Thursday, June 28, 2007

Medical "Air quality" in airplane cabins and resistant TB

I have held for a long time an erroneous idea of the risk of disease transmission aboard airplanes.I envisioned the passenger cabin as some sort of 3-d Petri disk crammed full of various viruses and other pathogens.

An excellent article in the July 2007 issue of Mayo Clinic Proceedings corrected my misconceptions. The editorial " Dealing with threat of Drug-resistant Tuberculosis" written by Dr. Priya Sampathkumar is an excellent review of the basics of drug resistant TB and the quality of air in a plane from a medical point of view and can be found free, full text here.
The recent news stories of a person with XDR-TB (extensively drug resistant TB) traveling repeatedly by air from country to country greatly increases the interest level of this article.

He tells us that the recommended rate of air exchanges in a hospital isolation room for TB is 6-12 exchanges per hour. Modern aircraft have 20-30 exchanges per hour.Further,there are high efficiency particular air filters that remove 99.9% of particles that are between 0.1 and 0.3 micra. Mycobacterium is about 0.5 to 1.0 micra. More reassurance comes from the fact that air enters and leaves the cabin at the same seat row so that there is little flow from the front to the back of the plane. Of course, all of this assumes everything is working as it should and as always anything that can work can break down.

Consistent with this description of how the air is handled in planes is the observation that in all instances of transmission of TB on board a commercial airliner occurred to passengers who were seated within 2 rows of the index case.

The scary factor of the Andrew Speaker case was greatly enhanced by the fact he had XDR-TB. Regular-that is drug sensitive TB-is no longer a scary disease. Treatment with first line drugs for six to nine months results in a cure in 95% of patients.MDR-TB is defined as TB being resistant to both INH and Rifampin and treatment with the less effective,often poorly tolerated second line drugs for 18 to 24 months results in cure anywhere from 50% to 70% of the time.

MDR-TB burst on the scene in the early 1990s mainly in patients who were infected with HIV in whom the mortality rate approached 80% and there were reported instances of transmission to health care workers and prison guards.In 2005 there were 95 cases reported in the U.S but according to the National Jewish website 450,000 cases worldwide.

XDR-TB appeared in 2005 in an outbreak in South Africa and is characterized by resistance to INH,Rifampin,a fluroquinolone, and at least one of the three injectable drugs.From 1993 to 2006 in the United states, 49 cases have been reported with 12 deaths and 12 loss to followup.National Jewish has treated a small number of cases and states that their treatment including resectional surgery may result in a 50% cure rate.Until MDR-TB and XDR-TB came on the scene, surgery for TB was largely a history book chapter, not so now.

Wednesday, June 27, 2007

Some of the unintended consequences of restrictions on house officer hours

The NEJM (June 28,2007) has two commentaries regarding the fall out and continuing analysis of the effects of the changes in house officer hours and rules governing how much time the trainees can work at the hospital.One of the two is available full text for free and can be found here. There is also an audio file interviewing Dr. Ethan Fried, a residency program director.

There is a tension between the hoped-for reduction in errors by having better rested residents and the fear of increased errors and dropped balls by having frequent hand-offs between teams of residents. Dr. Fried believes there may be more risk of the latter in the first day of admission to a hospital but also believes that the supervision and backup by more senior residents can mitigate that tendency.

In addition to the issue of is-the -new- system -less- error prone, there is the fact that since house officers are working less someone else has to. Accordingly, there is a trend to having non-teaching services maned by hospitalists and NPs and PAs at a cost some institutions are hard pressed to bear.

But, in my view even more important is what the new system might do to the evolving competency and mind set of the residents. This issue is discussed by Dr.Wes with his usual insightful analysis.
He wonders if an error free residency what we really want? Do we not learn in part by making errors in an environment where we are buffered and protected by our mentors and more senior colleagues?How will this cohort of residents fare when they are truly out on their own and there will be no team to hand off to when they have been up most of the night taking care of patients and fielding phone calls? Will they call their office and tell them they won't be in until noon because they need their protected ten hours post call ?.

The ACGME kicked off this major change in post graduate medical education in July 2003 and now four years later we seem to be seeing the fall out of a program that may have been initiated and mandated without sufficient planning regarding what now seems obvious collateral effects.The jury is still out regarding if this restricted duty plan actually improves safety or paradoxically has the opposite effect while increasing costs.

When I am old (OK, older) and sick will I want my medical advocate (wife) to insist on a physician who finished his training before July 2003? I have ranted before about the effects of changes in the IM program brought about by ACGME that in my opinion result in a marked loss of the sense of personal responsibility by the doctor for the patient. Teams and systems and protocols and flow charts are no substitute for a physician who believes she is personally responsible for the medical welfare of her patient even if she may be tired. A shift work mentality may be fine for a factory worker but when I grew up medically it was unthinkable for a physician.

Tuesday, June 19, 2007

Alternative Medicine-homeopathy allowed in ACCP's journal, Chest

I was thumbing through a older issue of the journal, Chest and by looking at the summary and title of a particular article nothing much seemed unusual or really very interesting. However, the last paragraph of the discussion section gave me a very different view .

The title was "Influence of Potassium Dichomate on Tracheal secretions in Critically Ill Patients". Nothing out of the ordinary there. But go down to the affiliation of the authors and we see that three are from a School of Homeopathy in Austria. (Chest/127/3/March 2005, p. 936).
Here is a link to the article.

Then, in the material and methods section we are told that:

"we used a preparation of C30,which is equivalent to a potentiation of 30 dilutions in which each of the 30 dilutions steps is foll0wed by subsequent succussions.Therefore the [well known toxic effects of chromium if undiluted] were eliminated". Certainly at that dilution (a 30C dilution is dilution by a factor of 100 to the 30th power), the test liquid is very unlikely to have any K dichomate in the liquid at all.It is just water. Apparently, in the homeopathy belief system one can make a solution so dilute as to make it non toxic but somehow allow it to retain-or gain-some therapeutic effect.

But the discussion section is best of all. It ends with the following:

While the mechanism of potentized ( diluted and vigorously shaken )drugs remains subject to research...the effect may be best explained by cybernetics,which means that the information of the homeopathic drugs act consensually on the regulator.Thereby, the body regains its original property to regulate physical parameters

This is not written in the language of science but in the language of woo. It is hard to believe that the editors of the journal of the American College of Chest Physicians,none of whom claim to be homeopathic practitioners,would publish such an article.The final paragraph does not even make sense to a non-homeopathic believer and no effort is made to even try and explain what the heck they are taking about when they refer to a drug acting consensually on the regulator or regaining one's original property.

The Journal does a disservice to its readers when it presents a homeopathic jargon filled discussion as if a scientific discussion is taking place. There was no editorial explaining the reasoning behind publishing such an article.One of the characteristics of science is its coherence.The sciences of pharmacology,physiology and toxicology build upon and are consistent with the laws of chemistry and physics.To talk about diluting a substance to the point where it is undetectable and then explaining how it works to heal flies in the face of the principles of those disciplines.It is too late to write a letter to the editor but I hope someone did.

Saturday, June 16, 2007

Old wine-new bottles-you have to be a doctor to the whole village?

Dr. David Eddy authored a series of articles in JAMA ( Eddy DM. Rationing resources while improving quality.How to get more for less.JAMA.1994:272,817-824) promising to tell the great unwashed cadre of trench dwelling physicians how they could increase quality and save money at the same time. The trick was the utilitarian imperative-do the greatest good for the greatest number. In his moral calculus it was not only appropriate but it was ethically demanded that, for example, one would not waste money by for example offering yearly mammograms to women between 40 and 50 if a greater bang for the buck could be achieved by offering smoking cessation session to pregnant women. Cost effectiveness analysis was to guide what was offered to the group It was the health of the collective that mattered and that was true even if the collective was a thrown together bunch of strangers whose employers happened to sign up to a given HMO. The traditional fiduciary duty of the doctor to the patient as well as the legal manifestation of that relationship and the aspect of human nature that says I want what is best for my health and my family's health not for some alleged aspect of a fictional collective would have to moved past and we would be on the road to the solution for all that ails American medicine and health care. Doctors should not be hoarding resources for their patients.

Policies create winners and losers , a point that Dr. Eddy did not deny.He spoke of the consequences of "allocating a limited pool of resources to maximize the health of all of the people[in the]pool"even if that meant some would loose out on a benefit. The argument that the "insurance pool" or HMO population or some other organizational collective would gain if the net gains would outweigh the net loses is to endorse a utilitarian ethic but also relies on the cost-benefit assumption that everyone is the same so that costs and benefits can be appropriately aggregated.

In a recent JAMA commentary, the President of the American College of Physicians and the Chief Medical Officer of Aetna ( Dr. Christine K Cassel and Dr. Troyen E.. Brennan) expound on how the ails of American medical care can be remedied. Their exposition seems to me a rehash of Eddy's series although I missed where the authors admitted that there are some who would loose out in the collective cost benefit analysis driven policy decisions.(JAMA ,June 13, 2007, Vol 297, no. 22, p. 2518, "Managing Medical resources.Return to the Commons"

They speak of an abstract hypothetical " medical commons" and how the current emphasis by the physician on the welfare of the individual patient will spoil the commons much as the farmer who selfishly grazes his cattle on public land without regard for depleting the resource will destroy the resource.Physicians are implored to "reconstitute the medical commons" and think in terms of resource conservation and allocation so at the end the greatest medical good can be done for the greatest number of patients.They admit there is not currently such a commons. There never has been so I am unsure how a return is possible.

The medical commons figure of speech seems particularly lame.While a grassy knoll for the villager's sheep can be defined by a specific surveyor description, the "medical commons" is a extremely large amorphous array,the elements of which almost defy enumeration, and every changing, with some elements growing ,others contracting and innovations cropping up constantly.There is no easily defined entity called "medical resources";it is an amorphous abstraction.Further, to speak of allocation means some one or some elite group will be the "allocator in chief ". Decisions will not be made by thousands of individual physician-patient pairs.

Cassel and Brennan assert that a market based or a regulatory approach will allocate resources without the caring and wisdom that clinicians can bring to the endeavor. In their analysis the only choice is a medical commons with physicians and patients moving hand in hand willing to put aside the petty concerns of the individual when necessary for the greatest good of the group.Collectivism has been so successful in the past, why would it not work here?

Does American medicine have many troublesome problems? Yes, it does. I cannot see a rehash of Utilitarian ethics and a very bad analogy and some pie-in-the sky medical collective farm fixing much of anything.

Friday, June 15, 2007

Oncologists accused of giving chemo.for profit not patient benefit

I do not want to believe that oncologists would give chemotherapy(CMT) to patients who they do not believe would likely benefit simply because they can make a profit on their mark-up on the drugs they administer. I have always had nothing but admiration for oncologists who day by day deal with seriously ill and dying patients and manage to be current and proficient in the variety of cancers they treat and the multiplicity of drug regimens and toxicities and complications.

The ones I have practiced with deserve to be called physicians with all the positive connotations that term can garner.

A recent article in the NYT paints a different picture of some oncologists. Here is some background.For a number of years CMT has been given in oncologists offices. The CMS and third party payers fees exceeded the costs to the docs so there is a make up profit involved. Recently, changes in CMS rules have cut the margin .

The gist of the NYT article is that oncologists are making up for the shortfall with an increase in volume of patients treated with CMT implying that some patients are being given CMT inappropriately.

NYT quotes Dr. Richard Deyo ,a professor at the University of Washington,describing him as a"expert in health care spending" as saying:

There's pretty good evidence at this point that there are plenty of patients for whom there's little hope,who are terminally ill,whom chemotherapy is not going to help, who get chemotherapy

That comment, like most of the NYT article, is heavy on accusations and generalizations and light on supporting data and facts. Dr. Deyo may have analyzed numerous cases and determined that in many instances the CMT was inappropriate but if so I would like to see that analysis. What is the nature of the evidence for his statement? I would be very surprised if Deyo's comments are based on patient level data in which cases are analysed by physicians expert in CMT and wherein inappropriate treatment was found in "plenty of patients". I would not be surprised if that type thing has happened in some cases but I doubt that level of data is what Deyo's statements is based on. Broad brush, coarse grain data is the more likely currency for the type outcomes research that Deyo has been known for (and has gained a well deserved reputation for his work in low back pain treatment outcomes). He may have well done some outcomes research in the CMT area and his comments may have based on that but if there is such data he should have made that fact known to the NYT reporter so the article would appear less like a typical drive-by-media encounter. If he does not have that data, then he may have done disservice to the thousands of patients now receiving CMT who may now wonder if it is avarice and not likelihood of benefit that formed the basis of the decision to treat them.

Thursday, June 14, 2007

JAMA commentary: Medical commons -conflict of interest?

The journal of the American College of Physicians (ACP), the Annals of Internal Medicine, in 2006 featured a five page article in which the former CEO, and then current board member of Aetna, Dr. John W. Rowe, pontificated on the "moral basis for participate in...[P4P]." I commented on that article at the time and noted that Aetna's reputation among practicing physicians was such that Dr. Rowe might not have been the most credible witness to present the case for P4P , a movement which the ACP has tended to favor.

More recently, the current President and CEO of the ACP, Dr. Christine K. Cassel, has teamed with another officer of Aetna, Dr. Troyen E. Brennan, to offer further ethical and moral pronouncements regarding the "responsibility" of physicians. This commentary, " Managing Medical Resources-return to the Commons?", can be found in the June 2003,2007 issue of JAMA (vol.297,no.22 pg 2518).

I will leave a more detailed analysis of their apparent proposal for the establishment of "integrated delivery systems" as "accountable care organizations" (sound like big HMO-like entities to me) and the assumption of those groups of responsibility for a population to another time and focus now on what seems to be a major conflict of interest regarding Dr. Brennan.

Early in the article the authors correctly point out that the inclusion of the duty on the part of physicians to "manage medical resources" that is found in the Physician's Charter on Medical Professionalism is controversial as it conflicts with the primary duty of the physician to the patient. They then ask is "this [responsibility] really our duty?

"Our" is used by Dr. Brennan to apparently speak as a member and express commonality with the group of physicians who "live and work in [what he describes] as a medical commons and bear responsibility for it". Dr. Brennan does hold a M.D. degree and has practised medicine but he is currently an officer (A senior vice president) of large insurance company involved in medical insurance and managed care and as such has a fiduciary duty to foster that organization and work to improve its profits.

The authors , later in the commentary, again correctly note that practicing physicians are skeptical about any savings generated by "quality" or P4P programs will find its way to actually improving or expanding medical care. Would not this firmly based skepticism regarding the motives and actions of insurance companies not also target any proposal made by a officer of Aetna?

I cannot understand how officers of ACP and editors of their journal believe that their case for whatever changes they recommended in U.S. health care will be moved forward by having as a partners in that advocacy officers of a insurance company whose business practices ultimately lead to a very large settlement in a class action brought by a number of state medical societies. (Details of that settlement can be found here). When one argues for a given proposal tactical concerns would seem to favor presenting a credible spokesman.

The capitation type system proposed is unlikely to gain traction as long as physicians continue to believe and act as if their primary duty is to the individual patient and not to the collective.This article seems , in part, an effort to disabuse physicians of this ethical imperative which the authors may consider an obstacle to their scheme to "ensure proper allocation of health care resources".

Both Dr. Cassel and Dr. Brennan close their disclosure statement stating that the views expressed are those of the authors and do not necessarily reflect the opinions of either institution. It would be hard to believe that Aetna would allow one of its officers to publish an article in a widely read medical journal without agreeing with its contents.

Wednesday, June 13, 2007

Whole new ball game-case in point Avandia

The spin-off as well as the spin seems endless in regard to the Avandia issue.Nissen's NEJM article catalyzed various reactions many of which were predictable at least in direction if not in intensity. Predictable downstream effects included the reactions by GSK,by pro and anti Pharma blogs and Grass root and astro turf patient-interest groups and by plaintiff attorneys. Also expected are thoughtful posts by medical bloggers such as the one entitled "Avandia:two questions" by Dr. RW. and "The Avandia spin cycle" found at Health Care Renewal.

One of the latest developments is a class action suit by stock holders of GSK accusing the directors of withholding information about the cardiac risk of Avandia. The directors are accused of not providing adequate data to stockholders regarding the company's meta-analysis of cardiovascular deaths that was reported to the FDA.

Over thirty years ago another medical publication dealt with a purported increase in cardio vascular deaths from an oral diabetic medication. The University Group Diabetes Program (UGDP) was presented at the June 1970 meeting of the American Diabetes Association. Data presented indicated that tolbutamide increased cardiovascular deaths by over two and a half times.( R.R of 2.61, C.I.-1.29-5.27 It did not take long for the UGDP study to be referred to as the "controversial" UGDP.

The dispute over methodological issues was played out largely out of the public eye and patients and physicians alike had to largely rely on medical journal hard copy publications to follow the events that they unfolded in what would be considered slow motion in today's frenetic internet pace.Today with the Web within minutes the word spreads over the world and quickly bloggers and news sites and lawyers post messages. It is not long before a Senate hearing is held.

The UGDP study in many ways presented more robust evidence that the Nissen article.It was a randomized clinical trial ( Yes Virginia, clinical trials were done before the folks from Canada descended from the mountain with the precepts of EBM carved into stone) and the R.R. was greater than 2, a number less than which many epidemiologists put little weight as small RR's can be pushed around by small biases.Putting too much emphasis on medical analyses which derive RR's less than 2 has been a issue of interest to me for some time and I have ranted on about that before.

In time, the reputation of the class of diabetic drugs to which tolbutamide belonged was salvaged to some degree by proposing that tolbutamide might interfere with a purported pathophysiologic mechanism called "ischemic preconditioning" while others drugs in this family might not. At the end of the day, a PDR sulfonylurea family warning was issued. As new drugs have been developed to treat type 2 diabetes little discussion seems to take place about these drugs while they continue to be used with little alarm about causing heart attacks.

Sometimes controversies just die out without really being settled with apodictic medical certainty.I think that was the case with tolbutamide.Many articles critical and supportive of the UGDP were generated and for the most part probably largely unread and were it not for the internet amplified and magnified Avandia issue few would even currently think about a possible increase in c-v risk from the sulfonylureas which are still widely used in the early treatment phases of type 2 diabetes. The dogs bark and the caravan moves on.Today with the internet the dogs seem to be able to do much more than just bark.

Monday, June 04, 2007

Seafood, x-ray contrast material allergies and Iodine

A long standing dogma is that seafood allergies and radiologic contrast material (RCM) allergies are both due to an iodine allergy and therefore a history of seafood allergy places a person at high risk of an allergy reaction to RCM.

Dr. Andrew D.Berry gave a talk at a recent meeting of the American Academy of Allergy,Asthma and Immunology (reported in the may 11,2007 edition of that should disabuse doctors of what seems to be a medical myth.

According to the article-seafood allergy is due to a IgE mediated antibody to certain proteins in the seafood and the severe RCM reactions are not mediated by IgE at all.

Dr. Berry reported on a survey in which many radiologists and cardiologists would recommend pretreatment with antihistamines and/or steroid for a patient with a history of seafood allergy before injecting a RCM.

Sunday, June 03, 2007

Pneumonia guidelines-Europe versus U.S.

The American Thoracic Society (ATS) and the Infectious Disease Society of America (IDSA) agree that the empiric therapy of mild community acquired pneumonia (CAP) should include coverage for the atypical pathogens.These are Mycoplasma,Chlamydia and Legionella.

In Europe, although ID physicians agree that about 40% of CAP is due to the atypicals,that beta-lactam antibiotics alone should be used anyway even though they have no activity against the atypicals. They argue that these pathogens (except for Legionella)usually cause mild, self-limiting illnesses and that adding broader coverage medications will exacerbate the public health problem of increasing antibiotics resistance.In the U.S, typically, a macrolide would be included in the treatment of CAP.

ID docs in the U.S. argue that the illnesses are shortened by broader coverage and there is also data showing a decreased mortality in hospitalized patients with CAP.One could argue that if hospitalization is needed that the CAP is more than mild.

The European approach seems to place a theoretical concern above individual patient concerns.Further a chest x ray is apparently not required to diagnose pneumonia so it can be argued they over treat viral bronchitis and add to the growing resistance problem. It is hard to argue against the view that more antibiotic use may lead to more pathogen resistance but you have to wonder how much effect under treating CAP would have to mitigate that trend.