1920-1980: The evolution of oxygen delivery devices

By the mid 1920s many of the challenges of oxygen therapy had been tackled.  Oxygen could be easily produced, stored in tanks, and delivered to the patient.  There also existed the means of confirming oxygenation status of patients, and the effects of oxygen therapy.  So the stage was set for oxygen to be introduced to hospitals.

In 1922 John Haldane wrote about his research in "The Therapeutic Administration of Oxygen."
Soon thereafter oxygen tanks became more and more common at the patient bedside.  The tanks were stored in closets, and when needed were strapped by the patient bedside.

There were various devices available for providing oxygen, which included a metal nasal cannula, a nasal catheter, the oxygen chamber, the Haldane Apparatus, and the oxygen rebreather mask or mouthpiece and an oxygen tent.  For patients that were comatose, any device needed to provide therapeutic oxygenation could be used.  For awake and alert patients, the mask posed a claustrophobic feeling, and it was also hot.  The same was true with the oxygen tent.  So the physician would basically have to base what oxygen device he used on the patient.

One of my readers at my Respiratory Therapy Cave blog informed me that, the first practical oxygen tent was invented by Doctor Benjamin Eliasoph in 1921, at The Mount Sinai Hospital,New York, with rubberized fabric from the Goodyear Rubber Company, Aeronautical Division used for balloons such as the widely known Goodyear Blimp." 

This information is confirmed in a New York Times obituary for Dr. Benjamin Eliasoph, which notes: "Dr. Benjamin Eliasoph, a physician at Mount Sinai Hospital who was a pioneer in the design of the oxygen tent, died Sunday at the hospital. He was 70 years old."

The first mass producible oxygen tent was invented by Doctor Leonard Hill.  It consisted of a canopy with slots so the patient could see out that was placed over the bed and patient, and a machine was set at the bedside that blew oxygen into the tent and over the patient.

Dennis Glover, in his 2010 book "A History of Respiratory Therapy," said there was no means of cooling the atmosphere inside these tents, and being inside was almost unbearably hot and uncomfortable for many patients.

Glover said that the most common use for the oxygen tent was for patients presenting with cyanosis due to heart failure or pneumonia.  Some patients would beg to get out of the tents, Glover explained, yet once out they would became short of breath and they'd beg to get back in.  So it was sort of a double edged sword for the patient until the patient got better, if they got better.  Some critics complained such tents basically provided a tortuous method of ending a person's life, and petitioned for their demise.

In 1926 Alvin Barach invented an oxygen tent that blew air over ice chips to cool the temperature inside the tent.  This made it so being inside the tents was much more bearable.  Usually these they were reserved for patients with pneumonia and heart failure. (2)

In 1931 John Emerson invented an oxygen tent that had a cooling system.  Previous devices were prone to rust and failure.  (7)

The metal cannula was another device that was used.  It was a narrow metal pipe that was secured to the forehead by a strap that wrapped around the head, and at the lower end of the pipe were two prongs that were inserted into the nares.  I can imagine this may have felt awkward for the patient, but it may have been much nicer than having to lie inside an oxygen tent or having a rubber mask on your face.

The nasal catheter was introduced to the world by Lane in 1907, and introduced to the United States in 1931 by Waters and Wineland. (3)  Between 1920 and 1960 the nasal catheter was the most widely used method of delivering oxygen to patients. (8)

Glover explained that by the 1960s vinyl had been invented and this technology spread to the medical profession.  Masks, catheters, nasal cannulas and tubing were then made of this new material, and were much more comfortable for patients.  (2)
l
Another benefit was the material was see through, and this allowed the caregivers to see right away if the mask was filling with secretions, vomit or pulmonary edema. This made the masks much safer. They were also disposable, so it removed the need to clean and sterilize between patients.

Vinyl nasal cannulas quickly became the preferred basic oxygenation device, and this slowly caused the demise of the nasal catheter.

The nonrebreather was also introduced during the 1920s.  For those not familiar with these, they involve placing a mask tightly over the patients face to prevent the entry of room air. A one way valve on the mask allows the patient to exhale, but it closes on inhalation. This forces the patient to inhale only oxygen, which enters the airway from tubing which is connected from the mask to an oxygen flow meter. A bag connected to the mask collects oxygen while the patient is exhaling. When the patient inhale, inhales oxygen that is stored in the bag.

It is called a nonrebreather because the patient is not rebreathing any exhaled air. The idea here is that, if there is that if the mask is sealed tightly around the patient's face, and the one way valves are working, then the patient should be inhaling 100% oxygen.

Of course a problem with this system is that there were no surefire methods of knowing how much oxygen was left in an oxygen tank. So when a tank became empty, the patient had not oxygen to inhale, and would die of asphyxia. Learning this the hard way must have given quite a fright to some early orderlies, nurses and doctors.

The remedy to this problem was to remove one of the one way valves to assure that, if the oxygen tanks to run empty, that the patient can still inhale some room air. This is how most nonrebreather masks are produced today. So, while some people still report that nonrebreathers give patients 100% oxygen, the actual percentage is estimated to be between

Nonrebreathers of today aren't even nonrebreathers at all: they are partial rebreathers. Still, it is very common for them to be called nonrebreathers. They aren't generally referred to as partial nonrebreathers until both one way flaps are removed. With both flaps removed, the patient's estimated FiO2 is about 50-60%.

This represents one of the medical conundrums in medicine.

Early masks were also not see through, so if a patient vomited you might not know right away. Newer masks are made of disposable material that is see through, eliminating some of the older complications from these masks.

Regardless, nonrebreathers were good devices for oxygenating patients suffering from acute anoxia.

The next evolutionary breakthrough in oxygen delivery devices came as a result of observations made during the 1950s that some patients given 100% oxygen were becoming lethargic. It was soon realized that these were patients with emphysema and chronic bronchitis, or what we now refer to as chronic obstructive pulmonary disease (COPD).

This was where the hypoxic drive theory was derived from. You can learn about this theory in my post, "Hypoxic Drive Theory: A History of the Myth."  Essentially, this theory postulates that giving too much oxygen to some COPD patients might blunt their drive to breathe. So this resulted in the market for a better oxygen delivery device, and the invention of the Venturi Mask.

The new masks were based on the Venturi Principle, and allowed physicians the opportunity to provide accurate oxygen levels up to 50%. Nasal catheters, and later cannulas, were the preferred method of oxygenating these patients. However, because these devices are low flow devices, changes in the rate and depth of breathing make these less effective. Venturi masks were nice because they guaranteed the patient would get the desired oxygen level.

This was because the masks were based on the Venturi Principle. An adjustable opening allowed the caregiver to determine how much air was being inhaled. The larger the opening, the more air was inhaled and the less oxygen inhaled. The smaller the opening the less air was inhaled and the more oxygen was inhaled. So oxygen could now be set at between 28 and 50%, and this would not be affected by changes in rate or depth of breathing. It was a nice concept, especially for COPD patients.

These masks are still used today as a nice option for patients who are in respiratory distress, or who need a little more oxygen than a nasal cannula can provide, but don't quite need anything higher than 50%. They are generally only made as a temporary oxygen device, although some patients with terminal lung diseases (such as lung cancer) may occasionally use one at home.

By the 1980s plastic had been invented, and during this decade most respiratory therapy devices were slowly replaced by plastic.  Plastic nasal cannulas, masks, and nebulizers were introduced in the early 1980s and slowly phased into various hospitals through assimilation.

The earliest oxygen humidifiers were either made of metal or glass.  Until plastic was invented, none of the equipment here was disposable, and needed to be washed, sterilized, dried, and restocked on the shelves before being set up on the patient. So cleaning respiratory therapy equipment became sort of a secondary job for therapists until this aspect was phased out by turn of the 21st century.

References:

1. Hess, Dean,  Neil MacIntyre, Shelley Misha,"Respiratory Care:  Principles and Practice," page 281
2. Glover, Dennis, "History of Respiratory therapy: discovery and evolution, ," 2010, Indiana, page 94
3. Wyka, Kenneth A., Paul J. Mathews, John Rutkowski, editors, "Foundations of Respiratory Care," 2012, U.S., Delmar, page 9
4. Hess, Dean,  Neil MacIntyre, Shelley Misha,"Respiratory Care:  Principles and Practice," page 281
5. Barach, Alvin L., "The Therapeutic Use of Oxygen," The Journal of the American Medical Association, Vol 79, No. 9, Chicago, October 26, 1922, page 693-699
6. Barach, Alvin L, Margaret Woodwell, "Studies in oxygen therapy with determinations of blood gases," Archives of Internal Medicine, Vol. 28, 1921, Chicago, American Medical Association, pages 367-393
7. Branson, Richard D, "Jack Emerson:  Notes on his life and contributions to Respiratory Care," Respiratory Care, July 1998, vol. 43, no. 7, pages 567-71

Further Reading:

1. Use of oxygen in pneumonia in an oxygen chamber, page 466
2. RT Cave: Oxygen Therapy Made Easy
3. RT Cave: ypoxic Drive Theory: A history of the myth
4. RT Cave: The Physics Lexicon

1910-1920: The oxygen revolution

Joseph Barcroft (1872-1947)
In 1886 he received his M.D. from Cambridge,
and began his study of hemoglobin.
He exposed himself to different environments
to determine their effects on the human body.
.

Three significant events occurred at the dawn of the 20th century that resulted in increased interest in supplemental oxygen therapy. The first was the invention of a means of measuring oxygen saturation. The second was an experiment that Dr. Joseph Barcroft performed on himself. The third were experiments by WWI physicians to find a treatment for pulmonary edema caused by gas poisoning.

The ability to draw arterial blood was a significant discovery. It was hurter in 1912 who introduced the method. (2, page 693)

Yet even more significant was the machine blood could be inserted into that would determine the how saturated hemoglobin molecules in the blood were with oxygen molecules. This is referred to as oxygen saturation. Once inserted into the machine, the saturation was reported as a percentage.

John Scott Haldane (1850-1936)
He graduated from Edinburgh University in 1884,
and worked with his uncle at Oxford,
where he became interested in air,
its composition, and effects on humans.

Adolf Fick of Germany and Paul Bert of France described oxygen tensions as units of partial pressure, and it was these units that made it possible to describe the difference between arterial and venous blood. Since the partial pressure of oxygen in arterial blood is higher than the partial pressure of oxygen in venous blood. Or at least this is the case in a healthy individual. (1, page 4) (2) (6)

Donald Dexter Van Slyke (1883-1971) and John Scott Haldane (1892-1964) of Scotland developed effective means of measuring these differences. (1, page 94) (2) (6)

Further studies by various experts determined the normal levels and critical levels of oxygenation. It was determined that a normal arterial saturation of hemoglobin is between 95 and 98 percent, and a normal venous saturation is between 70 and 75 percent. These new values allowed physicians to monitor a patient's oxygenation status, and the effectiveness of oxygenation therapy. (2)(3, page 369)

Among the first to prove the significance of this discovery was Sir Joseph Barcroft, who lived for six days in an atmosphere that had 18 percent oxygen in the air, as opposed to the normal 21 percent that's in roomair. Alvin L. Barach, a pioneer in oxygen therapy, liked to use Barcroft's experiment as an example to prove the significance of oxygenation.

Barach explained:

"On the last day, the oxygen saturation of his arterial blood was 88 per cent., and after the performance of work 83.8 per cent. He lay in the chamber racked with headache, with occasional vomiting, and at times able to see clearly only as an effort of concentration. He became faint on exertion. His pulse, normally 56, had risen to 86. These effects were apparently due purely to oxygen want. The degree of anoxemia that produced them has frequently been found in pneumonia and heart disease by the investigators mentioned above. In many instances, the saturation of the arterial blood falls to far lower levels. It would, therefore, seem likely that lack of oxygen in the degree often found in disease would produce bodily discomfort, disturbances in function and damage to living structure." (3, page 369)

The effects on Barcroft were similar to the effects of pneumonia and heart failure for some patients. Studies showed that the oxygen saturation could range from 75-95 percent in cases of cardiac insufficiency, and 60-95 percent in cases of pneumonia. (2, page 693)

So it became apparent these diseases, as they progress, decrease the amount of oxygen that gets to the blood and to hemoglobin.  

Various studies, including the Barcroft study, proved that a low level of oxygen stimulates the central nervous system to stimulate various changes within the body in an attempt to return oxygenation back to normal: heart rate increases, respiratory rate increases in rate but decreases in depth, patient may become delirious and may have hallucinations  If not treated, death may result.  (2, page 694)

So these studies proved to the medical community the significance of observing the signs and symptoms of poor oxygenation and speedily treating them with oxygen. (2, page 694)

Oxygen was not meant to cure, but to treat the symptom of low oxygenation long enough to allow the physician to remedy the underlying condition, which may include: (2, page 694)

• Pneumonia
• Acute Cardiac Failure
• Severe Hemorrhage
• Epidemic Encephalitis
• Ascent to high altitudes
• Complications of chronic cardiac insufficiency
• Pulmonary Edema
• Acute Bronchitis
• Carbon Monoxide Poisoning
• Nitrous Oxide Poisoning
• Other anesthesia

Further studies also allowed physicians the opportunity to determine that a therapeutic percent of oxygen for most diseases was between 40 and 60 percent, and it's for this reason the oxygen chamber, oxygen catheter, and nasal cannula generally are not effective for oxygenating patients with severe oxygen deprivation. (2, page 696)

Studies likewise showed greater than 70 percent could cause pneumonia, and did so in rabbits. (3, page 373)

It was probably based on these and similar studies that John Haldane, another pioneer of oxygen therapy, would recommend 41% oxygen administration continuously for patients suffering from anoxemia (Haldane would coin a new term to describe this: hypoxemia). (6) (7) (8)

In fact, it is said Haldane once mused:

Intermittent oxygen therapy is like bringing a drowning man to the surface of the water—occasionally. (7) (8)

Yet even while he and other physicians proved the usefulness of continuous oxygen therapy during WWI, it would take a few more years for it to catch on. (6)

Oxygen mask designed by Haldane in 1917

A third significant event was the gas poisonings that occurred during WWI. Phosgene was used by the enemy on the war front because, when it combines with water in the lungs, it creates hydrochloric acid, which damages lung tissue. If inhaled in high enough doses it may cause pulmonary edema within 6-10 hours, leading to acute respiratory distress syndrome (ARDS).  As the illness progresses, the lungs lose their ability to pass oxygen to pulmonary capillaries, therefore causing anoxemia or hypoxemia. (6)

While oxygen was not thought to cure these patients, it was believed that it would treat the symptoms caused by anoxemia, particularly cyanosis and dyspnea.

Sometimes patients who presented with pulmonary edema due to gas poisoning were treated in oxygen chambers, which could be supplied with 40-60 percent oxygen. These chambers were found to be effective in treating cases of chronic gas poisoning. Some patients would spend up to 16 hours a day inside one with good results. (3, page 360)

However, this therapy wasn't practical for common use.

Another means of providing these patients oxygen was to use a tube or funnel to aim the oxygen at their faces, although studies showed this provided no more than a 2 percent increase in oxygenation of inspired air.

So this opened the door for an improved oxygenation apparatus that was easily portable by medics, comfortable to wear, could be used long term for chronic cases, and provided a therapeutic dose of oxygen. John Haldane invented such a device, and it was called the "Haldane Apparatus." (3, page 370)

Alvin Barach said Haldane's apparatus provided oxygen blended into the air the patient inspired, and by doing this the amount of oxygen making it to the alveoli was greatly increased. By this means, the patient was supplied with a therapeutic level of oxygen. (3, page 370)

Barach described the device as consisting of an oxygen tank, a reducing valve, and a face mask. He said:  (3, page 370)

"The mask was connected with a connecting bag which received oxygen from the tank, and with the outside air, from which the patient breathed. Oxygen was added to the inspired air in amounts of from one to four liters per minute. This was largely used in acute cases with generally good results." (3, page 370)

The problem with the Haldane apparatus was the only patients who tolerated it were those who were comatose. It worked great for these patients. Yet for others, for those who were awake and alert, it was not comfortable. Patient's complained that having the mask over their faces created a feeling of claustrophobia, and the mask was also hot and stuffy. This was especially a problem on hot days. Some patients simply didn't tolerate the mask, and some even ripped it off, refusing to wear it. (3, page 370)

Another problem, a pretty severe one actually, was it was impossible for clinicians to see through the opaque rubber masks. Clinicians learned to be vigilant, although this sometimes didn't prevent them from getting busy and not recognizing a patient was vomiting or expectorating foaming pulmonary edema. When not recognized, secretions occluded airways resulting in worsening anoxemia.

This concern opened the door for a more comfortable and safer oxygenation device.

One such device was the nasal cannula or prongs devised by Captain Adrian Stokes, M.D., in 1917. Stokes created the device while triaging patients on the war front who were suffocating due to pulmonary edema, and to which the tight fitting rubber mask of Dr. Haldane was not feasible. The metal cannula provided less oxygen than Haldane's device, although it helped medics keep pulmonary fluid from re-entering and blocking the airway. (1, page 38) (3, page 370)  (5, page 8) (6)

Stoke's cannula was a device similar in design to what we use today, although it was supplied by rubber tubing and the prongs were made of metal, and therefore was not very comfortable. However, patients tolerated it much better than the rubber mask, and of course it was safer. (1, page 38) (3, page 370)  (5, page 8) (6)

A similar device was the rubber nasal catheter, which was initially invented by Arbuthnot Lane in 1907, although re-introduced by Stokes in 1917. The catheter was introduced into the United States in 1931 by Waters and Wineland.  (1, page 17) (5, pages 8-9) (7, page 20)

The soft, rubber catheter (later made of pliable plastic) was a 12 inch long tube that was blindly inserted into one of the nostrils and then secured to the forehead. The patient would then open his mouth, depress his tongue to the bottom of his mouth, and the physician or nurse would check to see that the catheter was in place at the back of the airway. (4)

The end that remained outside the patient had a fitting to which oxygen supply tubing was connected.  On the distal side of the catheter, the side inside the patient's airway, were a series of small holes to allow oxygen to enter the patient's airway.  (4)

Catheters were designed for adults and pediatrics, the flow was set at 1- 5 lpm, and the the delivered oxygen was 22-35%.  The catheters would stay in the nose for a day or two.  If it was needed longer a new catheter had to be inserted. (4)

Most experts recommended changing the catheter every 24 hours to prevent tissue breakdown, and most hospital protocols eventually called for changing it every eight hours.

So you can see that while it was more convenient for the patient, there was some risk to the patient too.  It also provided some inconvenience for those taking care of patients requiring it.

While nasal catheters were simple to insert and manage, and while they were generally well accepted by patients, they did not provide enough oxygen in patients presenting with acute pulmonary edema or worsening pneumonia to eliminate cyanosis.  (3, page 370)

The nasal catheter was the most commonly used device for supplying supplemental oxygen prior to the invention of the modern nasal cannula in the 1960s.

Figure 2 --Apparatus for giving oxygen.(3, page 374)

Another option was a device similar to the one in figure 2.  The apparatus works this way: 

"The patient breathes through the rubber mouthpiece M (or a mask could be used) through the can of soda-lime C into a rebreathing bag B. The carbon dioxide exhaled is removed by the soda-lime, and oxygen is admitted from the tank O at a sufficient rate to keep B inflated.In this way the patient rebreathes pure oxygenfrom the apparatus,but since his nose is left open he dilutes this with a certain proportion of atmospheric air. In practice this results in the inhalation of from 40 to 60 per cent, oxygen." (3, page 374)

Yet another option was the oxygen tent. These were clear canopies that were made to cover the entire bed. A machine at the bedside provided an environment inside the tent of about 30 percent oxygen. These were effective as far as oxygenating some patients, although the original oxygen tents were hot and stuffy, and this particularly posed a problem on hot days.

Patients would generally go inside one long enough to catch their breath, and then they'd return to breathing room air. (1, page 94)

Barach recommended to physicians that the best means of measuring oxygenation status was by monitoring the heart rate, respiratory rate, and especially the level of cyanosis (bluish skin color). This was much more logical than an invasive blood draw. (3, page 370)

Caregivers would ultimately learn to monitor these signs, along with level of consciousness, before, during and after therapy.  This, they found, was the best means of monitoring the effectiveness of oxygenation therapy, and whether or not it was still needed.  (2)

What equipment to use to supply oxygen depended on what equipment was available, the physician taking care of the patient, and the independent oxygenation requirements of patient.

How long oxygen therapy was used primarily depended on the patient and how quickly, or slowly, the underlying condition resolved. (2)

Still, by 1922, when Barach wrote many of his papers, he explained that...

"the use of oxygen in medical therapy occupies at present an uncertain role." 

Despite Barach's doubts, the 1920s was an oxygen revolution of sorts.

Barach would go on to study the effects of oxygen therapy on a variety of respiratory diseases, including pneumonia and cor pulmonale. He would also study the effects of oxygen therapy on respiratory failure. For his work, he is often considered the father of modern oxygen therapy.

References:

1. Glover, Dennis, "History of Respiratory therapy," 2010, Indiana, page 94.
2. Barach, Alvin L., "The Therapeutic Use of Oxygen," The Journal of the American Medical Association, Vol 79, No. 9, Chicago, October 26, 1922, page 693-699
3. Barach, Alvin L, Margaret Woodwell, "Studies in oxygen therapy with determinations of blood gases," Archives of Internal Medicine, Vol. 28, 1921, Chicago, American Medical Association, pages 367-393
4. Hess, Dean,  Neil MacIntyre, Shelley Misha,"Respiratory Care:  Principles and Practice," page 281
5. Wyka, Kenneth A.,  Paul Joseph Mathews, William F. Clark, editors, "Fundamentals of Respiratory Care," 2002
6. Grainge, CP, "Breath of Life: the evolution of oxygen therapy," Journal of the Royal Society of Medicine, October, 2004, 97 (10), pages 489-493
7. Heffner, JE, "The story of oxygen," Respiratory Care, January, 2013, volume 58, number 1, pages 18-30
8. Sekhar, KC., "John Haldane: The Father of Oxygen Therapy," Indian Journal of Anesthesia, May-June, 2014, 58 (3), pages 350-352

1870: Bert's experiments help anyone with respiratory ailments

Paul Bert (1833-1886)

"It can be said of Paul Bert as it has been of Vesalius, Harvey and Boyle, that the full significance of his work could not be fully appreciated until long after his death." (8, page v)

This was a quote from John F. Fulton, who wrote the forward to the 1843 edition of Paul Bert's book "Barometric Pressure."

Bert's experiments would have a broad and lasting impact on surgery, aviation, mountain climbing, deep sea excursions, mining, pressure breathing machines, and even the definition of asthma.

He was born in Auxerre, France, on October 17, 1833, attended school in Paris, and received his medical degree in 1863. (2)(8, page V)

Fulton said that while in Paris he was assistant to Dr. Claude Bernard in his laboratory. Fulton said "Bernard recognized his ingenious mind and predicted a brilliant future." (8, page VI)

Denis Jourdanet (1815-1892)

His thesis on grafting of animal tissue gained him public acclaim, and this helped him to quickly earn fame in the medical community. (2)(8, page VI)

Animal grafting, and later skin grafting, was "an operation consisting of the removal of a living part and transplanting it so that it shall continue to live on another part of the same individual or on another individual," said the authors of an 1888 biography of Dr. Bert in Popular Science Monthly.(2)(8, page V)

In 1865, the Academy of Sciences awarded him a prize in experimental physiology for his work on animal grafting and skin grafting.  This work was significant because it allowed physicians to perform plastic surgery on soldiers injured during the war of 1870.  (2)(5, page ?)(8, page V-VI)

In 1867 he was appointed to a chair in the Faculty of Sciences at Bordeaux where he taught zoology. Then he became Bernard's successor in December of 1869 when he was named Professor of Physiology at the Faculty of Sciences in Paris. (2)(8, page VI)(13, page 599)

In 1870 Bert became interested in respiratory disorders, such as asthma, chronic bronchitis, and emphysema.  He performed experiments to learn more about these diseases, and to find methods of helping people suffering from them.   (1, page 194)(8, page VII)

In 1854 Alton Wintrich performed experiments that seemed to disprove the spasmotic theory of asthma in favor of the diaphragmatic theory of asthma. For 16 years Wintrich gained many followers. But Bert aimed to prove him wrong.

In 1870 Bert attempted, with improved methods of scientific research compared to that used by Williams and Longet, to stimulate the vagi of dogs. As he expected, this indeed produced dyspnea. His experiment reaffirmed for the medical community the spasmotic theory of asthma. (10, page 10)(11, page 37)(12, pages 5-6)(13, page 16)(14, page 599)

According to W.H. Geddings in 1885, along with demonstrating that respiration could be "arrested by irritation of the pneumogastri (vagi)," it could also be arrested by irritation of the "laryngeal nerves or the Schneiderian membrane of the nose (membrane lining the maxillary sinus cavity)." (1, page 194)

In 1855, Ludwig Traube came to a similar conclusion.

Bert's experiment was important because it prevented physicians from spending what minimal time and money was dedicated to asthma form being wasted on areas that were already disproved.

Around this time, said Fulton, a friend of his, Dr. Denis Jourdanet, had just returned from an excursion to Mexico where he had spent time in the mountains at great heights and suffered mountain sickness. The two decided that Bert should dedicate his time performing experiments on the effects of pressure on plants, animals and humans. Jourdanet was a wealthy man, and he offered to provide any funds that Bert needed. (8, page VII)

Bert's first experiment was performed on April 15, 1874. He sent three balloon enthusiasts and equipment in a hot air balloon called Zenith. The mission was to collect data from the the upper atmosphere. Another goal, however, was to exceed 24,000 feet, which was the height accomplished by an English balloonist named Glaisher in 1862.

At 26,000 feet all of the men were unconscious. Upon the Zenith's return to the earth, two of the men had perished, and the third was insensible. Bert hypothesized the reason was due to lack of oxygen to the brain (2)(5, page 112)(8, page VII)

This was a set back for Bert in which none of the equipment, and obviously none of the men, were able to function at that height due to cold and rarified air. Most of the equipment was also damaged in the efforts made to get the balloon back down to earth, so no data could have been obtained anyway. (2)(5, page 112)(8, page VII)

While this was a set back, it did not keep him from marching forward. Instead of using humans to perform his studies from here on our, he did them in his laboratory using small animals. Only when perfected his experiments did he resort to using humans. (2)(5, page 112)(8, page VII)

The first order of business for Bert was to invent a device for measuring pressure and put together compression chambers. He used a smaller compression chamber for small animals, and a larger one for himself and his friends. (see figures)(2)(8, page VI)

In a laboratory experiment Bert placed a sparrow in the compression chamber made of pneumatic glass bells and exposed it to low pressures. When it started to suffer he administered oxygen, at which point the bird "at once became himself again." Upon this success, he performed the same experiment on himself, and he observed at higher pressures that his heart would beat faster and he'd have palpitations. At one point he wanted to write in his tablet, but could not. When he inhaled oxygen these symptoms went away. (7)

By these experiments he concluded that the lower the atmospheric pressure (as what would occur with high altitudes) results in oxygen tensions in the air and blood too low to support life. Instead of inhaling 21% oxygen which is present in normal room air, he was inhaling a lower percentage of oxygen.  (7)

High altitudes, or high atmospheric pressures, subject humans to the risk of suffocation or asphyxia. Early symptoms are increased heart rate,weakness, malaise, nausea, and vomiting. The colder the air the earlier these symptoms appear. For instance, the symptoms appear earlier in earlier in the Alps than in the Himalaya, Bert said. (7)

The remedy here would be "the respiration of an air sufficiently rich in oxygen to maintain the tension of that gas at its normal value." (2)

In another laboratory experiment Bert placed a sparrow in the compression chamber made of pneumatic glass bells and exposed it to high pressures (compression). He then decompressed the bird rapidly to atmospheric pressure, at which time the bird suddenly died. Upon inspection of the body he found air bubbles in the arteries and heart. The same effect resulted during similar experiments performed with rats and small dogs. (5, page 115)

Robert Boyl had observed bubbles in the eyes of a snake he placed in a compression tank he invented, although no further investigations were made at that time into the nature or cause of the bubbles. Bert, however, benefited from improved laboratory equipment. (5, page 116)

Bert concluded that higher atmospheric pressures (as what would occur as one travels deeper under water) result in increased oxygen tensions in the air and blood. The remedy here would be avoidance of too high a pressure (such as greater than 5-6 atmospheres), and gradual decompression back to atmospheric pressure (1 atmosphere). (2)

He observed that the effects of high pressures may kill not only humans and animals, but plants too.  (2)

While the significance of this work may not have been immediately known, the value of it was immediately recognized by the scientific community.  For this work the Academy of Sciences awarded him a prize of twenty thousand francs. (2)

His experiments would have an impact in many areas of science and medicine.

His conclusions about the effects of diminished pressure resulted in equipment, such as oxygen tanks and masks, that made aviation possible.  For this reason, he is often referred to as the father of aviation medicine.

Improved methods of storing and delivering oxygen was also thought to benefit people with respiratory disorders, and so research was eventually done in this regard, some of it by Bert himself.

His conclusions about the effects of increased pressure resulted in better knowledge of decompression sickness or bends. It occurs when a person moves from deep water (where the pressure is higher) to the surface (where the pressure is lower) too fast. This causes bubbles to escape into the blood and tissues, and can cause symptoms such as headache, joint pain, nose bleeding, vertigo, shortness of breath, nausea, vomiting, and sometimes death.

This is a small compression chamber made of a pneumatic glass jar.
Bert was able to use it to expose a sparrow to low pressures.
He reduced the pressure using a manometric tube,
observing at what point the bird started to suffer.
He used the India rubber bag to administer oxygen to the bird,
and "at once the bird becomes himself again," he wrote.
He concluded that at high altitudes, where the pressure was low,
: "it appears it is not the lowering of mechanical pressure
that produces the symptoms, but the low tension of oxygen
of the dilated air, which low tension prevents the oxygen from
entering the blood in sufficient quantity." (7)

So Bert became interested in helping people with breathing difficulties during the early 1870s. He said it was already known (such as by the works of Tavarie) that compressed air (higher pressure) helped people with anemia, chronic bronchitis, and emphysematous asthma. The result was easier breathing, and a lower heart rate. (7)(8 page VII)

Improved knowledge of the effects of high pressure on the human body resulted in Bert, and various other physicians, trying to invent machines that would adjust the pressure of inspired air to relieve the feeling of air hunger. Such machines would be experimented on patients of various lung disorders, including asthma.

In fact, in his 1877 article "Atmospheric pressure and life," Bert said:

The great influence that may be exerted upon living beings by atmospheric pressure is now questioned by none, and there is even a disposition to exaggerate its importance. If the barometric column rises or falls a few millimetres, nervous people affected with the asthma perceive phenomena, whether of a beneficial or of a noxious kind, which they do not hesitate to attribute to the weight or to the lightness of the atmosphere. But if this were the only cause of their sensations, then they should experience the same symptoms whenever they subject themselves to equal variations of pressure, as in passing from the level of the sea to a point only a few feet above it, or vice versa. (7)

In his 1878 book "Barometric Pressure," he published the results of his experiments on barometric pressure. He dedicated the book to his friend, and the man who funded the project, Dr. Jourdanet.

This is a compression chamber that allowed Bert to measure
the effects of barometric pressure on himself and others.
Inside was an Indian rubber bag so he could inhale oxygen.
Access points allowed him to take blood samples
to determine changes in blood oxygen tensions.
He exposed himself to decreased pressures.  Once he
started to feel symptoms he inhaled oxygen.  He wrote:
"But all these symptoms disappeared as by enchantment
so soon as I respired some of the oxygen in the bag;
returning, however, when I again breathed the air in
the cylinder."  (7) 

There would be many devices invented, and many failed experiments, over the next hundred years, before a truly effective, and mass producible, device would be invented to truly help patient's with respiratory disorders. Yet it was Bert's work that

He also performed work using anesthetics such as chloroform, and to administer it he devised an apparatus that allowed the patient to inhale an ideal percentage of the compound. (2)(3, page 427)

Along with being a successful physician and scientist, he was also a successful politician.

As he was performing his experiments on pressure,
he started to wonder how the world was created.
In regards to animals dying due to compression, he wrote:
"Thus it is the oxygen that is to blame.  Oxygen at too high
a tension destroys animal life.  Long I hesitated to characterize
as a poison the 'nursing father' of everything that lives, but there
was no help for it.  Oxygen, which gives us life, slays also,
when administered in too strong a dose.  I have had to study
thoroughly this paradoxal poison to determine the different
effects of varying doses, and its action upon our tissues. (7)

So after Williams, Longet and Bert all performed experiments to prove the spasmotic theory of asthma, you probably thought the subject was settled. Well, not quite. There still remained skeptics with credible arguments against it.

J.B. Berkart, in his 1878 book "On Asthma," explained that, during his work on asthma, Bert had a difficult time getting the air passages to contract until he realized that he had been over inflating the lungs.

Berkart said it was only when he provided less inflation that he was finally able to induce the air passages to...

"...contract... upon electrical irritation, applied either directly to it or to the pneumogastric nerve. But the contractions were so feeble and slow as to induce Bert to think that they had no active share in the mechanism of respiration. Moreover, the paralysis of the bronchial muscles, following the section of the vagus, did not appear to influence in that least the function of nutrition of the lungs. Thus the integrity of those muscles, not being indispensable to an efficient ventilation of the lungs, it seemed not unreasonable to conclude that their spasmodic contractions could hardly have the effect generally assigned to them." (4, page 42-43)(9,page 5)

Berkart said that Bert's experiments did not initially demonstrate contraction of the lungs because he over inflated them.

Berkart believed that Bert's experiments demonstrated proof that the air passages may constrict as Williams proved, but this did not occur in asthma because most asthmatics also present with emphysema, which is essentially over inflation of the lungs. (4, page 103)

Berkart's theory was respected among the medical community, although it did not have a long lasting influence.

In 1886 he was appointed governor-general of Tonquin, and soon thereafter his health started to fail. On a return to France during the year he gave a farewell speech at a meeting of the Academy of sciences, supposedly because he knew he was ill. He died of dysentry on November, 11, 1886. (2)

References:

1. Geddings, W.H., author of the chapter on "Bronchial Asthma," in the book  "A System of Practical Medicine," edited by William Pepper and Louis Star,Volume 3, 1885, Philadelphia, Lea Brothers and Co.
2. "Sketch of Paul Bert," Popular Science Monthly," July, 1888, Volume 33, compliments of wikisource.org, http://en.wikisource.org/wiki/Popular_Science_Monthly/Volume_33/July_1888/Sketch_of_Paul_Bert, accessed 2/6/14
3. Waller, A., "Meeting of the society of Anaesthetists: Dosage in Anaesthetics," The Clinical Journal, April 6, 1898, pages 426-430, volume XI, October 27- April 20, 1898, Sixth Year, Edited by L. Eliot Creasy, 1898, London, The Medical Publishing Company
4. Berkart, J.B., "On Asthma: It's pathology and treatment," 1878, London, J. & A. Churchill
5. Phillips, John L., "The Bends," 1998, Yale University
6. Tissier,Paul Lewis Alexandre, edited by Solomon Solis Cohen, "Pneumotherapy: Including Aerotherapy and inhalation methods," volume X, 1903, Philadelphia, P. Blakiston's Sons and Co., pages 296-224.  If the profession of respiratory therapy existed in their era, we would be reading their books.  However, as it was, their books were written for the medical profession. All of the material from this post is from Tissier's book unless otherwise noted in the above paragraphs. Tissier page 72
7. Bert, Paul,  "Atmospheric pressure and life," Translated from the French by J. Fitzgerald, Popular Science Monthy, July, 1877, volume 11, http://en.wikisource.org/wiki/Popular_Science_Monthly/Volume_11/July_1877/Atmospheric_Pressure_and_Life, accessed 2/8/14
8. Fulton, John F., author of the Forward to Paul Bert's book "Barometric Pressure," 1843, Columbus, Ohio, The F. J. Heer Printing Company
9. Bert, Paul,  "Barometric Pressure," 1843, Columbus, Ohio, The F. J. Heer Printing Company
10. Dobell, Horace, "On Asthma: It's nature and treatment," 1886, London, Smith, Elder and Co
11. Brown, Orville Harry, "Asthma, presenting an exposition of nonpassive expiration theory," 1917, St. Louis, C.V. Mosby Company
12. Thorowgood, John Charles, "Notes on Asthma," 1878, 3rd edition, London, J and A Churchill
13. Thowowgood, John Charles, "The Lettsomian Lectures: delivered at the Medical Society of London, 1879, on bronchial asthma: it's causes, pathology and treatment," 1879, London, Bailliere, Tindall, and Cox
14. West, Samuel Hatch, "Diseases of the organs of respiration," volume II, 1902, London, Charles Griffin & Company, Limited 

RT Cave Facebook Page
RT Cave on Twitter

1844: Dr. Andral writes about asthma

Gabriel Andraw (1797-1876)

Gabriel Andral, in the 1857 edition (the 4th edition) of his book, "Clinique Medicale," described asthma as nervous, and "in one instance at least," wrote Orville Brown, "he expressed his opinion that it might have come from a 'metastasis of rheumatism to the lungs.'" (1, page 34)(2, page 99)

Dr. Andral was a French physicians who became known as the father of "analytical and inductive pathology. (4, pages 186-187).

He is likewise known as the first person to use the terms anaemia and hyperaemia to describe the presence of too few and too many red blood cells in the body.  He is likewise referred to as the father of haemotology (the study of blood).

In the 1844 edition of "Clinique Medicale," he said that people with air passages that are chronically inflamed are diagnosed with chronic bronchitis.  This chronic inflammation often results in the walls of the air passages becoming "thickened," which results in "a diminution in the size of the cavities through which the air is to pass..." and these patients "have ordinarily a certain degree of dyspnoea, which from time to time assumes all at once a much greater intensity, and becomes changed into a real attack of asthma." (2, page 86)

Andral also described another  form of asthma that occasionally formed by "engorgement of the bronchial mucous membrane.  He referred to it as bronchial asthma:

There are persons who ordinarily present no sign of bronchitis, who do not cough, who have no shortness of breath, and who at certain intervals, are suddenly seized with the following symptoms: oppression, which rapidly becomes most intense; imminent suffocation; violet injection of the face, as in persons in a state of asphyxia; pulse small, hard, and rather frequent; cough at first dry, but afterwards accompanied with a copious expectoration, the appearance of which .coincides with the dyspnoea. These different symptoms set in suddenly; they very quickly attain their highest degree of intensity; then they diminish, and at the end of a few days they disappear, without leaving any trace behind them. What is the cause of this frightful dyspnoea, which thus seizes an individual in the midst of the most perfect health, which throws him all at once into unspeakable anguish, and threatens to kill him by asphyxia? (2, page 86

The patient will probably also present with emphysema of the lung, and palpation of the heart due to "temporary embarrassment of the pulmonary circulation."  The embarrassed circulation may ultimately "become modified in its texture, and in a later period become really diseased." (2, page 87)

There are a variety of causes for an attack of asthma in an otherwise healthy individual.  In one example a child has "tumefaction (swelling) which momentarily affects the mucous membrane of the bronchi, most frequently after a new cold contracted by the patient." (2, page 87)

When sudden onset dyspnea causes with no signs of organic lesions, when no other causes can be found, "either in young or plethoric persons, or in persons remarkably nervous. Young persons of both sexes, women affected with irregular menstruation, present frequent examples of "nervous asthma." (2, page 112)

He wrote:

Intense dyspnoea, genuine fits of asthma, have been sometimes seen to come on all at once, after a violent mental emotion, in persons whose breathing had been till then perfectly free. (2, page 112)

In such cases of nervous asthma he wondered if "the best remedy for them is often intense distraction." (2, page 112)

He does describe one case (as noted above) where there were no lesions, and nervous asthma was suspected.  However, upon "close inspection of the bronchi... metastasis of rheumatism to the lungs" was discovered. (2, page 112)

Such cases as this show the inexplicable nature of asthma for this era.  

Generally, however, his treatment for asthma included "blood letting, both local and general, blisters applied to the chest and extremities, repeated purgatives, antimonials, such are the means which have appeared to us to afford most relief under such circumstances." . (21, page 87)

It is of his opinion that purgatives work best, "but it is on the condition of their producing copious evacuations." (21, page 87)

Along with being associated with emphysema and bronchitis, and along with describing cases of nervous asthma, he likewise believed it was spasmotic in nature.  (2, page 250)(3, page 14)

This places him in line with many of the other asthma experts of his era.

References:

1. Brown, Orville Harry, "Asthma, presenting an exposition of nonpassive expiration theory," 1917, St. Louis, C.V. Mosby Company
2. Andral, Gabriel, "Medical Clinic: Diseases of the Chest," Volume II, Diseases of the Chest, 1843, Philadelphia, Ed Barrington and Geo D. Haswell
3. Thorowgood, John C., "Asthma and Chronic Bronchitis: A New Edition of Notes on Asthma and Bronchial Asthma," 1894, London, Bailliere, Tyndall, & Cox
4. Kellog, Day Otis, editor, " The Encyclopedia Britannica," volume XXV, 1902, New York, Ohio, Chicago, The Werner Company 

RT Cave Facebook Page
RT Cave on Twitter

1800-1920: Oxygen cylinders and chambers

Fig 1-- Left to Right: Oxygen tank, rubber bag (400 cc), thermometer
in glass tube, water-manometer and small cannula (1908)(1, page 288)

While the benefits of oxygen therapy were known, it took a long time for its use to be accepted by the medical community. The main reason was that there were no efficient and inexpensive means of making it and delivering it to patients. Plus experiments provided sketchy results at best.  

So for the most part, oxygen wasn't used therapeutically during the 19th century until a cholera outbreak in Europe in 1832. In 1857 S.B. Birch described a "renaissance of oxygen." His writings did create a "renaissance" of sorts. Yet, once again, results were sketchy.  (1, page 282)

Ernst Victor von Leyden (1832-1910)

During the 1860s Ernst Victor von Leyden performed experiments, and soon thereafter gave up the task. He postulated the following theories why oxygen failed to be accepted by the medical commuity:

1. It was thought to have curative powers, and it doesn't
2. It's difficult and expensive to make, and difficult to transport and deliver to patient
3. When prepared by physicians it often contains poisonous gases
4. The apparatus to deliver it is clumsy
5. Hypercritical attitude of physicians
6. Negative results by experiments

The most effective means of employing oxygen during the 19th century was mainly by putting the patient in an oxygen chamber or room, pumping in pure oxygen, and having the patient breathe normal. This concept was used in the variety of oxygen parlors that opened up. Patients with various ailments, and probably some people just wishing to stay healthy, came to breathe the medicated air.

Henry Fleuss (1851-1933)

Henry Fleuss was working to create a method so that scuba divers didn't have to rely on a person working a pump to provide air for him to breathe. He was aware that the first person to discover oxygen in 1773 kept bees alive in a jar by drawing out the carbon dioxide. Later studies showed animals could survive in a sealed chamber if oxygen was supplied.(2, page 83)

So Fleuss intended to use this knowledge to invent an apparatus that allowed divers to supply themselves with air. He, in turn, invented the compressed air or oxygen cylinder in 1879.  (2, page 83)

The device allowed for a "breathing bag mounted on the chest and scuba canister mounted on the back. His device was called a "rebreather" because air was repeatedly rebreathed. Oxygen was added from the tank, and carbon dioxide removed. He used his device to rescue coal miners who were trapped in a mine.   (2, page 83)

So the oxygen cylinder was now available for use in therapeutics as well, if the medical community was willing to use it.  Various manufacturers were now producing oxygen and storing it in steel cylinders.  

Fleuss Apparatus

Tissier describes the tank in Figure 3 as containing "40 gallons of oxygen under 1800 pounds of pressure are contained in a cylinder 3 inches in diameter, less than 13 inches in height, and weighing but 11 pounds. The gas will have a purity of 95 or 96 per cent., being diluted by the small quantity of air in the container. Mounted on the cylinder are a rubber bag of one gallon capacity, and a wash-bottle—so arranged that the gas passes first to the bag and then through the wash-bottle to the patient." (3, page 304)

Tissier explained that a manometer may be attached, although generally the pressure can be estimated by watching the bubbles through the wash bottle. He said that a "gentle, steady stream that does not cause appreciable splashing, and in which the individual bubbles can be distinguished, is best." I imagine regulators at this time weren't very accurate anyway, and someone would be required to make regular checks on the cylinder anyway to make sure there was still oxygen in it. (3, page 304)

Figure 3 -- Oxygen tank, rubber bag, wash bottle,
rubber tubing, mouthpiece (3, page 304)

Oxygen flows from the oxygen tank, some is stored in the rubber bag, which acts as a reservoir, through the wash bottle, through the rubber tubing, and to the patient by means of a nose piece, mouth piece, or face mask. Tissier recommended a hard rubber mouthpiece to prevent the patient from biting through it. For the nostril, glass or rubber could be used. (3, page 304)

He also said: "if nothing better, a funnel of paper cone may be held over the nose and mouth, but not touching the face -- so that expiration may take place beneath it." (3, page 304

The oxygen is set at the desired flow, which there was no way of measuring with accuracy, so it was basically by the gut feeling of the operator. Then the flow is "allowed to flow for a definite time, or, in urgent cases, almost continuously, unless distressing to the patient." (3, page 304)

The funnel is really not preferable because, as Tissier said, it will probably waste a considerable amount of oxygen. However, particularly with pneumonia, it "may save a life."  

Oxygen Chamber for the treatment of pneumonia (6, page 480)
To view more pictures of the chamber click here.

Oxygen can also be given with a desired amount of pressure, if pressure is desired to assist with the patient's breathing and/or to help diminish dyspnea. If this is the case, the oxygen system may be hooked up to one of the various gasometers. Oxygen may also be blended into the air of pneumatic chambers if so desired. (3, page 305) (I will describe gasometers and pneumatic chambers in later posts)

By the 1890s pure oxygen could be piped into rooms or chambers, although this method wasn't often used. Still, in 1922 Alvin Barach (remember this name) wrote that piping oxygen into a room, or a room within a room (also known as an oxygen chamber) provided for the best means of giving oxygen to patients simply because it was the least cumbersome. However, the oxygen provided wasn't always enough to be therapeutic, and the the chambers were inconvenient and expensive. Plus they weren't portible.

Sir Joseph Barcroft (1872-1947)

An efficient oxygen chamber that was somewhat portable was introduced to the world during WWII by Sir Joseph Barcroft. He created an air tight chamber that is "leak tight in order to provide an atmosphere rich in oxygen and which is artificially ventilated in order to provide a comfortable environment. The oxygen content of oxygen is between 40-60 percent (21 percent is available in room air), which is considered the therapeutic range. It is ventilated in order to remove excess carbon dioixde, moisture and heat." (7)

Oxygen could also be provided to the patient by means of crude oxygen tents. These tents were comprised of a canopy that covered the patient's bed, and oxygen was piped into the canopy from a cylinder at the patient's bedside. Yet these early oxygen tents were poorly engineered.

Dr. Andrew H. Smith of New York provided one of the greater contributions to therapeutic oxygen when he wrote "The Inhalation of Oxygen in Acute Affections of the lungs," in 1898. He recommended oxygen for lung diseases that caused dyspnea. In the 1860s he showed the effectiveness of using oxygen to treat animals, and in 1870 he proved the inhalation of pure oxygen was harmless (although we later learned oxygen is a drug with side effects). (5)

Smith explained how methods of creating oxygen and filling rooms with oxygen were actually available in the 1860s, and experiments on animals proved that filling rooms with enriched oxygen can prolong the lives of people who would otherwise have died. Smith also wrote about the use of compressed oxygen, (5) which was discovered in 1895 by Karl Paul Gottfied von Linde of Germany and William Hampson of England.

Generally speaking, if patients required oxygen they would have to seek out an institution or physician with access to it. Oxygen wasn't available in hospitals until the 1920s.  

References:

1. Brainbridge, William Seaman, "Oxygen in Medicine and Surgery -- a contribution with report of cases," New York State Journal of Medicine, 1908, Vol. 8, June, No. 6, pages 281-295
2. Stephens, Jack, "Living Mirrors: A Coral Reef Adventure," 2003
3. Tissier,Paul Lewis Alexandre, edited by Solomon Solis Cohen, "Pneumotherapy: Including Aerotherapy and inhalation methods," volume X, 1903, Philadelphia, P. Blakiston's Sons and Co.
4. Arthur, T.S., et al, editors,  "Oxygen, The Great Health Restorer," Arthurs Home Magazine, 1882, Philadelphia, page 770
5. Smith, Andrew H. "The Inhalation of Oxygen in Acute Affections of the lungs," Trans Am Climatol Assoc, 1898, volume 14, page149-153
6. "Studies from the Rockefeller Institute for Medical Research,",volume XLII, New York, 1922,  Rockefeller Institute for Medical Research
7. Barach, Alvin L., "A New Type of Oxygen Chamber," April 26, 1926,  http://www.jci.org/articles/view/100060/files/pdf, reviewed 10/28/12

RT Cave Facebook Page
RT Cave on Twitter