Archive for the '[Medicine&Pharma]' category

Vitamin D

Aug 18 2010 Published by under [Medicine&Pharma], Medicine

Vitamin D is a fascinating molecule with a fascinating story.  Historically, "vitamins" were defined as chemicals that humans required from their environment that were "vital" to human health.  These chemicals were needed only in very small amounts to prevent disease; an absence of a particular vitamin in the diet led to a specific deficiency disease: vitamin C, scurvy; thiamine, beri beri.  Other vitamin deficiencies were found to be a bit more complicated: vitamin B12 deficiency was found to cause a type of anemia, dementia, and spinal cord problems.

Because vitamins are required in such small amounts, and are often present in small amounts in foods, their discovery was an opportunity to prevent and cure several diseases.  One of these diseases was rickets.

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19 responses so far

Revisiting placebo

Aug 16 2010 Published by under [Medicine&Pharma], Medicine

The New England Journal of Medicine recently published a troubling article on acupuncture, which was ably deconstructed by Dr. Mark Crislip. This incident has reignited a discussion of what, exactly, "placebo" is.

A common argument is that placebo is like any other intervention, something that can be intentionally harnessed for the benefit of patients.  This is both true and overly simplistic.

First, we must review what "placebo" is.  There are basically two primary uses of the word.  The first is technical.  In randomized controlled trials, making sense of an intervention requires some sort of control group.  If I give Fabulostatin to one group, any changes I see in the group may be due to chance alone or to bias.  I can minimize this effect by subjecting a similar group to an identical-appearing sugar pill, one which we call a "placebo".  If the only significant difference between the two groups is Fabulostatin or placebo then significant differences between the two groups can be more readily attributed to Fabulostatin.

This doesn't mean that the placebo group will be unchanged.  If there is a third arm of the study, one in which no pill was given, we can often measure a difference between this group and the placebo group.  This difference is usually called the "placebo effect", that is, the group that is treated with a sugar pill improves despite being given no active drug. Continue Reading »

25 responses so far

To live deep and suck out all the marrow of life

Aug 13 2010 Published by under [Medicine&Pharma], Cancer, Medicine, Science-y stuff

There are few procedures in medicine more complex, dangerous, and remarkable than stem cell transplantation. This procedure has enabled us to successfully treat cancers that were previously uniformly fatal. For certain types of acute myeloid leukemia, for example, stem cell transplant increases 5-year survival from less than 15% to about 44%.

But the full story of stem cell transplant is much more complicated.  The data are complicated and the research is full of fits and starts, new questions and dead-ends.

Chimera. Apulian red-figure dish, ca. 350-340 BC. The Louve, Paris, France. Image from Wikimedia Commons

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Homeoprophylaxis: An idea whose time has come---and gone

Aug 11 2010 Published by under [Medicine&Pharma]

One of the strengths of modern medical education is its emphasis on basic science.  Conversely, the basic weakness of so-called alternative medicine is its profound ignorance of science and its reliance on magical thinking.  Nowhere is this more apparent than in the attempts of altmed cults to conduct and publish research.  From "quantum water memory" to "almost as good as placebo", the altmed literature is filled with basic failures in the proper formulation and testing of hypotheses.

One of the finest examples of these failures was just published in the journal Homeopathy.  Leaving aside for the moment the absurdity of a journal devoted to magic, let's see what they did here. Continue Reading »

4 responses so far

Why do chiropractors order so many X rays?

Aug 10 2010 Published by under [Medicine&Pharma]

People often visit primary care physicians and chiropractors for low back pain (LBP).  It is a very common problem, and one that usually resolves on its own.  Research has repeatedly shown that X rays are rarely useful in the evaluation and treatment of simple back pain.  Outside of certain "red flags" (fever, history of cancer, weight loss, and a few others), there is rarely any reason to get an X ray of someone's spine when they come to see the doctor for low  back pain.

Both anecdotal and quantitative studies have shown that chiropractors are very likely to order spine X rays. Given the inutility of these studies, and the radiation exposure, what reason could there be (aside from financial incentive) for chiropractors to order X rays?

Diagnosis of bone and joint disease

X rays can be very effective at diagnosing traumatic bone and joint injuries such fractures and dislocations.  These films can be very tricky to interpret, and nearly all doctors have their films over-read by a radiologist.  Given that chiropractic is not useful in the treatment of an acute fracture or dislocation, and that chiropractors are not qualified to read these films, this seems a poor excuse for ordering films.

X rays are not very sensitive or specific for the diagnosis of other important bone diseases such as osteoporosis, and can be very tricky when cancer is a consideration, as some bony cancer lesions show up on X rays and some do not.  X rays done and interpreted by a chiropractor or any other unqualified individual can lead to a false sense of security.

Diagnosis of "subluxation"

Subluxation is a word with two meanings.  In orthopedics, it refers to a specific kind of dislocation of a joint, one that can be clearly identified on an X ray.  In chiropractic, it refers to an often-invisible displacement of the vertebrae that can cause back pain and even systemic disease.   Subluxation in the chiropractic sense has never been shown to exist.  Vertebral subluxations in the orthopedic (i.e., real) sense are rarely clinically significant and are outside the purview of chiropractors.

X rays are a significant intervention. Anytime ionizing radiation is applied to a human being, there better be a good reason for it.  If there is no evidence that the X ray will help in a meaningful way with diagnosis or treatment, then no X ray should be done.  There is no clear reason any chiropractor should ever order an X ray.

32 responses so far

A monster?

Aug 09 2010 Published by under [Medicine&Pharma], Fatherhood, Medicine, Uncategorized

I'm certain that I've written previously on the perils of being your own physician.  Many of these perils should be obvious to a disinterested observer, and many apply to being a physician to family members.  But in small, close-knit communities, some familiarity with one's patients is often inevitable.  Where does a patient become "too close"? Sibling? Cousin?  Next door neighbor?  Person you grew up with and have dinner with from time to time?

These questions don't have obvious solutions, but to be a doctor, whether to those close to you or to strangers, one must recognize that wishes (in the psychological sense) can kill (in the concrete sense).

One day my daughter was on rounds with me and as usual I bought her a cookie.  A little while later she was complaining of not feeling well, having a sore throat, and a stomach ache.  By the time I got her home, she had hives.  We called the doctor, who didn't seem too concerned, and we gave her benadryl and an albuterol treatment.  She was better within the hour.  My wife pointed out to me that our daughter was having an allergic reaction---a severe one.  I hadn't even considered it, but of course she was right.  An ingredient list of the cookies showed they were made with walnuts, and later testing confirmed a walnut allergy.

As parents, we are like doctors to our own children.  We don't want to believe anything bad can happen to them and we may naturally minimize their complaints.  This is not always a bad thing.  Frequently, physical complaints are what we get from kids when actually they are anxious or tired or cranky.  And for many, it feels saner than its opposite; we may ridicule parents who take the kid to the doctor every time they blink funny.

I recently came upon an interesting blog, whose latest post is called, "I am a monster."  I can understand the author's fears, being a parent myself, but it's interesting how he takes a normal occurrence (trying to judge a  child's level of illness or injury), and conflates it with his own pathology.  Most parents feel guilty when anything happens to their kids, and many parents are burdened with various constitutional biases that determine how they make these judgments.  Barriers to seeking medical care are innumerable.  Aside from the obvious difficulty in determining which boo-boos require a doctor's evaluation, parents may worry about economic barriers.  They may have difficulty getting transportation to an adequate facility.  They may have their own fears of finding something wrong if they do go to the doctor.

But these fears are not the problem.  Introspection---a real examination of motivations in decision making---and collaboration with another adult can help with each individual decision and those that come after.  The blog post was a brave confession of fears all of us parents carry.

2 responses so far

On oaths and ethics

Aug 09 2010 Published by under [Medicine&Pharma], Medicine

A couple of days ago, Dr. Janet Stemwedel posted an interesting analysis of professionalism and the Hippocratic Oath.  The Hippocratic school apparently relied on ritual and tradition, the most famous of which is the Oath.  Medicine is still a world infused with ritual.  These rituals can be explicitly "ritualistic", but many aren't seen as rituals.  Compare, for example, the Oath to the successful passage of pre-med classes.

While the Hippocratic Oath appears to set a high (and specific) moral standard, it is an incomplete introduction to ethical behavior, one that often masquerades as something more.  Dr. Isis has come close to finding the heart of the problem.

The rituals of becoming a doctor begin very early, and are a bit of an ethics-free zone.  Success in pre-med classes such as organic chemistry and physics depends on hard work and competition. Altruism and professionalism aren't a part of the discussion.  The first formal ritual upon entering medical school is the donning of the white coat, a tangible act carrying, one hopes, significant meaning for each of the students.  What that meaning is, however, isn't clear. Continue Reading »

5 responses so far

Making mistakes

Aug 08 2010 Published by under [Medicine&Pharma], Medicine

Yesterday's sunrise brought for me a mix of melancholy and ecstasy.  It rose over my favorite setting on the last day of my trip to the Ontario woods.  After finishing up my duties as camp doctor, my daughter, my sister and I hopped in a canoe and paddled out to the islands in the middle of the lake.

Sunrise over Tea Lake

My daughter led us around the islands, blazing trails in an uncharacteristically fearless fashion.  But we had an eight hour car ride ahead of us, and a boat to catch to take us to that car, so we paddled back to camp, caught our boat, and that was that. Continue Reading »

20 responses so far

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