Friday, April 27, 2012

1810: The first PEP therapy, Incentive Spirometer x

Figure 1 -- Ramadge Iinhaling Pipe (1, page 93)
If you're a respiratory therapist in the 19th century -- if the profession existed as it does today -- chances were you'd be familiar with the Ramadge Inhaling Pipe.  It was the first device that acted both as an inhaler, PEP (Positive Expiratory Pressure) therapy, and Incentive Spirometer

The device was a pipe with hot tar stuffed into it that you inhaled for therapeutic means.  The tar, and the narrow diameter of the tube, provided resistance to inspiration and expiration, and this was supposed to provide "gymnastics" or "exercise" for tuberculosis patients.  

Samuel Sheldon Fitch in his 1847 book, "Six lectures on the uses of the lungs" (1, pages 91- 93) explains that the most common respiratory ailment during the 19th century was consumption, or what we now refer to as tuberculosis.  He believed it could be prevented by doing things that prevent too much air from leaving the lungs and causing the small, frail rib cage as seen with consumption.

He believed one of the things that could prevent the disease was asthma.  Why?  Because asthma is a disease that causes excessive air to remain in the chest, and this results in a large, expanding full chest (barrel chest), or the exact opposite effect as tuberculosis. 

So he believed asthma prevented tuberculosis, and one means of generating the effect of an "expanded chest" is to breatht to a device he invented that ultimately became known as the Ramadge Inhaling Pipe.

Truly it really wasn't a PEP valve, because the concept hadn't been though up yet. And truly it wasn't a spirometer, because there was no means to measure inhalation or exhalation volumes or pressures, yet it provided a similar effect to both those devices.

Ramadge was a student of Rene Laennec, who was the inventor of the stethoscope. Together they did extensive studies on tubverculosis and how to prevent it, and Laennec wrote about them in his "On Mediate Auscultation."  From their research Ramadge believed that so long as you took care of your asthma you would prevent tubercolosis.  This was the basis for Ramadge inventing the Ramadge Inhaling Pipe.

In his book, Laennec described Ramadge's discovery (1, 2):
"(That) having the patient breathe through a small opening or pipe much smaller, say 20 times smaller than the opening of the windpipe.  To effect this, he made an instrument then called an inhaling tube.  It was four feet long with an opening through it's whole length, provided with a mouth piece to go between the lips, and the patient sucked in, or inhaled the air as long as he could, and then through the same tube, blew it out again.  By this process the chest would rapidly enlarge.  Dr. Ramadge also made an inhaling tube a little like a whistle, with a valve in it so constructed that the air would go into the mouth and lungs through a much smaller opening.  The effect of which is, to allow the lungs to fill rapidly and without exhaustion of strength, and on leaving the lungs it is all passed through an opening not much larger than a knitting needle by which the air was slowly forced our of the lungs, and by this pressure the lungs were greatly expanded, and the air every where opened the chest in the largest manner."
Laennec recommended these tubes be made of gold, silver or at least wood so that they last long, and the patient can take the tube wherever he goes and can use it often to keep his lungs expanded and prevent consumption.  (1,2)

Incentive spirometers have advanced quite a bit through the years, and they are now generally used to exercise and open alveoli by patients who are bedridden, postoperative, or are on sedatives and pain relievers.  PEP therapy is quite the same, although the devices are now much more advanced.

References:

  1. Fitch, Samuel Sheldon, "Six lectures on the uses of the lungs," 1847, New York, H. Carlisle, pages 91-93, 
  2. Laennec, Rene, "On Mediate Auscultation," 1827, London, T and G Underwood.  The above quotes are from Fitch's book, although they can also be found in this reference

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