“Half of what you’ll learn in medical school will be shown to be either dead wrong or out of date within five years of your graduation; the trouble is that nobody can tell you which half—so the most important thing to learn is how to learn on your own”
David Sackett, M.D.
“Nullius in verba” – Motto of the 1660 Royal Society
I had an excellent clinical experience while rotating through the internal medicine service at Cook County Hospital in 1977. I distinctly recall that when making rounds with the chief medical resident, he brought along with him a chart cart with multiple medical textbooks for us to confirm what was being taught.
While reading a recent paper on physical examination findings in endocrine disorders, I came across the famous ‘Queen Anne sign’, also known as the sign of Hertoghe, which describes loss of the lateral third of the eyebrows in some patients with hypothyroidism. I had read, years ago, that this sign was not factual and stopped teaching it to medical students and residents. This got me to thinking about all the things we have been taught in medicine which are not true but have ensconced themselves in the medical literature and have come to be believed as true. This is analogous to the aphorism, “Repeat a lie often enough and it becomes the truth.”
By way of example, I describe a small smattering of medical “truths” which, in fact, are not as a means of highlighting the need to continually reassess what one knows.
1. Evaluation and treatment of acute appendicitis.
As a surgical intern in 1979, acute appendicitis was believed to be a one-time event which required surgery for definitive diagnosis. In 15% of cases, the excised appendix showed no evidence of inflammation or infection. This moderately high false positive rate was felt to be necessary so as not to allow any cases to go untreated (i.e., surgically).
The most recent data on treatment of acute appendicitis is that, barring any complications such as perforation or systemic infection, treatment with antibiotics in low-risk patients is recommended. This represents a change in guidelines based on new data. However, one form of appendicitis I have never heard discussed is of chronic (or relapsing) appendicitis. The literature on this entity is decades old but primarily in European journals. Recurring episodes of appendicitis have been documented in patients with recurring episodes of abdominal pain. I personally have two family members who were found to have chronic appendicitis discovered after they underwent appendectomy while undergoing laparotomy for unrelated reasons. One had recurring episodes of abdominal pain for years which had evaded definitive diagnosis.
2. Roth spots.
Ask any medical student or resident what eye findings are found in infectious endocarditis and they will immediately respond, “Roth spots”. I, myself, taught that for years until I discovered that Roth had never described white centered hemorrhages (the description of what constitutes a Roth spot) in patients with infectious endocarditis. In 1872, he did describe retinal red spots (previously described by Bowman) as well as white spots but not white centered hemorrhages. That description was made by Litten in 1878, six years later. The eponym “Roth spot” is, nevertheless, enshrined in the medical literature. Joseph Sapira, in his exquisite physical diagnosis book, goes into the history of the description of these retinal lesions.
3. Tactile fremitus.
Most of us were taught that to check for tactile fremitus, one should have the patient say “99” while palpating the chest with the palm of the hand. It turns out that this is not ideal but came about because of a direct translation of a German medical paper which advocated having the patient say “neun und neunzig” (i.e., ninety-nine in German) when checking tactile fremitus. The diphthong “eu” creates the sound “oy” which proves to be a more effective way of detecting changes in fremitus than the sound “ine” (in most cases). I, therefore, had patients say “toy boy” while checking fremitus until a resident pointed out that that phrase sounded inappropriate. I switched to having patients say, “oy oy”, instead.
4. Thyroid hormone replacement therapy.
There is a near unanimous consent in the medical field that hypothyroid patients that require thyroid hormone replacement, levothyroxine (i.e., T4) is all that is needed to restore a euthyroid state. Recommending a mixture of T4 and T3 is frowned upon. That was my stance for many years until I read an article by Kent Holtorf, MD who made a very convincing case that that may not always be ideal. Nearly every physician who has taken care of hypothyroid patients has had several who continued to complain of not feeling completely well despite having normal TSH and free T4 levels. This has frequently been explained away by stating that, since hypothyroid symptoms are nonspecific, the patient’s sense of not feeling perfectly well was not related to their thyroid status but to other nebulous causes. The article by Kent Holtorf goes into great detail in explaining the physiology of thyroid hormone action, the varying effects of the three deiodinase enzymes and how there might be a disconnect between pituitary deiodinase activity and cellular thyroid function and the effects of various disorders and states on thyroid hormone activity at the cellular level which are not reflected by the pituitary TSH level. A discussion with an endocrinologist colleague acknowledged that the final say on proper thyroid hormone replacement was still a work in progress.
5. Determining right atrial pressure via jugular venous examination.
This one is my mea culpe. Although I have always been extremely impressed by Dr. Sapira’s textbook on physical examination, I never did review the section on examination of the jugular venous system as I arrogantly felt that I had reasonably mastered the skill. Today, however, I did read that section to my great embarrassment. The method recommended by Dr. Sapira is nothing like the traditional method which has been etched into numerous high-quality textbooks. Dr. Sapira makes a very good case against the traditional method and its landmarks (i.e., the sternal angle of Louis) which he cynically dubs “the cardiologist’s constant”. I will let the reader pursue this topic at his or her leisure.
Maintaining one’s knowledge base and skills in medicine is difficult. Expanding on that knowledge base is very difficult and time-consuming. In addition, confirming the validity of what one already “knows” is nearly impossible. Nevertheless, an effort should be made as often as reasonably possible to confirm that what one knows is, in fact, factual.
Thx