Aeromedix.com - flightBlog - Essentials news concerning safety and medical issues in AVIATION

I get a lot of questions from pilots experiencing problems with their medical exams. Most of these problems could have been solved if they had chosen their Aviation Medical Examiner (AME) correctly.

For instance, look at this excerpt from an email response to a pilot with a medical issue I sent out recently:

“You should be yelling at XYZ company’ help get your medical (name withheld to protect the guilty). You paid them money for a job they are not doing. They should have insured that all the medical documents were sent together by a service which requires a signature for receipt (e.g., FedEx) and then made sure you were inline for the review by the cardiologist. I still do not know why people waste their money with companies who promise to help pilots get their medicals. Your AME should have done all this. He is the best source for calling OKC and getting status information on your exam. If your AME will not do that, I suggest you find someone else the next time.”

Select your AME carefully. It is not much of an issue if you are totally healthy; however, if you do have a medical problem take some time to investigate. First of all, ask the pilots around your local airport for recommendations—especially pilots who may have had medical problems. (You do not have to ask which pilots have had medical problems, just ask the old ones!) AMEs who get good recommendations for having gone out of their way to help someone with a medical is great reassurance.

Second, make sure the AME is a pilot. You can do check this out at the FAA database (http://www.faa.gov/pilots/amelocator) where the pilot ratings are listed for each AME.

Why a pilot? There are several reasons. One is that an AME who is a pilot knows how important the ability to fly is for each of us. They generally are more interested in aviation, understand what it takes to be in the cockpit, and will go the extra mile for a pilot who needs help with medical problems that threaten his ability to fly.

Although there are exceptions, non pilot AMEs are using the status to build their practice. Being an AME may be a pain for a physician because of the time it takes for the exam, the data input of exams, keeping up with FAA regulations, and the every-three-year required classes. Most pilot AMEs are doing it as a service and because it keeps them involved in the pilot community. A non pilot AME may be interested in aviation but given the hassle, bringing cash patients through the door is a more likely scenario.

How does the AME make a difference? There are many ways but willingness to spend time is the most important way. When there is any medical issue on a pilot medical application, the AME can deal with it in several ways. For instance, if a pilot has new onset hypertension, the AME can make sure he has the proper documentation from the treating physician or have the pilot get the proper documentation. The AME has 10 days to submit the information so the pilot has 10 days to obtain it. With the proper documentation of good blood pressure control and no side effects from the medication, the AME can issue the medical immediately.

However, if the AME is not paying attention he can grant the medical without the paperwork and the FAA will contact the airman and request all the information.

Even the FAA does not like this way of conducting pilot medicals because the AME is not doing what they are suppose to do and is creating unnecessary work for the FAA.

The worst case scenario is that the AME defers the medical. This saves the AME a lot of time because he just says to the pilot that he has to send everything into the Regional Flight Surgeon or OKC and just checks a box on the form. Easy for the AME—a world of paperwork for the pilot and FAA even if the pilot was deferred inappropriately. (Fortunately, the FAA is cracking down on AMEs who defer inappropriately just like they have on AMEs who grant medicals that should have been deferred.)

There are many cases which absolutely require deferment but the right AME can help here as well. A pilot who has had a heart attack will require review by the FAA for the 1st application after the event. The AME can help by making sure the pilot has all the appropriate paperwork and records for the application. The AME should submit the exam with all the paperwork in the same package and send it to the FAA via a “signature required” service. This insures that the FAA receives all the required paperwork and everyone knows what date it landed at the FAA.

If records and testing are submitted separately, there is no one checking off when the file is complete. A file ready for review may wait until the pilot or AME calls and asks if the file is complete. This is a waste of time for everyone and a good AME will not let this happen.

For renewals, the FAA allows AMEs through their AASI (AME Assisted Special Issuance) program to issue medicals for stable conditions on the spot. The pilot needs to READ THE FAA LETTER which accompanies his initial certification for what testing and reporting will be necessary for renewal and when that testing should occur. If the pilot brings the proper renewal documentation to the AME and it shows a stable condition, the AME can issue the medical right then and send the paperwork into the FAA for review after the fact. Unfortunately, there still are Medical Examiners out there who still do not know how this program works.

Brent Blue MD is a Senior Aviation Medical Examiner in Jackson Hole, Wyoming, who flies a Cessna 340 and just finished building a Blue Bear (a Murphy Moose modified for safety). He was the team physician for the US Aerobatic Team for the 1994 World Competition in Hungary and has served on the EAA’s Aeromedical Council. He also owns Aeromedix.com which specializes in medical and safety products for pilots, their families, and their dogs.

Aeromedix was founded to introduce portable, economical pulse oximeters to general aviation. Prior to this advanced equipment, pilots were at the mercy of the FAA regulations to determine when and how much oxygen to use. Those regulations, originally developed in the 1950s, were based mostly on politics and economics and minimally on human physiology. Basically, the 12,500 and 14,000 MSL rules were instituted after the GA lobby convinced the FAA that anyone should be able to fly a GA airplane anywhere in the US without supplemental oxygen. Thus, this 12.5 for 30 minute rule made it possible for any pilot to fly across any mountain or mountain pass without the need for what was then, heavy, expensive oxygen equipment.

What we now know is that some pilots need oxygen at 8,000 feet and some younger, healthy ones, who live at 6,000 feet, might not need oxygen till much higher. Pulse oximetery gives a modern determination of when and how much oxygen a person needs. No more guessing (more about pulse oximeters later).

One caveat before I get into oxygen systems—everyone who flies high and certainly anyone who flies over 18,000 feet needs to undergo high altitude training in an altitude chamber. This is not for the commonly held reason that it teaches the pilot how to recognize hypoxia in their system. That is hog wash. The basic problem with early hypoxia is that it impairs cognitive thinking. No one who gets goofy is going to know when they are getting hypoxic and needs supplemental oxygen.

The purpose in altitude training is to prove to pilots that they too can get goofy when hypoxic. The best chambers video this display of hypoxic effects on each participant so when back to normal oxygen levels, the pilot can see exactly how dumb they got. Convincing each and every pilot that they too will be affected is the important part of this training.

There are many types of oxygen equipment but the bottom line is oxygen is oxygen. Probably the most significant issue for pilots is the hassle of filling the oxygen, how big a tank to buy, and whether conserving equipment is necessary which is based on the prior two issues.

Since the 1960s, all oxygen sources have been from liquid oxygen. There is no difference between aviator’s and medical oxygen. When oxygen was first used in hospitals, the gas was humidified in the tank which is a problem for aviation because water will freeze in oxygen plumbing in cold, high altitude aircraft environments. Since medical oxygen is humidified after it leaves the tanks, this is no longer an issue. However, getting something taken off the FAA regulation books requires undue time and energy so everyone uses whatever oxygen they can find and no one apparently cares. If you truly get “aviation” oxygen, you will find the only difference is that it is tested for water and is more expensive.

First, let me address built in oxygen systems. When an unpressurized aircraft is certified with oxygen, the oxygen system delivers oxygen at a flow rate which is set for the service ceiling of the aircraft. The FAA rule is 1 lpm for each 10,000 feet. If your turbo aircraft is certified for 25,000 feet, your oxygen system would deliver 2.5 lpm regardless of whether you were flying at 15,000 or 20,000 feet. (One disclaimer, there are some aircraft which have automatic pressure controllers but few work properly.) This is a true waste of oxygen. Although oxygen is dirt cheap, if you have to fill at an FBO, the mark up is ridiculous and you are supposed to have an A&P sign off the fill. Most people who have built in systems and use them frequently have gone to filling their systems themselves using readily available hose kits which fit large H cylinders which they keep in the hangar. Not quite legal but I have never heard of anyone being busted for it! Besides, you can always have your friendly A&P sign it off.

A big improvement for the built in systems was the Nelson flow meter introduced in the 1970’s which was essentially a medical flow meter with settings in thousands of feet instead of liters per minute (lpm). The pilot just dialed 15,000 feet into the device which had a floating metal ball and they received the FAA required 1.5 lpm and saved 1 lpm over the preset flow the unadulterated aircraft systems would have given them. These style flow meters are readily available from Aeromedix and others. Another improvement was the FAAs decision to allow the use of nasal cannulas instead of masks up to 18,000 feet. This allows the use of oxygen saving cannula and increased comfort (translates in to more willingness to use). More on cannula and mask later.

Pulse Oximetry

Pulse Oximetry is the biggest advance in oxygen use in aircraft since, well, the use of oxygen in aircraft. It brings the use of oxygen into the 21st century.

Pulse oximeters measure the oxygen saturation in the blood. They do this by comparing the red pulsation of ones pulse in the finger to the background red between pulses via a special red light emitted from the unit. Via a complicated formula embedded in a microchip in the unit, it calculates oxygen saturations. This system works with almost every finger but is impaired with black or some other deep colored nail polish, people with low blood pressure, cold fingers, Reynaud’s syndrome, and a surprisingly few other situations.

Normal saturation at sea level is 95 to 100%. In Jackson Hole, at 6,200 feet, normal is 90 to 95%. When and how much oxygen to use is an interesting question. There are no FAA recommendations based on oximetery. However, when we introduced pulse oximetery to aviation, we did some physiological testing and have made the following recommendations.

The pilot and passengers should take note their saturation levels at their home airport (obviously different if they live at sea level versus a ski town). We recommend that the person “should” use oxygen if their saturation drops five points below their home airport saturation. We recommend that the person “must” use oxygen if their saturation drops ten points below their home airport saturation. Now some pilots will require oxygen at 8,000 feet and other might not need it to much higher. Once the decision to use oxygen is made, the level should be titrated by adjusting the oxygen flow to bring the saturation close to the home field levels. 

An important caveat to remember about pulse oximeters is one thing fools them—carbon monoxide (CO). CO actually falsely increases the saturation reading. It is one but not the only reason everyone should have a low level carbon monoxide detector. in their aircraft—high altitude flying or not. This silent killer is responsible for accidents every year and carbon monoxide accidents are completely preventable.

Portable Systems Fall between Cracks

Portable Systems fall between the regulatory cracks. Aviation systems are not regulated by the FDA and portable systems are not regulated by the FAA. For the most part, all oxygen equipment made in the US is of superior quality and can be trusted. Tanks do need hydrostatic testing every five years but that is about all the hassle besides filling the system.

Tanks can be filled at most medical, welding, or other gas suppliers. Some require a prescription but this is as variable as the TSA inspectors at airports. (I will be happy to provide a prescription for any of our customers.)

Generally the size of the tank is dictated by the normal mission length and altitude, the number of passengers usually taken, and the space on board the aircraft. Tanks come in different lengths and diameters and there never is a perfect choice. Systems have built in gauges showing their fill level and require a second regulator stage which lowers the pressure to the flow meter (if not built into the second stage itself).

Cannulas

One of the newest and cheapest oxygen saving devices to hit the market is the Oxymizer Cannula. This cannula has a thicker section which sits on the upper lip under the nose which contains a “bag” which collects oxygen during the exhalation and pause part of the breathing cycle. The normal breath cycle is inhalation, exhalation, and pause. With normal cannulas, the oxygen flowing during the exhalation and pause part of the cycle is wasted. With the Oxymizer cannula, the oxygen flow during these portions of the cycle is captured and the bag collapses during the inhalation portion of the cycle giving the “stored” oxygen to the pilot. This allows for lower oxygen settings to obtain the same inhaled amount of oxygen. This cannula can increase the oxygen tank duration up to 50%. For those who dislike the larger nasal portion under the nose, there is a pendant style Oximizer which has a “remote” storage “bag” and works the same way. We combine the pendant with the OxyArm cannula for a cross between convenience, comfort, and increased oxygen duration.

Although the FAA requires the use of oxygen masks above 18,000 feet, I have concerns about that. Depending on the individual, they may or may not be able to obtain a high enough saturation in the flight levels. (Anyone who flies unpressurized aircraft in the flight levels must have an oximeter. It is crazy to fly without one.) My concern with masks is that you have to take it off to drink water or to eat (hopefully, you have a built in mic). In the flight levels, even during a 15 second period of taking off the mask to drink some water, a pilot can get goofy and forget to put the mask back on. One great thing about nasal cannula is that they are kept on for eating and drinking. Besides, I have never seen a FAA inspector at 18,000 feet.

Find out more about our Oxyarm with Oxymizing Pendant Conserver here at Aeromedix.com

The Cirrus Problem

For Cirrus pilots only: The Cirrus Pilot Operating Handbook has presented an unusual problem dealing with oxygen. Cirrus has designated a specific portable system for the aircraft to be legal for oxygen use. This requirement is for the aircraft to be legal. For the pilot to be legal, they can use any source of oxygen. What this means is that to be totally legal, you must have the Cirrus required system on board but you can bring along any system you want to provide the oxygen. The only place you would have trouble with not having the designated system on board would be if you were ramp checked and told the FAA examiner you had just been flying above 12,500 feet MSL for more than 30 minutes or above 14K at all. Don’t you dare!

Many folks who love the OxyArm designed by Walt Atkinson and Rob Apens want
oxygen conservation as well.  Now Aeromedix has done just that by combining the
“pendant” Oximiser with the OxyArm.  The Oximiser pendant is a hockey puck shaped
plastic container which has a collapsible plastic bag.  This is normally connected to a
routine nasal cannula.  At Aeromedix, we combined the OxyArm with an Oximiser
pendant by cutting the pendant’s built in cannula and replacing with the OxyArm.
Testing shows effective oxygen savings in the 50% range.  (The device works by
storing the oxygen being delivered during the exhalation and pause portions of the
respiratory cycle and delivering the stored oxygen during the vacuum created during
inhalation.  Thus, flow rates can reduced by about one half.  We recommend an pulse
oximeter to check oxygen saturation with all oxygen use.)

 Oximiser pendants can be purchased separately if you already have an OxyArm for
$26.95.  With the OxyArm as a combo, it is $125.95.

 Only from Aeromedix.

 

 

When it comes to controlling severe bleeding, QuikClot is the best thing since sliced bread.

QuikClot is a very small beaded material that absorbs smaller water molecules from the blood leaving platelet and clotting factors that stops even severe arterial and venous bleeding.  Experiments on pigs with lacerations of the femoral artery in the groin showed a reduction of fatalities in this almost always fatal wound by 50%.  (This exact type of injury occurred to a local veterinarian working on a horse by himself near our office.  He unfortunately died at the scene.  I will always wonder if he would have been saved if QuikClot had been available.)                     

QuikClot is particularly useful whenever bleeding cannot be stopped by a tourniquet or direct pressure like the head, neck, chest and abdomen, the material aids homeostasis (control of bleeding) in the limbs with a tourniquet or direct pressure.  Instructions for use are basic–pour the granules over the wound until you can see a layer of the beads.  More than than is not necessary.  For the impregnated sponge type, just stuff the sponges into the wound.  The material is removed by irrigation when the appropriate definitive medical care can be delivery.

Only the amount of QuikClot that is necessary to cover the wound should be used since the material creates some heat.  This is not a big problem and the amount of material is directly related to the amount of heat.  Once the beads cover the wound, do not put any more on.  Once the QuikClot absorbs the fluids, the heat stops so it the heat only lasts for a few seconds.

Unfortunately, once a package is opened, it cannot be used later since the absorption of humidity renders QuikClot inactive.  The package can be used on multiple wounds or multiple patients once opened.

The shelf life of an unopened package is three years with the only restriction being not to leave it in direct sunlight.  It can be exposed to ambient heat and cold.

When it first came out a few  years ago for military use, I wanted Aeromedix to carry it but they only sold in large quantities unsuitable for individual use.  Z-Medica, the manufacturer, has now recognized the consumer and EMS market so they have made packaging consumer friendly.  Aeromedix only carries the prescription level QuikClot beads and the QuikClot ACS which is a fabric sponge impregnated with the beads, not the over the counter formulation, which does not work as well.

I recommend everyone carry QuikClot in their first aid kit and have it on the self in every shop where injuries can occur.  This stuff is truly lifesaving!