1900-1950: The evolution of artificial respiration

1907: The Pulmotor

Medics using Pulmotor to save a life

In 1907 Heinrich Drager obtained a patent for the Pulmator, which is often given credit as the first artificial respiration device.

It was gas powered and allowed medical personel to hold a rubber mask over the face of a patient who requires artificial respiration.

Once powered on, the device would blow "fresh air or oxygen into the lungs." 

Heinrich observed that he created this first ventilator to provide breaths to patients who inhaled too much gas that caused them to stop breathing.  The device would be used until the patient was able to breathe on his own.  Yet ultimately it would be used for other patients, such near drownings, electrocutions, and kids afflicted with poliomyelitis.  (1) 

The device was connected to an oxygen tank and was then powered by oxygen pressure and alternated positive and negative pressure to provide breaths.  It was the first time cycled ventilator, in that it gave a breath for a designated amount of time, guaranteeing the patient would get an equal breath with each inspiration.  

The operator would also have to have knowledge of pressure controls and of pressurized oxygen.  He'd also have to have an assistant watch the oxygen tank to make sure it was full and change it when it was close to becoming empty.  Yet since there were no efficient regulators at this time, the operators would have to use a formula to determine how long a tank would work.  (2)

The Pulmotor

So you can see this was good equipment, yet it could only be used for so long on one particular patient.  For one thing, the medic would have to hold the mask over the patient's face and this in and of itself could be tiring.  For this reason operators would rotate this task, especially for patients in the hospital who required artificial respirations around the clock.

Another major problem noted with the device is it forced air into the patients lungs, and had no way of sensing if it was giving too much air or too little.  In other words, it did not compensate for airway obstruction, such as would occur in asthma and COPD patients. If the patient was awake this would cause uncomfortable, even painful breaths.

For this reason it would occasionally force too much air to enter the patients lungs, and this would sometimes cause a pneumothorax, or collapsed lung.  To prevent this from happening again switch was added to allow the operator to end a breath.  Also, the machine was improved over time so that it was pressure cycled, or inspiration would end once a certain pressure was obtained in lungs.  In this way Drager's Pulmotor was the first pressure cycled ventilator. This type of breath closely resembles normal breathing.  

In a 1929 report published in the Journal of the American Medical Association, "The Use of a New Apparatus for the Prolonged Administration of Artificial Respiration: A Fatal Case of Poliomyelitis," pediatrician Charles Drinker and Charles F. McKhann highlighted the fact that manual resuscitators forced too much air too fast into lungs, and can only be used for so long.  These gentlemen were obviously poining out these weaknesses in order to spotlight the Drinker Respirator.  (3)

Despite their many drawbacks, which included the risk of asphyxia by operators who took too long setting it up, this and other similar respirators were used in the U.S. and Europe until around the end of the 1940s.  (4)

Other than medical institutions, these devices were often made available in rescue vehicles to be used on any patient who might stop breathing. One such example was provided by the January 13, 1913, issue of the Pipeline and Gas Journal:

"The first( Consolidated Gas Company) now has four of these devices in use, and the first practical trial of its was made November 7, 1912, when a call for the crew with the apparatus came in from the Flower Hospital, to which institution a woman had been carried.  She was suffering from gas asphyxiation... The emergency crew... responded to the call.  The patient was seemingly not breathing and the pulse could not even be detected.  (The foreman) attempted to show the doctors how to operate the apparatus, but they were slow to comprehend the actual method, wherupon (the foreman) assumed the task himself.  In about 10 mintues the patient was restored to consciousness." (5)

1929: The Drinker Respirator

The first effective ventilator that gave breaths without an operator was the Drinker Respirator by Phillip Drinker in 1929.  The product was  introduced to the world in the above mentioned article by Drinker and McKhann.

This respirator is often referred to as the Drinker and Shaw respirator because Drinker worked with his brother Cecil and Louis Shaw to create and test the device.  It was first introduced to physicians at Harvard in 1928.

While we now refer to these as negatieve pressure ventilators, or noninvasive ventilation, or iron lungs, back then these machines were referred to as mechanical respirators or tank respirators.  Actually, the original name was the Drinker Tankrespirator, but the name iron lung is the name that ultimately stuck.  While it was used for many different types of patients, it is most remembered as being associated with poliomyelitis patients.

It was a metal tank that completely enclosed the patient's body except for the head.  Inside the tank was completely air tight.  The device caused negative pressure within the tank, and this drew in the chest wall and caused the patient to take in a breath.  Many reports indicate that the machinery was quite noisy. (6)

One of the neat things about the design is that it would provide breaths at a constant depth and rate, and it would also accommodate patients of all sizes, including kids.  A patient would lie on his back with his head sealed around rubber collars to provide a seal to prevent air from entering or escaping.   The bed would be slid into the metal tube, or tank.  To examine the patient, the bed was slid out of the tube.

The pumps, which were basically two vacuum cleaners with bellows, and manometer used to operate the device,  sat on a table next to the tank, and were operated by electricity and an oxygen tank.  The rate could be set by adjusting dials on the gearbox.  However, there were no means of actually measuring the tidal volume.

Once the patient was inside and the device was turned on, they go to work providing artificial breaths.  By the 1950s the pumps and bellows would set under the tank to make the unit more compact and with wheels so it was more easily moved from one location to another.(7)

The new respirator was nice because it allowed physicians an opportunity to keep patients alive long enough to medically treat them back to health.  It likewise became extremely important in treating kids with poliomyelitis who would otherwise have stopped breathing due to respiratory paralysis, failure and fatigue.

While the devices may have been uncomfortable:

"The response of these patients to the respirator was very gratifying," according to a 1931 article in the Western Journal of Medicine.  "Usually before their condition became alarming they were told that if they became too fatigued they could have the help of the respirator, and in several instances patients asked to be placed in the machines for a trial.  A few of the children were very apprehensive and had to be given opiates over a short period when first placed on the respirator.  None of these patients had any difficulty in adapting themselves to the rhythm of the machine."  (8)

Many children with poliomyelitis recovered after a week or two in the iron lung, and regained their ability to breathe and live a relatively normal life.  My grandpa had a good friend named Jack who would come to hunting camp each year.  He used a cane and had a limp, yet he functioned quite well.  Having a history of polio didn't affect his sense of humor at all.   

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The Technical Exposition:  Opportunity to try the Dinker Respirator:  Warren E. Collins Inc. will exhibit the Dinker Respirator, for prolonged administration of artificial respiration in cases of infantile and diptheretic paralysis, gas and drug poisoning, electric shock, alcoholic, coma, etc.  Doctors are invited to make a personal trial of the Respirator to see how it feels. New improvements on the Roth-Barach oxygen tent and the Benedict-Roth Metabolism Apparatus will also be of interest, and demonstrations will be gladly given without obligation.  See these in Booth 110, near the main entrance.  (9)

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Nurse with patient in Emerson Iron Lung

1931:  The Emerson Respirator

 His father worked as Commissioner of Health in New York during the polio epidemic of 1916, and perhaps as a result of this John Haven Emerson had a recollection of suffering from the illness as a child.  So he had a vested interest in inventing a mechanical respirator that was more efficient and more comfortable than the Drinker and Shaw Respirator.  He ultimately refined the Drinker and Shaw Respirator.

Like the Dinker and Shaw Respirator the patient would lie on a table that could be slid in and out of the tank.  The table was often referred to as a cookie tray.  The side of the tank, which was blue, had portal windows so nurses could have access to the patient whenever they needed.  Over the patient's head was a mirror so he could see behind him. The bellows were stored under the tank, which was lightweight, and wheels were added to make the devices mobile. (10)

The machine could also produce a large range of tidal volumes by adjusting the pump settings, and it was relatively quiet.  In the event of power failure there was a hand crank at the foot end of the device so the doctor or nurse (or later the inhalation therapist) could provide breaths manually. It was also simple to produce, which made it affordable.   It was said to be about half the cost of the Drinker Respirator.   Well,  Emerson's design still cost as much as a house, yet it was still somewhat reasonable, or about half the cost of other such respirators at the time. (see chart below) (11)

Emerson introduced his iron lung during a polio epidemic in 1931, and it soon became the most popular respirator in hospitals in Europe and the U.S.  Emerson's respirators continued to be the most used ventilators until  the 1950s and 60s when the Jonas Salk and Albert Sabin polio vaccine became available for kids around the world.  The vaccine was first introduced in 1954, and injected into millions of kids between 1956 and 1960 "with dramatic results." An oral vaccine was later introduced and administered to millions of kids between 1962 and 1964. (12)

While iron lungs gave medical professionals an opportunity to save lives, they were also viewed as a terrible way to spend the end of ones life.  They were ultimately replaced by intermittent positive pressure breathing (IPPB) machines that provided positive pressure breaths such as the Monaghan Ventalung Respirator and the in 1948 and the Bird Mark 7 Respirator in 1958.

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http://americanhistory.si.edu/ notes some very interesting facts about iron lungs:

1. The National Foundation of Infantile Paralysis began mass distribution of tank respirators in 1939
2. In the 1930s, an iron lung cost about $1,500  -- the average price of a home
3. 1n 1959 there were 1,200 people using tank respirators in the U.S., in 2004 there were 39

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References:

1. Bahns, Ernest, "It began with the Pulmotor:  100 years of Artificial Ventilation,"  
2. Bahns, ibid
3. "Iron Lung: 1929 Dinker Respirator," University of Virginia Historical Collections at the Claude Moore Health Sciences Library,"  http://historical.hsl.virginia.edu/ironlung/pg4.cfm, accessed February 26, 2012
4. "Draeger Pulmotor," The Wood Library Museum,   http://woodlibrarymuseum.org/museum/item/96/draeger-pulmotor, accessed February 26, 2012
5. "Items of interest from various localities," Pipeline and gas journal, Jan. 13, 1913, page 34
6. x Shaw, op cit or  "Iron Lung," ibid
7. x x Shaw, op cit or  "Iron Lung," ibid
8. Shaw, E.B.,  H. E. Thelander, and M. A. Limper, "Respiratory Failure in PolioMyelitus -- it's treatment and the Dinker Respirator," Western Journal of Medicine, 1931 July; 35(1), pages5–7
9. "The technical exposition," Journal of the American Medical Association,  1931, vol. 96, no. 19, page 1617, http://jama.ama-assn.org/content/96/19/1615.full.pdf
10. "The Iron Lung and Other Equipment,"  http://americanhistory.si.edu/,  http://americanhistory.si.edu/polio/howpolio/ironlung.htm, accessed February 27, 2012
11. Previtera, Joseph, "Negative Pressure Ventilation: Operating Procedure (Iron Lung)," Tufts Medical Center, Respirator Care Programs, http://160.109.101.132/respcare/npv.htm, and http://160.109.101.132/respcare/ironlung.htm, accessed February 27, 2012
12. "Emerson Infant Respirator," Case Western Reserve University, Ditrick Medical History Center,  http://www.neonatology.org/pdf/EmersonInfantRespirator.pdf, accessed February, 27, 2012