report and evidence review from Pediatrics that discusses two cases of rheumatic fever, both of which presented after treatment of GAS pharyngitis with azithromycin.  While rheumatic fever has been almost completely wiped out - there are so few of the RF emm types in circulation, that it's almost nonexistent in the United States - there are still sporadic cases.  Macrolides are listed as second-line therapy for GAS, but single-institution studies have shown macrolide resistant streptococcus in up to 48% of patients.  Macrolide resistance varies greatly worldwide, from a low of 1.1% in Cyprus to 97.9% in Chinese children.

Why is macrolide resistance so high?  Azithromycin is the culprit; because it has such a long-half life, it spends a long time in the body at just below its mean inhibitory concentration, and preferentially selects for resistant strains.

Please stop using azithromycin.  Use doxycycline, or another alternative, when possible.  There has never been reported resistance to pencillin in GAS.

"Macrolide Treatment Failure in Streptococcal Pharyngitis Resulting in Acute Rheumatic Fever"

Thursday, March 8, 2012

The Future of Medicine...is Defensive

At Northwestern University in Chicago, anyway - and probably externally valid to other institutions, as well.

This is a survey of 194 fourth-year medical students and 141 third-year residents regarding whether they observed or encountered "assurance" practice (extra testing of minimal clinical value) or "avoidance" practice (withholding services from patients perceived as high risk).  65% of medical students and 54% of residents completed the survey - decent numbers, but low enough to introduce sampling bias.

The numbers, of course, are grim - 92% of medical students and 96% of residents reported encountering "assurance" practice at least "sometimes" or "often", while 34% of medical students and 43% of residents had encountered "avoidance" practice at least "sometimes" or "often" - nearly all of those being "sometimes".  These behaviors are apparently learned from their superiors - approximately 40% of medical students and 55% of residents were explicitly taught to consider practicing defensive medicine.

Interestingly, medical students, internal medicine residents, and surgical residents all reported nearly identical levels of "often"/"sometimes"/"rarely" regardless of the behavior sampled - although surgical residents were more frequently taught to be defensive than medicine residents.

Must be a tough legal quagmire up in Chicago.

"Medical Students’ and Residents’ Clinical and Educational Experiences With Defensive Medicine"

Tuesday, March 6, 2012

Zolpidem and Benzodiazepines Will Kill You


Especially if you're elderly.

It's an interesting observational, statistically matched-control study using Electronic Health Records to monitor prescriptions of zolpidem (Ambien) and other benzodiazepines (Temazepam), commonly used as sleep aids, particularly in the shift-work population.

I think this graph pretty well sums up their results:

Blue lines are hypnotic-free, orange lines are patients taking hypnotics.  Downward slopes - exaggerated by the vertical scale - are bad.  An increased hazard for cancer was also found in patients prescribed hypnotics.

There are, of course, flaws with this study - but it is consistent with other published literature suggesting harms associated with hypnotic use.  The huge limitation of a study like this is controlling retrospectively for all the comorbid cofounders.  They attempt to do this statistically with a small set of comorbid disease, but it remains a limitation.

"Hypnoticsassociation with mortality or cancer: a matched cohort study"

Sunday, March 4, 2012

One-Man Crusade For Steroids In Spinal Trauma

The Cochrane Review regarding the efficacy of steroids in acute spinal cord injury, first published in 2002, has been updated for 2012.  The author's conclusions: "Methylprednisolone sodium succinate has been shown to enhance sustained neurologic recovery in a phase three randomized trial, and to have been replicated in a second trial."

This is an interesting conclusion to draw from an analysis of, essentially, only negative studies.  NASCIS 1 (1984) was statistically negative - but was discounted because the dosing was possibly too low.  NASCIS 2 (1990) was also statistically negative, except for pinprick and light touch at six months, which disappeared at one year.  The supposed positive outcome comes from a post-hoc analysis in which the patients who received their steroids between 3 and 8 hours after injury shook out to have a statistically significant improvements in motor score at six months and one year.  However, post-hoc subgroup analysis cannot be considered practice-changing evidence until confirmed in subsequent studies.  Otani (1994) was statistically negative for the primary outcome, but post-hoc analysis identified greater sensory improvement in the steroid group - which therefore implies greater motor improvement in the control group, as the overall combined neurologic scores were not different.  NASCIS 3 is not placebo-controlled.

There is also no mention in the Cochrane Review of adverse events - the only mention of the safety profile of high-dose steroids in the discussion section references a systematic review of high-dose steroids given to general surgical patients, both elective and trauma.  This is rigorously invalid, as the correct assessment of the safety profile of an intervention should be derived from the safety outcomes of the studies included in the analysis - nearly all of which had consistent, non-significant (underpowered) trends towards increased infectious complications.

Would it surprise you to discover that the author of the 2000, 2002 and 2012 Cochrane Review articles is the same first author of NASCIS 1, 2, and 3?

"Steroids for acute spinal cord injury."