The pocket size spacer?

Every study I've ever seen on the subject show that using an inhaler with a spacer makes the medicine work up to 75 percent better than not using an inhaler.  Respiratory therapists, myself included, are taught never to give an inhaler to a patient without a spacer. 

This Optihaler is marketed as a "pocket spacer." Sure it's smaller than most spacers, but I can't imagine stuffing... no! Can you? It just wouldn't be good.

Manufacturers and marketers are gonna have to keep working on this one.  In the meantime, I find my rescue inhaler works just fine without a spacer. 

3000 B.C. to present: History of chest physiotherapy

Scientists have recently discovered evidence of emphysema, chronic bronchitis, pneumonia and other diseases that cause thick secretions in mummified human remains.  So it's evident humans have had to deal with these conditions from the beginning of human existence.

Ancient Assyrian texts that may date back 3,000 years show evidence that doctors way back then made efforts to help these patients.  One Assyrian text describes the following:

"If the patient suffers from hissing cough, if his wind-pipe is full of murmurs, if he coughs, if he has coughing fits, if he has phlegm: bray together roses and mustard in purified oil, drop it on his tongue, fill, moreover, a tube with it and blow it into his nostrils. Thereafter he shall drink several times beer of the finest quality; thus he will recover." (1, 2)

There were various herbal and medicinal options available to doctors in various regions of the world, although due to lack of communication between civilizations, and the lack of any organized medical groups, methods of airway clearance didn't become uniform in the medical community until recent times.

Chest physiotherapy (CPT) is one of the simplest methods of helping a patient clear thick secretions.  The technique involves cupping your hands and clapping on the patient's back and chest. This is often accompanied with postural drainage, which involves having the patient lie or sit  in different positions in order to promote the drainage of secretions from different areas of the chest.

The use of postural drainage was first mentioned by S. H. Quincke in 1898.  He recommended "intermittent" use of postural drainage to treat patients with thick secretions.  Yet this technique wasn't adapted by the medical community until William Ewart recommended CPT with postural drainage in 1901.  (2)

Ewart worked with children with bronchiectasis, and he recommended "continuous postural drainage" as opposed to "intermittent" to these children in order to promote the removal of thick tenacious secretions.  By continuous he meant that it should be done frequently, as opposed to just once a day.   Generally, the treatment was prescribed 3-4 times a day for up to 10 minutes, and this is still how it's ordered today for the same reasons.(3)

While Ewart may have spearheaded the idea of CPT and postural drainage for bronchiectasis and eventually cystic fibrosis patients, the use of these techniques was ultimately found to be useful to prevent and treat complications that result from performing surgeries.  Physicians noted many of their post operative patients were developing respiratory complications not related to the surgery itself, and they sought to understand and find a solution.

This concept of using CPT to prevent and treat post operative respiratory complications was first described in 1915 by MacMahon in an article about how to treat post operative trauma patients.  In fact, not only did he recommend the use of CPT, he also recognized the importance of exercising as soon as possible after a surgery to get the lungs back to normal, or their pre-operative status.  (4)

Most of the patients MacMahon treated were soldiers injured in battle.  He recommended CPT with exercise, and forced exhalation, and reported that the results were "remarkable," particularly within one week.  By 1919 there was an increasing body of evidence to suggest that where there is "serious lung collapse and chest deformity following wounds or illness, breathing and physical exercises should, in certain cases, be given as accessories to medical and surgical treatment, if the best possible recovery is to be assured."  (2)

Yet it wasn't until the 1950s, when surgeries started to be a mainstay in hospitals (due to improved anesthetics), that any extensive studies were performed to determine the efficacy of doing the procedure, according to Colleen M. Kigin in her 1981 article in Physical Therapy "."Chest Physical Therapy for the Postoperative or Traumatic Injury Patient,"  (5)

Kigin explained that Loius Pasteur first recognized atelectasis in 1908 after "temporary inhibition of muscular activity." In the 1930s studies showed a link between post operative respiratory distress and hypoxemia (low oxygen in the blood).  In 1952 atelectasis was recognized by R.N.V. Palmer and BA Sellick as the most common cause of post operative complications.  (5, 6)

Palmer and Sellick described that some of the best results in treating these complications are by using percussion, postural drainage, and treatments with isoprenaline.  They were among the first to recognize the value of using beta adrenergics to treat and prevent post operative complications.  The idea was that anesthesia causes "reflex bronchospasm" and this results in the retention of secretions.  They concluded that Isoprenaline given before and during anesthesia treated this perceived problem by dilating airways and enhancing secretion clearance in that way.  (7)

It was during the 1950s that the medical community decided that intermittent positive pressure breathing was an effective method of preventing and treating post operative respiratory complications.  This technique forced air into the patients lungs, and it was believed that this helped them take a deep enough breath to open collapsed alveoli.  This technique was proven to be ineffective in the 1970s.  I wrote about the IPPB revolution in this post.

Overall, and other than trials of IPPB therapy, the "gold standard" for preventing post operative pulmonary complications was chest physiotherapy until the 1960s when other methods, such as the incentive spirometer, were discovered to also benefit such patients.  There were also some mechanical percusors available, yet there was never any conclusive evidence they did any better of a job than CPT.  Whether to use cupped hands or a mechanical device was generally left to the institution or therapist. (2)

In 1970 the incentive spirometer (IS) was invented.  It was believed to be more effective than any of the other methods used to promote airway clearance because it could be done by the patient alone.  Seeing this device on the bedside table acted as a reminder or an incentive to take deep breaths.  Likewise, being able to see how high they could make the bellow or balls move up acted as positive feedback.  The patient and the physician could also monitor progress. I wrote about the history if the IS here.

During the 1970s many studies were done to determine the effects of both the incentive spirometer and CPT.  A 1974 article in the British Journal of Surgery studied a group of post operative patients that were treated with CPT and another group treated with IS therapy.  The CPT was done only twice a day, and the IS every hour.  Those in the group receiving CPT had a 63 percent chance of developing post operative complications, and those in the IS group had only a 37% chance of developing complications.  The researchers decided CPT may have been less effective because deep breathing exercises weren't encouraged. (8)

Flutter Valve

During the early 1990s the flutter device was introduced to the market as an alternative to CPT to help with mucus clearance.  It's a hand held device that the patient blows into.  This causes ball bearings inside it to "oscillate at a high frequency, aresulting in vibrations of the airways and intermittent positive expiratoto facilitate mucus expectoration."  While studies show CPT is a better method of helping patinets with cystic fibrosis remove secretions and improve lung volumes, other studies showed that use of a flutter device was even more effective.  Studies also showed that CF patients coughed up three times as much with the flutter as compared to CPT. (10)

Since study sample sizes of studies comparing the various devices for airway clearance have been small, it's difficult to get a dininitive answer as to which one is best to use.  However, based on present study results, it does seem that the flutter valve is a useful technique (11)  Still, which technique to use is a personal preference.  Use of a flutter device is nice because the patient can do it on his own, although the initial expense of flutter devices cost significantly more than CPT.

Acapella (PEP devices)

Another device introduced about the same time as the Flutter valve to help with airway clearance was a Positive Expiratory Pressure (PEP) device called the Acapella. These devices create both oscillations and PEP similar to the flutter valve, although the mechanisms are different.  (12) Some studies show PEP therapy may be even more effective than flutter valves in helping patinets remove secretions, although, once again, sample sizes are small, so obtaining a difinitive answer is difficult.  (13)

Other studies are even more inconclusive, and state there is no evidence one method is any better than the other.  (14)

While CPT, PEP and flutter valves are ordered in hospitals based on availability and personal preference, most hospitals continue to have regular protocols for giving incentive spirometers to most post operative patients.  While there has never been a study that has proven the incentive spirometer has any effect on treating and preventing post operative respiratory complications, (9) most hospitals have developed protocols that recommend all post operative patients be given an incentive spirometer by a respiratory therapist, be educated on how to use it, and encouraged to use it at least 10 times every hour.

Many hospital protocols go a step further and instruct patients how to use these devices prior to surgeries, especially those who will get upper abdominal and thoracic surgeries.  I think this is a good idea because it can be difficult to teach this device to patients when they are sedated after surgery.  It's also nice to know how well they did on it before surgery so we know when their lung volumes are back to normal.

Some physicians throw the gamete at all post operative patients. We have one doctor who orders post operative patients to get an albuterol breathing treatment, incentive spirometer, and CPT four times every day for three day.  Some doctors only order one or more of these procedures when a patient develops a fever, which is a common sign of atelectasis.  However, it must be known that there has never been a conclusive study showing any of these methods do any good.

Yet regardless of all the technology, CPT continues to be the gold standard method of helping patients promote airway clearance.  Regardless of what studies say, just havintg a respiratory therapist in the room moving the patient from side to side assures the physician the patient will be assessed and moved on a regular basis.  This alone may all that most patients need for a speedy recovery.

References:  

1. Sigerist HE, "A History of Medicine. Vol 1. Primitive and Archaic Medicine," 1951, New York, Oxford University Press, 1951; p. 481
2. Pryor, JA, "Physiotherapy for airway clearance in adults," European Respiratory Journal, 1999, 14, pages 1418-24
3. Nelson, HP, "Postural Drainage of the Lungs," The British Medical Journal, August 11, 1934, pages 251-255
4. MacMahon, C, "Breathing and physical exercises for use caes of wounds in the pleura, lung and diaphragm," Lancet, 1915, pages 769-70
5. Kigen, Colleen M, "Chest Physical Therapy for the Postoperative or Traumatic Injury Patient," Physical Therapy, 1981; 61; pages 1724-1736
6. Palmer, RNV, Sellick BA, "The Prevention of Post Operative Pulmonary Atelectasis," Lancet, 1953, 1; pages 164-168
7. Odell, J.R., "Prevention of Post Operative Chest Complicaitons," Anesthesia, January, 1959, Vol 14, no. 1, pages 68-75
8. Craven, J.L., et al, "The evaluation of incentive spirometer in the management of post operative pulmonary complications," British Journal of Surgery, 1974, 61, pages 793-7
9. Overland, Tom J., et al, "The Effect of Incentive Spirometry on Postoperative Pulmonary Complications: A Systemic Review," Chest, September 2001, vol. 120, no. 3, pages 971-978
10. Gondor, Megdalen, et al, "Comparison of Flutter Device and Physical Therapy in the Treatment of Cystic Fibrosis Pulmonary Exacerbation," Pediatric Pulmonology, 1999, 28; pages 255-260
11. Homnick, DN, K. Anderson, JH Marks, "Comparison of the flutter device standard chest physiotherapy in hospitalized patients with cystic fibrosis: a pilot study," Chest, 1998, 114, pages 993-997
12. Volsko, Teressa, et al, "Performance Comparison of Two Oscillating Positive Expiratory Pressure Devices: Acapella versus Flutter," Respiratory Care, 2003, 48 (2), pages 124-130
13. Mcllwaine, P.M., et al, "Long-term comparative trial of positive expiratory pressure versus oscillating positive expiratory pressure (flutter) physiotherapy in the treatment of cystic fibrosis, Journal of Pediatrics, 2001, June, 138 (6), pages 845-50
14. Westerdahl, Orman J, "Chest physiotherapy with positive expiratory pressure breathing after abdominal and thoracic surgery: a systematic review," 2009, Oct. 29, vol. 54, issue 3, pages 261-267

Happy Labor Day (and back on the health train)

If you go to just about any asthma blog, or listen to any asthma expert, you'll see how important it is to exercise when you have asthma.  It's important to keep your body in tip top shape in order to control the asthma beast.  

So the way I'm celebrating Labor Day this year is by getting back into the routine of a good diet and exercise.  My wife even came home from work this morning with donuts, and your humble writer here resisted the urge.  

It's normal for me to take off the month of August because it gets so hot and humid, although this year the hot and humid came in July, so that resulted in two months off.  So while I usually wait until October to start eating right and working out, this year I'm forced to do it right now.

Yes, I mean forced.  I see here that I'm not the only one who takes off time from a workout with "no good reason."  It's just amazing how you can work out for three months to lose weight and get in tip top shape, and in as little as one month you can lose it all, or lose the muscle and gain the fat back.  

1856-1858: The first nebulizer

Dr. Sales-Giron's portable nebulizer (5)

Dr. M. Sales Giron, of Pierrefond, France, is given credit for inventing the first portable nebulizer.  (8, page 461)

According to Mark Sanders at Inhalatorium.com, the device had a pump handle that operated like a bicycle to draw liquid from a reservoir and forced it through the atomizer.  This provided a fine mist for the patient to inhale whatever medicines were in the reservoir.  (1)

This idea actually came about because the main ways for people to inhale medicines in the mid 19th century was by either inhaling the smoke or steam of volatile medicine.  Doctors knew that many non volatile medicines would also be of use for diseases of the airways, and the only way to get the medicine to the lungs was to produce a mist.  (8, page 461)

James Prosser, in his 1884 book "The Therapeutics of Respiratory Passages," notes a mist would work well for non volatile and volatile medicines because "it carries with it particles of solids (the medicine) as it may contain in solution." (3)

This concept was first thought up when persons observed that when a rapid stream of water hits a rock a spray or mist is produced that can be inhaled.  The idea that this could be used for the inhalation of medicine was first played with by Auphan at the spa of Euzet-Les-Bains in in 1849.  (9, page 184)

At such spas mineral water was put over heated rocks and the steam was inhaled.  Prosser writes:  (2)

"The  idea of atomizing the mineral waters seems to have originated, or at any rate to have been first carried into effect, by Auphan at (the spa of) Euzet-les-Bains in 1849; he projected a jet of the mineral water on the wall of the inhaling room with sufficient force to break it up into a spray, which was inhaled by his patients.  This method was adapted at several spas."

The July 30, 1870 edition of The Medical Times and Gazette reported that the so called inhalation room was often referred to as an 'inhalation saloon,' and by this means did actually charge the atmosphere with the spray, or, as he termed it, the 'pulverized' or 'atomized' water.  (4)

The problem with inhalation saloons, as Prosser notes, was the difficult proving actual mineral waters were being used or just plain water.  This method of treatment was generally determined to be "ineffective" and "not suitable for private practice."  (8, page 461)

Figure 1:  The original Sales-Giron Nebuliser

So the market was open for a device that would allow a person to create a mist of mineral water in his own home.  M. Sales-Giron was charged with the challenge of inventing such a device by M. de Flube, owner of a watering place at Pierrefond. (9, page 184)

Sales-Giron worked on this project for many years, until finally introducing his final product to the Academy of Medicine in Paris on May 20,  1856.  In Pierrefond a Sales-Giron Inhalatorium was opened where 1-15 patients could inhale the mist at the same time.  (9, page 185)

By 1858 he introduced to the market a portable device that could be used anywhere. In it any medication can be used to produce a spray "as fine as the mist created in an Inhalatorium. (9, page 187) He referred to it as "Pulverisateur portatif des liquides medicamenteux."(8, page 461)

The original product can be seen by the woodcut in figure 1, and is described here:

"It consists of a vessel filled with the fluid to be atomised, while above it is placed an air-pump, A, which compresses the air above the surface of the water, the pressure being indicated by a manometer, c. When the instrument is at work the fluid escapes through the fine opening of a tube with a stopcock, D, and strikes against a small metal disc, E, where it is broken and turned into a very minute vapour, any of the condensed vapour escaping through a small tube, G." (8, page 461)

The device is also described by Dr. John Milton Scudder in his 1867 book "On the use of medicated Inhalations in the treatment of diseases of the respiratory organs."  He writes:

"(The instrument is) so constructed that the medicated fluid is forced, by the agency of compressed air, through a tube having a very small opening against a metal plate.  At this point the steam of fluid is checked, and it becomes divided into fine spray, (to which the term of pulverized, or atomized, has been applied), and in this condition can be inhaled by the patient."  (5, page 23)

While it appeared to be a great idea, something asthmatics had waited thousands of years for, it was slowly accepted by the medical community.  One of the main concerns at the time was whether the mist actually made it to the lungs.

Prosser writes:

"But at length Sales-Giron constructed a portable apparatus for atomising fluid, and brought it before the Academy of Medicine of Paris n 1858.  This was undoubtedly an epoch in the history of inhalations, and the greatest interest was excited.  It was not, however, until 1862 that the committee of the Academy appointed to investigate the new method brought in its report, and during the interval prolonged discussion had taken place as to whether the spray penetrated deeply into the air passages.  The report stated that it was proved that both the water and the mineral constituents employed penetrated not only to the bronchi but even to the air-cells; and this report was founded on extensive independent experiments and was almost unanimously adapted by the Academy.  The conclusion and practice of Sales-Giron, who has been called the Father of Atomization, thus received the highest authority and rapidly spread over the civilized world.  Demarquay was one of the earliest to adapt it, and to prove independently that atomized liquids rapidly pass into the respiratory passages."  (2, 6)

Prosser adds that the device was later improved upon by Dr. Lewin, Dr. Bergson, Dr. Siegle and Dr. Baigel.  I will write about these devices in a later post.

However, one problem with the device was it was large, fragile, and expensive.  Another major obstacle was that it was hand powered and difficult to use.  For this reason none of these original nebulizers were readily accepted.

References:

1. Inhalatorium.com, "Sales-Giron's Pulverisateur," viewed April 30, 2012
2. Prosser, James, "The Therapeutics of Respiratory Passages," 1884, New York, pages 281-282
3. Prosser, ibid, page 284
4. "The Progress of Therapeutic Science," The Medical Times and Gazette: A Journal of Medical Science, Literature, Criticism and News," volume II for 1870, 1870, July 30, London, John Churchil and Sons
5. Scudder, John Milton, " On the use of medicated Inhalations in the treatment of diseases of the respiratory organs," 1867, Cincinnati, 2nd edition, Moor, Wilstach, and Baldwin
6. "The Progress of Therapeutic Science," , ibid, provides a more precise description of the process of doubt and inevitable proof that the Sales-Girons nebuliser did get medication directly to the air passages is provided in this article.  See page 125
7. Picture compliments of Mark Sanders of the inhalatorium (inhalatorium.com

8. Beatson, George, "Practical Papers on the Materials of the Antiseptic Method of Treatment," Vol. III, "On Spray Producers," Coats, Joseph, editor, "History of the Origin and Progress of Spray Producers  ", Glasgow Medical Journal, edited for the West of Scotland Medical Association, July to December 1880, Vol. XIV, Alex and Macdougall, pages 461-484

9. Cohen, Jacob Solis, "Inhalation in the treatment of disease: it's therapeutics and practice," 1876, Philadelphia, Lindsay and Blakiston

The four asthmatics

There once was one asthmatic, now there are four.  It's official now that three of my four children now have asthma.  This lifelong asthmatic has successfully transferred his asthma genes to three of his children.  

My two-year-old has had eczema since birth, so it was only a matter of time before the asthma struck.  And the retractions were noticed right away this time.  Instead of waiting, we called the doctor right away and got the oral steroids ordered.  Breathing treatments of Albuterol were given every two to three hours until the steroids took effect.  Then all was well.

It was kind of funny (well, not really) when my kids were lined up and I had to listen to them with my stethoscope one after another.  All three were wheezing.  I had to take turns giving them breathing treatments, and washing the equipment between nebs so not to share germs (one of my these kids also has mono).  

So later in the day all my kids are on the swing set and the dad decides to rake the acorns (all 3 billion of them) from the backyard.  All the dust that billowed up and now the dad has to wait in line for his turn at the nebulizer.  Yep, we now have four asthmatics in this house.  

Respiratory Therapy History Timeline

Compared to physicians, who can trace their roots to ancient times, and nurses, who can trace their roots to Clara Barton's Civil War heroics, the profession of respiratory therapy is a relatively young profession that can be traced only as far back as 1922.

We could trace it back to 5,000 B.C. when Egyptians inhale smoke from dried and crushed herbs burned on heated bricks to get breathing relief, or 100 A.D. when in India herbs were smoked in pipes, or even the 19th century when the first nebulizers were patented.

Yet the profession as we know it can only be traced back to 1922 when John Scott Haldane wrote about his research on oxygen in "The Therapeutic Administration of Oxygen."  It was this book that sparked interest in the therapeutic use in oxygen to treat diseases.

One of the first people to gain interest in attempting to create some sort of effective device for delivering therapeutic oxygen to patients was Dr. Leonard Hill of England.  In 1921 he announced his invention of an oxygen tent capable of delivering approximately 30 percnet oxygen.  It consisted of an airtight canopy that covered the patient and the bed.  (1) 

A major problem with these tents is they had no methods of controlling humidity and temperature, and patient's would become very uncomfortable inside them.  However, patients who needed supplemental oxygen to breathe would request the tent be taken down, and as soon as their breathing became labored again they'd request to be back inside.  So it was sort of a double edgled sword for these patients. 

In 1926 Alvin Barach invented an oxygen tent blew air over ice chips to cool the temperature inside the tent.  This made it so being inside the tents were much more bareable.   Usually these tents were reserved to patients with pneumonia and heart failure. (2) In 1931 John Emerson invented an oxygen tent that had a cooling system.  Preious devices were prone to rust and failure.  His cooling mechanism was  also ice.  (3)

In 1928 the Shaw respirator was introduced to the market.  This was the first electric and mass produceable negative pressure ventilator.  It was large, very expensive, noisy, and very heavy.  Yet it soon became very useful in keeping patients inflicted with polio and other such disorders that caused a person to stop breathing alive.  These ventilators, referred to as the tank or iron lung, were improved by John Haven Emerson, and in 1931 he introduced the Emerson Respirator.  Emerson's design was simpler, quieter, and had a method of manually breathing for the patinet should their be a power outage. Emerson's respirator would quickly become the most common iron lung used in hospitals in the U.S. and Europe. 

Nurses were initially responsible for oxygen equipment during the 1920s, and doctors and their technitians were initially responsible for setting up and manageing the iron lungs.  Yet lugging heavy oxygen tanks into rooms, and monitoring how much oxygen was in them, remained the task of the nurses.  Since the gauges were primitive, nurses would have to use formulas to calculate how long the tank of oxygen would last, and would have to switch tanks before they became empty. 

Complicating matters was that along with performing their nursing duties they also had to manage the oxygen tents and, eventually, iron lungs.  Their were a variety of gauges on the iron lungs that had to be monitored, along with making sure oxygen tanks used were likewise constantly full of oxygen.  To make matters worse, the gauges used were known to be innacurate (4)

Oxygen masks are designed by John Haldane and others, and are made of leather.  The first non-rebreather masks are fitted with vinyl bags for storing excess oxygen to be rebretahed, and had two one way valves, one on each side of the mask, to prevent air entrainment.  These masks at times turned out to be deadly when an oxygen tank ran empty.  And since the leather masks fit snug over the patient's face unlike modern plastic masks, one of the flaps would ultimately be required to be removed in order to prevent accidental asphyxiation.  This is the reason one of the flaps is missing on modern non-rebreathers. 

Vinyl nasal catheters were also designed by Haldane.  To humidify oxygen glass and metal humidifiers were invented.  Nebulizers were also made of glass, although until the 1930s a bulb had to be used to cause the medicine to turn into an aerosolized mist.  In the 1930s an electric nebulizer was invented and was mass produced that made for breathing treatments to become easy and more effective.  It became the job of nurses to administer such breathing treatments.  It was their job also to clean all this equipment between patients. 

By the 1940s nursing assistants are recruited to set up, monitor, and clean oxygen equipment.  They are ultimately referred to as inhalation tharapits and also pick up the task of doing the same for iron lungs and other respiratory equipment.  These first inhalation therapis are generally trained on the job, often referred to as OJTs (on the job training) and are usually poorly educated about what they were doing.  It was for this reason that an organization called the Inhalation Therapy Association was created in 1946 to form a means of educating inhalation therapists and further improving credentials and respect for the new profession.  The name was changed a few more times until it's current name of the American Associatino of Respiratory Care (AARC). 

By the 1930s oxygen is beginning to be piped into hospitals, and this continues during the 1940s.  For a while there is a fear that the profession will become to an end, as most inhalation therapits, now referred to as respiratory therapists, are often referred to as tank jockeys.  Yet the profession would evolve into more than just oxygen as in 1952 the first intermittent positive breathing machines become available.  These machines would at first be used to ventilate patients for short periods of time either via a rubber mask or cannula inserted into a tracheostomy.  Their are a variety of IPPB machines to hit the market, yet the most common are the Bennet PR 1 and 2, and by 1955 the Bird Mark 7. 

These machines were used as ventilators until the late 1950s and early 1960s until they and the iron lungs were ultimately replaced by more effective volume ventilators, the most popular of which were the Emerson Volume Ventilator that hit the market in 1964 and the MA1 that hit the market in 1967.  The Emerson ventilator was often referred to as a big green washing machine.  The MA1 was such a sturdy and compact unit that it was still around in 1997 when I became an RT at my present location. 

Monitoring and maintaining these machines was a complicated job, and respiratory therapists were needed.  While oxygen equipment became simpler over time, respiratory therapists were still required to monitor it's use, set it up, and clean it between patients.  RTs were also needed to do IPPB treatments.  During the early 1950s it became a common belief that giving aerosolized medicine, such as bronchodilators, by an IPPB machine three to four times per day would force the medicine deeper into the lungs.  This type of therapy was also believed to open collapsed alveoli and improve atelectic lungs in post operative patients.  It was also believed to prevent atelectasis.  For this reason, IPPB therapy became very common in hospitals and was ultimately used for more than just post operative patient.  It was used for COPD patients, asthma patients, and patients with just about any other lung disorder.  RTs were needed to do all this.

It was also during the late 1940s and 1950s that observations were made about COPD patients becoming lethargic and even dying due to exposure to too much oxygen.  This gave birth to the hypoxic drive theory whereby it was believed some COPD patients who were chornic CO2 retainers no longer used CO2 as their drive to breathe and instead used oxygen.  For this reason, it was believed that  too much oxygen would knock out their drive to breathe.  This was ultimately proven by Dr. E.J.M. Campbell in the 1950s based on a study of only four COPD patients.  In a report to the physicians in 1960 he reported his findings, and ever since doctors have been taught the hypoxic drive theory. 

The hypoxic drive theory is significant in that it was another reason for the importance of respiratory therapist monitoring oxygen therapy.  As therapist obtained more and more responsibility, it was realized the scope of knowledge needed for these individuals far exceeded their education and training.  This was particularly apparent on the weekends and night shifts when the least experiences therapists were working alone. (5)

By the 1960s most respiratory therapists have to study and take a test to work in the field, and this put an end to on the job training.  The first tests are oral, although eventually the written tests are created.  This also put an end to respiratory therapist being an ancillary staff, and instead RTs became a respected part of the patient care team. 

In these early days most respiratory procedures were profitable.  Many believe this was one of the reason so many IPPB therapies were ordered during the 1950s and 1960s.  Yet during the 1970s insurance companies started questioning the need for all these IPPB treatments.  Studies performed proved that nebulized aerosols provided better distribution of medicine into the lungs that IPPBs, as much as 35% better distribution.  Other studies proved that insentive spirometry was more effective than IPPBs in preventing and treating post operative atelectatis.  So IPPB therapy in this way started to decline.  However, it would be until the turn of the 21st century that most Bird Mark 7s would be bound and tied in the basements or sent to foreign countires or simply jettisoned into the trash pit.  These machines were durable, and my hospital still has one that doctors still put into use even to this day. 

In 1983 DRGs are created, and hospitals no longer get reimbursed for each procedure performed.  For this reason, many RTs fear their jobs will be eliminated. Instead, hospitals would be paid a flat fee for each patient.  In this way it was believed that hospitals would do as few procedures as possible when taking care of a patient.  Thus, it was thought DRGs would reduce hospital costs.  Yet the exact opposite happened.  In order to meet reimbursement criteria, many doctors simply diagnosed patients with diseases they thought were the most reimbursable, such as pneumonia, asthma, cardiac failure and COPD.  Perhaps it's for this reason, or just a coincidence, that asthma rates have skyrocketed since 1980. 

Since 1980 IPPB therapy has seen a decline, but aerosol therapy has seen a incline.  Doctors now order breathing treatments instead of IPPB therapy for all lung ailments.  In many cases, breathing treatments are ordered so the patient or family member thinks something is being done to make sure the patient or family doesn't sue the doctor.  Breathing treatments are also often ordered as part of order sets that make sure everything is ordered that may be needed for the patient to meet government set criteria for reimbursement.  This has all resulted in an exhorbitant amount of breathing treatments being ordered, and this has helped many RTs to continue to work.

Yet many hospitals have added protocols that allow the therapist to use his education and skills to only provide those services that are necessary and proven to work.  Many hospitals allow RTs driven protocols that allow RTs to decide who should get breathing treatments, and other protocols allow for RTs to decide what oxygen device to use, and what ventilator settings to use.  Many hospitals also have ventilator weaning and extubation protocols, and, of course, respiratory therapists are a major part of the hospital's critical care team responsible for attending all code blues, or instances where a patient doesn't look quite right, has severe difficulty breathing, or goes into cardiac or cardiopulmonary arrest. 

There are a miraid of responsibilities for today's respiratory therapists.  A minimum of two years is now required to work in most RT settings.  The field is continueing to grow and gain respect.  Surely there is a ways to go, but since nursing has had an extra 60 years to evolve, it may take another 60 years for the profession of respiratory therapy to reach the full level of respece of the nursing profession.  Still there are obstacles to cross, yet the profesion will continue to be a necessary one for many years to come. 

References:

1.  "Questions and Answers," The Modesto Bee, Thursday, Dec. 2, 1948
2. Glover, Dennis W., "The History of Respiratory Therapy," 2010, page 40
3. 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
4. Glover, ibid, page 48
5. Wyka, Kenneth A, Paul Joseph Mathews, William F. Clark, "Fundamentals of Respiratory Care," 2001, page 10, "The Late 1950s and 1960s: Organizational and Clinical Maturation."

1980-2012: Evolution of Artificial Respiration

1980s: Down's Flow Generator:  Continuous Positive Airway Pressure, something that was researche in the 1930s but basically ignored as the iron lung was the popular mode of ventilating patients, made a comeback in the 1980s as studies showed it was effective in treating patients with COPD and sleep apnea.  The most common method of delivering CPAP in the hospital setting was with a Down's Flow Generator. The device was plugged into a wall oxygen outlet and hooked up to wide bore tubing.  The tubing was connected to a face mask that was securely strapped to the patient's face.  A pressure manometer is attached to the mask and an oxygen analyzer is added to the circuit via a T-piece to monitor percent of oxygen delivered to the patient.  A venturi system allowed you to adjust the FiO2 delivered to the patient.  Studies show a CPAP of 7.5 increases the partial pressure of alveolar air by 1 percent which is enough to force enough oxygen into the blood to make a clinical difference.  This was used until the mid to late 1990s when larger machines such as the Vision were determined to be more efficient deliverers of CPAP.  From my experience, CPAP is rarely ever used by itself in the hospital setting as BiPAP is usually preferred (see below).  However, when oxygen alone is the issue, CPAP may work just fine.  CPAP is, however, used as an effective means of weaning patients from ventilators, and thus is incorporated as a mode in most modern ventilators.  A downside to these generators is they didn't have any alarms.  A variety of CPAP generators are presently still available, such as the WhisperFlow generator which allows for contorl of flow and accurate FiO2s and various Caradyne Isobaric CPAP Valves to allow the clinician to adjust CPAP based on the patient's clinical condition. 

1983:  Puritan Bennett 7200

This was the first microprocessor ventilator to hit the market.  The machine was very durable and simple to use.  The settings were set by scrolling through an led screen, and alarms were set in the same way. It was easily used, portable, and worked well for the patient.  It quickly became the "most widely used ventilator around the world, capturing a 60 percent share of the international market by the end of the decade.  (c)

1987:   The Bird 6400ST

This ventilator was the first of the new generation of volume ventilators to hit the market.  It was a rectangular shaped ventilator with all your basic knobs on the front, including volume control, assist control, SIMV, PS and CPAP modes.  It also had a PEEP valve that was easily adjusted by a dial, and a full set of alarms.  The only knock on this simple device was the expiratory valves needed to be cleaned between each use and were a pain in the butt to put back together and keep in functioning order.  It was a very compact ventilator for its time.  We actually used this ventilator as either our main vent or back-up until about 2008.  

1991:  Servo 300 Ventilator

This was a replacement ventilator for the Servo 900 and was generally created to complete with the the Puritan Bennett 7200.  It was much simpler to use than the old 900 version, and therefore was less intimidating.

It had a new mode called Pressure Regulated Volume Control (PRVC) which made it so the patient could get a guaranteed volume, yet a sensor in the machine sensed changes in patient lung compliance to make sure the lowest pressure possible was given.  This is a ventilator that is still used where I work, although as a back up to the Servo i.

The ventilator also had an option called automode that allowed the patient to switch from a controlled rate (such as PRVC, or pressure control) to a patient driven mode (such as volume support or pressure support).  Many newer ventilators have their own version of PRVC and automode.

Another neat feature was it was one of the first ventilators that it provided the option of allowing either pressure or flowby to be used.  Before this all positive pressure ventilators sensed a patient breath as pressure was decreased when the patient inhaled.  Flowby is actually more sensitive in that all the patient has to do is inhale a small amount of flow and this is sensed by the machine.

 It also had a nice set up of graphics screen so you could see what the patient was doing and make adjustments accordingly.  This feature was nice because it allowed the patient to control the ventilator instead of the other way around.  It had a few flaws, yet it was a great ventilator.

It was also the first ventilator that could be adjusted so it could supply breaths to a patient of any age or size.  It was a good ventilator for newborns, pediatrics and adults. As you look at the entilator the what the patient was doing was lit up as red, and the ventilator settings were green.  So we'd often tell nurses:  "Green machine, red bed."  (d)

1992:  V.I.P. Bird Infant Pediatric System

It was referred to as the T-Bird ventilator. At the time it was also the first and only ventilator that was mobile.

1995:  BiPAP:  Noninvasive Positve Airway Pressure, sometimes referred to as simply Bilevel Positive Airway Pressure (which is a patented name but we often generic it), became common in the 1990s as another method of ventilating patients in a more non-invasive manner.  This is a means of providing support breaths with CPAP or PEEP, which is generally called end positive airway pressure (EPAP) on these machines.  Some of the initial models were crude and called for supplemental oxygen to be connected into the system, but new systems, such as the Vision, are touch screen, have flow and pressure waveforms, and allow the machines to be used pretty much like a ventilator.  The advantage is you can ventilate a patient and improve oxygenation without having to intubate the patient.  Masks can be removed for eating and drinking and taking medicine, and also oral care.  Studies show these machines work great for COPD, CHF and even some asthma patients.  They also work well for home use for patients with obstructive sleep apnea. Modern BiPAP machines are also more effective than the aforementioned down's flow generator in delivering CPAP, and the machines also allow for alarms and patient monitoring. 

2000:  Servo i, 840, Avea Ventilators

It has all the same features as the Sero 300 except that the flaws of the 300 have been corrected.  Instead of having all the dials on the front the settings are set by an easy to use touch screen.  The basic settings of rate, tital volume, and FiO2 could be set either this way or by quick access dials on the bottom of the screen.  The ventilator was also connected to a graphics screen for easy to see ventilator graphics.  (d)  Other similar ventilators include the Puritan-Bennett 840 and the Avea Ventilator.  These newer vents are microprocessor vents that include a variety of modes to improve patient comfort.  They also include waveforms to monitor the patient, and a variety of alarms.  Modern vents are also upgradeable. 

The future:  What will the future bring?  


References

1. (d)"About us:  History of Ventilation," maquet.com,  http://www.maquet.com/sectionPage.aspx?m1=112599762812&m2=112599885558&m3=112600545105&m4=112806653448&wsectionID=112806653448&languageID=4, accessed February 27, 2012