In the wake of a healthy woman's collapse on a transatlantic flight from blood clots, Australian doctors have warned travellers not to pop sleeping pills during long-distance flights.
The death from deep-vein thrombosis (DVT) of a 36-year-old passenger on a transatlantic flight has provided a frightening reminder of the risks of taking sleeping pills on aircraft, particularly when travelling long-haul.
The New England Journal of Medicine reported last week that the woman, an American citizen, had taken a single sleeping tablet shortly before departure and spent most of the flight asleep in one position – undoubtedly the critical factor in her death.
A doctor on board attempted to resuscitate her and the plane made an emergency landing two hours later in Boston, US.
Her life support was turned off a week later. Tests confirmed that she died from deep-vein thrombosis (DVT) – blood clots formed in her legs had travelled through her body and lodged in her heart and lungs, causing brain damage.
Unhealthy to sleep sitting up
The incident has prompted doctors to renew warnings to travellers of the risks of taking sleeping tablets during flights.
“Sleeping tablets are not recommended on aircraft, since they tend to immobilise you and increase your risk of thrombosis,” Dr Deborah Mills, Medical Director of The Travel Doctor in Australia, said. "Sadly, on an aircraft it's good for you to be uncomfortable. It's not healthy to sleep in the sitting position."
While in the air, many fliers try to shut out noise and – particularly when travelling long-haul – attempt to catch up on some sleep. A significant number – whether to avoid jetlag or because they are nervous fliers – rely on medication to help them drop off, thinking little of the potentially fatal consequences.
Unfortunately, the human body is simply not designed for deep sleep in a sitting position. Sitting compresses the veins of the pelvis, and slows down blood flow through the veins of the calves. Calf muscle contraction – simply moving around without restriction – counteracts this effect.
Reduced blood flow leads to stagnation, activation of the blood's innate clotting mechanism, and therefore an increased tendency for blood clots to form. Reduced oxygen pressure in the cabin increases the clotting tendency still further, and so too can a variety of individual medical factors.
In such circumstances, a sleeping pill can make things considerably worse – by relaxing calf muscles, reducing movement, and rendering the sleeping passenger motionless for hours, even in an uncomfortable and adverse position.