TMJ Dislocations: A Better Mousetrap?

Anterior temporomandibular dislocations are generally quite satisfying closed reductions.  Patients, understandably, are exceedingly grateful to have their function restored.  However, it typically requires parenteral analgesia, sometimes procedural sedation, and puts the practioner at risk of injury from inadvertent biting.

This interesting pilot describes a technique in which the patient, essentially, self-reduces the TMJ dislocation by using a syringe held between the posterior molars as a rolling fulcrum.  I’d describe it in more detail, but I think, from the image reproduced here, you’ll get it:


These authors used this technique for 31 cases, and only one was ultimately unsuccessful.

While this is not the intended use for a syringe, I can’t hardly imagine any terrible harmful adverse effects from materials failure – and they don’t exceed the risks of procedural sedation.  I certainly find it reasonable to experiment with this technique.

“The ‘Syringe’ technique: a hands-free approach for the reduction of acute nontraumatic temporomandibular dislocation in the Emergency Department.”
http://www.ncbi.nlm.nih.gov/pubmed/25278137

Who Loves Tamiflu?

Those who are paid to love it, by a wide margin.

This brief evaluation, published in Annals of Internal Medicine, asks the question: is there a relationship between financial conflicts-of-interest, and the outcomes of systematic reviews regarding the use of neuraminidase inhibitors for influenza?  To answer such a question, these authors reviewed 37 assessments in 26 systematic reviews, published between 2005 and 2014, and evaluated the concluding language of each as “favorable” or “unfavorable”.  They then checked each author of each systematic review for relevant conflicts of interest with GlaxoSmithKline and Roche Pharmaceuticals.

Among those systematic reviews associated with author COI, 7 of 8 assessments were rated as “favorable”.  Among the remaining 29 assessments made without author COI, only 5 were favorable.  Of the reviews published with COI, only 1 made mention of limitations due to publication bias or incomplete outcomes reporting, versus most of those published without COI.

Shocking findings to all frequent readers, I’m sure.

“Financial Conflicts of Interest and Conclusions About Neuraminidase Inhibitors for Influenza”
http://www.ncbi.nlm.nih.gov/pubmed/25285542

Original link in error ... although, it's a good article, too!
http://www.ncbi.nlm.nih.gov/pubmed/24218071

More CT Coronary Angiography Dreaming

CT coronary angiography has been touted as a lovely test for the acute setting – a relatively fast, non-invasive method of obtaining information on the coronary vasculature with reasonable-sounding diagnostic characteristics.  However – despite what these authors seem to be trying to convey – it’s simply a test, not a protective intervention.

This is a prospective longitudinal cohort study of 585 individuals at a single institution undergoing CT coronary angiography for suspected ischemic chest pain.  Patients with negative troponins were enrolled during weekday, daytime hours, had TIMI 0-4 (mostly 0-2), and absent the usual contraindications to CTCA.  Patients were followed for nearly two years – and, of 506 patients with zero or insubstantial plaque seen on CTCA, all were still alive, and none had suffered an acute coronary syndrome.  Thus, the fantastic protective effect of a negative CTCA.

The only issue – all those patients would have achieved such event-free survival whether they underwent CTCA or not.

Of the 79 admitted for invasive angiography with severe stenosis, only 34 received PCI or CABG, and 10 were found to have less than 40% stenosis.  So – ultimately – 585 CTCAs to identify the 6% of patients who may potentially have benefited, harming just as many with invasive procedures and the remainder with radiation.  There is a reasonable, ultimate question regarding whether those with negative evaluations are obviated from additional chest pain work-up over the long run – but that has yet to be demonstrated in practice, and the costs associated with the initial false positives subtract from those future potential savings.

Rather than demonstrate the utility of CTCA in the Emergency Department, these authors better demonstrate the unfortunate characteristics of its overuse.

“Long-term Outcome after CT angiography in Patients with Possible acute coronary syndrome”
http://www.ncbi.nlm.nih.gov/pubmed/24738614

Using Patient-Similarity to Predict Pulmonary Embolism

Topological data analysis is one of the many “big data” buzzphrases being thrown about, with roots in non-parametric statistical analysis, and promoted by the Palo Alto startup, Ayasdi.  I’ve done a little experimentation with it, and used it mostly to show the underlying clustering and heterogeneity of the PECARN TBI data set.  My ultimate hypothesis, based on these findings, would be that patient-similarity is a more useful predictor of individual patient risk than the partition analysis used in the original PECARN model.  This technique is similar to the “attribute matching” demonstrated by Jeff Kline in Annals, but of much greater granularity and sophistication.

So, I should be excited to see this paper – using the TDA output to train a neural network classifier for suspected pulmonary embolism.  Using 152 patients, 101 of which were diagnosed with PE, the authors develop a topological network with clustered distributions of diseased and non-diseased individuals, and compare the output from this network to the Wells and Revised Geneva Scores.

The AUC for the neural network was 0.8911, for Wells was 0.74, and Revised Geneva was 0.55. And this sounds fabulous – until it’s noted the neural network is being derived and tested on the same, tiny sample.  There’s no validation set, and, given such a small sample, the likelihood of overfitting is substantial.  I expect performance will degrade substantially when applied to other data sets.

However, even simply as scientific curiosity – I hope to see further testing and refinement of potentially greater value.

“Using Topological Data Analysis for diagnosis pulmonary embolism”
http://arxiv.org/abs/1409.5020
http://www.ayasdi.com/_downloads/A_Data_Driven_Clinical_Predictive_Rule_CPR_for_Pulmonary_Embolism.pdf

Does Cardiac Catheterization Help After OHCA?

Yes!

Probably.

It sure seems like it.

But, we still don’t really know for whom.

We’ve reviewed several of the prospective and retrospective studies regarding post-arrest cardiac catheterization on this blog over the years.  The general conclusion – the authors are very enthusiastic about their outcomes, but their comparison groups are invalidated by selection bias.  So, unsurprisingly, when a systematic review and meta-analysis of these studies is performed – the same critiques hold.

This review identifies 50 studies with sufficient reporting and design for analysis.  27 of these studies describe use in STEMI complicated by OHCA – and outcomes are largely excellent, compared to typical OHCA survival.  Good neurologic survival, in the 18 studies reporting such, averaged 68.4%.  There’s not much debate regarding STEMI complicated by OHCA – cardiac catheterization, when available.

The problem, however, arises when evaluating patients with OHCA and no clear cause for arrest.  There were 15 studies comparing outcomes with and without cardiac catheterization – and, overall, good neurologic outcome was present in 58% versus 35.8%, with and without cardiac catheterization, respectively.  However, 11 of these 15 studies were retrospective, and patients undergoing conservative management tended to have poorer prognosis at baseline and those who underwent cardiac catheterization tended to have more prominent ischemic changes on post-arrest ECG.

So, it’s another garbage-in, garbage-out sort of meta-analysis and review.  It cannot be used to support universal expansion of the target population for cardiac catheterization after OHCA, and tells us, essentially, what we already knew.  Clearly, some patients – particularly those for whom a culprit lesion is identified – benefit.  For the remainder, the treatment population remains unclear, particularly in the face of the extraordinary resource utilization.

“Cardiac catheterization is associated with superior outcomes for survivors of out of hospital cardiac arrest: Review and meta-analysis”

ARISE, and Cast Off the Shackles of EGDT

The sound you hear is a sigh of relief from Emergency Physicians and intensivists regarding the outcomes of the Australasian Resuscitation in Sepsis Evaluation (ARISE).

As ProCESS suggested, and as many have suspected all along, it seemed the critical intervention from Early Goal-Directed Therapy was the early part – and less the SCO2 monitoring and active management of physiologic parameters using dobutamine and blood transfusion.  Now, we have a second study, in addition to ProCESS, supporting the same general conclusions.

ARISE enrolled patients with confirmed or suspected sepsis, and either hypotension refractory to 1L crystalloid fluid challenge or a lactate level of 4.0 mmol/L or more.  31 centers randomized 1,600 patients to undergo either EGDT or “usual care”, which entailed routine local clinical practice, excepting measurement of SCVO2 was forbidden.  EGDT, however, was provided by specially coordinated teams to ensure all patients received the intervention.  The primary outcome was death from any cause within 90 days, powered to detect an absolute risk-reduction of 7.6%.

Baseline characteristics between the two groups were quite similar, few patients dropped out of each arm, and, finally, there was no difference in the primary outcome – 18.6% vs. 18.8% (does it matter which is which?)  Indeed, of all the outcomes measured, only two differed in statistically significant fashion: the EGDT cohort departed the Emergency Department 30 minutes more quickly, and the EGDT cohort received greater vasopressor support – attributable entirely to the use of dobutamine in 15.4% of patients vs. 2.6% in the usual care arm.

As expected, resource utilization unique to EGDT, of course, was different – more and different types of central venous catheters, more arterial catheters, and more frequent use of blood products.  And, as we’re seeing – all of this is unnecessary.  As with ProCESS, “usual care” has become EGDT, excepting these elements.  Both groups received substantial, early crystalloid resuscitation, early appropriate antibiotic coverage, and departed the Emergency Department to a critical care setting quite quickly.

EGDT receives credit for making us aware the impact early identification and intervention can have on mortality.  However, it is time to leave EGDT behind and identify new resuscitation targets and sensible strategies for achieving them.

“Goal-Directed Resuscitation for Patients with Early Septic Shock”
http://www.nejm.org/doi/full/10.1056/NEJMoa1404380