Deep vein thrombosis (DVT) – can occur in healthy people if they are immobile for long periods of time, this includes car journeys and ‘e-thrombosis’ caused by sitting still for too long at a desk or computer. Everyone should either try to walk around every couple of hours or exercise the calf and foot muscles; if that is not possible, then simply fidgeting can be beneficial as it gets the circulation moving.
However, it is air travel that is most closely associated with DVT particularly long-haul flights over four hours long. The actual number of people who get DVT from travelling on long-haul flights is unknown and is difficult to determine, simply because the condition can be symptomless and may not occur for some time after travel.
If a person with APS is taking anticoagulant medication, then the risk of thrombosis (clotting) is very low. Air travel should be safe if you take the following points into consideration:
If you are treated with 75-150mg aspirin or clopidogrel daily
Aspirin and clopidogrel have not been shown to be useful in preventing travellers' thrombosis so do remember to keep moving and hydrated when you're on a flight.
If you are taking warfarin
Patients who are being treated with warfarin, and whose INR is well controlled, have good DVT prevention.
For those people who do not self-test and have regular INR blood tests at an anticoagulation clinic, you should get your INR checked before you travel, take your yellow anticoagulation therapy booklet and an adequate supply of warfarin tablets. You should also let the clinic know how long you will be away. It is recommended that you have your INR tested after the outward flight and before the return flight home to ensure you are within your range; therefore, you will have to research the availability and location of anticoagulation clinics at your destination.
If you are being treated with direct oral anticoagulants
Some APS patients find the direct oral anticoagulant, rivaroxaban, is an effective anticoagulant but others do not. Rivaroxaban is taken in tablet form daily, does not need to be monitored at all and stays in your system around 24 hours.
If you need to inject with heparin
Currently, preventative low molecular weight heparin (LMWH) injections such as dalteparin (Fragmin) or enoxoparin (Clexane) are only recommended before long haul flights (flights of more than four hours) if you have had a previous DVT and are not already taking anticoagulants.
As heparin is not always stocked by smaller pharmacies and surgeries, you should make an appointment with your GP a few weeks before your flight so there is plenty of time to process the prescription. You should also ask your doctor to write a letter stating why you need to take heparin as you may need to explain why you are carrying needles when you fly.
On the day of the flight you must ensure you are carrying a copy of your prescription (this is the most important documentation) and the letter from your doctor. It is important that you have relevant contact information on these documents in case airport officials need to clarify your condition.
Heparin injections are individually packed syringes so are convenient to carry in your hand luggage. It is best to carry all the syringes you need on your person in case your hold luggage goes astray; currently, in the UK it is necessary to put them in a clear plastic bag due to the restrictions on liquids allowed in hand baggage.
You should take the injection as close to the time the flight leaves as possible. This is because heparin has an instantaneous effect, but only lasts for 12-24 hours which is sufficient for most short to medium haul destinations. If you have a very long haul flight, you may need to inject for a second time after 24 hours.
Although all airports usually have a clinic where you can pay the medical team to administer the injection, it is simpler and more cost effective to do it yourself. You will need to find a private place where you are not disturbed; this could possibly be the disabled toilet or even just in a quiet area in the airport.
When you have finished, place the lid back on the syringe and put it back into its packaging, then hand it to a member of airport staff informing them there is a needle inside which should be disposed of safely. The whole process can be rather daunting for the first few times so please read our Fact Sheet: How to inject with heparin.
Travelling check list for patients on warfarin:
- Research the hospitals/clinics in the areas you intend to travel to.
- Make sure you have your up-to-date yellow anticoagulation book, prescription/letter for the heparin injections and insurance policy.
- Carry information about APS with you, ideally in the language of the country you are visiting.
- Use your phone or digital watch to set an alarm to take your warfarin tablets at the correct intervals.
- Be aware of any changes in diet and drinks while you are away, as these can also affect your INR.
Whether you self-manage or visit the anticoagulation clinic, if you experience any symptoms you must get your INR checked as soon as possible in case you need to increase your dosage of warfarin or inject with heparin.
If you are pregnant
If you have APS and are pregnant, you may already be taking heparin injections. The same guidelines apply to all passengers taking heparin, but you should be aware that most airlines will only be prepared to carry you up to your 27th week of the pregnancy.
If you choose to fly after the 27th week, the risk of going into labour increases and you may need a letter from your consultant or midwife confirming your due date. Each airline has its own particular set of rules and cut off point when they refuse to carry you, so do check with your booking agent or airline website if booking online.
You should get travel insurance if you’re going abroad when pregnant as you may have to cancel the trip or go into hospital while away. Pregnant women are considered high risk by travel insurance companies, and most will not cover you if you have less than eight weeks until your due date when you return from your trip. Make sure the policy covers you for any eventuality such as early birth, medical care during labour, and expenses incurred if you do go into labour while away.
If you are disabled
Travelling can be a daunting experience if you have reduced mobility or are disabled, so you must ensure that you inform your booking agent so they can make sure the appropriate assistance and support is available at the airport. If you book online, you should check that the flight provider can also offer you the services you require.
Airport parking comparison tool, Parkat, provide an excellent guide to travelling if you have a disability or restricted mobility. The guide has been created to inform and advise you about the services available to make your journey as easy and pleasurable as possible.
When you are on the plane
- Wear loose, comfortable clothes.
- Flight socks (compression stockings) may reduce the risk of leg swelling during flights of four hours or more. However, they must be the right size and worn correctly.
- Store luggage overhead so you have room to stretch out your legs.
- Do anti-DVT exercises. Raise your heels, keeping your toes on the floor, and then bring them down. Do this ten times. Now raise and lower your toes ten times. Do it at least every half an hour or more often if you like.
- Walk around whenever you can, but at least every couple of hours.
- Drink plenty of water or soft drinks – this helps accelerate the blood flow.
- Do not drink too much alcohol as this can cause dehydration and immobility.
- Do not take sleeping tablets as these will cause immobility.
If you are travelling abroad it is wise to take out a travel insurance policy, but is essential you fully disclose your medical conditions to the insurance company, even if they do not ask. Failure to do so could lead to a claim being rejected.
In the past, it was very difficult to obtain travel insurance for anyone with APS, even if the patient had minor clotting events and had a stable medical history. It seemed that the underwriters for the travel insurance industry had deemed all patients uninsurable due to the 'unknown risk' and a blanket ban was in place.
However, after our charity contacted the Association of British Insurers in 2011, there appears to have been a reversal and now most travel insurance companies offer travel policies to people with antiphospholipid syndrome. The cost and availability will depend on individual circumstances and you may find you have to pay higher premiums if you have just had a clotting event.
How to inject with heparin fact sheet
Download and keep our factsheet on how to inject with heparin.