HFOV

The high frequency oscillatory ventilator (HFOV) has been around for quite some time now. It has been used on adults to treat ARDS, but its main implementation is on the neonate RDS (respiratory distress syndrome) population. 

HFOV has 5 main knobs. 

1. Amplitude 

2. I-Time %

3. Frequency (Hz)

4. Flow

5. Mean pressure

Amplitude - This knob can also be referred to as "delta P" or "driving pressure." This is the main knob adjusted for CO2 correction. Increasing the amplitude will increase the amount of volume delivered through each oscillation. As in conventional ventilation, increased volumes will decrease CO2 levels in the blood. So always remember that this is the first line of defense to reduce the PaCO2 on a blood gas. 

To ensure the patient has adequate volume, obtain a blood gas and adjust for CO2 accordingly. 

In addition, adjust the amplitude for chest wiggle. Chest wiggle ensures that there is an adequate volume being delivered. For a neonate, the chest should wiggle. For a pediatric, the chest down to the navel should wiggle. For the adult, the shoulders down to the mid-thigh should wiggle. 

I-Time % - A typical I:E ratio is 1:2. On the HFOV, a patient doesn't have a true I:E ratio as in conventional ventilation. The oscillations happen so fast that one can not physically count and determine the I:E ratio. But the oscillator will deliver an oscillation at the 1:2 ratio. 

So how do you set an I:E of 1:2? First, take the sum of the I:E (1+2). Then, divide 1 by the sum of the I:E (1/3). This comes out to 33%. Therefore, for an I:E of 1:2, set the I-Time % to 33%. 

Typically, this knob is rarely adjusted. I suppose if you wanted to dedicate more time to "exhalation" during the oscillation, you can change the I:E to 1:3. This translates to an I-Time % of 25% (1/4). 

Frequency - The frequency determines how many cycles ('breaths') the patient will receive. 1 hertz (Hz) delivers 60 cycles per minute. Depending on the size of a premature neonate, the Hz can be set as high as 15. This comes out to 900 cycles per minute!

Some wrongly think that increasing the Hz will have the same effect as in conventional ventilation when the RR is increased. However, this isn't the case. In HFOV, increasing the Hz will actually reduced the amplitude (volume) of each oscillation. If volume is reduced, PaCO2 increases. 

Here's what I mean: If you had a PaCO2 of 60mmHg, in conventional, you could increase the RR to reduce the CO2. In HFOV, if you increase the Hz, you'll increase the CO2. If anything, the Hz should be decreased because this will increase the volume, which will help correct a high CO2. 

The general rule of thumb is: The faster it oscillates, the smaller the volume. 

Therefore, the primary control to correct a high CO2 is to increase the amplitude. The secondary control would be to decrease Hz. 

Flow - Flow is set to allow the circuit to be pressurized. This ensures that there is no lapse from when the oscillator sends a volume to when the patient receives the volume. If the patient exhibits retractions, increase the flow. They're trying to 'pull' a breath. Increasing the flow ensures it reaches the patient quickly. 

What's a good initial setting? The smaller the patient, the lower the flow. The bigger the patient, the higher the flow. For a small premature neonate, a flow of 10-15L/m is acceptable. For an adult, 40L/min is acceptable. 

Mean Pressure - Mean Pressure inflates the lung to the set pressure and keeps it there. The lung does not deflate. This helps distend the alveoli, whereby recruitment is enhanced. This is the primary control to improve lung compliance and oxygenation. You can initially set it between 15-20cmH2O, and adjust it upwards to 30cmH2O for non-compliant, atelectatic lungs. 

Others suggest to set the mean pressure to the same, or slightly above, the plateau pressure the patient had on conventional ventilation. This is a good idea if the patient was previously on a conventional ventilator and the therapist had the ability to perform and record an accurate plateau pressure. This is achieved by performing an inspiratory hold for about a second. In other words, on a conventional ventilator, you can press the 'inspiratory hold' feature, and when the patient inhales, the ventilator will hold that breath and measure the pressure in the lung. That pressure is the plateau. 

When all is said and done, the HFOV looks intimidating but as you play with it, you'll discover it is pretty simple. It's been around for quite some time for a reason. As long as you maintain a safe mean pressure, HFOV is a safe method in treating patients with ARDS. 

FACT: Thin people have sleep apnea, too!

Sleep apnea is a common disorder in which you have one or more pauses in breathing while you sleep.[1] Oftentimes, the pauses can last from a few seconds to minutes. This can happen 30 times or more an hour. As it happens, and breathing restarts, a loud snort or choking sound can be heard. It is during this period that you actually move from a deep, comfortable sleep to a light, poor sleep.

Imagine being woken up 30 times or more an hour. You may not be completely woken up, but shaken to the point to where your body is no longer in that deep sleep. This is similar to what takes place with those affected with sleep apnea. It’s no wonder why sleep apnea is a leading cause of excessive daytime sleepiness.

It was commonly held that if you were not overweight, there was no real risk factor for sleep apnea. Although it is more frequent among men than among women,[2] sleep apnea can affect anyone. Whether you’re thin or thick, if you have the symptoms of sleep apnea (excessive snoring, daytime tiredness), you should consult with a physician for a possible work-up (sleep study) and solution.

Untreated sleep apnea can increase the risk of:

• High blood pressure
• Heart attack
• Stroke
• Obesity
• Diabetes
• Driving accidents
• Memory loss

CPAP devices are the most effective in treating sleep apnea. But its size and volume can often be viewed as too invasive. There is another solution aside from CPAP or surgery: Oral Appliance.

The American Academy of Sleep Medicine has endorsed the use of an Oral Appliance for selected patients with sleep apnea. They typically look like the mouth guards worn by athletes. It works by positioning the lower jaw slightly forward to its usual rest position. This allows for air to freely pass from the upper airway to the lower airway without resistance. These appliances cannot be purchased over the counter. Fortunately, most insurance plans cover the cost.

If you are a respiratory therapist, you should brush up on the various risk factors and treatment options with regard to sleep apnea. There are many risk factors and CPAP is not the only option. If you think you or anyone you know may have sleep apnea, follow up with a physician and ask about the oral appliance option.

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[1] http://www.nhlbi.nih.gov/health/health-topics/topics/sleepapnea/

[2] http://www.sleepapnea.org/learn/sleep-apnea.html

Will The RRT Credential Be A Requirement?

This has been an ongoing debate for quite some time. Will respiratory therapists be required to have an RRT credential? The answer is, yes and It depends, but eventually, yes! If California is any indication as to what will take place, the California Society of Respiratory Care (CSRC) wrote a letter to the Respiratory Care Board of California (RCB) to take “immediate action in implementing the RRT credential.”[1]

Did the RCB comply? Yes. California is mandating RRT credentialing beginning 2015. 

In addition, have you read about the change to the NBRC exam for 2015? Here is a snippet:

Changes will include a single multiple choice examination with separate passing points for the CRT credential and eligibility for the Clinical Simulation Examination which will include a larger number of shorter simulation problems.[2]

In other words, if you score high enough on the CRT exam, you will be eligible to take the simulation exam, and if you pass, you will be given the RRT credential. Currently, the process is that students must

1. Pass the CRT exam
2. Pass the RRT multiple choice (written) exam
3. Pass the RRT clinical simulation exam

That’s all changing by 2015.



[1] CSRC Open Letter

[2] NBRC Change6 

Respiratory Career Colleges

Career Education Schools have been getting a bad rep for years. However, not all Career Colleges are the same. Just because there are some underachieving career colleges does not mean that all career colleges are “bad.”

Students throughout the years have been to both good and bad public colleges. Are there good public colleges as well as bad public colleges? Yes. Are there good Career Colleges as well as bad Career Colleges? Yes. It would be unwise to make a general statement and say “all” public colleges are underachieving. Likewise, it would be unwise to make a general sweeping statement regarding “all” career colleges.

Also, sometimes a college is only as good as the effort the student puts in. I have worked with underachieving clinicians who graduated from a great school.

So here’s the big idea. When looking for a good Career College, consider the following:

• Does the program address real business needs?
• Do the students retain and apply the skills acquired in the program?
• Do the students find employment related to their new skills and knowledge?
• Is the on-job performance of graduates any better than graduates of other programs?
• Do program graduates contribute to performance improvements within the hiring companies?

Career Colleges for Respiratory are not going away. Some are leaving, but not all. The ones that will stick around are probably doing something right. Do your research before enrolling into a college and put forth the effort required to be a successful respiratory care practitioner.

What Does The Future Hold?

What is the future of a Respiratory Therapist? Well, it depends on whom you ask. The skeptic will say that the current market is saturated with respiratory therapists and that the outlook is dim. Unfortunately, this contradicts the report from the Bureau of Labor Statistics (BLS)[1]. BLS predicts a 19% positive job change between 2012-2022. This is faster than the average occupation.

The median pay in 2012 was $26.86 per hour. The entry level position currently requires an Associates degree. Some hold a bachelor’s degree. 

The duty of a respiratory therapist includes:

• Interviewing and assessing patients with breathing difficulty
• Help physicians develop a plan of care
• Perform diagnostic tests to measure the lung function
• Treat patients through various therapies
• Monitor and make changes to treatment
• Educate patients on disease process and proper use of treatments
• Manage the life-support machine

If you’re ready to contribute to the needs of others, and selflessly enter a profession that requires skill and compassion, the respiratory field is for you!

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[1] http://www.bls.gov/ooh/healthcare/respiratory-therapists.htm#tab-1

Arterial Blood Gas - The importance of pH

Having difficulty interpreting arterial blood gases (ABG)? Perhaps the most important aspect in interpreting ABGs is the pH. If you have ever seen a pool man do his job, then you should be able to interpret ABGs with ease.

A pool man tests the water. What exactly is he testing? He is testing the pH of the water. He is ensuring that it's neither too acidic or alkaline. The water must have a normal pH to ensure the safety of the swimmers.

Likewise, the blood has a normal pH. A perfect adult pH is 7.40. If the pH drops below 7.40, the blood is said to be Acidic. If the pH rises above 7.40, it is said to be alkalitic. If the blood pH is below or above 7.40, it does not necessarily mean that the body is in danger. There is a normal range of the blood pH that is acceptable and safe. The range is 7.35 to 7.45.

So the body can still be acidic and safe (7.35-7.39). Likewise, the body can be alkalotic and safe (7.41-7.45).

What can alter the pH? Well, that's the million dollar question! There are two main organs that add acid and alkaline to the blood.
1. Lungs (Respiratory System)
2. Kidneys (Metabolic System)

The lungs are responsible for exhaling CO2. The lungs add acidity to the blood when the lungs do not properly exhale CO2. Also, the lungs can add alkaline to the blood when the lungs get rid of too much CO2.

How much CO2 should be in the blood? A perfect CO2 would be 40mmHg. Anything above that indicates that the lungs have "added" acidity to the blood. Anything below that indicates that the lungs have "added" alkaline to the blood. A safe range for CO2 is 35-45mmHg.

The kidneys (Metabolic System) are responsible for bicarbonate (HCO3). The kidneys add acidity to the blood when there is a low level of HCO3. Also, the kidneys can add alkaline to the blood when there is a high level of HCO3.

How much HCO3 should be in the blood? A perfect HCO3 is 24mEq/L. Anything above that indicates that the kidneys have "added" alkaline to the blood. Anything below that indicates that the kidneys have "added" acidity to the blood. A safe range for HCO3 is 22-26mEq/L.

Those are just the normal values. To get a good handle on how to interpret ABGs, this tutorial is for you. Click and watch how quickly you learn!
http://www.youtube.com/watch?v=b2dTPBwuiyM 

That was simple. - Hemodynamic Interpretation

Have you ever struggled understanding hemodynamics? When I went to school years and years ago, I hated the topic. It all seemed confusing. Thankfully, as I gained experience and knowledge working in the medical profession, I ran across great resources that helped explain the ‘sick-to-my-stomach’ topic of hemodynamics.

The more I learned, the more I realized that it was not as difficult as I once thought. The whole thing reminded me of freeway traffic here in sunny southern California. Here is a great video tutorial to help you learn the basics of hemodynamic monitoring.

Why did I make it so simple? A 4-minute tutorial will not make you an expert in all things cardiopulmonary. But it will give you confidence that you CAN learn all the intricacies of the cardiopulmonary system. You can learn and you should learn.

So watch this video tutorial. Let me know your thoughts!

http://www.youtube.com/watch?v=48F-Zv-2_F0

How are you using your credentials?

Whether you are a new grad respiratory therapist or a seasoned respiratory therapist, you have probably witnessed other RTs not put their credentials to full use. Let me give one example:

A few years ago, while working at a prominent southern California Hospital, I witnessed a page answered by a co-worker. The RN requested a PRN breathing treatment at around 11pm. The therapist laughed when he saw the page-request because he knew that the patient was ordered BID Normal Saline treatments. Puzzled, I asked him, "Are you going to go up and check it out?" He responded, "Why? Normal Saline won't do anything." I politely said, "What room is that patient in? I'll check it out."

As I approached the room of the patient, the nurse thanked me in advance for coming up to administer the breathing treatment. I walked into the patient room and saw a young girl having difficulty breathing and receiving oxygen therapy via 6L/min nasal cannula and bubble humidifier. I asked a series of questions regarding her history (asthma, home meds, etc). I then auscultated her breath sounds, and her entire left lung field was clear. I auscultated over her right lung field, and I could not hear a thing.

I quickly asked her if and where she had pain. She nodded and said her right side hurt. I was able to gather from her that a port-a-cath was inserted and after she awoke from the procedure, she felt pain. I called her physician and asked to order a STAT chest X-Ray to rule out a pneumothorax. 

After the chest X-Ray, I went down to our department to view it with my co-worker who was originally paged. I asked him what he thought of the film. I was very much surprised when he said, “Looks clear.” I responded and asked, “What about the absence of the vasculature?” I could not view any lung markings on the right side. This was a classic case of a pneumothorax.

Sure enough, when I went back to the patient, I spoke with the family that my impression was a pneumothorax and depending on the size, the treatment plan would be basic oxygen therapy or evacuation. Soon after, the Intensivist walked in, looked at the film, and after a professional discussion between him and I, put in orders to have the patient moved to the ICU to remove the air that caused the pneumothorax.

What’s the point? If you are a respiratory therapist, you have to remember that to become one, you took an examination with scenarios similar to the one I described. If you passed, that means you are credentialed to do what I did. I’m not claiming to be a superhero, but I am claiming to be superhonest: too many RTs are being sloppy in their profession. Put your credentials to use and get involved. No, the patient did not require normal saline. But the patient did have shortness of breath. That’s enough for you to answer a page, visit your patient, and help figure out a treatment plan together with the nurses and physicians.

Coping with Myasthenia Gravis

As a respiratory therapist, it is vitally important to know more about Myasthenia Gravis. Unfortunately, most therapists know little about the disease. Most likely, they remember that the disease works its way from the “mind to the ground” – a catchphrase implemented to help remember that Myasthenia Gravis (MG) works its way down from the “M to the G.”

Myasthenia Gravis comes from the Greek and Latin words and means “grave muscular weakness.”[1]  It is an autoimmune neuromuscular disorder that weakens the body. Currently, there is no known cause or cure. Common treatments include Anticholinesterase agents (Mestinon), steroids (Prednisone), and immunosuppressant agents (Imuran). In addition, thymectomy, plasmapheresis and intravenous immunoglobulin (IVIG) have all been used to help treat patients.

As a respiratory therapist, your roll will be to monitor and care for the MG patient. Performing NIF tests and vital capacity measurements are crucial in monitoring the strength of the respiratory muscle.

Moreover, should your MG patient be intubated, stay on top of auscultating breath sounds and suctioning frequently. Do not rush the weaning process as most patients who are intubated have been intubated due to an inability to breathe adequately. Let the ventilator give the patient a break. Treat the endotracheal tube as a friend, not an enemy. Although we must wean aggressively patients who have been intubated for respiratory conditions (patients recovering from ARDS), consider slowing down a bit for a neuromuscular condition.

Lastly, provide words of encouragement and display compassion as you work with both the patient and family. It is very scary to have the ability to breathe taken away from you. Be diligent in your ventilator checks, patient assessment, and family interaction.

(This post is dedicated to Sarah G., who showed tremendous faith in Jesus Christ, while being intubated secondary to a Myasthenia Gravis crisis. At a young age (early 20's), no one could have been prepared for what she went through. But Jesus was prepared to go through it with her!)

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[1] “Myasthenia Gravis,” accessed December 29, 2013. http://www.myasthenia.org/WhatisMG.aspx