When Is An Extremity CTA Necessary?

Here’s another piece regarding low-value testing in trauma, focusing on another topic: the use of CT angiograms for evaluation of extremity vascular injury.

This single-center, retrospective series looks at use of the extremity computed tomography angiogram in the setting of orthopedic and multi-system trauma. For what it’s worth, at least, there were only 275 scans identified during their 10-year study period. However, the bad news, of course: only 16 (6%) of those scans identified an injury requiring treatment.

Of greatest interest to those trying to eradicate low-value care comes the entirely unsurprising observation that 109 (40%) of patients received CTAs despite the absence of hard or soft signs of vascular injury – and all were normal. Additionally, all 16 cases requiring treatment had diminished or absent distal pulses on presentation.

I do anedcotally see the clinical examination being devalued, especially in trauma – it shouldn’t be!

“When are CT angiograms indicated for patients with lower extremity fractures? A review of 275 extremities”
http://journals.lww.com/jtrauma/Abstract/publishahead/When_are_CT_angiograms_indicated_for_patients_with.99386.aspx

From Way Too Many CTs to Many CTs

I am always keen to hear reports of successful imaging reduction interventions – and, even moreso, in trauma. The typical, modern, approach to trauma involves liberal use of advanced imaging – almost to the point of it being a punch line.

This single-center before-and-after report details their experiences between 2006 and 2013. Before 2010, there was no specific protocol regarding CT in trauma – leading to institutional self-examination in the setting of rampant overuse. After 2010, the following protocol was in effect:

trauma algorithm

There isn’t much besides good news presented here. Their primary imaging use outcome, abdominopelvic CT, decreased from 76.7% to 44.6% of all presentations. This was related to an increase in mean ISS for those undergoing CT. When free fluid from non-traumatic causes was individually accounted for, the rate of positivity of these CT rose from 12.3% to 17.5%. Finally, mortality was unchanged – 3.1% vs. 2.7%.

No doubt, any reduction in imaging will miss some important findings. The net counterbalancing effect, however, is likely a massive reduction in costs and harms from further evaluation of false-positives, renal contrast injury, and radiation. And, after all, they’re still performing CTs on nearly half their patients!

“Effect of an Institutional Triaging Algorithm on the Use of Multidetector CT for Patients with Blunt Abdominopelvic Trauma over an 8-year Period”

http://pubs.rsna.org/doi/abs/10.1148/radiol.2016152021

The 5-Second Rule, Meet Science!

Again with the headlines: “The ‘5-second rule’ is disproved in new study”.

And, again, checking the veracity of their knowledge translation distillation: not exactly.

These authors placed four different foods (watermelon, bread, buttered bread, and gummy candy[Haribo, Strawberries]) on four different surfaces (steel, tile, wood and carpet). They let the food stay in contact with the surface for <1 second, 5 seconds, 30 seconds, or 300 seconds. However, where this study falls off the generalizability wagon: each surface was pre-coated with bacteria-rich broth.

So, yes, in their study, even instant contact was adequate to transfer some bacteria from surface to food. Five seconds quite obviously transferred plenty of bacteria. Otherwise, the amount of bacteria transferred was roughly related to moisture in the food item and surface area in direct contact.

But, is the “5-second rule” obsolete? Hardly. Consider the context of history – where humans have been eating in less sanitary situations for hundreds of thousands of years. Then, chances are your hands are more likely to contaminate your food than the floor in your house. So, food that has been dropped on most clean floors may pick up some bacteria – but these authors’ results are only a surrogate for multifactorial confounded potential downstream harms.

However, if your floor is coated with a thriving culture of pathogenic bacteria – all bets are off.

“Longer Contact Times Increase Cross-Contamination of Enterobacter aerogenes from Surfaces to Food”
http://aem.asm.org/content/early/2016/08/15/AEM.01838-16.abstract

Imprecise Dosing of Liquid Medications

Many parents are overdosing their kids, study says”. Is this true? Are parents poisoning their own children, as the headline implies?

Of course not; this is not in fact a study regarding overdose incidence at all. It is, quite simply, a measurement precision study.

This study involves 2,110 parents randomly assigned to measure doses of liquid medication in various quantities using either a cup, a 0.2mL syringe, or a 0.5mL syringe. Approximately a quarter of parents were >20% off with their measurement, and 2.9% doubled the instructed dose. Taking these results as a surrogate for overdose depends on the therapeutic range for a medication – so, while the headline is not technically incorrect, the implication is an exaggeration.

With regard to measurement and dosing errors, there were a few important trends to note. Health literacy had a large influence on dosing errors – regardless of whether teaspoons or mL were used in the instructions. Then, the cup: avoid the cup when possible. Almost three-quarters of parents committed measurement or dosing errors when asked to provide a 2.5mL dose in the cup. Stick to the syringe and target round numbers (5mL) to minimize errors.

With regard to the premise of overdose – for medications with a wide therapeutic range, these data are not quite as clinically relevant. However, for high-risk medications, more time and effort should be taken to demonstrate proper dosing with parents.

“Liquid Medication Errors and Dosing Tools: A Randomized Controlled Experiment”
http://pediatrics.aappublications.org/content/early/2016/09/08/peds.2016-0357

Stumbling Around Risks and Benefits

Practicing clinicians contain multitudes: the vastness of critical medical knowledge applicable to the nearly infinite permutaions of individual patients.  However, lost in the shuffle is apparently a grasp of the basic fundamentals necessary for shared decision-making: the risks, benefits, and harms of many common treatments.

This simple research letter describes a survey distributed to a convenience sample of residents and attending physicians at two academic medical centers. Physicians were asked to estimate the incidence of a variety of effects from common treatments, both positive and negative. A sample question and result:

treatment effect estimates
The green responses are those which fell into the correct range for the question. As you can see, in these two questions, hardly any physician surveyed guessed correctly.  This same pattern is repeated for the remaining questions – involving peptic ulcer prevention, cancer screening, and bleeding complications on aspirin and anticoagulants.

Obviously, only a quarter of participants were attending physicians – though no gross differences in performance were observed between various levels of experience. Then, some of the ranges are narrow with small magnitudes of effect between the “correct” and “incorrect” answers. Regardless, however, the general conclusion of this survey – that we’re not well-equipped to communicate many of the most common treatment effects – is probably valid.

“Physician Understanding and Ability to Communicate Harms and Benefits of Common Medical Treatments”
http://www.ncbi.nlm.nih.gov/pubmed/27571226

All Glory to the Triple-Rule-Out

The conclusions of this study are either ludicrous, or rather significant; the authors are either daft, or prescient. It depends fundamentally on your position regarding the utility of CT coronary angiograms.

This article describes a retrospective review of all the “Triple-Rule-Out” angiograms performed at a single center, Thomas Jefferson University Hospital, between 2006 and 2015. There were no specific circumstances under which the TRO were performed, but, grossly, the intended population were those who were otherwise being evaluated for an acute coronary syndrome but “was suspected of having additional noncoronary causes of chest pain”.

This “ACS-but-maybe-not” cohort totaled 1,192 patients over their 10 year study period. There were 970 (81.4%) with normal coronary arteries and no significant alternative diagnosis identified. The remaining, apparently to these authors, had “either a coronary or noncoronary diagnosis that could explain their presentation”, including 139 (11.7%) with moderate or severe coronary artery disease. In a mostly low-risk, troponin-negative population, it may be a stretch to attribute their symptoms to the coronary artery disease – but I digress.

The non-coronary diagnoses, the 106 (8.6%) with other findings, range from “important” to “not at all”. There were, at least, a handful of aortic dissections and pulmonary emboli picked up – though we can debate the likelihood of true positives based on pretest odds. However, these authors also credit the TRO with a range of sporadic findings as diverse as endocarditis, to diastasis of the sternum, and 24 cases of “aortic aneurysm” which were deemed important mostly because there were no priors for comparison.

The authors finally then promote TRO scans based on these noncoronary findings – stating that, if a traditional CTCA were performed, many of these diagnosis would likely be missed. Thus, the paradox. If you are already descending the circles of hell, and are using CTCA in the Emergency Department – then, yes, it is reasonable to suggest the TRO is a valid extension of the CTCA. Then again, if CTCA in the acute setting is already outside the scope of practice, and TRO is an abomination – carry on as if this study never existed.

“Diagnostic Yield of Triple-Rule-Out CT in an Emergency Setting”
http://www.ncbi.nlm.nih.gov/pubmed/27186867

But Where is the Antidote to the Poison @NEJM?

Andexanet alfa is the long-awaited antidote for the Factor Xa inhibitors – rivaroxaban, apixaban, edoxaban, and their ilk. This publication, featured at the European Stroke Congress and in the New England Journal of Medicine, is Portola’s latest update regarding its utility. Is it better than their previous update – their failure to receive initial FDA approval – or just another “incomplete” like their publication last fall?

This is ANNEXA-4, an open-label, single-group study purporting to evaluate the efficacy and safety of andexanet for clinical hemostasis in actively bleeding patients with concomitant use of Factor Xa inhibitors. Or, more specifically, these are interim results – the first 67 of 250 planned for enrollment. The clinical efficacy endpoint is a complex series of adjudicated judgements regarding the cessation of bleeding, hematoma expansion, or change in hematocrit, depending on the type of bleeding enrolled. The primary safety endpoint is death or thrombotic event within 30 days – stroke, myocardial infarction, venous thromboembolism, etc.

There is virtually nothing positive to relate here. The authors, of course, relate that somewhere around 80% of the 47 patients included in their efficacy analysis obtained “good” or “excellent” hemostasis with 12 hours following their andexanet infusion. But, these essentially arbitrary labels at a potentially clinically unimportant timepoint tells us virtually nothing regarding its value versus observation, or an alternative treatment such as prothrombin concentrate complexes.

On the negative side, the list is endless. There is the baffling offensiveness of publishing what amounts to a quarter of a trial in the New England Journal of Medicine.  The mean time to andexanet bolus was nearly 5 hours, raising concern regarding the acuity and severity of bleeding in enrolled patients.  The vague, patient-oriented endpoints are meaningless – with or without a comparator – and thus, this boils down to basically a pharmacokinetic observational study. Even then, the pharmacokinetics don’t appear terribly favorable – andexanet dramatically reduces Factor Xa activity during infusion, but pops back to therapeutic anticoagulation following cessation. A concerning 18% had thrombotic events within 30 days – but, again, without any control group, little can be concluded regarding safety.

Finally, clearly, the NEJM has given up publishing the conflicts-of-interest for the authors because it would sum up to half the journal – this article directs the reader to the disclosure forms on the web. For the eagle-eyed reader, however, they can pick out this text as part of the author affiliations: “Portola Pharmaceuticals, San Francisco (J.T.C., A.G., M.D.B., G.L., P.B.C., S.G., J.L., B.L.W.)”. Yes, eight of the authors are employees of Portola Therapeutics, the manufacturer. Better even, are their ICJME form disclosures. John Curnutte, the Head of Research and Development, has checked the box stating he has no relevant conflicts of interest with the work under consideration for publication – but, you know, outside the submitted work he happens to be an employee for Portola. In fact, from what I can tell, every employee authoring this article declared they have no COI with the work under consideration for publication.

Inconceivable!

Andexanet Alfa for Acute Major Bleeding Associated with Factor Xa Inhibitors
http://www.nejm.org/doi/full/10.1056/NEJMoa1607887

Not Seeing Any Value in RINSE

If a little bit of cooling – or at least Targeted Temperature Management – can preserve brain function, why not start it when the brain is most susceptible to injury? Why not start it when CPR is in progress, and the initial injury from poor perfusion begins?

That was, essentially, the question asked by the RINSE Trial, which randomized out-of-hospital cardiac arrest patients to either rapid infusion of cold saline or standard “ambient” fluid administration. Eligible patients received an initial round of CPR, defibrillation if indicated, and epinephrine if indicated, and were then randomized to one of the two arms.

Unfortunately, there’s not much in this trial favoring the intervention. RINSE was stopped early after receiving hospitals changed their temperature management protocols following the publication of TTM, but still managed to randomize 1,198 patients with similar baseline characteristics between cohorts. About half of patients had non-shockable rhythms, and pre-hospital results were similar. The other half, however, had shockable rhythms, and an excess of 10.2% of these patients died at the scene after cold saline infusion was initiated. Thus, the only trend observed here is one favoring standard care.

There are a few quirks to consider. Only a little more than 10% of all potentially eligible OHCA were enrolled, with no information regarding the unenrolled cohort or reasons for exclusion. The temperature difference between the two groups, based on pre-hospital tympanic membrane measurements, was only 0.7°C. Lastly, the primary outcome measure used was survival to hospital discharge, and not one of neurologic function – which may have been better aligned with the underlying neuropreservation hypothesis.

Regardless, there certainly isn’t anything here to trump up enthusiasm for further exploration, even if the magnitude of harm observed probably exceeds the expected effect of their intervention.

“Induction of Therapeutic Hypothermia During Out-of-Hospital Cardiac Arrest Using a Rapid Infusion of Cold Saline (The RINSE Trial)”

http://circ.ahajournals.org/content/early/2016/08/25/CIRCULATIONAHA.116.021989

Beware Good Times; Beware!

I imagine some of you are active travelers, eating on the go. Perhaps you have business interests and frequently dine out of the home. Sadly, your rock and roll lifestyle may yet be the end of you.

This is an interesting analysis of the “Progression of Early Subclinical Atherosclerosis” study, breaking down participants into dietary spectra. Based on cross-sectional analysis of the reported eating habits of participants, there were three distinct dietary patterns cohorted together: Mediterranean, Western, and and a “social-business” eating pattern. Approximately 40% were in each the Mediterranean and Western cohorts, with the remainder in “social-business”. The general attributes of each diet are shown in the figure below:

eating patterns image

The finding of note – after all participants underwent atherosclerotic screening tests – is that the “social-business” pattern of consumption is, quite obviously, the highest risk for disease progression. Whereas the Mediterranean cohort had only 36% with generalized or intermediate atherosclerosis, the “social-business” cohort totaled an impressive 68%. The Western diet was slightly above the Mediterranean, at 41%.

Stay healthy, my friends.

“Association Between a Social-Business Eating Pattern and Early Asymptomatic Atherosclerosis”

http://content.onlinejacc.org/article.aspx?articleID=2544530

Tylenol & Case of the Flawed Fetus

If you’re like most folks advising pregnant patients on pain and fever control, you’ve advised against ibuprofen and recommended acetaminophen. It is, after all, considered to be generally safe throughout pregnancy, in contrast to the alternatives.

I’m afraid I do not know precisely what to make of this study, but it is the latest in a context of several other studies linking maternal acetaminophen use during pregnancy with behavioral issues in young children. These authors link surveys of pregnant women performed over a decade ago with follow-up surveys of their children, with specific emphasis on identifying potential cofounders for their observed association.

The ultimate conclusion is fairly clear from just the title, with the subtitle of “Evidence Against Confounding”. An association is clearly observed between those they identify with likely or confirmed usage of acetaminophen and increased behavioral and attention difficulties in childhood. However, the evidence against confounding is rather incomplete. There are small differences in maternal psychiatric illness, maternal smoking, and maternal alcohol use favoring normally behaved children – and, while these authors attempt to control for these factors, this still introduces some element of statistical tomfoolery. There are also several non-genetic and non-prenatal risk factors for ADHD, and these authors are able only to collect a handful of these – absent completely any observations of the home environment of the children evaluated. Finally, no dose-response relationship is ultimately measured, as well.

I would, of course, ultimately advise minimal medication exposure in pregnancy, regardless. If pain control is necessary, it is not clear this risk – if true – is specifically of greater magnitude than those associated with alternative analgesia. For, this does not yet change practice.

“Association of Acetaminophen Use During Pregnancy With Behavioral Problems in Childhood”

http://archpedi.jamanetwork.com/article.aspx?articleid=2543281