slideshow widget

Thursday, June 19, 2014

Hypoxic drive myth, another exmaple of a dogmatic medical profession

A dogmatic doctor.
Despite convincing evidence that sheds doubt on the hypoxic drive theory, medical professors continue to teach it as fact, and physicians continue to worship it as the Holy Grail.  This is not, however, the first time the profession has been dogmatic, and it probably won't be the last, either.

There is actually convincing evidence suggests that a "reduction in hypoxic ventilatory drive may not be the sole mechanism causing increasing hypercapnia in (COPD patients)." (3)

Now, before I go on, it must be noted here I have much admiration and respect for the medical community.  The history, facts, and opinions shared in this post should in no way diminish my respect for the profession.

Yet while I respect and admire them, I also understand the medical profession is notorious for being proud, dogmatic, and slow to accept new ideas.

Take 1543, for example.  Back then it was normal for an assistant to dissect a human corpse while a professor read from one of Galen's books.  Andreas Vesalius observed that what was being read was different from what he was seeing.

For instance, Vesalius observed that Galen's writings described the sternum as having eight parts, yet the human sternum being dissected in front of him had only three parts.

Later, when Vesalius was dissecting an ape, he learned it was the ape that had an eight part sternum.  He learned that Galen had based his writings on dissections of apes.  This makes sense, considering in Galen's day it was illegal to dissect a human corpse.

In the 16th century, artists like Michelangelo knew more about the human anatomy than physicians, so Vesalius hired Johannes Oporinus to draw accurate pictures of human anatomy , and Vesalius published the first ever book on human anatomy De humani corpus in 1543.

Yet Galen could nary be wrong, and Vesalius was laughed out of town by a dogmatic profession.

In the end, however, Vesalius was proven right, and his wisdom gave birth to the science of human anatomy.

In 1816, Rene Laennec invented the stethoscope.  Instead of the medical community embracing and adapting the tool that would greatly improve their diagnostic skills, they mocked Laennec.  They were too proud to carry such a frivolous tool.

In the end, however, this tool became a required tool for all physicians.

In 1847, Ignaz Semmelweis observed that moms whose babies were delivered by medical students were far more likely to die of child bed fever compared to moms whose babies were delivered by midwives. He proved that this was because the medical students did not wash between patients, while the midwives did. He made it mandatory for the students to wash their hands as the midwives did, and this resulted in mom's dying from childbirth plummeting.

Back then, you see, medical students were proud to show how hard they worked by blood on their hands and aprons. So, since Semmelweis could offer no scientific proof why hand washing resulted in fewer deaths, he was mocked and forced to leave town.  (6)

In the end, however, semmelweis was proven right when, in 1864, Louis Pasteur proved the germ theory of disease.

So it is quite evident that physicians being dogmatic about the hypoxic drive theory, despite convincing proof that it's nothing more than a myth, are hesitant to give up on it.

  1. Schmidt, Greggory A., Jesse B. Hall M.D "Oxygen Therapy and Hypoxic Drive to Breath:  Is There Danger in the patient with COPD?" Critical Care Digest, 1989, 8, pages 52-53
  2. Wilkins, Robert L, James K. Stoller, ed. "Egan's Fundamentals of Respiratory Care," 2009, pages 309-310
  3. Caruana-Montaldo, Brendan, et al, "The Control of Breathing in Clinical Practice," Chest, 2000, 117, pages 205-225 (This article also provides a good review of the central and peripheral chemoreceptors and the drive to breathe)
  4. Wojciechowski, William V., "Entry Level Exam Review for Respiratory Care:  Guidelines for success," 3rd edition, 2011, U.S., page 487?
  5. Cooper, Nicola, Kirsty Forrest, Paul Cramp, "Essential guide to acute care," 2nd edition, 2006, Massachusettes, page 24
  6. Tines, John Hudson, "Exploring the History of Medicine," 1999, great read for obtaining a pithy history of medicine
RT Cave Facebook Page
RT Cave on Twitter
Print Friendly and PDF

No comments: