Month: February 2014

Gently Euthanizing the Elderly

It is well-known the elderly are at higher risk for medication adverse effects.  It is, likewise, recognized opiates are one of the most dangerous prescription medications in use.  Therefore, the prudent thing to do would be avoid opiate use in the elderly – and, certainly, not be irresponsible regarding multiple, concurrent prescriptions for opiates.

However, as this 20% random sample of Medicare beneficiaries demonstrates, an estimated 5.2M Americans covered by this insurance source received opiates – with approximately 85% of this cohort aged greater than 55.  Most patients who received opiates filled more than one prescription – including a full 7% who received >4 prescriptions, from >4 different providers.  This last group received a mean number 15 opiate prescriptions in a single calendar year.  Unsurprisingly, increased opiate prescriptions were associated with increased subsequent hospitalizations.  While there is no mortality data in this report, I don’t think it’s a stretch to speculate the illness-adjusted outcomes would be much poorer.

The use of opiates for pain control for acute and chronic illness is a necessary evil, particularly in the elderly.  This study, given its limitations, cannot precisely elucidate whether the opiates provided represented irresponsible prescribing – but it supports much of what we anecdotally observe regarding the fragmented healthcare process.  Whether the magnitude of the problem is as great as these authors seem to suggest, there should be no argument we have plenty of room for improvement in treating some of our most vulnerable patients.

“Opioid prescribing by multiple providers in Medicare: retrospective observational study of insurance claims”
http://www.bmj.com/content/348/bmj.g1393

Outpatient Management of Large Pneumothorax

A guest post by Justin Mazzillo, a community doc in New Hampshire.
“Okay Mr. Smith now that your chest tube is in we’re going to go ahead and discharge you.  Just come back to the Emergency Department if you have any problems.”

That’s pretty much what these investigators set out to do…with a few minor differences. Instead of following the more common practice of aspirate and observe or place a chest tube and admit, the authors’ goal was to demonstrate that patients with large primary and secondary pneumothorax can be managed as outpatients with pigtail catheters. This prospective case series of 132 patients aimed to evaluate the success rate of outpatient management, as well as the one-year recurrence rate, pain medication use, safety and cost of this approach.

Patients who presented to this French hospital with large primary or secondary pneumothoraces had a pigtail catheter placed, were observed for two hours without a confirmatory chest radiograph and then discharged. Patients were seen in follow-up clinic on days 2 and 4 and admitted to the hospital on day 4 if the pneumothorax failed to resolve.

Of the 132 patients, 78% were managed entirely as outpatients. Patients with primary and secondary pneumothoraces had similar success rates, although the latter group was considerably smaller.  Two patients had mechanical catheter issues that were addressed as outpatients on their follow-up visit on day 2. The recurrence rate at one-year was 26%. The average cost of being managed as an outpatient in this study was $926 vs. $4,276 for the conventional inpatient approach.

This seems like an attractive and safe option as health care costs continue to skyrocket and more patients are managed in the ambulatory setting.  
“Ambulatory Management of Large Spontaneous Pneumothorax With Pigtail Catheters”


ABCD3 – Better, But Good Enough?

The ABCD2 score for the prediction of stroke after TIA was initially touted as a possible risk-stratification tool geared towards determining which patients could undergo delayed evaluation for modifiable risk factors.  Unfortunately, the “low risk” cohort generated by the ABCD2 score still has an unacceptably high risk of stroke at 7 days, with poor predictive and discriminative power.

These authors try to take it to the next level – the ABCD3 score and the ABCD3-I score.  Derived retrospectively from the Kyoto Stroke Registry, the third element of D3 is “Dual TIA” – which is having had another TIA within the prior 7 days.  Then, the “I” is dependent upon having a positive MRI DWI lesion associated with concurrent ipsilateral carotid artery stenosis.

In their retrospective application of ABCD2, ABCD3, and ABCD3-I, as expected, the ABCD2 score showed minimal utility for the outcome of interest for the Emergency Department – the 7 day risk of stroke in the low-risk cohort was ~6%.  The low-risk ABCD3 and ABCD3-I cohort, however, had a ~1 to 2% risk at 7 days.  If verified prospectively, this begins to approach reliable utility for discharge decision-making in the ED.  Given the ABCD2 score’s checkered past, I would certainly wait for the next bit of evidence.

“ABCD3 and ABCD3-I Scores Are Superior to ABCD2 Score in the Prediction of Short- and Long-Term Risks of Stroke After Transient Ischemic Attack”
http://stroke.ahajournals.org/content/45/2/418.full

Warning: Jolt At Your Own Risk…

A guest post by Rory Spiegel (@CaptainBasilEM) who blogs on nihilism and the art of doing nothing at emnerd.com.

Jolt accentuation is a means of perturbing the meninges of a patient presenting with a headache, in the hopes of delineating those who have meningitis from those with a more benign cause. Similar to the “rock the gurney” test in appendicitis or the Dix-Hallpike in BPPV, we are exacerbating the patient’s symptoms in the hopes of better understanding their illness. It has been claimed that the jolt accentuation test is the most sensitive physical exam finding available to rule out meningitis. A recent article published in American Journal of Emergency Medicine suggests otherwise.

This elegantly constructed prospectively gathered cohort was performed at two inner city hospitals over a 4-year period. Authors enrolled all neurologically intact patients older than 18 years old presenting with symptoms suspicious for meningitis. Physicians were asked to answer a questionnaire of physical examination findings before receiving CSF results.  Cunningly the authors surreptitiously placed the LP trays at the research staff’s station to ensure capture of eligible candidates.

47 patients (20%) out of 230 total enrolled were found to have CSF pleocytosis (defined as > 5 WBC ). The jolt accentuation test performed poorly at identifying these patients, with a sensitivity of 21% and a specificity of 82%. Kerning sign, Brudzinski sign, and nuchal rigidity performed no better with sensitivities and specificities of 2%, 2%, 13% and 97%, 98%, 80% respectively. Dishearteningly, the Emergency Physicians overall gestalt performed just as poorly with a sensitivity of 44% and a specificity of 40%.

Unfortunately the authors do not tell us how the jolt accentuation test performed in patients diagnosed with bacterial or fungal meningitis.  In this cohort only 3 of the 230 patients had culture positive meningitis, with only 2 from bacterial or fungal sources (one Cryptococcal and one Meningococcal ). The Emergency Physician identified both of these cases as high-risk upon initial evaluation. The authors failed to mention whether the jolt accentuation was positive in either of these patients. To truly examine jolt accentuation’s diagnostic performance, further studies using culture positive bacterial meningitis rather than pleocytosis as our diagnostic criteria are needed. This would require a much larger cohort, including a significantly larger quantity of cases of bacterial meningitis. But until then perturb with caution…

“Jolt accentuation of headache and other clinical signs: poor predictors of meningitis in adults” www.ncbi.nlm.nih.gov/pubmed/24139448

Irreproducible Research & p-Values

I circulated this write-up from Nature last week on Twitter, but was again reminded by Axel Ellrodt of its importance when initiating research – particularly in the context of studies endlessly repeated, or slightly altered, until positive (read: Big Pharma).

The gist of this write-up – other than the fact the p-value was never really intended to be a test of scientific validity and significance – is the important notion a universal cut-off of 0.05 is inappropriate.  Essentially, if you’re familiar with Bayes Theorum and the foundation of evidence-based medicine, you understand the concept that – if a disease is highly unlikely, the rule-in test ought to be tremendously accurate.  Likewise, if a scientific hypothesis is unlikely, or an estimated effect size for a treatment is small, the p-value required to confirm a positive result needs to be greater than the one-in-twenty approximation of the traditional 0.05 cut-off.  The p-value, then, functions akin to the likelihood ratio – providing not a true dichotomous positive/negative outcome, but simply further adjusting the chance a result can be reliably replicated.

This ties back into the original purpose of p-value in research – to initially identify topics worth further investigation, not to conclusively confirm true effects.  This leads very obviously into the recurrent phenomenon through clinical and basic science research of irreproducible research.  And, indeed, Nature’s entire segment of the challenges of reproducibility in research is an excellent read for any developing investigator.

“Scientific method: Statistical errors”
http://www.nature.com/news/scientific-method-statistical-errors-1.14700

“Challenges in Irreproducible Research”
http://www.nature.com/nature/focus/reproducibility/index.html

The Eloquence of Stroke Neurologists

Entertainingly enough, as tPA proponents continue their push for longer time windows and less-stringent inclusion criteria, Stroke recently published a sort of head-to-head debate regarding tPA within the 3 – 4.5h window.

Despite the breathless madness typically exhibited by stroke neurologists and the current Level B recommendations from the AHA, Lawrence Wechsler from the University of Pittsburgh writes a very reasonable critique of ECASS III, incorporating data from ATLANTIS and IST-3.  His general point, overall, is the theoretical effect size, if any, is small beyond 3 hours.  Therefore, he proposes patients should be carefully selected – perhaps by penumbral perfusion imaging.

His opponents, from Germany, in their response, offer a critique featuring this well-written, professional, academic segment:

Is advanced imaging necessary to make this decision? Why, No?! Would a lacunar versus nonlacunar syndrome make a difference here? No!! It would not make a difference within 3 hours, would it? And what about an MRI without perfusion imaging/diffusion weighted imaging mismatch or with proof of a lacunar stroke, would this make a difference? Hell, no!!! There is no evidence at all for this conclusion. And is there any reason to believe that rt-PA does not work in the 3- to 4.5-hour time window or that it does work only in “a carefully selected set of patients”? What the h…, No, No No!!!!

In keeping with Patrick Lyden’s lovely ad hominem attacks on Anand Swaminathan (“young”, “naive”), it is yet again abundantly clear some proponents of tPA have no response in reasonable, scientific debate other than nonsensical, authoritative bluster.

“The 4.5-Hour Time Window for Intravenous Thrombolysis With Intravenous Tissue-Type Plasminogen Activator Is Not Firmly Established”
http://www.ncbi.nlm.nih.gov/pubmed/24526061

“4.5-Hour Time Window for Intravenous Thrombolysis With Recombinant Tissue-Type Plasminogen Activator Is Established Firmly”
http://www.ncbi.nlm.nih.gov/pubmed/24526060

Finding Value in Emergency Care

The Choosing Wisely initiative is, despite its flaws, an necessary cultural shift in medicine towards reducing low-value expenditures.  In a fee-for-service health system, and given the complicated financial framework associated with training and reimbursing physicians, noble endeavors such as these face significant challenges.

Regardless, many specialties – including ACEP – have published at least one “Top 5” list of recommended practices to improve value.  The ACEP Choosing Wisely list, while certainly reflecting sound medical practice, are of uncertain incremental value or applicability over current practice.  Additionally, the methods and stakeholders involved remain opaque.  Luckily, in a coincidental parallel, Partners Healthcare embarked on an unrelated internal process to improve the affordability of healthcare and reduce costs.  This study provides a transparent look at a such a process, as well as the ultimate findings.

Using an expert panel, 64 potential low-value care practices were identified in a brainstorming session, subsequently narrowed down to 17.  Then, 174 physicians and clinical practioners responded to a web-based survey, ranking the value of each.  Based on this feedback, then, the original expert panel voted again on a final “Top 5”:

  • Do not order computed tomography (CT) of the cervical spine for patients after trauma who do not meet the National Emergency X-ray Utilization Study (NEXUS) low-risk criteria or the Canadian C-Spine Rule.
  • Do not order CT to diagnose pulmonary embolism without first risk stratifying for pulmonary embolism (pretest probability and D-dimer tests if low probability). 
  • Do not order magnetic resonance imaging of the lumbar spine for patients with lower back pain without high-risk features. 
  • Do not order CT of the head for patients with mild traumatic head injury who do not meet New Orleans Criteria or Canadian CT Head Rule. 
  • Do not order coagulation studies for patients without hemorrhage or suspected coagulopathy (eg, with anticoagulation therapy, clinical coagulopathy).

It always surprises me to see these lists – which, essentially, just constitute sound, evidence-based practice.  That said, given my exposure primarily to an academic, teaching environment, rather than a community hospital environment concerned with expediency and revenue generation, these may be larger problems than I expect.  This list also does not address the estimated cost-savings associated with adherence to these “Top 5” best practices.  While many of these may result in significant cost-savings through reductions in imaging, the yield would be variable based on the quality of care already in place.

Regardless, this list is as much about the derivation process itself, rather than the resulting “Top 5”.  Certainly, the transparency documented in this study is superior to the undocumented process behind ACEP’s contribution.  That said, this list ultimately reflects the biases and practice patterns of a single healthcare network in Massachusetts; your mileage may vary.  Many of the final “Top 5” had overlapping confidence intervals on the Likert Scale for benefit and actionability, suggesting a different survey instrument may have provided better discrimination.  Finally, while we are culturally enamored with “Top 5” lists – all 64 of their original set are important considerations for improving the value of care.

We, and all of medicine, have a long way to go – but these are steps along the right path.  It is also critically important we also (wisely) choose our own destiny – rather than wait for government or insurance administrators to enforce their misguided priorities upon our practice.

“A Top-Five List for Emergency Medicine: A Pilot Project to Improve the Value of Emergency Care”
https://archinte.jamanetwork.com/article.aspx?articleid=1830019

ADAPTing & Improving

By far, the most promising of the publications to yet emerge from the ADAPT cohort – 1,974 patients evaluated for acute chest pain in the Emergency Department – is this re-analysis and decision instrument.

The original ADAPT publication, despite over 80% of the patients having no major cardiac event at 30 days, was only able to identify 20% of patients as “low-risk”.  The HEART Score and the Vancouver Chest Pain Rule improve on this, but only incrementally.  This publication, however, improves the identification of a low-risk cohort to nearly 50%.  By incorporating and weighting 37 different predictor variables, then adding a layer of expert review and acceptability evaluation, these authors ultimately arrive at the “Emergency Department Assessment of Chest Pain Score (EDACS)”.  Using age, gender, history, and symptoms, when combined with negative ECG and 0 and 2 hour troponins, a score of 16 constitutes a breakpoint for a decision instrument with ~99% sensitivity and ~55% specificity for MACE at 30 days.

As far as decision instruments go, it’s relatively reasonable – although, certainly, nothing you’d be able to keep in your head.  Scores for age range from +2 to +20, while four different symptoms and signs have varying positive and negative values.  However, in the age of computerized decision-support, at least, mildly complex rules are not as burdensome as they once were.

I would like to see, at least, prospective validation in a North American population – but this appears to be a lovely step forward.

“Development and validation of the Emergency Department Assessment of Chest pain Score and 2 h accelerated diagnostic protocol“
http://onlinelibrary.wiley.com/doi/10.1111/1742-6723.12164/abstract

Again on Giving tPA to TIAs

When I suggested to Jeff Saver in JAMA his analysis of the Get With the Guidelines Registry may have become unbalanced due to the presence of TIAs within the tPA cohort, he went back to the NINDS data and identified seven patients from the placebo arm with TIAs.  Because 3 were in the 58 to 90 minute cohort and 4 were in the 91 to 180 minute cohort, he concludes there is an equal distribution of TIAs – and thus confounders – across all time periods.  This, of course, is nonsense – he is generalizing a handful of patients from the placebo arm from NINDS, a carefully controlled trial run by stroke neurologists, to the GTWG-Stroke registry, a cohort of community hospitals rushing to hit time-based stroke quality measures.  The contemporary evidence, such as this observational series from Japan, is that most TIAs present early in their symptom course – and earlier, if symptoms are more severe.

These authors retrospectively identified 464 patients admitted to 13 stroke centers in Japan with ultimate diagnosis of TIA based on complete clinical resolution of symptoms.  233 of them (55%) presented within the first three hours and the next 65 (15%) within six hours.  The common elements for the TIAs presenting earliest were the greatest severity of symptoms, primarily motor and speech disturbances.  A full 42% of their cohort had persistent symptoms upon arrival.

In the brave new world of tPA, hospitals are falling over themselves to treat these patients with thrombolytics – patients that ultimately would experience full clinical resolution of symptoms without intervention, and receive only the risks associated with tPA administration.  These patients ultimately make their way into the GWTG-Stroke registry, and come out the back end analysis looking like tPA miracles, “proving” time-to-treatment matters with tPA.  As “code stroke” protocols become more widespread, we will see even further such collateral damage.

“Factors Associated With Onset-to-Door Time in Patients With Transient Ischemic Attack Admitted to Stroke Centers”
http://www.ncbi.nlm.nih.gov/pubmed/24262324

No LVADs Were Harmed in the Making of This Blog Post

A guest post by Rory Spiegel (@CaptainBasilEM) who blogs on nihilism and the art of doing nothing at emnerd.com.

Do not perform chest compressions on an LVAD patient in arrest is a pseudoaxiom for the 21st century. The concern is the force of the compressions will dislodge the cannula, turning a critically ill patient into a critically ill patient with an LVAD-sized hole in their left ventricle. The manufacturers staunchly warn against performing compressions at the risk of causing the sky to fall, our patient’s chest to explode, and an incredibly enraged cardiothoracic surgeon to magically appear at bedside spewing hellfire and brimstone.

Authors of this recent retrospective case series attempt to disprove this modern day axiom. This series describes 8 LVAD patients who presented to their facility, Sharp Memorial Medical Center, in arrest over a 4 year span, all of whom received external chest compression as part of the resuscitative efforts. They assessed device integrity post-arrest in two fashions, either by blood flow data from the LVAD control monitor or examination of the device itself on autopsy (a poor prognostic indicator for the patient). 7/8 patients had flow data post-arrest recorded, all of which indicated a functionally intact VAD. 3/8 had an autopsy performed, including the patient with missing flow data. All confirmed an anatomically intact VAD. The authors conclude that at least in this small case series no VADs were harmed during chest compressions. Whether they were helped is another question all together. These are complex patients with multiple variables including the function of both the VAD and the patient’s intrinsic heart. In this series, 5 out of 8 patients arrested due to pump malfunction, 4 of which were due to accidental disconnection (yikes!). Even in this cohort of a seemingly correctable malady (just plug the thing back in), only one patient had return of neurological function.

A case series of 8 patients is clearly not a large enough n to prove chest compressions are safe in the LVAD patient.  What can be said for sure is the sky did not fall and no angry cardiothoracic surgeons materialized from thin air spewing fire and brimstone. Well, at least a half a psuedoaxiom disproven…

“Chest compressions may be safe in arresting patients with left ventricular assist devices (LVADs).” www.ncbi.nlm.nih.gov/pubmed/24472494