Pilot Protection Services Medical Mailbag- February Q&A

QUESTION: I know you advocate oxygen use more liberally than the FAR AIM states but what is the difference between medical and aviation oxygen? My friend wants to adapt his aircraft to accept medical grade oxygen.

ANSWER: FAR AIM talks about pilots having available and using supplemental oxygen in 135.89, for instance referencing flights between 10 - 12,000 feet for more than 30 minutes the precious gas should be inhaled. Many FBO's offer an oxygen refill and I certainly advocate more liberal use than the regulations. Aviator's breathing oxygen is designated "Grade A, Type 1" and must also meet military specifications MIL-O-27210 for purity and moisture content.  Aviators' breathing gaseous oxygen must be 99.5% oxygen by volume and contain no more than 0.02 mg of water vapor per liter at sea level and 70 deg F. It must be odorless and free from contaminants including drying agents.  

Aviators' breathing oxygen is NOT the same and should not be confused with "medical oxygen." Medical oxygen usually contains excessive amounts of water vapor. Air containing a high percentage of moisture can be breathed indefinitely without any serious ill effects. However, the moisture affects aircraft oxygen system in the small orifices and passages in the regulator; freezing temperatures associated with ascent to high altitude can clog the system with ice and prevent oxygen from reaching the user.  

Interestingly, as aviators we can purchase oxygen - I have paid anywhere from $17.50 - $90 to fully charge the system in my plane (and the spare pony bottle I always carry) whereas for medical oxygen a doctor's prescription is required and like all things medical, it costs more! 

So in summary this adaptation does not seem wise, or, quite frankly, necessary. 

QUESTION: I’m due for my Class III in a few months and am currently about 15 lbs. over the a BMI of 40 (5’7”, 265lbs) and I have heard that at this point FAA will require a sleep study to exclude sleep apnea. I am unsure about what course to take as I want to avoid the expense of the sleep study.  As I see it I have two choices: 

1.       Lose 15-20 lbs. between now and the date of my medical and maybe liposuction is not out of the question or;

2.       Get the physical done before the new rule is placed into effect.  

What do you think?

ANSWER: Firstly, sleep apnea is often found in the presence of obesity and is a serious health risk, the name says it all – you are not breathing for periods of time during sleep. Additionally, being obese or overweight does not just mean you are burning more avgas to fly from Point A to Point B, but you are at risk of many life-threatening situations. Losing weight is critically important not just to obtain your medical but to stay alive and disease free! As for liposuction, it is a quick fix and without lifestyle modifications, the fat will come back. The new rule, mandating sleep studies for those with a very high BMI (Body Mass Index, an indication of how close one is to an ideal weight) is on hold at the moment and AOPA has politely suggested that a proper process be initiated by FAA, that being said I am sure it is coming. Some folks can have sleep apnea in the presence of a much lower BMI and in contrast, some with morbid obesity may not have sleep apnea.  Good luck with embarking a healthier and happier life. 

QUESTION: I am a member of AOPA and in June, 2012 took advantage of the 'Lifeline screening' benefit organized by AOPA. It was a good idea, as it turned out, because they discovered a 7.5cm abdominal aortic aneurysm (AAA), which was subsequently operated on.

I have complied with subsequent requirements and am keen to start flying again soon.

ANSWER: Thanks for writing. AAA is the eighth leading cause of death in men and is often a silent killer. Basically, the main artery in the body, the aorta, becomes weakened and a bulge develops, rather like in an old-fashioned inner tube. As the wall balloons, it weakens allowing further distension until eventually it bursts. At that point the patient feels severe back pain and if not hospitalized and operated as an emergency the event proves fatal. Screening for these lurking killers is a good idea if one is over 60, has high blood pressure, raised cholesterol, has smoked cigarettes or has a family history although sometimes they develop in the absence of any such factors. Doctors use 5cm diameter as the upper limit of what we feel comfortable leaving alone so it is a good job yours was caught in time. 

To regain your medical after surgery for AAA the airman needs to provide their medical history, physical examination, and discharge summary from the surgery admission. Additionally the operative report, and if the aneurysm sac was sent for review, the pathology report. 

One also needs to provide a current cardiovascular evaluation to include a maximal stress test (nuclear test if a 1st or 2nd class medical is required).

This story is indicative of the best of screening. 

QUESTION: My doctor wants me to put me on Lipitor 20mg daily. If I do this, will it be an issue for my aviation medical? I am 66 years old, have been taking Norvasc & Cozaar  for high blood pressure which have been reported on my last several aviation medicals. My lipid profile shows a raised LDL and low HDL which I am told is the opposite of what one should wish for.

ANSWER: When we measure blood fats we note total cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), the ration between them as well as measuring the triglyceride levels. It is good practice to have your levels checked regularly so that problems can be addressed. Of course, eating a healthy diet, exercising and keeping one’s weight down are very helpful. 

All of the current lipids lowering agents are acceptable for medical certification but the airman must report the medication in question 17 a. on their next medical examination. Hyperlipidemia does not require a special issuance, nor is one obligated to report the results of a lipid panel.

However, the physician visit should be noted in block 19 (Visits to Health Care Professionals) within the past 3 years.  The "reason" the airman should place in the block could be "treatment for elevated Cholesterol".

Fly Well!
Jonathan, Warren, and Gary

Topics: AOPA, FAA Information and Services, Training and Safety

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