Thursday, June 1, 2017

1920: The Lungmotor (a resuscitation device)

Lungmotor carrying case.
The Lungmotor was a simple device for assisting emergency crews during the 1910s and 1920s. It's intended use was for patients exposed to gases, electrocutions, or near drownings. 

As you can see by the pictures, it was basically a pump, like a bicycle pump, connected to the patient by tubing and a mask that fit over the patient's mouth and nose.

The Lungmotor with case and booklet.e
The company booklet, simply titled "The Lungmotor," basically recommended the device for near drownings.  The recommendation was for immediate removal of patient from the water. Manual methods should be used to remove mucus and water from the mouth and to provide breaths until the Lungmotor was on the scene.

 "The LUNGMOTER," the booklet says, "will remove the remaining water and mucus at the same time supplying a sufficient volume of air to resuscitate the victim." (1, page 8)

It's "a simple and easily understood device."  (1, page 14)

The LUNGMOTOR consists of two air pumps which operate in unison, yet are not connected in any way as far as the interchange of air is concerned. At no time does the devitalized air come in contact with the fresh air or oxygen.

The Lungmotor was supposedly "foolproof." Operating it was generally "easy," according to the booklet. To operate it all you had to do was: (1, pages 9, 11, 15)
  1. Set the pin to the approximate size of the victim: (1, pages 9, 15)
    • Newborn
    • 5 Years
    • 10 Years
    • 15 Years (or small adult)
    • Adult Average
    • Adult Large
  2. Place the mask on the patient  (1, page 11)
  3. Pump (1, page 11)
The booklet, thus, notes various advantages of their product over competitor products: (1, page 13)
  1. Easy to carry
  2. Easy to understand
  3. Easy to use
  4. It's worked by hand
  5. It can always give air (the kind you use every day)
  6. Or you can add an oxygen tank to supply supplemental oxygen
  7. Easy to increase and decrease volume (just move the pin)
  8. It's safe and sure
A picture of the Lungmotor.
showing predicted tidal volumes
based on size of patient.
A pin was inserted
at the appropriate age
to prevent barotrauma.
 (1, page 9)
It also offers other physiological advantages to the patient: 

1.  It delivers the exact volume of air necessary to maintain the circulation and respiration over a long period of time. This is, as noted above, determined by setting the pin to the estimated size of the patient. (1, page 14)  Thus: 
The LUNGMOTOR does the very next thing to normal breathing because it supplies, mechanically, the tidal volume of air each respiration (the amount you breathe at rest), enough air, but not so much as to possibly injure the Lung tissues and the circulation, thus not leaving the patient liable to pneumonia following. (1, page 
2.  It always gives air to lungs, not stomach:  "This is accomplished by means of a tube which is introduced into the gullet and a bulb on the end blown up bv means of a hand bulb, and a soft rubber tube clamped by a clip. This tube is easily inserted because when pushed backward and down, guided by the under finger, it can go no place else but into the gullet." (1, page 14)

3.  It prevents you from providing too much pressure to patient "thus making it impossible to rupture the delicate tissue of the lungs."  This is due to the operator setting the pin to deliver the appropriate volume of air according to the size of the victim.  (1, page 14)

4.  It offers suction.  This causes expiration, and also allows for the device to "remove instantly and positively the large quantities of slime, mucus and blood that accumulate in the air passages, thus making it possible for the air to be delivered to the lungs which is not always possible (with manual resuscitation)." (1, page 14)

The fact that it offers suction is noted as one of the major advantages of the product, as noted by this passage: (1, page 13)
The fact that it reestablishes the suction action of the thorax on the heart and great vessels in addition to supplying the lungs with the correct amount of fresh air, is the explanation of the wonderful results obtained by the use of the LUNGMOTOR. The unsatisfactory results of past experiments in mechanical resuscitation were due to a failure to attach to this phase of the subject the importance which it deserved. (1, page 13, 18)
5.  It can provide oyxgen:  When not connected to an oxygen tank it supplied room air to the patient, which contains about 21% oxygen.  An oxygen cylinder could also be attached to the device in order to supply the patient with supplemental oxygen. (1, page 9)

6.  No risk of damaging a rib or liver, as often occurs with manual methods of resuscitation.  This risk is "entirely eliminated" with the Lungmotor, at least according to the booklet.

By this photo you can see the simplicity of the device.
It basically consisted of the cylinders, the handle,
and the mask.  (1, page 16)
So, how does it all work?  Again, according to the booklet:
The LUNGMOTOR consists of two cylinders which operate in unison, yet not connected in any way as far as the interchange of air is concerned. At no time does the divitalized air come in contact with the pure air and oxygen.
An upward movement of the handle charges the inspiration cylinder with pure air or any mixture of air and oxygen desired, according to the setting of the mixing valve (b). At the same time the expiration cylinder is filled with the expired air gently expelled from the lungs by the patient due to the natural contractual power of the chest walls and the elasticity of the lungs.
Conversely the following downward movement of the pump handle and piston places the air or the mixture of air and oxygen into the lungs and discharges the impure air through the outlet (o) into the atmosphere. In the case of drowning or new-born babies the water, blood, mucus, etc., is taken care of through the device and discharged at this opening (o).
Thus you see that at every complete stroke of the handle up and down you have a complete respiration, an inspiration, and an expiration—normal breathing mechanically done. (1, pages 14-15)
An early concern of manufacturers of mechanical resuscitators
was to make sure that expired air was kept separate from inspired air.
This was necessary to prevent patients from re-breathing
exhaled air, or exhaled carbon dioxide (CO2).  For this reason
the Lungmotor was designed with 2 separate cylinders,
one for inspiration (left) and one for exhalation.   (1, page 15)
The average breath given to an adult is estimated to be about 700 cc of air, which is "sufficient to maintain life, being, in fact, about 150 cc more than the patient normally breathes; this 150 cc. of air being used to counterbalance the natural resiliency of the lung in order to maintain the normal pressures in the thoracic cavity, and aid mechanically the restoration of the automatic mechanism of circulation by removing the obstruction in the lung, caused by the arteries crooking upon themselves when unconsciousness occurs. " (1, page 6-7)

The makers of the Lungmotor recommended the product be available for use by Rescue Teams, and that when someone was noted to be in a state of "suspended animation" that the rescue team be called for right away. However, in the meantime: "We believe manual methods if there are no other means of resuscitation available. But the use and the results from manual methods are limited." (1, page 6, 17)

Manual breaths, therefore, should be given, preferably by using Prone Method (Shaeffer Method), until the Lungmotor arrives on the scene.  

Criticism of the device was generally similar to any other mechanical resuscitator of the day, that it forced too much air too fast into the lungs, sucked too much air out of the lungs, and could only be used for a short period of time due to worker fatigue.

Note:  An advertisement for the Lungmotor can be found in "Modern Hospital," January, 1915, volume 36, number 1,  page 39

References: 
  1. "Drowning: Historical-Statistical Methods of Resuscitation," no author nor editor listed, Published by Lungmotor Company, Boston, Massachusetts, 1920

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