Musings of a Dinosaur

A Family Doctor in solo private practice; I may be going the way of the dinosaur, but I'm not dead yet.

Thursday, February 28, 2008

Can You Say "Duh"!

Specialists; gotta love 'em (and their EMRs, too.)

Excerpts from specialist's letter:

Past Surgical History: appendectomy, cholecystectomy, oophorectomy, thyroidectomy, back surgery

Physical Exam:
Neck: trachea midline, scar from previous thyroid surgery, no obvious thyroid enlargement

Thank goodness!


(Now don't go getting your diapers in a bunch. I know you can do a partial thyroidectomies where some of the gland is left that can potentially hypertrophy later. In general, though, that would be specified as "partial", even though to be precise he should have specified a total thyroidectomy, which is what she'd had. Still, this was a non-surgical, non-endocrine specialist and the documentation was probably boilerplate.)

Wednesday, February 27, 2008

Yo, Pharmacists!

I have a favor to ask all you pharmacists out there: How about getting together and adopting a universal fax form for requesting refills on patient medications?

As things are now, each store or chain has a different form that has all the same things on it, but in different places. They all have the store name, phone and fax numbers; the same information about the patient and the meds; and the same confidentiality statement. Would it really be so difficult for you to standardize your form? (Also, now that the chains are gobbling up more and more stores, it should actually be possible to implement something like this.)

Once upon a time, all the insurance companies had their own individual claim forms. Even though they all wanted the same information, they each insisted on their own form. It was enough of a PITA so that eventually a universal claim form was developed. It didn't improve payment all that much, but it definitely made things easier in the billing office.

I know it's not earth-shattering, but having a pile of six refill faxes from six different pharmacies, some portrait and some landscape, with all the key info in completely different places, is tiring and inefficient. Is it really asking all that much to get your act together and cooperate, for the sake of our patients as well as us docs?

Tuesday, February 26, 2008

How to Get Pregnant

With all due respect to my friend TBTAM and all her OBG colleagues, I recently offered a patient some advice that was so simple, so obvious, so logical, so down-to-earth that I'm not sure how often anyone ever actually comes out and says it.

About two months ago I saw a woman in her mid-30's who had been trying for some months to become pregnant, without success. They were doing everything "right" (no birth control; vaginal intercourse; no, he hadn't had a vasectomy, etc.) and weren't really "worried" yet. Still, I offered the following advice in the form of a family story told by my aunt, who had difficulty conceiving (well over fifty years ago; my two cousins are both closer to 60 than 50):
My aunt has this friend with a heavy Southern accent, who gave her the following advice: "Doan' moove. Doan' even covuh yuhself; let hubby pull up the blanket."
I should point out that in my family, pronouncing the words "Doan' moove" in that particular drawl never fails to provoke hilarity. As it happens, my patient had the same reaction when I said it to her. We kept on laughing as I elaborated about not getting up at all (even "just" to the bathroom) immediately after intercourse, allowing at least an hour or so for the swimmers to do their thing.

Today she came in again, laughing all over again. She'd had a positive home pregnancy test and was seven weeks along, by dates. I keep thinking "Doan' moove!" and I start laughing all over again. I even called my aunt to thank her. She was thrilled as well; once she finally stopped laughing.

Monday, February 25, 2008

The Gambit

What with the new emptiness of my nest at home, I've taken to sticking around in the office for the last few months after the official end of "office hours". It's a chance to get completely caught up on all the paperwork, see an extra patient or two if they call with something acute, answer the phones and do some writing if it's quiet. An interesting by-product of my new schedule is that there are far fewer messages on the machine in the morning. Another is that I've picked up some very interesting phone calls:
(slightly breathless with urgency) Oh, hi. I'm calling from XYZ Supplies. I just wanted to let you know that the gloves you like have been discontinued, so I've put aside two cases for you. Will that be enough?
WTF?

Interesting gambit; unfortunately, the poor thing has no idea that I do all my own ordering, and have never even heard of XYZ Supplies, not to mention never having bought gloves from them. As it happened, I wasn't in the mood to play that particular afternoon, so I just told her we'd never done business with her company and our phone number is on the Do Not Call list. Never heard anyone hang up quite so fast. But what fun I missed out on:
Oh no! The doctors LOVE those gloves. Can't you manage to get us at least five cases to hold us over? No, this isn't Dr. Dinosaur's office; it's Ginormous Medical Practice. Just fax the forms over; here's our fax number. [Don't ask me why I have GMP's fax number memorized.] Could you please put a rush on that? Oh, do you still carry those top-of-the-line EKG electrodes? We're running low on those. Yes, ten cases should be plenty. Can you just put it on our account like you usually do? What? Sure, my name is Tom. Say, did Donna have her baby yet? We usually deal with her, but I know she was due to go out on maternity leave.
See how long she can keep up her end of the conversation.

Hey, I can BS with the best of them, having been taught (raised, that is) by the best.

Friday, February 22, 2008

Terminology

Words are power. The words we choose and the words that are thrust upon us by others do far more to shape perceptions than most of us realize.

No, I'm not talking about the word "Provider," although I may at a later date. The word is reimbursement as used in the context of payment for medical services. Here's the dictionary definition of reimbursement:
1. to make repayment for expense or loss incurred
2. to pay back; refund; repay
Reimbursement occurs when one party is responsible for an expense that has been paid by another party. If my office manager goes out and buys stamps for the office out of her own pocket, I reimburse her.

The correct word here is PAYMENT for medical services.

We don't reimburse mechanics for fixing our cars; we PAY them.
We don't reimburse barbers for a shave and a haircut; we PAY them.
We don't reimburse accountants for doing our taxes; we PAY them.

Insurance companies do not reimburse me for services I render to patients who have contracted with them. They PAY me for them (sometimes.)

On the rare occasion when a patient pays me first, the patient may then seek reimbursement from the insurance company. The continued use of the term reimbursement reduces the perception payment for medical services to that of a simple inter-office transaction.

Effective immediately, I call upon Kevin, Panda, the Happy Hospitalist and all the other bloggers so diligently addressing the financial issues confronting and confounding us to stop using the wrong word -- reimbursement -- and replace it with the right one: PAYMENT.

Do this exercise: swap out those words in every post you read about physician PAYMENT and see how much more compelling your arguments become. Words are power.

Thursday, February 21, 2008

The Surgical Mind

Patient presents with a locally advanced cancer in the left breast. ("Locally advanced" = large tumor; as in, breaking through the skin.) Large axillary and supraclavicular nodal masses bilaterally; metastatic lesions to bone (ribs and spine.)

This is metastatic breast cancer; already spread; not curable. Got that?

After a small biopsy to confirm (!) the diagnosis (ok; actually to get information about cell type and receptors for prognostic and treatment planning purposes) she begins chemotherapy -- and responds BEAUTIFULLY! Truly amazingly. All tumor masses shrink markedly. Bony pain from mets goes away. Awesome. Regular CT and PET scanning confirms the response.

Three years (yes, years; no typo) later -- still on chemotherapy -- repeat scans show only a small-ish residual primary tumor mass in the left breast. The not-unreasonable decision is made to send her for a simple mastectomy, as getting rid of what's left of the primary tumor can't hurt. The surgeon who performed the original teeny little biopsy has relocated, so the patient sees another surgeon who performs the mastectomy. It goes fine; the patient does great; everyone's happy.

I got a letter from the surgeon today in follow-up that details just how well the patient has done, but then goes on to say:
I see she hasn't had a mammogram of the right breast in over a year. PET scan is negative, which is reassuring, but she really needs a mammogram; I'll arrange for it.
Er, why?

We already know she has breast cancer. Metastatic breast cancer, as in already spread; not curable. She's still on chemotherapy, for crying out loud. STILL. ON. CHEMO.

Think this one through with me: What if they see something on mammogram? (No palpable masses in the right breast, either.) What are they going to do? The PET scan is already negative, arguing against cancer. But even so...even if she has another tumor, WHAT ARE YOU GOING TO DO ABOUT IT? Surgery won't cure her, and she's ALREADY ON CHEMO (in case I forgot to mention that somewhere above.) (And no, it's not going to change the chemo regimen.)

The oncologist agreed with me that this patient is not an appropriate candidate for screening mammography of the remaining breast. But how are you going to argue with a surgeon? We agreed the odds of actually finding something were remote enough to take our chances, so it's only money, time and unnecessary radiation we're wasting. As he put it, "The surgical mind is a wonderful thing." Unless what you need is a doctor.

(Sorry -- sort of -- about the dig. It fit the situation. And remember, some of my best fiends are surgeons.)

(No, it's not a typo.)

Tuesday, February 19, 2008

Awesome Satire

I'm starting to become concerned about the value of those exorbitant tuition bills I've been paying for the Nestling. Only two semesters in and he's playing with three different musical ensembles and Ultimate Frisbee. Despite the fact that he assures me he's taking some classes in his spare time, he keeps finding amazing web sites like this: The re-Discovery Institute.

Here's the beginning of their Mission Statement:
The reDiscovery Institute is non-profit, public-policy think-tank located in Tacoma, Washington, with branches in Atlanta, Georgia and Fort Worth, Texas. The reDiscovery Institute fosters integration of science education with traditional Judeo-Christian principles of free market, limited government, property, faith, and corporal punishment.
And it goes on:
Our primary focus is to extend and promote Design Theories, which have been so successful in Biology, to the fields of Chemistry, Astronomy, Geology, Atmospheric Science and Meteorology, Oceanography, Material Science, Acoustics, Condensed Matter Physics, Fluid Dynamics, Nuclear Physics, and Anthropology.
And just so there's no doubt:
The reDiscovery Institute promotes archaic religious dogma elegantly dressed in html code and modern scientific terminology, to school boards, museums, theaters, juries, and editorial pages across America. We support and maintain the Intelligent Design Hall of Fame. The reDiscovery Institute urges adherence to Phillip Johnson's Ice Pick Gambit: "Until we gain total control, keep the old testament part of our agenda quiet because it frightens normal people." The reDiscovery Institute is backed by members, a board, and an ultra-conservative, ultra-rich, California savings and loan heir who believes that the American democracy should be replaced with biblical theocracy.
Cool!

By all means, go and peruse (with beverages set safely aside.) After all, Chemistry, Gravity, Astronomy and Geology -- hell, even Literature -- are "only a Theory." (In addition: "Stay tuned for next weeks revelation, "Intelligent Composing - did Bach have no byte of his own?")

Shifting Definitions: The Diabetes "Epidemic"

Bodies don't change.

Human physiology is essentially the same now as it was twenty years ago; a hundred years ago; a thousand years ago. What has changed, of course, is our environment (in terms of sanitation, diet, activities, etc.) and our understanding of that physiology, which includes our ability to affect it through our technology, drugs and so on. Of course there are new microbes that have evolved in our environment (HIV, SARS, various other multiply resistant bacteria, etc.) but while they may tax our bodies' abilities to deal with them, those bodies don't really change.

Frequent mention has been made of the "epidemic" of diabetes, usually attributed to an increased incidence of obesity, which in turn is attributed to a higher consumption of processed foods and a decrease in exercise. These things may well be true, but there's something else that has changed just over the years I've been in practice that undoubtedly accounts for a certain percentage of the increased "incidence" of diabetes: the increased understanding of disordered glucose metabolism (and the associated role of dyslipidemia) and accelerated atherosclerosis.

Back when I was in medical school, the cut-off for an abnormal fasting blood sugar was 140. Today it's 100. We measured cholesterol, but there wasn't much we could do about it, so we didn't pay much attention unless it got over 300. We didn't even have glycosylated hemoglobin measurements; in fact, fingerstick machines for home use were just being developed. Over the years I have seen a "normal" fasting blood sugar (roughly defined by the "normal ranges" on the lab reports) drop; first from 140 to 125, then to 115, then 110, and now 99.

In retrospect, how many patients in years gone by were reassured by us that they didn't have diabetes, when by today's criteria they would indeed be diagnosed as such? Because I don't really believe that human metabolism has changed radically in only the twenty-some years since I've been in the medical field, I believe that a great many people considered to be in perfect health by the definitions of the times were in fact what we would now consider at fairly high risk for cardiac events. Along with the greater prevalence of smoking in decades past, I think this accounts for the phenomenon of "perfectly healthy" 50-somethings dropping dead of "coronaries" back in the 1960's and even into the 1970's. Although the criteria at the time said that they weren't diabetic, I think many of them probably were, at least by our current understanding of the disease.

What does that mean for patients today? Just as the "epidemic" of autism is recognized to be in large part a function of expanded definition (and perhaps greater recognition) of the condition, I believe that a greater number of people are being recognized as having the syndrome of insulin resistance -- which can progress to diabetes in the setting of carbohydrate overload and chronic couchpotato-hood -- thus artificially inflating the numbers of "people in this country with diabetes."

I don't mean to minimize the roles of a Mickey D on every corner and an SUV in every garage. Certainly a higher percentage of the population carrying the insulin resistance gene go on to express it in terms of glucose intolerance and frank diabetes when they pig out on carbs and never walk farther than the refrigerator than in decades of yore. But I am convinced that the expanded definition of diabetes in recent years contributes a hefty chunk to this "epidemic."

Monday, February 18, 2008

I Already Said That

The very first novel I ever wrote sucked so badly it has been permanently relegated to a trunk under the bed. The main problem -- aside from more cliches than you could shake a stick at -- was that there wasn't really enough plot to sustain an entire novel. It was about the next flu pandemic, but I guess I just couldn't find enough of a story in it. Lots of people die; doctors are helpless; yeah? So?

As bad as it was overall, though, I did come up with some nifty lines, including this (talking about flu vaccine):
Each year a committee met at the Centers for Disease Control and Prevention in Atlanta and, using statistics so advanced they scarcely differed from guesswork, determined which three antigens were the most likely to be the major players in the next flu season. If they guessed wrong there was nothing they could do about it.
That was from my novel. Here's an excerpt from one of several news stories making the rounds:
...This winter is likely to be one of the few times that public health experts lose the bet they make each year when they devise the formula for the flu vaccine — eight months before the virus starts circulating in the fall. Experts must decide on the formulation then because of the time it takes to produce mass quantities of the vaccine.

"Most years, the prediction is very good," said Joseph Bresee, an influenza epidemiologist at the Centers for Disease Control and Prevention. "In 16 of the last 19 years, we have had a well-matched vaccine."

But probably not this time.

I called it.

Sunday, February 17, 2008

Finished

I know, I know; it's only two and a half months late, but this evening I finally finished the novel I began in November. The final word count came in at just about 69,000 words, 50,000 of which were done in the first 25 days.

Why did it take so long? Who knows? The "magic" of NaNoWriMo, the energy that puts writing on the front burner and makes it a priority for 30 days certainly played a huge role. Once I had that Winner's Certificate the pressure was off. It was easier to make excuses not to write. Interestingly, I knew exactly how I was going to finish the story and what was going to happen; though of course when I actually sat down to it, it still went off on its own twists and turns. But the other big change is that once the word count didn't matter anymore -- once quality reasserted its ugly head as taking precedence over quantity -- it was harder to just hammer it out. That old evil "inner editor" came back with a vengeance. Why use that word? You can find a better way to say that. That just sounds stupid. Somehow during November, it was easier to banish him.

Even so, I finally finished it. Now I can get back to the really exciting novel I gave myself permission to put aside for the duration. In addition to being on the home stretch for that one too, it also gives me a chance to put this one aside for a while, so that when I go back to it in another month (cough*or three or four or six*cough) I can see it through fresh eyes for the ever-important editing, re-writing and polishing required before it goes anywhere else.

Nevertheless, I finally got to type the sweetest words any novelist every wrote:

THE END

Wednesday, February 13, 2008

Just Because Everyone Else is Doing it?

Thanks to Dr. Wes for his comment regarding the new kickback racket known as Carol.com. Let me see if I've got this straight, though:
Dude! Kickbacks are currently rampant in the finest great medical centers in the country. One only needs to look at how many have arrangements with medical device companies who give kickbacks for volume concessions (yet charge full price to patients) or how many use only the devices invented by their program directors?

And advertising? Should we ignore the transgressions of TV stations that fail to mention that stories about "breakthough" treatments at our finest medical centers were paid for, of course, by those medical centers?

To think that there is not a subterrainian undercurrent of backroom deals far more pernicious than this web-based "kickback" advertising scheme [Carol.com] is naive.
So just because other people are doing it -- far more egregiously, perhaps -- it means this is ok? Last time I looked, wrong was wrong (it being considered wrong to "kick back" a part of one's fee for a referral, as in paying for patients) regardless of whether or not "everyone else is doing it." I wouldn't accept that as a justification for underage drinking from my kids. Why is this any different?

All they have to do is change how they finance the site; charge physicians and providers a flat fee instead of per appointment, and all my objections disappear like strep throat on amoxicillin.

Born to be Sort of Wild

Caution: beverage alert. Swallow before clicking.

Tuesday, February 12, 2008

Nothing New Under the Sun

Several blogs (cough* Dr. Wes*cough) are all atwitter about Carol.com, supposedly a new way of accessing and comparing information about medical care costs:
(CNN) A new Twin Cities company called Carol is trying ... a Web site that gives consumers a "care marketplace" to search for medical services, compare quality and price and make appointments.

Carol joins an effort to transform the U.S. health care system by putting consumers in charge and letting the market do its work.

"We want to let consumers define value," said Tony Miller, Carol's founder and chief executive officer. "We don't have care competition in the marketplace today."

The free site, which went live in January, generates revenue from health care providers who become "tenants" on the site. When a consumer sets up an appointment with a clinic or doctor on Carol.com, the provider pays the site a fee. (emphasis mine)
Never mind about the hoopla of price transparency, consumer choice and all that other impressive verbiage. This is nothing but an internet version of physician referral services that have been around for over a generation. (I remember my mother's skeptical take about a service that would even "make the appointment for you.") The kicker (or should I say "kickback") is that providers pay by the appointment.

Think about advertising for a moment. The correct way to compare pricing is not the absolute cost of one ad versus another, but how many potential patients it will attract. Say a Yellow Pages ad yields 50 patients a year. Suppose there's a neighborhood newspaper ad that costs one tenth as much yet produces 25 patients. It's not rocket science (or even advanced calculus) to figure out which is the better deal.

The best ad is the one that costs you the least amount of money per patient it generates. Once you start talking about an arrangement where you pay directly for the patients who respond instead of for the ad itself, that is no longer advertising: it's a kickback scheme.

What's the difference between Carol.com and my friend Carol, who comes to me and says, "If I tell all my friends about you, will you pay me $10 for each one who comes to you as a new patient?" Nothing at all.

The utility of networks like Carol.com is completely dependent on the number and quality of the medical providers it can sucker into its scheme sign up as "tenants." Any provider with even a modicum of business savvy should run, not walk, as far away as they can from Carol.com (as currently structured) and all of her friends. Move along; there's nothing new here.

Monday, February 11, 2008

Seven of Nine; Not Bad

Thanks to an Israeli med student who sent me this link to "Nine Secrets Health Insurers Don’t Want You to Know." No offense to Jeri Ryan, but aside from two whoppers, much of the advice seems sound to me.

Here are the nine points:
  1. Don’t pay if you don’t have a say.
  2. You may be eligible for more coverage.
  3. To get tested, talk up your symptoms.
  4. Stall first, answer questions later.
  5. Letters are your best bet.
  6. Doctors can be good weapons.
  7. A little research can go a long way.
  8. There are ways to get drugs cheaper.
  9. An advocate can help you win.
I don't much care for the phrasing of #6; I think it would be more accurate to call us "advocates," but I suppose they want to save that word for #9. #8 is based on the somewhat insulting assumption that doctors are powerless against pharma assimilation; (resistance isn't futile at all.) But the downright insulting ones are #3 and #7.

Here's what they mean by "talk up your symptoms" in #3:
Your insurer doesn’t want to pay for a colonoscopy if it’s not necessary. But if your best friend is diagnosed with colon cancer and you want the $675 test to put your mind at ease, here’s how to get one covered: Mention to your doctor that you’ve had some blood in your stool and a lot of gas lately—or simply that your bowel habits have changed. Your plan has to pay for the test if you have gastro complaints, health experts say. (Only 21 states require insurers to cover colonoscopies for general screening.)
In other words, lie to the doctor. Very bad idea.

It is MY JOB to put your mind at ease. Never mind about paying for an unnecessary procedure; trust me: you DON'T want to have a colonoscopy unless you really need it. Too many people seem to feel it is their responsibility to diagnose themselves, decide what treatment they need and then simply convince the doctor to provide it. Not so fast. An intelligent patient with the internet at his or her disposal can sometimes do a half-decent job performing those tasks, but certainly not always! (Please note my willingness to admit that not every patient and not every problem require my full expertise and experience to bear on them.) Still, I'm far more than a rubber stamp. Accurate diagnosis -- and therefore effective treatment -- depends first and foremost on patient history. Never "talk up your symptoms" trying to tell a doctor what you think he ought to hear. Never. Please. Not only does it seriously undermine your treatment now, but by destroying your doctor's trust in your accuracy as a historian, he will never be quite sure of you. Believe me; you don't want that. You wouldn't want your doctor lying to you; why should we tolerate it from you?

#7, "A little research can go a long way," is along the same lines:
If you want a special CT scan or MRI, your doc probably won’t authorize it unless it’s an absolute must. Persuade her with expert info from the American College of Radiology’s Appropriateness Criteria, says Anne Roberts, executive vice chair of the department of radiology at the University of California, San Diego. Used primarily by doctors but open to the public, it’s an up-to-date list of the types of imaging that are right for various conditions. (Ed: The link in the article doesn't work, but this one does.) Arming yourself with the info doesn’t guarantee coverage, but it’s a proactive step in the right direction.
News flash: you cannot have ANY diagnostic test just because you "want" it. Ever. Damn straight I won't "authorize" it (actually, I "order" tests; insurance companies "authorize" payment for them) unless you really need it. Trust me: you don't want the excess radiation; the hours stuck immobile in a tiny tube, whatever the procedure is if it's not medically necessary. Once again, it is MY JOB to figure out what is wrong with you (or what may be wrong) -- which requires accurate information from YOU -- and what to do about it, including ordering any tests. It is also MY JOB to "put your mind at ease" if the likelihood of some condition you're worrying about is so low it doesn't warrant an expensive test.

MY JOB. The fact that other docs may do it badly does not change MY JOB one iota.

But the rest of the article seems to have some good points.

Saturday, February 09, 2008

What's Wrong with This Picture?

We went out to the office this morning to install a new desktop computer. Afterwards, Darling Spouse suggested we check out the new outlet mall that opened a few miles up the road several months ago. The buzz was that it was a very elegant, upscale collection of high end stores, but with bargains to be had only for the well-informed. That is, if you didn't already know what particular brands cost, you wouldn't recognize full price when you saw it; as we did several times. But we also found some legitimate bargains, so it was a very worthwhile trip.

The place was indeed gorgeous. Clean; elegant; sophisticated. Really nice...

Except for this view on the way back out to the parking lot:

'Nuff said.

Tuesday, February 05, 2008

Clinical Case: Leg Pain (Part 2)

Part 1 is here.

(As before, I wrote this at the same time as the presentation, so none of the comments are taken into account.)

The neurologist ordered an MRA (magnetic resonance angiogram) of the aorta and iliac arteries which showed:
...Complete occlusion of the right common iliac artery. Distal disease involving the trifurcations bilaterally in the lower leg, with no discernible flow within either the left dorsalis pedis or posterior tibial.
The translation is that I was absolutely correct in my original diagnosis: she had severely compromised blood flow to her right leg. She has been seen by a vascular surgeon (of great interest, it appears to be the same individual who read her original non-invasive study) and is scheduled for surgery.

A note to those who may feel duped by the fact that a neurologist ordered a "non-neurological" test: Yes, Virginia, there is such a thing as a smart neurologist. Specialists are capable of making diagnoses outside their areas of expertise (though it doesn't happen as much as they like to think it does); that's what happened here. Out in the real world (as opposed to the artificial realm of "case presentations") doctors aren't limited to certain types of testing based on their specialties, and on occasion, they save my ass by doing so.

My mistake was relying too heavily on the negative results of the first test, the doppler flow study.

The medical literature routinely discusses the statistical concepts of sensitivity and specificity, false negatives and false positives. All of these characteristics are highly dependent on the "pre-test probability" that the condition is present. That "probability" is essentially an estimate based on the history and physical; ie, the clinical impression. In this case, my clinical impression was extremely strong. She was a setup for vascular disease: a smoker with exertional pain relieved by rest. Was it incumbent upon me, in retrospect, to pursue a more definitive study before considering the diagnosis ruled out?

The ideal doctor would be completely familiar with each one of these characteristics for every single test ordered. I admit that as a busy clinician, I function more with a general sense of how reliable the test is. For example, I know that the specificity of a rapid strep test is better than its sensitivity. If it is positive, I can believe it; if negative, I send a regular throat culture to confirm it. But if pressed, I'm not sure I could quote the actual percentages for either of those figures.

Cursory web searches reveal sensitivity and specificity figures for pulse volume recordings to be in the mid- to high-90% range for detecting severe vascular disease. I did find an article about the limitations of measurements at rest. Although it recommended repeating the test with exercise to enhance specificity, it was still felt to be more an issue of identifying less severe disease.

However you spin it, it turned out I was looking at a false negative test. The patient told me that the vascular surgeon explained to her that it was likely due to the development of extensive collaterals. Because the blockages had developed slowly over a long time period, the surrounding arteries were able to dilate and carry more blood than usual; sort of like widening the surrounding network of neighborhood streets when there is long-term construction on the main highway.

The teaching point here is what to do when a test shows results that differ from a strong clinical impression.

I think the universal first reaction is to doubt oneself. This is probably more common in training, while clinical judgment is just beginning to develop. It continues well after that, though; no matter how strongly we may think we know what's going on with a given patient, we continue to be surprised on a regular basis. That's why they call it "practicing" medicine. The question here is when do you stick to your guns, and at what point do you admit you were wrong and go looking elsewhere?

This is a case illustrating just how hard it can be to strike that balance.

Afterword: Apparently my error wasn't all that obvious or uncommon. Only MSG and Artemis explicitly entertained the notion that the initial diagnosis was correct. I suspect that -- despite all the warnings I tried to give -- this was approached as a "clinical puzzle" type of case; ie, claudication was considered "ruled out" by the first test. Then again, it is a pretty darn good test; it doesn't often miss severe vascular disease. But this was real life, where these things happen on occasion.

In retrospect, or "the next time I'm in this situation," what would I do differently? That's an extraordinarily difficult question; I'm not at all sure I'd do anything differently. Chances are I'll order a couple more MRAs or CTAs that will probably be negative. Perhaps order "Stress PVRs" to enhance the test's sensitivity. I really don't know. Any thoughts?

Friday, February 01, 2008

Clinical Case: Leg Pain (Part 1)

Here is another in my occasional series (ok, it's only the second) designed to illustrate specific teaching points in Primary Care. As before, this is most definitely NOT the typical case presentation of some bizarre diagnosis intended to show off how smart I am. In fact, my intent is to highlight an error in my thought process with the hope that others might learn and avoid the same pitfall in their own clinical practices. (Unless I was just really stupid and no one else would ever make the same kind of mistake I did.) I have received the patient's full and explicit permission to post this case.

A 60-year-old white female smoker came to my office complaining of right leg pain for five years. it was described as a tightness in the front of the thigh that came on after walking five blocks or less. When she stopped to rest, the pain abated promptly within one minute. Over time she had noticed it gradually increasing in severity. There was no complaint of any pain or discomfort in the left thigh, either lower leg or foot. She was taking Lipitor for an elevated LDL (224 in 1997; on statins since then.) She was on no other medications and had no other medical problems.

On examination, her blood pressure and BMI were within normal limits. The right leg was unremarkable. There was no swelling, tenderness, deformity or asymmetry of color or temperature. I thought her right pedal pulses were somewhat diminished compared to those in the left foot. The rest of her general physical examination was completely normal.

My diagnosis was claudication; pain caused by a blockage in the flow of blood to the right leg that only produced pain when extra blood flow was needed -- as with walking. As soon as she stopped and the muscle's need for extra blood flow decreased, the pain went away. Although the classic location for intermittent claudication is the calf, I felt the patient's description and timing of the pain -- along with her status as a smoker -- made it the most likely diagnosis.

The simplest, cheapest and least invasive test to document problems with blood flow to the legs is pulse volume recordings performed with doppler ultrasound. Here was the report:
Normal amplitude of the arterial curve, a normal contour of the curve and a normal systolic pressure with an [ankle brachial index] of 1.0 on the right and 0.98 on the left. This study is essentially normal, with no evidence of vascular occlusive disease involving either lower extremity.
With a report showing normal blood flow to both legs, I began thinking about other causes of leg pain with exercise that abates with rest. There's something called spinal stenosis, a narrowing of the spinal canal that exerts pressure on the spinal cord with an upright posture. Bending forward relieves the pressure and the pain. I called the patient and asked again about how her pain was relieved; does she typically bend over when she takes a rest from walking? She wasn't sure; she thought she usually sat down. It was easy to visualize someone hunching over while seated, so I thought, "Close enough." I got an MRI of her lumbar spine which showed focal right-sided paracentral disk protrusion at T12L1, but no stenosis or cord compression. The patient then requested an x-ray of her right hip, thinking the pain might be from arthritis. The films were normal.

Next, she saw an orthopedic surgeon who felt the MRI abnormalities had nothing to do with the pain. He felt it was neurogenic, started her on Lyrica and referred her to a neurologist.

The neurologist ordered another study which confirmed the correct diagnosis.

Post guesses in the comments. I expect that many, if not most, will be correct. I'll put the answer up in a few days. Remember, this is not an exercise in diagnostic obscurity. It is an example of an erroneous thought process interfering with a simple diagnosis.