purplecthulhu

[Modified from a comment posted elsewhere]

As many of you know, I fly quite a lot. One of the most annoying things on long haul flights is being stuck in 'mewling and puking' class with upset children. It seems that the effects of altitude and air travel, especially extended air travel, on infants is quite poorly researched. What evidence there is suggests there is cause for worry, so the decision to take young children on planes should not be made lightly.


See for example BMJ 1998;316:874-875 ( 21 March ) (British Medical Journal):

'Until further information suggests otherwise, when trekking in a remote setting a conservative approach would be to sleep no higher than 2000 m for children aged under 2 and no higher than 3000 m for children aged 2-10 years. High treks are no place for little children.'

Parkins et al. BMJ 1998;316:887-894 ( 21 March )

'Exposure to airway hypoxia similar to that experienced during air travel or on holiday at high altitude may be harmful to some infants. '

and in the followup comments on that paper by James:

'The infants in the study were exposed to hypoxia for only six hours, but many flights last for over 12 hours. The current maximum cabin altitude for commercial aircraft of 2438 metres derives from the introduction of the jet engine and cabin pressurisation when flight durations were limited. Although living at high altitude is associated with an increased capillary density in the brain and other organs, this acclimatisation to hypoxia takes several weeks.

There is a trend in aircraft manufacture to use a higher cabin altitude, and flight durations of over 12 hours are common. The upper limit of 2438 metres, established many years ago, needs to be revised. The risks that are associated with the hypoxia that some newborn infants and adults experience while flying need to be investigated.'

There's also a more recent review of the current state of knowledge in this area (Archives of Disease in Childhood 2004;89:448-455) which concludes:

'Recent recommendations for children included advice to start descent immediately in any child who becomes unwell above 2500 m. Because of the risks of subacute infantile mountain sickness, it was also recommended that children under 2 should sleep no higher than 2000 m, and children 2–10 years, no higher than 3000 m. In addition, travellers should be aware of the underlying illnesses that increase susceptibility to hypoxia related problems'

This review also notes: 'Air flight regulations require aircraft travel with maximum cabin altitudes of about 2440 m, although a study that measured in-flight cabin altitudes on 204 aircraft flights found the median altitude was 1894 m (6214 feet), with a maximum of 2717 m (8915 feet). It was noted that newer generation aircraft flew at higher altitudes than older aircraft, with a greater risk of altitude exposure to passengers.'

Since children under 2 regularly sleep on planes at an effective altitude higher than 2000m this should be cause for concern, especially since there is little chance for immediate decent during a long haul flight.

I should also add my own experience at Mauna Kea where I know of children and infants getting severe acute altitude sickness after rapid travel from sea level to altitude. The specific danger for an infant is that they can't describe the symptoms and allow a speedy diagnosis of altitude sickness. All they can do is cry and shriek and vomit, and these can easily be mistaken for the symptoms of lack of sleep, meal disruption, temper or of more minor, though still incredibly painful, effects such as pressure imbalance in the ears. You do know you have a problem when, as happened at Mauna Kea, the infant turns blue, and there may already have been damage done by that point. You may still have damage done even without such obvious symptoms. This is where the research needs to be done.


My own summary of the above papers is that taking infants on planes exposes them to currently unknown levels of risk, and should be avoided.