Archive for: January, 2011

This post is about vaginas

Jan 27 2011 Published by under Medicine

The human body is host to many different microbial micro-environments, and the vagina is no exception.  The healthy human vagina is quite acidic, with a pH less than 4.5, similar to that of grapes or orange juice.  This pH is maintained by a healthy population of Lactobacilli which produce lactic acid and hydrogen peroxide.  These products of Lactobacillus metabolism appear to keep in check populations of other vaginal bacteria, many of which are intolerant of hydrogen peroxide and of acidic environments.

http://commons.wikimedia.org/wiki/File:Vaginose-G15.jpg

Clue cells in bacterial vaginosis, from Wikimedia Commons

From time to time, this normal balance of bacteria is disrupted.  When this happens, the normally dominant Lactobacilli are outgrown by various anaerobic bacteria.  These bacteria break down proteins in the vagina and create various malodorous compounds that create a thin, grey discharge.  It is this symptom that normally drives a woman to the doctor where she is diagnosed with bacterial vaginosis (BV).
As the vaginal environment changes and the pH rises, Garnerella bacteria begin to stick to vaginal epithelial cells and are visible under the microscope as "clue cells" (the big blobs are squamous cells, the little dots are bacteria stuck to the surface).

BV is not a sexually transmitted disease, but it is strongly associated with sexual activity.  Sexual activity with men or women increases the risk of BV, as does douching.  Both sexual activity and douching can change the normal vaginal environment, and one of these activities can be safely and comfortably done away with.

Normally, BV is a benign condition, but in pregnant women it can increase the risk of premature delivery. It is also a risk factor for acquiring STIs such as HIV, chlamydia, and herpes, perhaps because the normal acidic and oxidizing environment is protective. Because of these risks, BV should be treated, and treatment is relatively easy, although relapse is common.

Because strains of Lactobacilli are present in many yogurts, yogurt has been touted as a possible prevention and treatment for BV, taken either orally or intravaginally, but there are many different species in this genus, and only some of them produce hydrogen peroxide, a trait thought to protect the vagina. One review found some evidence that yogurt can be helpful, but most of the studies out there don't compare it to the gold standard antibiotic.

The vagina and its microflora do a pretty good job staying healthy, but certain human activities can create significant problems.  Douching is never necessary and can lead to BV.  It's a bad idea.  While giving up douching should be pretty easy, I'm fairly certain people are still going to have sex.  When symptoms of BV develop, a simple gynecologic exam, including checking vaginal pH and looking at secretions under the microscope, leads to rapid diagnosis and treatment of an annoying and potentially harmful disorder.

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Is abortion associated with mental illness?

Jan 26 2011 Published by under Medicine

Anti-abortion groups, having largely failed to convince the American public that abortion is morally abhorrent, have tried to shift the debate to their concern about women's health.  The same groups who would forbid abortion after rape or incest, or when the mother's life is endangered claim to be saving women from "post-abortion syndrome", a mythical psychological disorder.  There are many reasons good people may oppose abortion, but lying about health risks such as breast cancer (a long-discredited hypothesis) is simply immoral.  But it does seem plausible that abortion might have psychological consequences, although whether these would be good or bad certainly isn't obvious. A new Danish cohort study published in the New England Journal of Medicine tries to inject some data into this debate.

The study relies on the excellent health records kept by the Danish health care system.  They looked at the approximately 3/4 million women born between 1962-1993. They were able to find out how who sought  psychiatric care (there is no private psychiatric care in Denmark), and who had abortions or gave birth.  Abortions before 12 weeks gestation are legal in Denmark, and nearly all abortions there are done during that period, and nearly all are performed in public clinics or hospitals, so the data are pretty complete.

Combing this data, the authors identified a study population of young women with no history of psychiatric disease and no history of abortion.  They then compared rates of psychiatric care sought in the period from 9 months before abortion or child birth until 12 months after.  They crunched the numbers and the crux of their conclusion was:

The risk of a psychiatric contact did not differ significantly before and after abortion (P=0.19), but the risk after childbirth was significantly greater than the risk before childbirth (P<0.001).

The primary finding was that women who had abortions were just as likely to seek out psychiatric care before their pregnancy as after their abortion.  Having an abortion was not a risk factor for seeking out psychiatric care.

This is an impressive study, made possible by the excellent data collection in Denmark.  Abortion, medical, and psychiatric care are all easily available, significantly lowering confounding economic and social factors that might be found in the US, and in this population, abortion did not appear to lead to psychological illness.  The interesting secondary finding, that having a baby can lead to psychological distress, is a fact often left out by anti-abortion groups.  Post-partum depression and anxiety are common and serious.  Since the question of abortion and mental health is largely asked and answered, it is time to focus our energies on groups truly at risk.

References

Munk-Olsen, T., Laursen, T., Pedersen, C., Lidegaard, �., & Mortensen, P. (2011). Induced First-Trimester Abortion and Risk of Mental Disorder New England Journal of Medicine, 364 (4), 332-339 DOI: 10.1056/NEJMoa0905882

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Practice good medicine, go to jail

Jan 24 2011 Published by under Medicine

A Florida legislator wants to imprison doctors for practicing good medicine.  "Really?" you ask.  Is this another anti-abortion bill?  Assisted suicide?

No, it's about guns. It is the policy of my professional organization and many others to inquire about firearm ownership and safety.

Is this a valid position, and if so, why?

Physicians are charged with prevention and treatment of human disease/injury. Prevention encompasses screening for risk, and preventative treatments such as vaccination. It also includes counseling regarding important health behaviors, such as seat belt and helmet use.

Are firearms an important, preventable health problem?   If so, how do we intervene to prevent firearm injury and death?

The data regarding firearms and preventable injury is unassailable. The CDC and DOJ both track statistics, but as an example, homicide and suicide by firearm are the second and third leading causes of injury-related death in the US in the 15-24 age group. The exact magnitude of the problem can be debated, but its health significance cannot.

The American College of Physicians (in a 1998 position statement) has taken a two-pronged approach: asking patients about gun ownership and safety, and advocating for gun-control legislation. The first should be uncontroversial---who can argue with asking a patient if they own the means to end life rapidly and violently, if they know how to secure it properly, and if they keep it out of the reach of children?

The second point is, needless to say, very controversial, although not so much among physicians, who consistently poll favorably on the issue.

Lets add some science-based medicine to the cauldron. Is it plausible that doctors' interactions with patients and legislators can reduce gun violence? Certainly.  To what degree can we physicians help reduce gun-related injuries?  Studies have shown variable efficacy of firearms safety counseling in changing patients' behavior.  Can this intervention cause harm?  It's hard to see how.

Given the extent of the problem, even a small positive effect on patient behavior can have a large impact.  The only negative outcome is having a patient ignore your advice.  Most patients understand that the doctor has their best interests at heart, and that recommendations come from data rather than ideology.  I don't tell my patients that the must remove guns from the house, although I do point out that they are statistically likely to be safer without them.  I do recommend that they practice safe storage of firearms.

So what about this proposed law? What does it say?

1)(a) A verbal or written inquiry by a public or private physician, nurse, or other medical staff person regarding the ownership of a firearm by a patient or the family of a patient or the presence of a firearm in a private home or other domicile of a patient or the family of a patient violates the privacy of the patient or the patient's family members, respectively.

(b) A public or private physician, nurse, or other medical staff person may not condition receipt of medical treatment or medical care on a person's willingness or refusal to disclose personal and private information unrelated to medical treatment  in violation of an individual's privacy as specified in this section.

(c) A public or private physician, nurse, or other medical staff person may not enter any intentionally, accidentally, or  inadvertently disclosed information concerning firearms into any record, whether written or electronic, or disclose such 43 information to any other source.

A violation would be a third degree felony and could be punished with a fine “of not more than $5 million if the court determines that the person knew or reasonably should have known that the conduct was unlawful.” As the Palm Beach Post reports, the NRA has identified the bill a priority item on its agenda for this Florida legislative session. The legislative proposal would clearly invite a strong challenge as an unconstitutional prior restraint if enacted.

This is, in technical terms, a steaming crock of feculent idiocy (and, I would think, unconstitutional).  For a legislature to decide what a doctor and patient may not talk about is a profoundly unconservative idea.  What if the junk food industry lobbies a legislator next?  No more proper counseling for my diabetics?

Even in the current insane political climate, I doubt this bill would pass or stand. But for someone to propose it, and for a major lobbying body (the NRA) to support it is equally sad and dangerous.

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*One wonders what the Official Club for Wingnut Doctors would think of this proposed bill.

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Weekend musings

Jan 15 2011 Published by under Fatherhood, Medical Musings, Medicine

It's another cold, windy, winter day here in the Great Lakes state.  From my kitchen table I can see the snow drifts pile up against an old oak tree.  There's a baby swing still hanging from the lowest branch.  PalKid hasn't been able to sit in it for years, but for some reason, I've never bothered to take it down.

Yesterday around five a.m., a small voice woke me up.

"Daddy, I can't sleep."

"Come on in bed next to me and you can stay here, just be quiet, honey."

A few minutes later: "Daddy, I don't feel good.  I have a headache. Can I have a cold cloth?"

Mrs. Pal called me at work later to tell me PalKid had a fever of about 102 and was feeling miserable.  I ran into a colleague today at the hospital and he told me, "You're only as happy as your least happy kid," and that seems about right.  Last night was rough, and that cute little voice got me up at four this morning.  She was feeling miserable, and after getting some tylenol in her, she asked for a cool bath.  A few hours later, I was on my way to the hospital, not for her thankfully, but to see patients.

My new practice uses a hospitalist service, so I'm not the one taking care of my patients in the  hospital anymore, but I still like to check on them once in a while when time permits.  The new practice is very, very busy, which is great, but there really isn't time to round regularly.  I did manage to visit a couple of folks today (and missed a few also...sorry).  I got a big hug from one patient, and nearly cried.  I was happy to see he was recovering nicely after a big scare.

Someone asked me this week how I deal with giving bad news, with maintaining a clinical distance.  I have no idea.  Much has been written about this, but there is no right way to deal with these boundaries.  Being a physician is a privilege, and a strange one.  It's a bit like being a writer, inhabiting lives that aren't yours, being privy to the private dialog of others, to their happiness and tragedy.  Sometimes it hurts.  Sometimes it is ecstasy.  Rarely is it simple.

But for today, at least, I'm mostly a daddy taking care of a sick kid, bringing her ginger ale in bed, enjoying a smile meant just for me.

8 responses so far

Blood Libel: You keep using that word...

Jan 12 2011 Published by under Politics

Sarah Palin jumped the bigotry shark today, and bloggers are trying to explain just how offensive her comments really are.  Mark CC of Good Math Bad Math gives a terrific summary, but I can't help but give my take on this.

The shooting of Rep. Gabby Giffords and 19 others happened in a particular time and place, and history will look back at this context in trying to understand the event.  What Sarah Palin and others in the New Right are arguing is that context is meaningless; that their inflammatory, violent rhetoric is irrelevant (and that the left is just as bad, which is patently absurd---we hate guns, remember?).  This anhistoric view is typical, and is typified by Palin's cry of "blood libel".

Let's summarize events:

  • Right wing reactionaries use gun rhetoric and Christian imagery and language to speak to their base, including such statements as "don't retreat, reload", and posting pictures of "targeted" districts like Rep. Giffords' with gun sights on them.
  • Giffords is gunned down by a presumed nut-job who easily purchased a firearm and ammunition, a "right" favored by the New Right.  He drew and fired on her point blank range, rendering idiotic any claims that being personally armed could have helped her.
  • "Blood libel" is a specific term referring to anti-Jewish violence in Europe.  Christians claimed that Jews murdered Christian children for their blood, and Christians would use this to justify genocidal violence over the course of centuries, and culminating in the Shoah (Holocaust).  The Nazi's did not always use blood libel imagery, but they certainly encouraged it in their European collaborators, especially in Poland and Russia.
  • Giffords is a Democrat and Jewish.
  • Palin is a Republican and Christian.
  • Palin claims that calling her out on her violent rhetoric as having anything to do with political violence is "blood libel".
  • Irony meter explodes.

Palin, who favors eliminationist rhetoric directed at, in this case, a liberal Jewish Congresswoman, absolves herself of any responsibility for the violence just happens to bear close resemblance to her rhetoric.  Part of her reasoning is that it's just rhetoric, and the guy was a nut.  She then claims harm from the rhetoric leveled against her.  Irony meter reassembles and explodes again.

I'm not one to see an anti-Semite behind every door, but this is blatantly anti-Semetic rhetoric, giving a whole new appearance to the attack.  Palin's claims of not knowing what "blood libel" is are meaningless, as she has handlers who, in contrast to their boss, are educated.

They should all be ashamed.

But of course, they have no shame.

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Cold day reflections on medicine

Jan 08 2011 Published by under Medicine

Those of us who grew up in the north can sometimes tell how cold it is just by looking out a window.    It is so noticeable that it can reveal continuity errors in films (one that comes to mind is Men in Black, where the seasons seem to change from scene to scene).   But it is also subtle, something that is often hard to nail down.  "It looks cold out." Why?  What in particular makes it "look cold"?  Is it a character to the light, the texture of the steam from exhaust, chimneys, and manholes? How accurate is that assessment?

In medicine we are often faced with such gestalt opinions.  The practice of office-based medicine requires a high tolerance for uncertainty.  Unlike treating hospitalized patients, the doctor rarely has immediate access to lab results, complex imaging studies, and frequent measurements of vital signs.  Knowing the difference between someone who "looks sick" and someone who doesn't is a critical skill.

Are we good at it?  Like all things that rely on human intuition, probably not, or at least we likely over-estimate how good we are, so in medicine we try as hard as possible to develop objective criteria and decision tools to help us along.  Take pneumonia for example.  Community-acquired pneumonia (CAP, contrasted with pneumonia acquired in health care settings) is a common bacterial illness. Once known as The Captain of the Men of Death,  its rank has been diminished by the invention of antibiotics.  But it is still an importaint illness. There are about 4 million cases diagnosed in the US each year, with more than a million hospitalizations, and around 53,000 deaths.

Chest X-ray of left lower lobe pneumonia

Left lower lobe pneumonia, from Wikimedia Commons

Pneumonia is diagnosed by a good history and physical exam, and an X-ray showing lung tissue filled with fluid (mostly pus).  We know which organisms usually cause CAP and can treat it successfully most of the time with an empirical antibiotic choice.  The harder choice is whether to treat someone at home or in the hospital. The choice is often made on the basis of how "sick" the patient looks, but this strategy has obvious drawbacks.  Perhaps as many as half the people admitted to the hospital with pneumonia could be safely treated at home.  Being in the hospital adds to the cost and the danger of treatment, increasing the risk of hospital acquired infections such as C. dificile colitis.  Of course, failing to hospitalize someone who is ill also has potential consequences.

So doctors have come up with various criteria to help them decide when a patient can be safely treated at home or when to send them to the hospital.   Most of these criteria explicitly include the severity of the patient's clinical condition, the risk of death and complications, and other less tangible characteristics such as how likely it is that the patient will take medication properly at home.  Online calculators can help put the data together.

But sometimes, whatever the objective data, someone just "looks sick", and that sort of determination is at the heart of medicine.  If the decision tools tell me someone can probably be treated safely at home (and it's "probably", not "definitely"), and they look too sick to me, I'm putting them in the hospital.  This is hard to teach, and doctors probably get this wrong from time to time.  Still we do the best with what we have.

Sometimes I envy engineers.

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Looking for stronger statements from Sanjay

Jan 06 2011 Published by under Journalism, Medicine

Last night I watched CNN as Sanjay Gupta interviewed accused medical fraudster Andrew Wakefield, and the subsequent discussion with Seth Mnookin, author of The Panic Virus, (along with Anderson Cooper).  Aside from having given a podium to Wakefield, the interview was a good one.  I have nothing to say about Wakefield's performance except that it was hardly exculpatory.   Mnookin was brilliant---knowledgeable, articulate; everything a science journalist should be.  I was less happy with Dr. Gupta.

Sanjay made it clear that he favors vaccines, and that he has had his own children immunized fully and on time, and for that message he deserves kudos.  But as has been his habit, he strayed a bit too far into a "both side-ism" that creates more confusion than  clarity.

Gupta, a very bright and well-respected public figure and physician, has  a lot of influence and his words matter.  He had the opportunity here to speak loudly and clearly about this fraud and its negative effect on public health.   Instead he peppered his remarks with qualifiers.  He reiterated that Wakefield has no credibility in the scientific community, when he might properly have stopped at "no credibility".  He states that it's impossible to prove a negative (sic?), and if we knew "the" cause of autism, the debate would be entirely different.

I'm not so sure.

We know, with as much certainty as is reasonable in science, that vaccines do not cause autism.  The fact that we do not know the cause of most cases of autism is not as relevant as this fact.  I really do appreciate his strong statements in favor of vaccines, but his other statements feel like an attempt at "balance" where none is warranted.

I respect Dr. Gupta (except the execrable John of God report) and I think he has a lot to offer in communicating medicine and science to the public.  He might have used the Wakefield Fraud report to make a strong statement about good science, bad science, and the impact these have on public health.  Instead, he was wishy-washy and for that I'm disappointed.

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Another worry for breast cancer patients?

Jan 05 2011 Published by under Cancer, Medicine

Breast cancer is the most common (non-skin) cancer in women, and despite advances in treatment, it is still deeply feared, and with good reason.  But breast cancer is really several different diseases.  Breast cancers can arise from several different cell types, they can occur during the pre- or post-menopausal period, and they can have various cell surface receptors, all of which can change their behavior (and their lethality) significantly.

One of the things common to all cancers is that cells that were formerly normal begin to proliferate inappropriately, and fail to die when they should.  The h0rmone estrogen tells normal breast cells to proliferate, which maintains normal, functional breast tissue.   Estrogen can also tell breast cancer cells to proliferate, which is not a good thing.  One of the great advances in the treatment of breast cancer is the drug tamoxifen, which can block the action of estrogen on breast cells.

When an estrogen molecule enters a breast cell, it binds to a receptor molecule and knocks off a molecular "lock", allowing two estrogen receptors to bind together.  This "dimer" enters the cell's nucleus and interacts with DNA, increasing the activity of certain genes which lead to increased cell growth.  Tamoxifen works similarly, but when the tamoxifen-activated dimers interact with DNA, they inhibit cell proliferation.  This is a good thing, and tamoxifen has been shown to save lives in breast cancers that have estrogen receptors.

But when you take a tamoxifen tablet, it's not the tamoxifen itself that enters the breast cells.  The drug is absorbed by the stomach and eventually transported to the liver where it is converted to a chemical called "endoxifen".  It is the endoxifen that is the active molecule that helps prevent breast cancer recurrence and reduces mortality.  In order for tamoxifen to become endoxifen, it is processed in the liver by an enzyme called cytochrome P450.  The P450 system serves as a factory for changing chemicals into other chemicals, often in order to help eliminate them from the body; it is essentially a "detoxifying system".  Cytochrome P450 comes in many different flavors, each one working to transform different chemicals, especially drugs.  Drugs can be transformed in a way that makes it easier to eliminate them, or can be transformed in a way that activates them, as with tamoxifen/endoxifen. The P450 that transforms tamoxifen to endoxifen is called CYP2D6.

P450 is a tricky system.  While one drug may be metabolized by P450, another may inhibit or ramp up the enzyme.  This means that if, for instance, I give a patient tamoxifen, and also give them a drug that inhibits CYP2D6, the tamoxifen may not be turned into endoxifen efficiently.  And this is what apparently  happens with the antidepressant paroxetine (Paxil).

Paroxetine is a very potent inhibitor of CYP2D6.  It's also a very popular drug.  Depression is very common, especially in breast cancer patients.  Paroxetine is also used to treat hot flashes, a symptoms of both menopause and of tamoxifen treatment.  Given the relatively high chance of a woman being treated with both of these drugs, it would be good to know how significant this drug interaction might be.

A 2010 study published in the British Medical Journal did just that.  It used Canadian health records to look at usage of both drugs and at mortality in post-menopausal women with breast cancer.  What they found was that concomitant use of tamoxifen and paroxetine, but not other similar antidepressants, increased the risk of death.

This is a really, really big deal, but there are some limitations to the study.  First, they did not actually measure endoxifen levels, so that particular link in the causal chain is assumed.  They also did not evaluate patients to see which type of CYP2D6 they had; some people naturally have a more or less functional version, and we don't know how these patients may have been distributed in the groups.

But the hypothesis is plausible, and the fact that other SSRI antidepressants did not show a significant association with increased mortality should give us pause.  There are many, many inexpensive and reasonably effective choices for the treatment of depression, and after reading this study, as a clinician I would hesitate before prescribing paroxetine to a woman being treated for breast cancer with tamoxifen.

References

Kelly, C., Juurlink, D., Gomes, T., Duong-Hua, M., Pritchard, K., Austin, P., & Paszat, L. (2010). Selective serotonin reuptake inhibitors and breast cancer mortality in women receiving tamoxifen: a population based cohort study BMJ, 340 (feb08 1) DOI: 10.1136/bmj.c693

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