Ask Captain Lim ~ All about Aviation

As more airplanes are flying non-stop to save cost and time, a new complaint have arisen. Passengers are more conscious and fastidious about seating and legroom in the coach or economy class. Some airlines are trying to pack seats tighter and tighter to squeeze in as many passengers in the cabin as possible to cut cost. This result in less legroom, causing frequent flyers in economy class to cry foul. Hence the name 'economy class syndrome' or deep vein thrombosis (DVT).

This 'economy class syndrome', in reality, can affect all classes of passengers in all forms of transport. The exact cause of DVT is not very clear, but prolonged immobility and dehydration can increase it risks. Other risk factors include hormone therapy, the use of contraceptive pills, pregnancy, smoking, post surgery, advanced cancer, obesity and hereditary factors.

But a UK hospital in 2001 stated that air passengers have a higher than normal tendency to problems like embolism, a condition where an artery is blocked by blood clot after landing from long haul flights. Usually many of these clots dissolve quite harmlessly but those that remained intact may spell trouble.

Deep Vein Thrombosis arises when blood clots in the deep veins of the legs. These clots can break up and travel to the heart, lungs and brain and this can lead to serious medical complications. DVT is so called because it occurs in a deep vein, usually in the calf or thigh. However, any person who sit in a constant position in a cramped coach or in a computer room has a potential of developing DVT but it appears that conditions in the airplane make the risk greater. How? A thrombosis is more likely to happen in condition when the blood is thickened. This is the side effect of the thin air in the aircraft cabin.

According to experts, people with the greatest risks of developing DVT are those with an inherited predisposition to blood clots. They are people who have suffered previous incidents of thrombosis. A consultant hematologist, Patrick Kesteven, at Newcastle's Freeman Hospital said that age is also an important factor. A person in his mid-20s has a less than one-in-10,000 chance of developing DVT. In October 2000, Emma Christofferson, 28 year old, died of DVT after taking a Qantas flight from Sydney to London. By 75, the risk of getting DVT is closer to one in 1000. Many airlines have maintained that there is no evidence so far to suggest a busy aircraft cabin might be more dangerous than sitting still anywhere, whether on a crowded train, car, bus or even at home.

The symptoms of DVT are swelling and pain in the leg with slight bruise-like coloration. It can happen after a few days or even weeks after a flight. When the clot reaches the danger level, it would trigger chest and shoulder pain. Thereafter, death can come quite quickly.

How airlines are responding to complaints of DVT?

Smaller or commuter airlines and charter companies usually offer the worst seating with a pitch of 28 inches. Thus an passengers of average height (1.75 m or 5 feet inches) will find the pitch too crammed for his or her legs. In fact, the legal requirement in UK is even a more restrictive 26 inches! The rationale for this minimum pitch is that, such a spacing is deem sufficient for passengers to evacuate safely during an emergency!

Needless to say, with more threat of legal proceedings, many major airlines have reconfigured their seat pitch from 30 to 32 inches. Some have used this as a selling point, particularly Cathay Pacific, Air New Zealand and Alitalia with a pitch of 33 inches. In practice, the legroom varies from airlines to airlines, from airplane to airplane and even from seat to seat on the same airplane. They range from 31 to 34 inches in the coach or economy section. On American Airlines Boeing 777 planes crossing the Atlantic, most of the cabin seat have 34 to 36 inches of legroom but the seat in the middle cabin have only 33 inches. British Airways and Continental have a leg room of 31 inches. Delta Airlines, 31-33 inches and United Airlines with 31-32 inches.

According to Consumer Reports , American Airlines Boeing 777 scores best in terms of legroom comfort.

Tips on reducing risk of DVT:-

Avoid high consumption of caffeine and alcoholic beverages.

Increase consumption of other fluids, especially water or fruit juices to improve body hydration.

Take supplementary preventive measures such as use of support stockings or aspirin-side effect, thinning of blood helps.

Do simple regular in-flight workouts. One such exercise is to raise the buttocks and thighs off the seats while seated and at the same time squeezing the toes and contracting the calf muscles. Another exercise is to bend and straighten the legs while seated. Both these exercises will improve blood circulation.