Saturday, December 31, 2005

Top ten issues in hospital medicine for 2005------issue 3

Emerging infections

1) Avian flu. Is it a big deal? Yes. Are we prepared? Not yet. Has it been hyped? Definitely. I have posted several times on this topic through the course of the year. [1] [2] [3] [4] [5] [6] Unanswered questions include: When will it arrive? Will the genetic shift necessary for efficient human to human transmission also weaken its virulence? (Let’s hope so. That’s what happened with two of the three pandemics this century).

2) Community associated methicillin resistant Staphylococcus aureus. It’s different from the old MRSA. The resistance pattern and the genome are distinct. Although we’ve had a friendly debate here on the blogosphere about the clinical significance (or lack thereof) of certain unique virulence factors, the clinical profile is different, with more skin and soft tissue infections, occasional necrotizing fasciitis, a possible increased threat of necrotizing pneumonia, and increased transmissibility. On the other hand the risk of intravascular and bone and joint infections may be less. Here are my previous posts on the topic. [7] [8] [9] [10]

3) New profiles of Clostridium difficile infection. I blogged previously about the outbreak of a new strain of C. diff in Quebec. An alarmingly higher mortality compared to usual infections was noted, attributable to a mutation in a regulator gene which controls toxin production, resulting in production of 15-20 times more toxin than usual. The reports from Canadian Medical Association Journal which I cited suggested that shared bathrooms in outmoded hospital facilities was the most important risk factor. Subsequently, two reports [11] [12] and an accompanying editorial in NEJM described outbreaks in the U.S. as well as the Quebec outbreak. It appears that the U.S. outbreak is similar to the Quebec outbreak, in that both are due to a strain that contains the toxin regulator gene deletion and has the ability to produce a previously uncommon binary toxin. The virulence potential of the regulator gene mutation is well known, while the significance of the binary toxin is less clear. The NEJM editorial by J. Bartlett summarizes the problem nicely, and points to two curious features of the severe cases, those being leukemoid reactions and hypoalbuminemia.

Top 10 issues in hospital medicine for 2005------issue 4

Controversies in hypercoagulability

Recent guidelines have recommended testing certain patients for hypercoagulable states following an episode of venous thromboembolism (VTE) and others suggest how such test results might influence treatment decisions. But controversy arose last May with the publication of this study in JAMA of patients who underwent thrombophilia testing after an episode of VTE. The study showed that certain clinical factors, but not laboratory testing, were predictive of recurrent VTE events. The popular spin, simplistic as always, was that thrombophilia testing be abandoned.

How can this seemingly disparate evidence be integrated with what was known before? Older data, upon which the guidelines were based, had established that thrombophilia testing was predictive of the relative risk for initial VTE. The situation is completely different for patients who have already had a spontaneous VTE. Why? It has long been known that patients with spontaneous VTE are hypercoagulable, (untreated recurrence rates of 2% to 5% per year) no matter the result of thrombophilia testing. In part this is because comprehensive laboratory testing of clinically thrombophilic patients will yield negative results---no “laboratory lesion”--- in about 30%-40% of cases. The thinking is that those patients have a thrombophilic state that hasn’t been discovered yet. To keep it in perspective, remember that the concept of hereditary thrombophilia has been around since the discovery, in 1963, of antithrombin deficiency (Egeberg O: Inherited antithrombin deficiency causing thrombophilia. Thrombosis Diathesis Haemorrhagica 1963; 13: 516) but it was not until about a decade ago that the most common hereditary thrombophilia, Factor V Leiden, was discovered. The field will mature and as additional disorders are characterized thrombophilia testing will become more “evidence based.”

In a related controversy “NORVIT: Randomised trial of homocysteine-lowering with B vitamins for secondary prevention of cardiovascular disease after acute myocardial infarction” was presented at the European Society of Cardiology this year. The media spin---that the homocysteine hypothesis is a “bust”---was irresponsible. Forget the media reports and view the presentation slides. What the study actually did was to suggest that the popular notion of an upper “safe” limit of homocysteine for cardiovascular health of 9 or 10 may not be valid. It also debunked the popular practice (which was never evidence based in the first place) of giving everyone combination B vitamins for secondary prevention. Homocysteine testing and selective use of folic acid and/or B6 may be clinically valid.

Top ten issues in hospital medicine for 2005------issue 5

Emergency cardiac care

New guidelines were published late this year which place greater emphasis on cardiac compressions. I anticipated these changes in a blogpost last October which details the science behind the new emphasis on compressions. The guidelines came short of full implementation of the changes suggested by the group at the University of Arizona which has done pioneering work in this area.

Top ten issues in hospital medicine for 2005, ------issue 6

Electronic medical records and computerized physician order entry
Electronic medical records (EMR) and computerized physician order entry (CPOE) hold great promise, and hospitalists are expected to be leaders in the adoption of these technologies. The news this year, however, was not all good. As I posted earlier this month, adoption of EMR in Hawaii has been problematic. In March there was this study in JAMA suggesting that CPOE may actually increase errors. Meanwhile the system at Vanderbilt seems to be working well as reported in this podcast interview at Soundpractice.

Perhaps Medpundit summed it up best this year in saying “Successful implementation an electronic medical record requires a tremendous amount of cooperation and consultation with the people who are going to be using it. The bigger the group, the harder that's going to be.”

Friday, December 30, 2005

Top 10 issues in hospital medicine for 2005, issue 7

Integration of multiple modalities in the treatment of sepsis

Evidence based medicine to the rescue! An algorithmic approach to sepsis is emerging. Here are the guidelines for the Surviving Sepsis Campaign and here is information of the “sepsis bundle” from IHI. Two or three years in development, the guidelines are ready for prime time now.

Top 10 issues in hospital medicine for 2005, issue 8

Quality, accountability and P4P

With the Institute of Medicine’s publication in 2000 of “To Err is Human” the spotlight was placed on hospital quality and safety. Although the report’s claim that errors cause 44,000 to 98,000 hospital deaths each year is controversial it put patient safety initiatives in high gear. Since that time consumer activists have been demanding change. Although there has been some evidence that quality is improving, studies continue to show significant deviation from recommended practices. This study published in NEJM in 2003 suggested that adherence to recommended processes was just over 50% for acute care, suggesting significant room for improvement in hospital quality.

Meanwhile, data on hospital quality indicators is increasingly being made public as in, for example, the department of HHS Hospital Compare project and the independent health care rating company Healthgrades. (Although most of the information in Healthgrades is behind access control the hospital quality reports are open access).

Pay-for-performance (P4P) is one of the latest buzz words in the quality movement. The ultimate impact and sustainability of P4P is unknown, but this recent study in JAMA was not encouraging.

Although the concept of hospital quality is not new, the issue gained considerable momentum and was a major concern for hospitalists in 2005.

Thursday, December 29, 2005

Top 10 issues in hospital medicine for 2005, issue 9

Inpatient glycemic control

Although this issue has been out there a few years it continued to be a major focus of interest among hospitalists in 2005. Thinking was changed after ground breaking investigation was published in NEJM in 2001. This study of critically ill patients in a surgical intensive care unit demonstrated reduced morbidity and mortality attributable to tight post operative glycemic control. Of interest, only 13% of the patients had a prior history of diabetes. Now intensive insulin therapy in hospitalized patients had become an intervention to reduce mortality and complications. Subsequent studies have validated the intervention across a wider spectrum of hospitalized patients. I previously blogged and cited additional references here.

Top ten issues in hospital medicine for 2005

As the year draws to a close I will be writing a series of posts on the major issues of the year in the field of hospital medicine. Disclaimer: This list reflects solely the biases of a committee of one (me). The reverse numerical order of posting does not necessarily reflect the order of importance. I have blogged about some, but not all of the issues before.

Issue 10: The diagnosis of pulmonary embolism.
The long awaited results of PIOPED II were announced at the close of last year at the Radiological Society of North America national meeting. There was also some discussion of the results at Chest 2004. To the best of my knowledge the results have not yet been published. Despite hopes that CT would emerge as the clear diagnostic modality of choice the PIOPED II results suggested otherwise: the best approach is individualized, and usually based on the integration of multiple modalities and clinical data. I presented my thoughts on the issue earlier this year. That post has more information on the PIOPED II findings, which will not be repeated here.

I think Gregory S. Martin, speaking about PIOPED II at Chest 2004, sums it up best: Based on these results, the use of PE-protocol CT cannot be advocated as a stand-alone procedure for diagnosing PE.

Wednesday, December 28, 2005

Creighton University Alternative Medicine Links

Their web site on Voodoo describes the theory and methods. Though falling just short of promoting Voodoo in its entirety the article maintains that Voodoo pharmaceuticals are effective. Concerning the spiritual dimensions of Voodoo healing it takes a non critical stance: “As a philosophical and cosmological system, with its emphasis on spiritual reality, it is regarded by science with doubt and derision. Yet, this may be due, as mentioned earlier, to their disparate paradigms and may merely be a reflection of the conceptual prejudices of Western science.”

Here is a crystal therapy page which explains all about Chakras.

Here is their craniosacral therapy page.

Monday, December 26, 2005

Do not miss this diagnosis!

Here’s one of those medical mysteries from a New England Journal CPC. Although it should never actually be a mystery---it’s easy to diagnose if you think about it---it remains under appreciated. It’s a must not miss diagnosis.

If you haven’t read the CPC, test yourself. To play the game it’s enough to know that this patient presented in cardiac arrest. Without peeking (that is don’t scroll down too far) click on Figure 1 and click again to zoom. You should have the correct diagnosis in mind in seconds.

This is not a typical CPC case because it’s a look-see diagnosis. Although the discussant goes through the obligatory long differential diagnosis (and a brilliant discussion it is!) he indicates from the start that the exercise isn’t really necessary. He opens his discussion of differential diagnosis by saying “Although I am aware of the diagnosis in this case……..” It is, of course, Brugada syndrome.

Here are some additional useful resources. [1] [2] These latter are open access full text in case you can’t access the NEJM CPC.

Saturday, December 24, 2005

Thursday, December 22, 2005

Community acquired MRSA in athletes

This review from the American Journal of Sports Medicine reminds us of the increasing problem of outbreaks of community acquired methicillin resistant Staphylococcus aureus in contact sports teams. I have blogged on the subject previously. [1] [2] [3].

Wednesday, December 21, 2005

Autoimmune bradyarrhythmias

The autoimmune pathogenesis of cardiac conduction system disease is reviewed here (European Heart Journal 2001). The well known association between congenital heart block and maternal antinuclear antibodies (SSA/Ro and SSB/La) is discussed. Less well appreciated conditions are antibodies to sino-atrial node and atrio-ventricular node tissues and their clinical associations with bradycardia, sick sinus syndrome and heart block and the increased incidence of AV block in HLA B-27 positive individuals.

Tuesday, December 20, 2005

Docs ignore black box warnings

The large Harvard study is reported here via Medscape. We already knew this, as I blogged some time ago. In this study, compliance with black box warnings was variable. Doctors ignored the warnings almost half the time for some drugs. The study was published in Pharmacoepidemiol Drug Safety. 2005;14:1-18.
Through the years we’ve seen many drugs taken off the market as well as some class action law suits against drug companies. But studies like this should cause us to reconsider our views on drug safety. It’s simplistic to merely categorize drugs as good versus bad, safe versus dangerous. Some drug disasters are more related to inappropriate use. That’s exactly what happened to cisapride ---not inherently a bad drug, just a relatively unforgiving drug that saw widespread contraindicated prescribing. Public opinion placed far too much of the blame on the FDA and the drug company.

There are similar lessons in the Phen-Fen case. Though there was no black box warning, the two weight loss drugs were never approved by the FDA nor were they promoted by the drug companies for combination use. Nevertheless the combination became the rage in obesity treatment. A weight loss industry was born and large numbers of doctors inappropriately prescribed the cocktail. But what did the trial lawyers do? They followed Sutton’s Law and went where the money was. It had to be more cost effective to file a class action suit against a large company than to go after all those doctors individually.

What are the solutions to the problem of contraindicated prescribing? The author of the Harvard study suggests incorporating better information into the black box warnings and the use of alerts and warnings built into electronic medical records.

Monday, December 19, 2005

Food-cobalamin malabsorption syndrome

I recently blogged and cited references about this underappreciated yet most common form of vitamin B12 deficiency in the elderly. Another paper with similar conclusions has recently appeared in the American Journal of Medicine. Here are some of its key points.

1) Food-cobalamin malabsorption (FCM) is the most common form of B12 deficiency in the elderly, with classic pernicious anemia (PA) being seen in a minority.
2) The criteria for FCM are low B12 levels, normal Schilling test (using free cobalamin, not egg yolk bound cobalamin), absence of auto-antibodies and adequate dietary cobalamin intake.
3) These patients can absorb free (pill form) cobalamin but not food-borne cobalamin.
4) A spectrum of biochemical, hematologic and neurologic manifestations is seen, which may be milder than that seen in PA.
5) Oral B12 was effective. The investigators used 125mcg-1000mcg daily.

Caveat: All the patients in this study had FCM. Although oral cobalamin can also be used to treat PA, higher daily doses (1000mcg-2000mcg) are recommended. Oral vitamin B12 replacement is less well validated in patients with PA than in those with FCM.

Hypokalemia and hyponatremia from thiazides

Reported here in the British Journal of Clinical Pharmacology. This is occasionally severe enough to land people in the hospital. I think I’ve seen more of it since ALLHAT.

Sunday, December 18, 2005

Influenza pandemics

NEJM has this open access review of the subject.

Antipsychotic drugs and diabetes

This study in the Journal of Psychopharmacology examines the mechanism at the level of the beta cell.

A contrarian view of evidence based medicine

Evidence based medicine (EBM) intrigues and challenges me. While I embrace its principles I am concerned when some proponents take ideas to extremes.

Norman Latov, M.D, Ph.D, professor of neurology at Cornell thinks the zealots of EBM have gone too far. His recent article in the Journal of American Physicians and Surgeons takes them to task. Many proponents of EBM eschew expertise, case reports and physiologic rationale which, Latov points out, were important in the pioneering work of Harvey, Pasteur and Osler.

I don’t agree with all of Latov’s statements (e.g., his implications that guidelines do more harm than good, that EBM makes no allowance for physician judgment, or that guideline adherence has not been shown to impact outcomes) but he makes many valid points.

Latov effectively challenges the orthodoxy of EBM, much of which is dogma rather than science. Counter-arguments such as his should help us refine and balance our views of EBM.

Saturday, December 17, 2005

Rheumatology labs

The bewildering array of serologic tests for connective tissue disease is nicely summarized in this update from Clinical Medicine and Research. I found what I believe to be one small error in the paper. The anti-Sm antibody, an anti-nuclear antibody highly specific for systemic lupus, is referred to incorrectly as “anti-smooth muscle” antibody. It actually stands for “anti-Smith antibody”. Anti-smooth muscle antibody, not relevant to this article, is used to test for certain forms of autoimmune hepatitis.

Hyponatremia: must reads for hospital physicians

An excellent review (via Medscape) on hyponatremia appeared recently in Clinical Endocrinology. Other general reviews of note are linked here (open access full text) [1 ] [2 ]. This review from a few years ago in Archives of Internal Medicine addresses the underappreciated distinction between osmololarity and tonicity as well as the related concepts of effective and ineffective osmoles (not light reading but important—a classic article worth having in the original).

article from CMAJ, though dated, is important in that it highlights selective serotonin reuptake inhibitors as an under recognized cause of hyponatremia.

Finally there is the problem of post operative hyponatremia. Although it occurs in a variety of post operative settings, hyponatremia after orthopedic surgery is of particular interest to hospitalists for a couple of reasons. First, there has been recent interest in hospitalist collaboration in the management of orthopedic surgical patients. Secondly, hyponatremia after orthopedic surgery has been noted sufficiently frequently to warrant special attention [3].
It seems to be more of a problem in female patients and is often aggravated by recent thiazide diuretic use.

The difficult patient

In the November 15 issue of American Family Physician is a review entitled Management of the Difficult Patient. It offers an insightful analysis of the problem and some useful suggestions for primary care physicians. I spent about 20 years as a traditional office based internist before becoming a hospitalist. The article has a ring of truth, many of its points reminding me of things I learned from that experience.

It categorizes difficulties in the doctor-patient relationship into the areas of system problems, patient problems, and physician problems. System problems in primary care are all too well known, driven largely by financial pressures which translate into time constraints. Patient problems may be due to psychopathology in the patients themselves, often in the form of a personality disorder. Finally if you, the physician, think all or most patients are “difficult” you may have issues of your own to face.

Friday, December 16, 2005

The emerging association of anemia and heart failure

November’s issue of the Cleveland Clinic Journal of Medicine contains a review on the links between anemia and heart failure. Anemia occurs with increased frequency in heart failure by a variety of mechanisms, and is associated with increased mortality. There is evidence to support treatment of anemia in heart failure with iron and erythropoietin, but the level of evidence is low and does not support a firm recommendation.

There has been a lot of recent noise about anemia and heart failure. This review sums it up nicely and is worth reading in its entirety.

Thursday, December 15, 2005

Public Citizen opposes liability protection for vaccines

Why am I not surprised? Check it out here. They even have a canned letter you can send to your senators and representatives with a click of the mouse.

Wednesday, December 14, 2005

Is this the antimicrobial magic bullet?

Not quite, but tigecycline (Tygacil), a new tetracycline derivative (glycycycline) approved by the FDA in June 2005 and marketed by Wyeth pharmaceuticals is active against a wide spectrum of organisms and promises to be a useful addition to the antimicrobial arsenal. FDA approval processes are lengthy and drug companies, anxious to get products to the market, tend to launch antibiotics after approval of a limited number of indications that are restrictive when compared to the drug’s true range of efficacy. This invariably (and often appropriately) leads to “off label” use of antibiotics. Such may be true of tigecycline, approved only for complicated skin and soft tissue infections and complicated intra-abdominal infections. Certain pharmacokinetic advantages and a broad spectrum of activity suggest a wider range of potential use, but what other uses might be appropriate?

This review in the Journal of Antimicrobial Chemotherapy addresses the question by covering the basics of tigecycline’s antimicrobial activity and the relevant pharmacokinetics. As promising as tigecycline is, the article notes these caveats: 1) Gaps in the gram negative spectrum include Pseudomonas aeruginosa and the family Proteeae (the genera Proteus, Morganella, and Providencia). 2) Excellent tissue penetration occurs at the price of a very large volume of distribution and consequent low serum levels, raising concerns about its efficacy in bacteremic infections. 3) Predominant biliary excretion results in low urinary levels, limiting the efficacy in urinary tract infections. 4) Emergent resistance of some gram negative species was seen in phase three trials, serving to warn against indiscriminate use.

The article concludes “Whether or not significant resistance threats ultimately do emerge (and experience shows that they usually do!), it is excellent news to have a new agent with increased activity against Gram-negative as well as Gram-positive bacteria. Few others will come this decade” (Italics mine—I have previously blogged about the waning antibiotic development pipeline).

Polymerase chain reaction demystified

Well, not quite, but I found this review in Advances in Physiology Education helpful.

The importance of the electrocardiographic P wave

J. Willis Hurst of Emory University School of Medicine has written a great deal about electrocardiography, including this piece in Clinical Cardiology outlining pet peeves he terms “electrocardiographic crotchets”, or common irritating errors in interpretation. One of his crotchets is the failure to appreciate the importance of P wave abnormalities. P waves may reflect conduction abnormalities in the right or left atrium caused by atrioventricular (mitral or tricuspid) valve disorders or by disorders (hypertrophy or dilatation) of the right or left ventricle, respectively. It is important to note that the atrial conduction abnormality may or may not reflect hypertrophy or dilatation of the atrium. Thus it is proper to speak of right or left atrial abnormality as an electrocardiographic finding, but not enlargement or hypertrophy. The atrial abnormality is more telling about the corresponding valve or ventricle than the atrium itself. Regarding the importance of P waves he writes “To ignore P-wave abnormalities or to refer to them as being due to atrial enlargement or hypertrophy are crotchets.”

To the growing importance of P wave abnormalities we can now add findings from this recent paper in Stroke. Electrocardiographic left atrial abnormality (defined as dimensions of the terminal P wave component in V1 >40ms*mm) was associated with increased risk of ischemic stroke (OR 2.32) in this case-control study.

By the way---those with a scholarly interest in electrocardiography should read Hurst’s paper in the original.

Tuesday, December 13, 2005

The American Medical Student Association Promotes Chelation Therapy

The American Medical Student Association (AMSA) has launched the PharmFree campaign which encourages doctors and med students to distance themselves from drug companies and their representatives by refusing gifts, support and promotional materials. In this way, so they claim, they intend to change the culture of medicine toward higher ethical standards, increased professionalism and evidence based medicine. I would applaud such lofty goals, but there’s a problem. The AMSA’s promotion of pseudoscience and unproven health methods belies its stated ideals and one has to wonder what the true agenda of the PharmFree campaign is. I recently posted an overview of this hypocrisy and today will focus on chelation therapy, just one of the questionable health claims promoted by AMSA.

Though chelation’s proponents claim its effectiveness against cardiovascular disease and a variety of other disorders there is no supporting evidence or rationale except for the treatment of heavy metal poisoning. The American College of Cardiology’s position statement recommends against chelation therapy for cardiovascular disease. The Federal Trade Commission charged one group with false advertising for its claims that chelation therapy was effective in treating atherosclerosis. Although a large scale NIH sponsored study of chelation is in progress, researchers have for decades been unable to demonstrate clinical effectiveness or physiologic rationale. The most recently published evidence regarding chelation therapy is a systematic review which failed to find evidence of effectiveness.

Chelation is promoted on page 20 of AMSA’s Complementary Therapies Primer. This is not a balanced critical view of the treatment. The second paragraph makes the baseless claim that it improves blood flow and is helpful in the treatment of gangrene and intermittent claudications. The article also claims chelation is helpful for memory loss, arthritis, scleroderma and lupus. It goes on to say that oral chelation with either EDTA or penicillamine is useful as a “preventative measure” and lowers cholesterol.

This is patently absurd and destroys the credibility of the PharmFree campaign. It is also irresponsible. The AMSA needs to do some housecleaning of its own before pointing fingers at doctors for associating with the pharmaceutical companies.

Sunday, December 11, 2005

The hypocrisy of the American Medical Student Association

The American Medical Student Association (AMSA) was founded in 1950 as a subsidiary of the American Medical Association (AMA). Following “dramatic changes in the organization's objectives and philosophy” the organization severed ties with the AMA in 1967. In 1975, to further distance their image from the AMA they changed their name from the former Student AMA to the current AMSA. Among the association’s stated missions is the promotion of improvement in medical education. One of the education initiatives is the PharmFree campaign which encourages students to refuse gifts and support from drug companies which might influence them away from evidence based medicine. As I previously blogged, the campaign has recently received favorable press. The AMSA states on the campaign web site that PharmFree seeks to promote evidence based medicine and education about clinical guidelines, as well as foster honesty and integrity.

So far, so good----the AMSA says they’re all about science, evidence and ethics. But wait. Dig deeper and you find AMSA actively promoting quackery and pseudoscientific nonsense. Let’s look at a few links. Here we find that they advocate for complementary and alternative medical education. What does that mean? Well, they’ve just formed a naturopathic medicine interest group. (Here’s some reliable information on naturopathic medicine). They have also published a booklet entitled Between Heaven and Earth, a 46 page “Introduction to Integrative Approaches to Health Care.” Far from being a critical or scientific approach, the book actively promotes unscientific methods. Then there’s their Complementary Therapies Primer which teaches and actively promotes all sorts of nonsensical and outlandish claims. Included are promotions of chelation, homeopathy, aromatherapy, therapeutic touch, polarity therapy, rolfing, qigong and ayruvedic medicine.

The AMSA claims to promote evidence based medicine and ethical principles as exemplified by their PharmFree campaign. But their promotion of pseudoscientific nonsense (and, in my opinion, fraud), is neither evidence based nor ethical. It’s hypocritical and it’s outrageous. Thanks to the Health Fraud list for the links.

Update: Click here.

Saturday, December 10, 2005

Adopting electronic medical records: easier said than done

BMJ reports on Kaiser Permanente’s difficulties in Hawaii [1] [2]. And let’s not forget the disaster at Cedars-Sinai a few years ago.

Heparin Induced Thrombocytopenia

Here is a full text open access review in Thrombosis Journal. The take home points are:

1) There are two forms of thrombocytopenia related to heparin, and the nomenclature is confusing. A benign non-immune mediated form, little more than a laboratory phenomenon, reverses readily upon discontinuation of heparin. The more clinically important form is the immune mediated form. These have been known as HIT types I and II respectively. “HIT” often refers to HIT type II.
2) Immune mediated HIT is a state of extreme hypercoagulability, both arterial and venous. Hypercoagulability, not bleeding, dominates the clinical picture.
3) Mere cessation of heparin is insufficient. A non-heparin anticoagulant (danaparoid, lepirudin or argatroban) must be used. Low molecular weight heparin has cross reactivity and is therefore not appropriate. The synthetic pentasaccharide fondaparinux does not cross react and is therefore promising, but has not been adequately validated in clinical studies.
4) Mere substitution of warfarin is contraindicated. It must be overlapped with one of the non-heparin anticoagulants mentioned above. Otherwise the early depletion of protein C induced by warfarin would add one hypercoagulable state to another. Clinically, peripheral venous gangrene and warfarin skin necrosis have been observed after such inappropriate use of warfarin.

From other literature:

The initiation of a non-heparin anticoagulant must be based on clinical grounds, since laboratory confirmation is often not immediately available. A point score system for the estimation of pretest probability for HIT appears promising for clinical decision making. (Free registration required to view abstracts and poster sessions of the 45th annual American Society of Hematology Meeting. Browse for item 1963 Preliminary Evaluation of a Clinical Scoring System for Estimating the Pretest Probability of Heparin-Induced Thrombocytopenia: The 4 T s . Session Type: Poster Session 134-II ).

Thrombocytopenia may occur as a result of the primary thromboembolic process itself, reflecting a consumptive phenomenon. Although usually mild it may be severe and be confused with HIT.

Antiarrhythmic drug therapy review

Although antiarrhythmic drug therapy has declined sharply in the post-CAST device therapy era, limited indications persist and are reviewed concisely here in the Texas Heart Institute Journal.

Friday, December 09, 2005

Podcast at

My podcast interview has been posted. If you have half an hour or so with nothing better to do, give it a listen.

Tuesday, December 06, 2005

Eye of newt, and toe of frog…

More pseudoscientific med school fluff

This time it’s the University of Manitoba medical school. According to this report from the school’s alternative medicine program “encourages future doctors to find ways to combine old medical philosophies with modern knowledge.” The curriculum, designed for second year students, features acupuncture, yoga, homeopathy and chiropractic. Students “sip ginseng tea while handling bags of dried gecko lizards and jars of toad droppings.”

Dr. Greg Chernish heads the program. “Chernish says combining the benefits of ancient medicine with modern science provides the best care for patients – a concept that surprised student Heather Nowosad. ‘The integration part was surprising for me, because I've always had this belief that it's sort of like people believe in one or the other,’ said Nowosad, who plans to become a family physician.” Don’t feel bad, Heather. Abraham Flexner had that belief too.

Systemic thrombolysis for submassive pulmonary embolism?

The accepted treatment for pulmonary embolism (PE) uncomplicated by hypotension or acute right ventricular failure is heparin (low molecular weight or unfractionated). When PE is complicated by hypotension (classified as massive) there is general acceptance of systemic thrombolysis in addition to heparin. More controversial is the intermediate situation, known as submassive PE, defined as PE with normal blood pressure but in the presence of acute right ventricular dysfunction. Right ventricular dysfunction is generally defined by echocardiography.

A randomized double blind placebo controlled trial in 2002 demonstrated that in submassive PE systemic thrombolysis added to heparin was associated with improved patient stability, less need to add hemodynamic support, but no difference in mortality. Controversy has persisted, and in the October 24 Archives of Internal Medicine are pro and con articles with rebuttals. [1] [2] [3] [4].

CA-MRSA in perspective

In his post today on Staphylococcal infections RangelMD says methicillin resistant staphylococcus aureus (MRSA) infections are not inherently worse than methicillin sensitive (MSSA) infections, community acquired MRSA (CA-MRSA) is not a “super bug”, and the press has sensationalized and distorted the issue. I agree partially---especially with the point about media distortion. I also agree that the “old fashioned” MRSA is not necessarily more virulent than MSSA, although it may be associated with poorer outcomes related to greater difficulty in treatment and greater comorbidities in MRSA infected populations.

Concerning CA-MRSA, however, I feel some need to elaborate since I have posted about its unique attributes before. [1] [2]. Although its predilection for causing minor skin infections often makes it more of a nuisance than a threat to life there is evidence of uniquely heightened virulence and transmissibility in some CA-MRSA clones. These characteristics are associated with the Panton-Vanentine leukocidin, (PVL) found more frequently in CA-MRSA than in other strains. The PVL gene is only rarely found in hospital associated MRSA and MSSA.

Although the somewhat heterogeneous nature of CA-MRSA makes it difficult to generalize, some trends are emerging which raise concerns about increased transmissibility and virulence.

Sunday, December 04, 2005

On the death of Lisa McPherson

Lisa McPherson was given Scientology’s “alternative” to psychiatry. On the tenth anniversary of her death under the care of Scientology staffers the Health Fraud List posts these links about the case. This article chronicles the tragedy and the subsequent legal wrangling. A large collection of links on the case is provided here. The wrongful death suit against Scientology lasted seven years and was finally settled last year.

Sloppy media coverage of avian flu

Popular media coverage of avian flu is confusing. This piece from WorldNetDaily is headlined “OUTBREAK! Has feared mutation of avian flu arrived? Doctors in Thailand, Indonesia see 1st signs of human-to-human spread.” The article reports that in Thailand two recent human flu cases can’t be traced to contact with birds. The cases were mild, and doctors speculate that waning virulence may have accompanied a mutation enabling human to human transmission. The problem is that the article cites no report of serologic analysis or evidence that the cases indeed represent the H5N1 avian variety. Moreover, no human disease contacts were mentioned. If there’s anything to this, the article certainly doesn’t inform us.

On down it says “Meanwhile, in Indonesia, the disease is spreading so rapidly, particularly in the capital of Jakarta, some health officials strongly suspect the long-dreaded mutation has already occurred.” Oh? They why does it say a few paragraphs below that only 13 avian flu cases have been confirmed in Indonesia?

And, if human to human transmission is the case here it’s not new. Human to human transmission of avian flu was well documented over a year ago.

The strange story of Dr. John R. Brinkley

Pseudoscientific health providers have a colorful history. They range from alternative practitioners who honestly believe in an unproven method to the purveyors of outright fraud. In this latter category was the fabled Dr. John Brinkley. Not only was he one of the better known “snake oil salesmen” in American history, but he may also be the originator of the infomercial 80 years ago in the early days of radio.

But it seems society in those days was less tolerant of the likes of Dr. Brinkley than now (those of Brinkley’s ilk today seem to be doing quite well). In 1930 both his medical license and his radio station license were revoked. Virtually run out of Kansas, he moved his operation to the Mexican border where he constructed one of the first Mexican border blaster radio stations. You can listen to an NPR report on Brinkley and border radio here. It contains excerpts from Brinkley’s infomercials and as a bonus, about 16 minutes in, an interview with Wolfman Jack, propelled to fame on the third and last incarnation of Brinkley’s station, XERF.

Friday, December 02, 2005

Clostridium difficile: the Quebec strain

DB blogged about a new face of C-diff earlier today—it’s been showing up in healthy members of the community, some of whom had no recent antibiotic exposure. There’s another aspect that is worth our attention and that’s the Quebec strain.

A hypervirulent strain of C. difficile has emerged there over the last three years. A study of the attributable mortality, an editorial and a news piece appear in the October issue of CMAJ.

What’s different about the strain? As reported in these articles: 1) it produces 15-20 times the amount of toxin as the ordinary strains, due to an altered repressor gene; 2) it’s more lethal, with 23% of patients dead at 30 days and an attributable mortality at one year of 16.7%.

The author of the study points out that some patients appear to have died of direct complications of the infection such as shock or perforation while others succumbed to secondary events such as myocardial infarction, venous thromboembolism or secondary infection.

Infection control implications are discussed and the papers offer conjecture about risk factors at the Quebec hospitals. There was no difference in patient characteristics compared to other regions of Canada or the United States (the strain has shown up at a few locations in the US), and no evident difference in the use of antibiotics. The only common thread seemed to be the use of shared bathrooms. The authors conclude: The lack of investment in our hospitals infrastructure over several decades, with shared bathrooms being the rule rather than the exception, may have facilitated the transmission of this spore-forming pathogen, which can survive on environmental surfaces for months. Providing modern medical care within hospitals built a century ago is no longer acceptable.