Friday, January 11, 2013

Who Are the PE Positive PERC Negatives?

This little letter, tucked away in the Correspondence section of Annals delves into the Pulmonary Embolism Rule-Out Criteria – a decision instrument of some controversy in Emergency Medicine.  Specifically, this letter addresses a case report from a previous issue of Annals of, essentially, a large pulmonary embolus diagnosed in a young patient who was otherwise PERC negative.

The authors from Carolinas Medical Center have a registry of 1,880 PE+ patients with which to evaluation, and they performed a retrospective application of the PERC rule.  Overall, 6% of this cohort was PE positive and PERC-negative.  When compared with the patients with PE who were PERC-positive, there are a few statistically significant differences – pleuritic chest pain was more common in PERC-negative patients with PE, along with pregnancy or post-partum status.  Unfortunately, these statistically significant relative differences reflect only small absolute differences of essentially clinically irrelevant magnitude.  The only mildly interesting tidbit from the letter is the statistic that none of PERC-negative PEs died within 30 days, compared with 5.7% of the PERC-positive cohort.

The authors suggest a couple weak clinical implications from the data, but these are limited by the retrospective nature of the analysis.  It is enough to remember that PERC-negative does not actually "rule-out" PE – it is simply a collection of negative likelihood ratios working against a pretest probability, resulting in clinical equipoise regarding the expect benefits vs. harms of CT pulmonary angiogram and the resultant harms of treatment in physiologically uninteresting PE.

"Clinical Features of Patients With Pulmonary Embolism and a Negative PERC Rule Result"

Thursday, January 10, 2013

Tamliflu Redux

Just as relevant a year later, a quick re-post to the Cochrane Collaboration's Tamiflu exposé:

"Neuraminidase inhibitors for preventing and treating influenza in healthy adults and children."

See what I wrote about it last year:

(spoiler alert:  hardly worth the cost, at best; next to useless, more likely)

Wednesday, January 9, 2013

Diverticulitis – The Sinusitis of the Colon?

Antibiotics are wonderful things.  They treat and provide life-saving amelioration of symptoms from the common cold, the flu, bronchitis, sinusitis, and otitis – or, more accurately, they don't.  Rather than generalize the treatment with antibiotics for all these illness, it is rather the avoidance of antibiotics that should be generalized, with specific exceptions made as necessary.

The next "-itis" to go under the microscope is diverticulitis.  These authors from Iceland and Sweden deserve, at the minimum, kudos for innovation in swimming against the tide.  The treatment of acute diverticulitis – a febrile illness with an elevated WBC and left-lower quadrant pain – is generally gram-negative and anaerobic coverage as an inpatient or outpatient, depending on comorbidities.  These authors propose that diverticulitis is most frequently a self-limited process, rather than one that requires antibiotics.

This a non-blinded trial of antibiotics vs. non-treatment for CT-demonstrated acute, uncomplicated diverticulitis.  Over 600 patients were admitted, with half receiving simple observation and symptomatic treatment vs. half with the same plus antibiotics.  1% of patients in the antibiotic group suffered treatment failure – progression to abscess or perforation – compared with 2% of patients in the placebo group.

Unfortunately, we're not quite done with antibiotics based on just this study.  It is unblinded with variable enrollment between centers, leading to several sources of potential bias.  Then, ten patients in the no-antibiotics group crossed over to receive antibiotics for clinical worsening during hospitalization.  However, this is still below the 6.5% complication rate the authors thought might be an acceptable failure rate for conservative therapy.

Many more questions to be answered regarding external validity, so hopefully this inspires other investigators to further explore which subset patients will derive benefit from antibiotics in diverticulitis.

"Randomized clinical trial of antibiotics in acute uncomplicated diverticulitis"

Monday, January 7, 2013

The Future of Heart Failure Admissions

At least, this is how Cardiologists think the Emergency Department should be handling heart failure in The Future.

Specifically, Cardiologists would like us to stop admitting patients with acute exacerbations of established heart failure – and, interestingly, they're a bit apprehensive about discharging them.  Their earth-shaking, practice-modifying innovation is this:  observation unit management.

This strategy is founded partly out of interest of the patient's well-being, but mostly out of interest for the hospital's financial well-being.  In general, heart failure remains one of the most difficult hospital readmissions to prevent.  This is important because, suddenly, readmissions within 30 days are no longer reimbursed by CMS.  Now, rather than, re-admit patients for free, they've decided the New Fabulous Idea is to place them in outpatient observation status – which is a lower level of reimbursement, but still better than nothing.  In addition to the other obviously indicated admissions, they also feel some of the gray area discharges would probably benefit from observation, appropriately noting heart failure patients discharged from the ED are at high risk of having subsequent worsening due to a variety of contributing factors.

Overall, as far as actual patient care, there's probably little difference – somewhat cynically, the entire strategy seems mostly to be an advisory on how to minimize the impact of reimbursement losses from readmissions.

"Is Hospital Admission for Heart Failure Really Necessary?  The Role of the Emergency Department and Observation Unit in Preventing Hospitalization and Rehospitalization"

And, just as a rather inspirational aside, this is one of the longest disclosures list I have ever seen for an author:
"Dr. Gheorgiade has received support from Abbott Laboratories, Astellas, AstraZeneca, Bayer Schering Pharma AG, Cardiorentis Ltd., CorThera, Cytokinetics, CytoPherx, Inc., DebioPharm S.A., Errekappa Terapeutici, GlaxoSmithKline, Ikaria, Intersection Medical, Inc, John- son & Johnson, Medtronic, Merck & Co., Inc., Novartis Pharma AG, Ono Pharmaceuticals USA, Otsuka Pharmaceuticals, Palatin Technologies, Pericor Therapeutics, Protein Design Laboratories, sanofi-aventis, Sigma Tau, Solvay Pharmaceuticals, Sticares InterACT, Takeda Pharmaceuticals North America, Inc., and Trevena Therapeutics; and has received significant (>$10,000) support from Bayer Schering Pharma AG, DebioPharm S.A., Medtronic, Novartis Pharma AG, Otsuka Pharmaceuticals, Sigma Tau, Solvay Pharmaceuticals, Sticares InterACT, and Takeda Pharmaceuticals North America, Inc."