Many people are nervous of flying even though we are told that it is really a very safe form of travel. The statistics only take into account those accidents which are the result of pilot error and aircraft malfunction. Yet there is a very real risk of experiencing deep vein thrombosis (DVT) on a long haul flight. This can kill but the statistics for death by flying do not include these casualties.
Simply put, DVT is a condition where blood clots form in the deep veins of the legs. The clot can move and travel to the lungs where it causes a pulmonary embolism. If the pulmonary embolism is severe the lungs can collapse and heart failure can develop. One in every 100 people who develop DVT die. Each year approximately 1 in 2000 people develop DVT but the incidence varies greatly according to age and the presence of other risk factors. These risk factors include, among others, a family history of blood clots, the presence of heart failure, pregnancy and a recent history of surgery.
A possible link between DVT and flying was first suggested in the 1950s but it is only in the last decade that the subject has attracted much in the way of media attention. Any form of long distance travel can lead to DVT but long haul air travel appears to pose a particular risk. DVT is frequently referred to as 'economy class syndrome' because it has been linked with immobility, which is a greater problem in the more cramped conditions in the economy section of the plane.The greater attention to the problem means that air passengers can be seen gulping aspirin before take-off, donning flight socks, religiously carrying out recommended exercises, drinking lots of water and spurning alcohol. So, which of these measures actually work?
Low dose aspirin is often recommended but the jury appears to be out on how effective it really is and further research is definitely needed. Some studies have indicated that there is a benefit but other studies have not shown any difference between those who take aspirin and a control group. Even in low doses aspirin can cause side effects in approximately 10 per cent of the population so it is probably best avoided unless advised by a doctor.
The exercises are well worth doing. Those of you travelling Business Class should not be lulled into a false sense of security. Despite the 'economy syndrome' tag there have been deaths in business class so get those ankles moving! The other pitfall of business class travel is the ready availability of alcohol. Travel advice for many years has warned against alcohol but many travellers were 'happy' to arrive at their destination feeling a little dehydrated. The evidence is now stacking up that dehydration also adds to the risk of DVT so the case against alcohol (and tea and coffee) becomes stronger still. Many airlines now offer drinks of water and it is a good idea to ask for these if they are not automatically offered.
This leaves flight socks. Are they an expensive gimmick or do they really work? The thought of wearing surgical hosiery does not immediately conjure up the holiday mood so there has to be a good reason for wearing them. The Department of Health website states that there is evidence that elastic stockings may be useful. There have also been a number of studies which have demonstrated that use of compression hosiery reduces the incidence of DVT and has a significant effect on reducing swelling of the feet and ankles.
The evidence seems to be stacking up in their favour but I never cease to be amazed by those who happily spend hundreds of pounds on an air ticket and then object to paying out £15 or so for a pair of socks that could save their life!
I never cease to be amazed by those who happily spend hundreds of pounds on an air ticket and then object to paying out £15 or so for a pair of socks that could save their life
So, if you have ignored all of the 'do-good' advice and have travelled long haul what danger signs should you be looking out for? The symptoms can include swelling, pain, tenderness and redness. This is typically found at the back of the leg below the knee. These symptoms can develop during the journey or some time after (even as much as a few days later). If these symptoms occur it is important that they are investigated as soon as possible as a pulmonary embolism can develop. Although rare the risk is very real and symptoms can include breathlessness, rapid heart beat, chest pain and collapse.
Although nine out of 10 air passengers have heard of DVT the fact remains that approximately a third of air passengers still do not take any precautionary measures. More worryingly, although people were aware that some passengers carried a greater risk, there was little knowledge of what these risks actually are. For example, only eight per cent of women realised that if they were on the pill or HRT they had a greater risk.
More evidence is needed so that effective prevention measures can be developed and confidently promoted. The creation of the aviation health unit is welcome and the government led the way when it agreed to part fund the large scale WHO research programme. Once we have the answers it will then be up to the politicians to make sure that the best advice is available and that the airlines play their full and proper part in preventing the problem.
Sandra Gidley is theLib Dem MP for Romsey
