**7.1 Medical Criteria for Transportation of Patients by Airline:**

General considerations/requirements

Specific considerations/requirements based on the type of medical
problem

Logistical aspects, pros and cons

Follow-up procedures

This chapter will provide you with a basic understanding of the
parameters for transporting patients by air. Commercial carriers are
able to safely transport passengers with medical problems of many kinds.
Those with stable disabilities are entitled to access. Patients with
unstable problems must be evaluated before flying and commercial
transport may not be appropriate. Air ambulance services are available
to move patients from accident sites to definitive care to transport
unstable and those too ill to travel by commercial aviation. You will be
able to assess a patient for flight by applying your basic knowledge of
human pathology and physiology to the environmental conditions of air
travel. This section will deal with commercial airliner travel and the
next with air ambulance service.

**Medical Criteria for Transportation of Patients by Commercial
Airline**:

Commercial airliners exist as a method of transportation of large
numbers of passengers from origin to destination. They are not intended
as a medical transportation facility and should not be treated as such.
However, due to the large number of people traveling, it is inevitable
that some with known or unknown medical problems will travel, and the
environment of the aircraft cabin must be taken into consideration. In
general, an understanding of the aircraft flight physiology must be
addressed first. Further information regarding air ambulance
transportation will be covered in Section 7.2.

Commercial airliners use pressurized cabins and supply the air by
pumping in outside air, either by a separate pumping mechanism or
bleeding the air off the compressor section of the jet engines powering
the aircraft. As a result, the supplied air inside commercial airliners
is extremely clean and dry. For example, an aircraft flying at 37,000
feet would provide air to a cabin that has a relative humidity of only
1-2%, but is biologically virtually sterile. The temperature constraints
inside most commercial cabins during flight are in the 65-75°F range and
air quality content is regulated so that an entire turnover of the air
inside the cabin occurs every 3-5 minutes. Some of this air may be
recycled, but if recycling occurs it is passed through high efficiency
particulate air filters (HEPA), which remove any biological content
added by the occupants of the cabin. In aircraft where smoking is
prohibited (this includes all U.S. commercial flights), environmental
tobacco smoke is not a significant consideration and the only source for
biological contaminants will include exhaled products of occupants, such
as viruses and bacteria, or clothing contaminants, such as fungi and
dander, particularly cat and dog dander.

![](media/image1.jpeg){width="4.239583333333333in" height="6.25in"}

Outside air is compressed in the engine intake, flows through
environmental and pressure regulating components before entering the
cabin.

The pressure inside a commercial aircraft cabin will not exceed 8,000
feet above sea level or approximately 2,500 meters. Barometric pressure
will decline from 760 mmHg at sea level to a minimum of about 550 mmHg
at maximum cabin altitude. In a normal individual, this would cause
arterial oxygen saturation to fall from 98% to 88%. Additional concerns
in flight include vibration, turbulence, noise, and barometric pressure
changes. It is important to remember that the composition of the cabin
air remains essentially unchanged, with ambient oxygen content in the
20.5-21% range at all times, even under maximum crowding of the cabin.
Carbon dioxide levels are regulated to a maximum of 1500 parts per
million, although occasional slight higher excursions will occur due to
the use of carbonated beverages and dry ice. These limits are derived
from using CO~2~ as a surrogate for measuring odors, not due to health
limits from CO2 itself, which are several times higher.

Certain individuals should not travel as passengers. The basic criteria
is that the passenger should be stable and travel should not represent a
potential threat to the health and safety of the passenger nor to the
health and safety of the other passengers and crew. Exclusions would
include individuals with infectious diseases likely to be spread within
the aircraft cabin, such as active tuberculosis, mumps, measles or
uncontrolled diarrhea. Those with lice could spread the infestation to
others. Individuals likely to harm or threaten themselves or others
should also be excluded. In the past, such individuals have attempted to
claim that they are disabled and therefore entitled to special
consideration. However, the health and safety of the crew and other
passengers may override any individual's right to accommodation.

Specific medical conditions should be addressed by the individual
challenges of flight. The aircraft is a slightly hypoxic environment
which may negatively impact cardiac conditions. Persons who have had a
myocardial infarction within two weeks or who have an unstable cardiac
condition, congestive heart failure, recent open-heart surgery, and
unstable cardiac rhythms are contraindicated. While most commercial
aircraft do carry automatic external defibrillators, limited success
with these devices does not insure survival, much less survival without
severe morbidity.

If the treating physician is concerned about the mildly hypoxic
environment, Oxygen supplementation can be ordered. In the United
States, this is limited to either 2 L or 4 L per minute flow rates. Use
of oxygen in flight is a medical prescription and must be supplied by
the air carrier. The individual patient is not permitted, per FAA
regulation, to bring on board their own oxygen supply. The air carrier
should be contacted at least 48 hours prior to travel to coordinate the
use of oxygen. Likewise, patients with chronic pulmonary disease will be
more hypoxic at altitude and their condition may be mildly exacerbated
by the extremely dry environment, prompting consideration of humidified
oxygen.

The most common medical emergency in flight has historically been asthma
occurring in non-compliant patients. Patients should carry their own
medication with them on their person and not consign it to checked
luggage, which may be securely stowed in a baggage compartment and
unavailable in the event of an attack.

Deep vein thrombosis has been associated with commercial flying;
however,

statistical studies do not demonstrate any higher risk for DVT in
aircraft compared to any other environment. Any sitting for a prolonged
period of time, such as a bus or in a movie theater, creates a potential
risk for deep venous thrombosis or the further complication of pulmonary
embolus. Therefore, passengers should be encouraged to move about the
cabin every 60-90 minutes and to maintain as much leg space as possible.
They should also adequately hydrate themselves. Use of other devices
such as elastic stockings, aspirin, or subcutaneous heparin have not
been validated in prevention of DVT in aircraft or other settings.
Certainly an individual with a known DVT should not place themselves in
any situation where the condition can be exacerbated.

Obstetrical patients in later stages provide a significant risk of
precipitating delivery during flight; pregnancy past 32 weeks should be
carefully considered for restriction from flight and those past 36 weeks
should be prohibited from flying. An aircraft is not a delivery room.
Additional concern about deep venous thrombosis in the pregnant patient
may be another issue.

Patients with orthopedic concerns must take into account their limited
ability to move. Casts, if applied within 24 hours, may need to be cut
lengthwise, or "bi-valved" to avoid expansion of the tissues from
inflammation and edema, causing circulatory compromise. Individuals who
are unable to move or sit in a conventional seat may request specialized
seating. Accommodation is required under the Airline Passenger
Assistance Act and the Americans With Disabilities Act, although
48-hours notice is also obligatory. Individuals who require mobility
assistance devices, such as wheelchairs, are entitled to have these
transported at no additional charge. However, the passenger should
arrive significantly before scheduled departure time in order to permit
the wheelchair, particularly if it is battery-powered, to be safely
packaged and stowed for flight.

Psychiatrically, patients who are well controlled on their medications
should not have difficulties in flight. However, anxiety and fear of
flying could lead to precipitous actions. Appropriate and judicious use
of anxiolytic medications are sometimes indicated. Caution should be
exercised when using psychotropic medications because of idiosyncratic
reactions that could cause agitation in flight. Some sedatives can
suppress respiration in pulmonary-compromised patients. Passengers with
mild dementias, such as early Alzheimer's, are subject to increased
agitation in unfamiliar surroundings, "Sundowners' Syndrome". If the
personal physician has significant concerns, a medical attendant should
be assigned to accompany the traveling patient.

Diabetes mellitus controlled either by oral agents or insulin may be
complicated by air travel. Disruption of meal planning and sleep
schedule can seriously impact glucose regulation. The passenger should
carry a supply of insulin and syringes, but take care to appropriately
dispose of syringes in the needle disposal kits provided on the aircraft
and not leave these under seat cushions. Such irresponsible actions on
the part of some diabetics has created blood-born pathogen hazards for
subsequent occupants of the seat and airline employees who clean up
after the flight.

Post surgical conditions should be, in general, safe once the anesthesia
recovery period is complete and there is no significant residual trapped
gas in the body. Small amounts of residual gas in the abdomen may not be
of significant concern, although anticipated expansion by 25% of bubble
size should be anticipated under a normal flight operation. Under no
circumstances should any postoperative patient who has gas either within
the eye or the central nervous system (following spinal tap, myelogram,
or pneumoencephagram) be permitted to fly until all gas has been
absorbed. Even minimal expansion of gas in these spaces can cause reflex
cardiac arrest.

Scuba divers should take normal precautions following dives requiring
decompression stops. Twelve hours should elapse before flying after a
single dive without compression stops. For any other dive where
decompression stops are required or following multiple dives, at least
24 hours should elapse prior to flying. If an individual has been
treated for decompression sickness, a much longer period of time should
elapse and a hyperbaric specialist consulted prior to permitting the
patient to fly.

The airlines have medical departments and consultants available for
consultation prior to flight. Some airlines have in-flight consultation
via telemedicine. Passengers should be aware that aircraft are not
equivalent to a hospital emergency room and airline medical kits are
designed to handle only the most basic of emergencies. Unstable patients
should not travel by commercial airlines, and if air travel is
necessary, use of an air ambulance should be considered.