CHAPTER 7: OTHER
The cabin environment and vulnerable individuals
7.42 Our deliberations on
the aircraft cabin environment have revealed relatively few health
concerns for the great majority who are in normal health. However,
as the age and health spectrum of those travelling by air widens,
more and more people are flying with pre-existing or previously
unsuspected medical conditions, which might be compromised by
the cabin environment. MedAire has also told us that there is
some evidence that ill or injured passengers, who, if they were
to be moved by air at all, might previously have been transported
in air ambulances, are now being carried in airliners (p 249).
7.43 We are grateful to AsMA for the excellent commentary
and discussion on pre-existing medical conditions which may be
compromised by air travel that they submitted in evidence to us
(p 198) - indeed, their publications were frequently referred
to or cited in others' evidence. Valuable comments, information
and suggestions were also received from some members of staff
at the Imperial College School of Medicine (p 239), from Dr Matthews
(p 248) and in material from the Aviation Health Institute,
including lists of conditions which may either preclude flying
or require special medical attention before and during flight.
As noted in paragraph 8.42, there are also some useful specialist
textbooks and other guides on medical conditions which affect
fitness to fly.
7.44 Drawing on all that
material, we give some general guidance for such vulnerable individuals
in paragraphs 7.46-7.72, although this is no substitute for personal
medical advice. Individuals with many of the conditions concerned
will already be in close touch with appropriate specialists. Intending
passengers with any doubts about their fitness to fly should discuss
these matters with their medical advisers and with the airline
(or its agents) at the earliest possible opportunity.
7.45 At the risk of stating the obvious, it is essential
that those with known medication needs should take sufficient
supplies for the journey and, unless they are certain about supplies
at their destination, for their stay and return journey.
OF SPECIAL CIRCUMSTANCES
7.46 Intending air travellers,
or their medical advisers if appropriate, should inform airlines
at an early stage of any medical condition they have which may
require a decision on their fitness to fly, and of any special
requirements they may have in boarding, flight or disembarking.
There is an IATA standard medical information form (MEDIF) available
from travel agents and airlines for this purpose. The Form is
in two parts - Part 1 to be completed by the passenger and/or
the agent, and Part 2, when appropriate, to be completed by the
passenger's medical adviser. The airline will decide whether it
can accommodate the needs and thus accept the passenger, if necessary
after further medical examination and certification of fitness
7.47 There is also a standard IATA card (FREMEC)
for those who need frequent medical clearance by which their physical
travel requirements (excluding medical requirements such as on-board
oxygen supplies) can be registered in computer booking systems,
to avoid the need for repeated submission of MEDIF forms.
7.48 It is not realistic
to require airlines to accept as passengers everybody who might
wish to fly, which is why aircraft are exempted from the requirements
of the Disability Discrimination Act 1995 specifically
pertaining to the transport of passengers, including means of
access standards. Decisions on these questions are potentially
sensitive and may give rise to complaints, the general handling
of which we discuss in paragraphs 8.57ff. Airlines have, however,
a commercial imperative as well as a wider social responsibility
to make reasonable provision for people with disabilities. We
applaud the improvements achieved through IATA noted in paragraph
3.23, and encourage the industry as a whole to keep the matter
under continuing and positive review.
7.49 For those with heart
or circulatory disorders, the reduced in-flight oxygen availability
may lead to a state of hypoxia (lowered body oxygen levels) which
may further jeopardise their health. Many people with cardio-vascular
disease are able to compensate for flight-induced hypoxia by increased
breathing and increased cardiac activity, but some are unable
fully to cope and will develop symptoms unless they are given
supplementary oxygen. All cardio-vascular disease patients should
take professional advice before travelling. If it is considered
that they may need extra oxygen, they should declare this to the
airline, which will normally make the appropriate arrangements
at small or no extra charge. (Passengers are not allowed to take
personal oxygen supplies on board.) They should also declare any
need for pre- and post-flight physical assistance.
7.50 There are some cardio-vascular conditions, sufferers
from which should not travel by air without proper advice. These
are largely associated with the recency or severity of the disorder,
known complications or lack of stability, and significant hypoxia
at ground level. Pre-flight advice and declaration is essential
as the carrier has the right to refuse flight even to a ticket-holder.
Consideration must also be given to the altitude of take-off and
7.51 Patients with stable angina, stable congestive
heart failure, asymptomatic valve disease, controlled hypertension,
and most types of pacemaker, should be able to travel safely provided
they continue their medication. This should also be the case for
those with recent strokes, heart attacks or cardiac surgery when
they have recovered and stabilised.
7.52 Predisposition to DVT may also be associated
with some cardiovascular disorders, as noted in paragraphs 6.13ff.
7.53 The primary factor affecting
most respiratory disorders is also the potential for hypoxia.
Air travel must be considered as potentially risky for people
with any condition which limits lung capacity. These will include
bronchitis, bronchiectasis, emphysema, pulmonary hypertension,
cystic fibrosis, interstitial lung disease, pleural effusion,
pneumothorax and pulmonary infections. Some people with skeletal,
neuromuscular or malignant disorders may also be at risk because
of inability to enhance respiration in response to hypoxia.
7.54 Bronchial asthma is the commonest respiratory
disorder amongst travellers, and those whose condition is severe,
unstable or have recently required hospitalisation might be advised
not to travel by air until their condition is well-controlled.
All asthmatics should carry their standard medication with them
on board, and should also consider taking emergency medication
7.55 Many people with respiratory disorders are able
to travel by air, particularly with pre-booked supplementary oxygen
supplies, but all should take medical advice beforehand, and some
should be formally examined and tested for fitness to fly.
AND THROAT CONDITIONS.
7.56 The most important factor
affecting ear, nose and throat (ENT) conditions is the changing
cabin pressure during ascent and descent, which may cause barotrauma
as discussed in paragraphs 5.43 and 5.44. If any of the anatomical
passageways between ears, sinuses (air cavities in the bones of
the face and head), nose and throat are, or become, blocked during
flight, discomfort, pain and tissue damage may occur. Ear-block
and head pain are the commonest medical complaints associated
with air travel, and most passengers who fly frequently will experience
some ENT problems at times, particularly if they have recent or
current common colds. Dry cabin air may also contribute adversely
in some cases such as those who have recently undergone major
7.57 Acute and chronic sinusitis, middle ear infections
and recent ENT surgery are all potential reasons not to fly, but
pre-flight treatment with antibiotics and decongestants, and waiting
for an appropriate time after surgery, should enable most
people to become fit to fly. In-flight use of local decongestants
and moisturisers may also be helpful.
7.58 Generally, the cabin
environment presents no medical hazards to normal pregnancy. The
Royal College of Obstetricians and Gynaecologists cited evidence
of a slightly increased risk of miscarriage in cabin crew (p 279),
but the airline Emirates said that this finding had not been replicated
in later studies (p 229).
7.59 Flying while pregnant may be inappropriate for
those with a history of miscarriage or premature delivery, severe
anaemia, recent vaginal bleeding, pre-eclampsia, and a serious
fear of flying. It would be a wise precaution for all pregnant
intending passengers to seek professional health advice before
booking their flight.
7.60 In the early stages of pregnancy, air-sickness
might compound "morning sickness". In the later stages,
cramped seating, narrow aisles, limited mobility, seat belts,
gas-producing foods and general discomfort might cause physical
problems, and the risk of DVT must be considered. Airlines will
usually carry healthy pregnant passengers of up to 36 weeks' gestation.
As Virgin Atlantic noted, pregnant cabin crew are usually grounded
on declaration of pregnancy to avoid any occupational risks to
them or to the foetus (p 107), especially from cosmic radiation
(see paragraph 3.63).
7.61 Although new-born babies
should be able to fly safely, it is prudent to wait a week or
so before taking them on a flight in case of post-delivery problems
that might not be apparent at first sight, such as certain congenital
defects, metabolic abnormalities and post-natal infections. After
this period, the cabin environment presents no general problems
for infants, although their immature ENT function may cause problems
during ascent and descent. Feeding should ameliorate any potential
problems due to pressure changes.
7.62 Increasing numbers of
people are flying soon after surgery. Indeed, as AsMA noted, it
is not uncommon for people to fly to a destination for their surgery
and return home by air soon afterwards (p 198). The important
cabin environment factor which may affect post-surgical passengers
is pressure change, although reduced oxygen availability may also
be of concern (see paragraph 7.67).
7.63 Gases introduced into, or trapped inside, body
cavities will undergo volume expansion on ascent, and reduction
on descent. As noted in paragraph 5.43, this may cause problems
after any surgical procedure, but is primarily a problem after
abdominal, intestinal, cardiac, lung, ENT, eye and cranial surgery.
In the majority of cases, flying must be postponed until the gases
have dissolved or diffused and suture lines have healed. Surgeons
should always provide the appropriate warnings and advice about
flying too soon.
7.64 Patients who have recently undergone surgery
for detached retina may be seriously affected by pressure changes
and should take specialist advice.
7.65 Travellers with established colostomies are
not at risk, but throughput may be raised because of pressure
differentials between the gut and the outside of the body.
7.66 Travellers with encased limb fractures are at
some risk from pressure changes because of the unyielding nature
of the casing, and must take pre-flight advice.
7.67 While recent general
anaesthesia does not preclude flying (any residual medication
or effects clear rapidly), surgery and trauma invariably increase
the body's oxygen requirements and post-operative patients may
be unusually susceptible to the reduced oxygen in cabin air (see
paragraphs 4.4ff). Delaying flight until recovery is complete,
pre-booking oxygen supplies, or pre-flight assessment of fitness
to fly, will ameliorate potential problems.
7.68 There is nothing about
the aircraft cabin environment itself which should affect those
passengers with pre-existing neurological or psychiatric disorders.
However, as noted in paragraph 6.62, the discomfort and stress
of air travel could cause latent or controlled abnormal tendencies
to become overt. People who have disorders which are unstable
or potentially incapacitating, or whose reactions to unusual and
stressful environments are unpredictable, should carefully consider
(with their medical advisers as appropriate) the potentially stressful
nature of air travel and their fitness to undertake it.
7.69 People whose physical or mental abilities are
impaired, those on controlling medication, those who have frequent
or unpredictable seizures, those with relevant phobias, and those
with psychotic or socially disruptive disorders should particularly
take note of the nature of air travel. Physical constraints of
the cabin environment, limited access to toilet facilities, potential
mild hypoxia, air turbulence, air-sickness, fatigue, boredom,
jet-lag, management of medication when travelling across different
time zones, disturbed meal-times, and absence of normal supporting
features of their home environment - all potentially compounded
by the duration of the flight - may each or severally contribute
to affecting adversely their already compromised neuro-psychiatric
7.70 The only people in this group who should not
fly are those whose reactions could lead to behaviour which is
unacceptable or unsafe for themselves or fellow passengers. Most
others may be able to undertake air travel with suitable advice
and calming medication - and, in particular, accompaniment by
a knowledgeable companion.
7.71 There are very few other
conditions which would render those who have them vulnerable because
of the aircraft cabin environment itself. Decompression sickness
in passengers who fly too soon after diving was discussed in paragraph
5.47. Three others are discussed here.
(a) Severe anaemia from any cause, blood
disorders such as sickle-cell disease and some leukaemias, and
any other condition which reduces the oxygen-transporting capabilities
of the blood are potential reasons not to fly. However, subject
to pre-flight assessment and booking of oxygen supplies where
appropriate, most sufferers should be able to travel by air.
(b) People with some eye conditions, and those
who wear contact lenses, may be particularly affected by the dry
cabin air and may need to use "artificial tears" when
flying. Patients needing regular medication with eye-drops such
as those with glaucoma or conjunctivitis are not at risk provided
they maintain their medication throughout flight.
(c) Diabetes itself is not affected by the aircraft
cabin environment. However, the disruption of the timing and nature
of meals, and of strict medication dosing and scheduling, on long-haul
flights (particularly across many time-zones), can present major
challenges to the insulin-dependent diabetic and problems for
others. The diabetic air traveller should obtain appropriate advice,
and preferably written instructions to be kept on the person,
before any flight.
7.72 A remaining possibility
is that of allergy or sensitivity to substances in the cabin.
This was referred to in the Australian Senate BAe 146 Inquiry
Report (see paragraph 2.14) as a possible cause of ill health
arising from exposure to fumes and vapours from engine oil leaks.
Such idiosyncratic reactions - in the aircraft cabin or elsewhere
- are, by definition, unexpected and unpredictable. However, the
possibility should be borne in mind in unexplained ill health
closely associated with air travel, particularly if symptoms arise
during or soon after flight.
7.73 We received statistical
details on the nature and extent of in-flight medical events from
a number of sources (including airlines, trade organisations and
professional bodies) and figures published by airlines and regulatory
bodies were widely quoted in others' evidence. Unfortunately,
some of the statistical reports were not comparable between sources
because individual airline requirements for recording and reporting
of incidents differ substantially: for example, British Airways
reported in-flight medical incidents as occurring in 1 in 12,000
passengers (p 99), whereas Virgin Atlantic's reported incidence
was 1 in 1,400 (p 107). The current diversity in collecting data
on in-flight medical emergencies serves no-one's interests. We
welcome the news that standardised reporting procedures will be
introduced by the world's major airlines in the near future (Q
7.74 Taking account of the
overviews provided by AsMA, BATA and MedAire, a reasonable estimate
of the incidence of medical events requiring professional intervention
(including by cabin crew who are trained to deal with medical
emergencies) is about 1 in 14,000 passengers, with an in-flight
death rate of about 1 in 3 million passengers (pp 198, 104 &
249). Considering that nearly two billion passengers undertake
air travel per year (see paragraph 2.1), it is no surprise that
a substantial number of in-flight events occur that require medical
intervention or that deaths occur in flight.
7.75 The great majority of medical incidents are
minor complaints which are resolved on board. General aches and
pains, headaches, fainting, gastro-intestinal upsets and respiratory
symptoms are the most commonly reported. The much smaller number
of serious medical problems are mainly associated with cardiac,
lung and cerebral disorders, asthma and cancer; most sufferers
have pre-existing disease. Some of these will lead to in-flight
death, and some will require the aircraft to be diverted and landed
at the nearest airport with access to major emergency medical
facilities. Because of differing company policies, routes flown,
medical equipment and expertise on board, and availability of
ground advice by radio, diversion rates are very variable between
airlines. From the evidence given by British Airways, Virgin Atlantic
and BATA, there appear to be about five times as many diversions
are there are deaths in flight (pp 99, 104 & 107).
7.76 Many major domestic
and international airlines have, as noted by Dr Edgington of the
Royal Aeronautical Society, AsMA and airlines, chosen greatly
to exceed the requirements noted in paragraph 3.53, providing
substantial medical kits for use by health professionals and training
their crews to a high level of competence in managing in-flight
medical emergencies (pp 272, 198, 99 & 107). While the contents
of kits carried vary widely between airlines and aircraft types,
most now contain sufficient equipment and drugs to deal with a
wide range of common medical emergencies. At the time of writing,
the AsMA Journal is publishing a series of articles covering the
kits carried by the world's major airlines. A number of the major
international carriers now provide on-board automatic external
defibrillators (AEDs) for use in cardiac arrest and train all
or some of the cabin crew in their use. FAA has just issued a
Notice of Proposed Rulemaking
that all large passenger-carrying aircraft carry AEDs and augmented
emergency medical kits.
7.77 Bearing in mind the
greater numbers and range of people travelling by air, we recommend
the Government to upgrade the required minimum provision by UK
carriers for medical emergencies to current "best practice"
levels in relation to both crew training and medical emergency
kits. The latter should include automatic external defibrillators
(AEDs) on at least long-haul aircraft. Furthermore, we recommend
CAA to work through JAA to secure similar improvements across
7.78 A number of major airlines
have had arrangements for some years for ground-based health professionals
to pass medical emergency advice to aircrew whilst in flight.
New communication systems, including the establishment of tele-medicine
links (transfer of medical data by radio), have enabled this to
be improved rapidly. Ground-based consultant services are now
becoming available. We received evidence from airlines (pp 107,
229 & 288) and from one such service provider, MedAire (p
249), about the efficacy of these enhancements to in-flight medical
care. Contracted ground-based expert medical advice provides
not only considerably improved services to passengers but, as
BATA noted (p 124), may also save on airline operating costs by
reducing the number of medical diversions. We recommend all long-haul
airlines to consider engaging such ground-based specialist consultant
99 Thrombosis and Air Travel by Dr Paul Giangrande,
June 1999 and Contra-indications to air travel: guide for GPs,
June 2000. Back
Aviation, Space, and Environmental Medicine 71:866, August