Tuesday, August 30, 2005

you're it

busy day today, so i'm just gonna post a link:

http://www.nytimes.com/2005/08/30/health/policy/30nih.html

it's an article on dr. elias zerhouni, director of the NIH and former mentor to my former mentor at hopkins. he's a radiologist by training, and one of his innovations was a technology known as MRI tagging. MRI images can be taken and compiled much like frames in a video or movie. as a result, MRI videos show high-resolution movement of, say, a beating heart. tagging MRI means to impose a magnetic "grid" on the images, which acts as if it were embedded in the tissue itself. the grid then moves along with the heart, bending and warping accordingly. a computer precisely measures the movement of the grid. this allows for quantification of heart movement, which is useful in determining what parts of a heart have died or lost function after a heart attack, for example.

Monday, August 29, 2005

feeling nervous

whereas the hematology/oncology unit was well-organized and logical in its execution, the vaunted neurology unit makes no such promises. in fact, judging by today's introductory lectures, the neuro unit will be filled with the sort of senseless (hAR) jargon that i utterly despise. i imagine therefore that this blog will see some heavy use in the coming 1.5 months. to begin, let's start with something basic: a list of the cranial nerves.

I Olfactory
II Optic
III Oculomotor
IV Trochlear
V Trigeminal
VI Abducens
VII Facial
VIII Vestibulocochlear
IX Glosspharyngeal
X Vagus
XI Accessory
XII Hypoglossal

tonight's task: memorize these twelve buggers, preferably while grilling brats and dr. luo's special recipe pork chops with davey and huge euge.

Friday, August 26, 2005

hamburgers

did well on my exam today. i attribute my success to the full breakfast i ate this morning--two eggo waffles, a sausage patty, two strips of bacon, a pork sung sandwich, and a glass of low sodium v8. not the hamburger breakfast that got brett killed in pulp fiction, but still delicious. oh, and my lucky johns hopkins hospital scrubs probably helped too. atul gawande says that doctors--surgeons in particular--aren't very superstitious. i find that hard to believe though. surgeons, after all, are traditionally the jocks of medicine. and athletes are famously superstitious--wade boggs' chicken and reggie miller's pregame buzzer beaters, for example. i'll look into this...

Wednesday, August 24, 2005

QUITTER!


the happy family Posted by Picasa

lance armstrong is being accused of having used the performance-enhancing drug EPO in 1999, when he won his first of seven consecutive tour de france titles. EPO stands for erythropoietin, a hormone produced by the kidneys to stimulate the production of erythrocytes, aka red blood cells. for this reason, individuals who suffer from kidney disease may develop a serious anemia because they cannot produce homeostatic amounts of EPO. EPO also shortens the time for red blood cell maturation. therefore, an athlete who "doped" his blood with EPO would produce more red blood cells, increase his oxygen-carrying capacity, and experience a prolonged boost in stamina.

supposedly, back in 1999 EPO was undetectable but both its benefits and risks were well known. a marked increase in EPO results in more red blood cells, ultimately thickening the blood and heightening one's risk for stroke or other vessel-obstructing events (although, ironically, EPO has been found to help stroke patients recover neurologic function). also, in settings of extended exercise--like, i don't know, maybe riding a bicycle for thousands of miles--the body demands extraordinary amounts of water, some of which is eventually shifted out of the bloodstream and into the tissues for use. this thickens the blood even more.

in mr armstrong's case, he allegedly had taken EPO to help his recovery from cancer, although that was prior to his first tour victory. still, i can't say believe his unequivocal denials of doping, and i think he chose the right time to retire. but, regardless of truth behind the drug accusations leveled against him, as the daily show pointed out after lance's most recent tour de france win, he is a quitter.

and the above photo is my adoring family. notice how remarkably the genes from my parents segregated to produce me and my sister.

Tuesday, August 23, 2005

billy rubin

in the book the silence of the lambs, there is a scene where hannibal lecter walks senator martin (the father of the girl stuck in the pit) through the riddle of "billy rubin." buffalo bill's name is a pun on "bilirubin," the organic substance perhaps best known as the yellow tint in jaundiced individuals. i read the book after my sophomore year in high school, before i had seen the movie. jonathan demme cut out this scene from the movie, which i thought was a shame, but otherwise i found the film version to be almost as scary as the book. almost.

an elevated bilirubin level is a symptom of any number of physiologic abnormalities. in the context of hematology, elevated bilirubin levels indicate the breakdown of hemoglobin in the body, as can happen in settings of extravascular and intravascular hemolysis, i.e. the destruction of red blood cells either outside or inside the circulation. one component of hemoglobin in particular--protoporphyrin--is further broken down, resulting in unconjugated bilirubin. the liver typically conjugates bilirubin in order to produce bile, but excess unconjugated bilirubin cannot be processed fast enough by the liver nor excreted in the urine. as a result, it builds up in tissues, thereby yielding the yellowish tinge that characterizes jaundice and scleral icteri (yellowing of the eye).

the potential causes of this red blood cell destruction, as we were taught in class, are most likely either an autoimmune hemolytic anemia, where the body inappropriately produces antibodies against its own red blood cells, or hereditary spherocytosis, where a genetic defect results in the faulty construction of red blood cell membranes, causing RBCs to be abnormally small, inflexible (they look like tiny spheres under a microscope), and thus more susceptible to lysis. the test to differentiate between the two potential etiologies is the direct coombs test, which basically looks for antibodies against RBCs.

tomorrow: photos from the weekend

Saturday, August 20, 2005

getting old

i have loved bill simmons ever since discovering him the summer before college, back when he was still the boston sports guy and not the hollywood half-sports-half-entertainment wannabe hack that he is now. what used to make him so fresh and sublime was his status as sportswriter for the fans. most great sports columnists are great because 1) of decades of experience or 2) of their unparalleled access to superstar athletes. back in 2000, simmons had neither--he was a 30-yr old boston native who lived and died by his boston teams. and what made him funny was that you could relate to him, his angst, his highs and lows. he'd witnessed bird and the celtics at their peak and the red sox at their choking worst. that gave him a different kind of credibility, and top of that he was outrageously funny in his observations of the absurdities of gen X culture, a la letterman and jon stewart. my favorite series he wrote was his story about meeting charles barkley at tnt. he sounded completely awestruck, just like any fan would be, and that was completely unlike any other sportswriter.

but now simmons is past his prime. gone are creative gems like the ewing theory and the vengeance scale. what started as hilarious riffs on the karate kid are now full-scale reviews of movies, and it's painfully apparent that he's overstretching his expertise as he tries to make himself into some kind of pop culture guru. plus he's married now with a kid--can he still write about tecmo football with any sort of legitimacy? it's time for him to retire, or at the very least stop trying so hard. he still puts out good stuff every so often, like his recent column on the wide receiver prima donna phenomenon. but he's finally getting old.

and speaking of old people, my negligent senior thesis advisor, professor charles rosenberg, always referred to the history of pernicious anemia as a classic story in the history of medicine. i never really knew what he was talking about. but now that we've learned about pernicious anemia in class, i still don't really know what he's talking about. i do know, however, that pernicious anemia is the most common cause of vitamin b12 deficiency in adults in temperate climates.

Friday, August 19, 2005

"boob"

happy friday. here is an article from the latest new england journal, by docstar atul gawande, about the delicate nature of the physical exam.

Naked
Atul Gawande, M.D., M.P.H.

There is an exquisite and fascinating scene in Kandahar, a movie set in Afghanistan under the Taliban regime, in which a male physician is asked to examine a female patient. They are separated by an opaque screen. Behind it, the woman is covered from head to toe by her burka. The two do not talk directly to each other. The patient's young son serves as the go-between. She has a stomachache, he says.

"Does she throw up her food?" the doctor asks.

"Do you throw up your food?" the boy asks.

"No," the woman says, perfectly audibly, but the doctor waits as if he has not heard.

"No," the boy tells him.

For the exam, the doctor has cut a two-inch circle in the screen. "Tell her to come closer," he says. The boy does. She brings her mouth to the opening, and through it he looks inside. "Have her bring her eye to the hole," he says. And so the exam goes. Such, apparently, can be the demands of decency.

When I started my surgical practice two years ago, I was not at all clear about what my own etiquette of examination should be. Expectations are murky; we have no clear standards in the United States; and the topic can be fraught with hazards. Physical examination is deeply intimate, and the way a doctor deals with the naked body — particularly when the doctor is male and the patient female — inevitably raises questions of propriety and trust.

No one anywhere seems to have discovered the ideal approach. A surgical colleague who practices in Iraq told me about the customs of physical examination there. He said he feels no hesitation about examining female patients completely when necessary, but because a doctor and a patient of opposite sex cannot be alone together without eyebrows being raised, a family member will always accompany them for the exam. Women do not remove their clothes or change into a gown for the exam, and only a small portion of the body is uncovered at any one time. A nurse, he said, is rarely asked to chaperone: if the doctor is female, it is not necessary, and if male, the family is there to ensure that nothing unseemly occurs.

In Caracas, according to a Venezuelan doctor I met, female patients virtually always have a chaperone for a breast or pelvic exam, whether the physician is male or female. "That way there are no mixed messages," the doctor said. The chaperone, however, must be a medical professional. So the family is sent out of the examination room, and a nurse brought in. If a chaperone is unavailable or has refused to participate, the exam is not done.

A Ukrainian internist told me that she has not heard of doctors in Kiev using a chaperone. If a family member is present, he or she will be asked to leave. Both patient and doctor wear their uniforms — the patient a white examining gown, the doctor a white coat. Last names are always used. There is no effort at informality to muddy the occasion. This practice, she believes, is enough to solidify trust and preclude misinterpretation of the conduct of care.

A doctor, it appears, has a range of options.

In 2003, I set up my clinic hours, and soon people arrived to see me. I was, I realized, for the first time genuinely alone with patients. No attending physician in the room or getting ready to come in; no bustle of emergency room personnel on the other side of a curtain. Just a patient and me. We'd sit down. We'd talk. I'd ask about whatever had occasioned the visit, about past medical problems, medications, the family and social history. Then the time would come to have a look.

There were, I will admit, some awkward moments. I had an instinctive aversion to examination gowns. At our clinic they are made of either thin, ill-fitting cloth or thin, ill-fitting paper. They seem designed to leave patients exposed and cold. I decided to examine my patients while they were in their street clothes. If a patient with gallstones wore a shirt she could untuck for the abdominal exam, this worked fine. But then I'd encounter a patient in stockings and a dress, and the next thing I knew, I had her dress bunched up around her head, her tights around her knees, and both of us wondering what the hell was going on. An exam for a breast lump one could manage, in theory: the woman could unhook her brassiere and lift or unbutton her shirt. But in practice, it just seemed weird. Even checking pulses could be a problem. Pant legs could not be pushed up high enough. Try pulling them down over shoes, however, and . . . forget it. I finally began to have patients change into the damn gowns. (I haven't, however, asked men to do so nearly as often as women.)

As for having a chaperone present with female patients, I hadn't settled on a firm policy. I found that I always asked a medical assistant to come in for pelvic exams and generally didn't for breast exams. I was completely inconsistent about rectal exams.

I surveyed my colleagues about what they do and received a variety of answers. Many said they bring in a chaperone for all pelvic and rectal exams — "anything below the waist" — but only rarely for breast exams. Others have a chaperone for breast and pelvic exams but not for rectal exams. Some did not have a chaperone at all. Indeed, an obstetrician–gynecologist estimated that about half the male physicians in his department do not routinely use a chaperone. He himself detests the word "chaperone" because it implies that mistrust is warranted, but he offers to bring in an "assistant" for pelvic and breast exams. Few of his patients, however, find the presence of the assistant necessary after the first exam, he said. If the patient prefers to have her sister, boyfriend, or mother stay for the exam, he does not object — but he is under no illusion that a family chaperone offers protection against an accusation of misconduct. Instead, he relies on his reading of a patient to determine whether bringing in a nurse–witness would be wise.

One of our residents, who was trained partly in London, said he found the selectivity here strange. "In Britain, I would never examine a woman's abdomen without a nurse present. But in the emergency room here, when I asked to have a nurse come in when I needed to do a rectal exam or check groin nodes on a woman, they thought I was crazy. `Just go in there and do it!' they said." In England, he said, "if you need to do a breast or rectal exam or even check femoral pulses, especially on a young woman, you would be either foolish or stupid to do it without a chaperone. It doesn't take much — just one patient complaining, `I came in with a foot pain and the doctor started diving around my groin,' and you could be suspended for a sexual-harassment investigation."

Britain's standards are stringent: the General Medical Council, the Royal College of Physicians, and the Royal College of Obstetricians and Gynaecologists specify that a chaperone must be offered to all patients who undergo an "intimate exam" (i.e., involving the breasts, genitalia, or rectum), irrespective of the sex of the patient or of the doctor.1,2 A chaperone must be present when a male physician performs an intimate exam of a female patient. The chaperone should be a female member of the medical team, and her name should be recorded in the notes. If the patient refuses a chaperone and the examination is not urgent, it should be deferred until it can be performed by a female physician.

In the United States, we have no such guidelines. As a result, our patients have little idea of what to expect from us. To be sure, some minimal standards have been established. The Federation of State Medical Boards has spelled out that touching a patient's breasts or genitals for a purpose other than medical care is a disciplinable offense. So are oral contact with a patient, encouraging a patient to masturbate in one's presence, and providing services in exchange for sexual favors. Sexual impropriety — which involves no touching but is no less proscribed — includes asking a patient for a date, criticizing a patient's sexual orientation, making sexual comments about the patient's body or clothing, and initiating discussion of one's own sexual experiences or fantasies.3 I can't say anyone taught me these boundaries in medical school, but I would like to think that no one needed to.

The difficulty for those of us who do not behave badly is that medical exams remain inherently ambiguous. Any patient can be led to wonder: Did the doctor really need to touch me there? Even when doctors simply inquire about patients' sexual history, can anyone be certain of the intent? The fact that all medical professionals have blushed or found their thoughts straying during a patient visit reveals the potential for impropriety in any encounter.

The tone of an office visit can turn on a single word, a joke, a comment about a tattoo in an unexpected place. One surgeon told me of a young patient who expressed concern about a lump in her "boob." But when he used the same word in response, she became extremely uncomfortable and later made a complaint. Another woman I know left her gynecologist after he made an offhand, probably inadvertent, but admiring comment about her tan lines during a pelvic exam.

The examination itself — the how and where of the touching — is, of course, the most potentially dicey territory. If a patient even begins to doubt the propriety of what a doctor is doing, something is not right. So what then should our customs be?

There are many reasons to consider setting tighter, more uniform professional standards. One is to protect patients from harm. About 4 percent of the disciplinary orders that state medical boards issue against physicians are for sex-related offenses. One of every 200 physicians is disciplined for sexual misconduct with patients sometime during his or her career.4 Some of these cases involve such outrageous acts as having intercourse with patients during pelvic exams. The vast majority of cases involved male physicians and female patients, and virtually all occurred without a chaperone present.5 About one third of cases studied in one state involved actual sexual intercourse with patients; two thirds involved sexual impropriety or inappropriate touching short of sexual contact. Another goal might be to reduce false accusations arising from misinterpretation.

Nonetheless, eliminating misconduct and accusations would be the wrong aim to guide medical care. The trouble is not that such acts are rare (though the statistics suggest they are), nor that total prevention — zero tolerance — is impossible. It is that, at some point, the measures required to achieve total prevention will approach the Talibanesque and harm care of patients.

Embracing more explicit standards for medical encounters, however, might actually improve relationships with patients — and that does stand as a worthy goal. The new informality of medicine — with white coats disappearing, and patient and doctor sometimes on a first-name basis — has blurred boundaries that once guided us. If physicians are unsure about what is appropriate behavior for themselves, is it any surprise that patients are, too? Or that misinterpretation can occur? We have jettisoned our old customs but have not bothered to replace them.

My father, a urologist, has thought carefully about how to avert such uncertainties. From the start, he felt the fragility of his standing as an outsider, an Indian immigrant practicing in a rural Ohio town. In the absence of guidelines to reassure patients that what he does as a urologist is routine, he has made painstaking efforts to avoid question.

The process begins before the exam. He always arrives in a tie and white coat. He is courtly. Although he often knows patients socially and doesn't hesitate to speak with them about personal matters (the subjects can range from impotence to sexual affairs), he keeps his language strictly medical. If a female patient must put on a gown, he steps out while she undresses. He makes a point of explaining what he is going to do during the examination and why. If the patient lies down and needs further unzipping or unbuttoning, he is careful not to help. He wears gloves even for abdominal examinations. If the patient is female or under 18 years of age, then he brings in a nurse as a chaperone, whether the exam is "intimate" or not.

His approach has succeeded. I grew up knowing many of his patients, and they trust him completely. I find, however, that some of his practices do not seem quite right for me. My patients are as likely to have problems above the waist as below, and having a chaperone present for a routine abdominal exam or a check of groin pulses feels to me absurd. I don't don gloves for nongenital exams. Nonetheless, I have tried to emulate the spirit of my father's visits — the decorum in language and attire, the respect for modesty, the precision of examination. As I think further about his example, it has also led me to make some changes: I now uniformly use an assistant not just for pelvic exams but also for rectal exams of female patients and as patients desire, for breast exams as well. For the comfort and reassurance of patients, these seem to be reasonable customs, even expectations, for more of us to accept.

A professor once told my medical school class that patients can tell when you've seen a thousand naked patients and when you haven't. I now know that's true. But I have also come to recognize that no patient has seen a thousand doctors. They therefore have little idea, coming to a doctor's office, of what is "normal" and what is not. This we can change.

Source Information

Dr. Gawande is a general and endocrine surgeon at Brigham and Women's Hospital and an assistant professor at Harvard Medical School and at the Harvard School of Public Health, Boston.

References

1. Intimate examinations. London: General Medical Council Standards Committee, December 2001.
2. Gynaecological examinations: guidelines for specialist practice. London: Royal College of Obstetricians and Gynaecologists, July 2002.
3. Ad Hoc Committee on Physician Impairment. Report on sexual boundary issues. Dallas: Federation of State Medical Boards of the United States, April 1996.
4. Dehlendorf CE, Wolfe SM. Physicians disciplined for sex-related offenses. JAMA 1998;279:1883-1888. [Abstract/Full Text]
5. Enbom JA, Thomas CD. Evaluation of sexual misconduct complaints: the Oregon Board of Medical Examiners, 1991 to 1995. Am J Obstet Gynecol 1997;176:1340-1348. [ISI][Medline]

Thursday, August 18, 2005

the IRA

the first research job i enjoyed was as a clinical research assistant in cardiology at johns hopkins. i was in way over my head, reading all kinds of articles that i couldn't understand at all, but i enjoyed the hospital setting and just hanging out with doctors. my project involved compiling a database of patient info--in retrospect it was a shit job, but i thought i was doing something important and challenging at the time. specifically, i was concerned with a particular type of drug that patients were perhaps given during their balloon angioplasties. these drugs were of the GPIIb/IIIa inhibitor class, and there are three such drugs currently on the market--integrilin, reopro, and aggrastat. their scientific names are eptifibatide, abciximab, and tirofiban, respectively.

now i know what they do, and so i thought i would amend my previous post by pointing out that glycoprotein IIb/IIIa receptors are not the mediators per se of platelet aggregation. instead, they are the binding sites for fibrinogen, the precursor to fibrin, i.e. the glue that keeps clots together. incidentally, although drugs blocking these receptors are indicated for the prevention of unwanted clots, the congenital deficiency of these receptors is called Glanzmann's thrombasthenia, a rare but serious bleeding disorder.

sadly though, the love of my life is nowhere to be seen today. maybe tomorrow.

Wednesday, August 17, 2005

the girl next door

right now i am sitting at borders across from a beautiful, demure korean girl who is sifting through a massive pile of novels. i have decided that i love her. and so this entry, my first official post of the year, is dedicated to the lovely agashi across the way.

the coagulation cascade is a remarkable piece of biological machinery that keeps our blood flowing when it should and clots it when it shouldn't. in fact, it is so remarkable that it is a commonly cited example, like the eye, of how evolution may fail to explain all the complexities of the human body. the coagulation cascade, in other words, is a kind of "all or nothing" system, i.e. take away any one of its many parts and the whole things breaks. evolution is about incremental change, yet it is difficult to imagine the simpler precursor mechanism to coagulation that should have come before the present clotting system.

anyway, last year we learned about the basics of coagulation--the names of all the different factors, the intrinsic vs. extrinsic pathways, and a couple disorders resulting from disruptions to the cascade. this year we're learning all about what goes wrong in the body, and our first unit is hematology/oncology. a friend of mine from college used to wear a silver bracelet that indicated his having von Willebrand's disease. von Willebrand's factor (VWF) is one of the many coagulation cascade factors that mediate blood clotting. VWF in particular mediates platelet adhesion to the inner lining of blood vessels... ok hold on, the girl just talked to me! and she smiled at me! anyway, so VWF helps platelets adhere to blood vessel endothelium, so-called "primary hemostasis." in order to activate platelets so that they become sticky, VWF binds to the platelet receptor GP1b. this binding then activates a second binding site, GPIIb/IIIa, which allows for tight adhesion of platelets to one another. incidentally, GPIIb/IIIa inhibitors are now crucial drugs in the treatment of heart disease, and their use was made popular by my awesome boss, dr. topol.

so yeah, von Willebrand's disease is the result of some abnormality of VWF, either quantitative or qualitative. quantitative disorders are the most common, such as the partial deficiency of VWF known as type 1 VWD, and this is what i suspect my friend had, although now we'll never know because he lost his bracelet. there are other qualitative variations of the disease where the VWF binds too well to GP1b, or it binds poorly, or it is completely absent (this is quantitative but whatever).

ok i'm much too distracted to continue. go evolution, boo intelligent design.