Chymorrhea

“Perfect as the wing of a bird may be, it will never enable the bird to fly if unsupported by the air. Facts are the air of science. Without them a man of science can never rise.”

Although medicine has finally embrassed an evidence-based outlook on physiology and treatments, it has yet to shake off the last remnants of traditionnalist teachings based on mere “expert opinion”. Indeed, a recent study showed that long-refuted theories remain cited as if still true. [1] The following list of medical myths is thus doomed to grow with each passing day. I invite readers to submit myths not included here, and to correct any errors than may have unwittingly occured.

FALSE DOGMA 1 : Atelectasis is the leading cause of immediate post-op fever.

The idea that atelectasis (collapse of alveoli) could cause fever is outright ridiculous as there is, at seems, no physiological reason for the two phenomena to be related in any way whatsoever. Indeed, the factual lack of even mere statistical association was demonstrated more than 10 years ago. [2]  Alas, the paper never recieved much attention and has hardly ever been cited. The myth still endures …

FALSE DOGMA 2 : Homans’s sign is useful in the diagnosis of deep vein thrombosis.

There are at the very least three internists in the world to believe that calf pain on forced dorsiflexion of the foot (also known as Homans’s sign) is a strong argument in favor of deep vein thromobis in a patient presenting with calf edema. They are wrong and I only hope their students will not pass the old lies on to the young generation of physicians.The truth is Homans’s sign, whether positive or negative, does not change the probability of deep vein thrombosis among the other differential diagnoses. [3] The rumor has that Homans himself was aware of the shortcoming of the sign and resented the eponym.[4]

FALSE DOGMA 3: Extremities are to be anesthesized with plain lidocaine alone; one should never add epinephrine (adrenaline), especially in digital blocks, because of the unacceptable risk of gangrene.

Fundamental research disproves the fear than epinephrine-induced vasoconstriction may be more than transitory : blood flow was completely restored under 90 minutes in all studied subjects. [5] A careful review of the litterature did not find any reports of finger necrosis associated with the injection of commercial lidocaine-epinephrine mixture. [6]

What is clearly evidence-based, however, is than using lidocaine-epinephrine mixtures allows for a better view of the operating field, unobstructed by excessive bleeding, and prolongs anesthesia. [7]

1. Tatsioni A, Bonitsis NG, Ioannidis JP. Persistence of contradicted claims in the literature. JAMA. 2007;298(21):2517-26

2. Engoren M. Lack of Association Between Atelectasis and Fever. Chest. 1995;107:81-84

3. Kahn SRm, Joseph L, Abenhaim L, Leclerc JR. Clinical prediction of deep vein thrombosis in patients with leg symptoms. Thromb Haemost. 1999;81:353-357

4. Barker WF. To the memory of John Homans, M.D., 1877-1954. Maj Probl Clin Surg. 1966;4:v-vii.

5. Altinyazar HC, Ozdemir H, Koca R., et al. Epinephrine in digital block: color Doppler flow imaging. Dermatol Surg. 2004 ;30(4 Pt 1):508-11

6. Krunic AL, Wang LC, Soltani K, et al.  Digital anesthesia with epinephrine: an old myth revisited. J Am Acad Dermatol. 2004;51(5):755-9

7. Hafner HM, Röcken M, Breuninger H. Epinephrine-supplemented local anesthetics for ear and nose surgery: clinical use without complications in more than 10,000 surgical procedures. J Dtsch Dermatol Ges. 2005;3(3):195-9.