The DVT offshore risk

Medical student Toni Bull describes her Rolex Fastnet Race with a twist

While the Rolex Fastnet Race may be somewhat of a distant memory for competitors as we now move into autumn in the Northern Hemisphere, for one sailor, the resulting impact on her body is still being managed on daily basis.

Antonia (Toni) Bull was to find herself in Torquay Accident and Emergency a week after the finish, being discharged several hours later diagnosed with Deep Vein Thrombosis (DVT) behind her knee. DVT is more commonly associated with long haul air travel in a cramped economy class cabin – not offshore yacht racing.

All the more surprising in Toni’s case is that she is a young active, experienced sailor, who also happens to be in her final year as a medical student at Brighton and Sussex Medical School. Toni started racing Cadets at the age of eight and started in keelboats at University and more recently regularly racing on a Farr 52. She also has a BSc in Sports Medicine.

Her account of DVT is a must read for any offshore sailor:



This year I completed my first Fastnet race. I was on a Farr 52 and we finished on the Wednesday evening after three and a half days at sea. The race was great, hard work but well worth the effort, our team had its fair share of breakages and problems, but achieved a very good result despite little preparation time.

After leaving the boat I travelled back to Brighton. By Friday, five days after the start, I had developed an ache in my calf. Over the next few days it got worse; I assumed it was a pulled muscle and carried on walking (lots) and driving. The following Wednesday I headed down to Torquay for the J-Cup. By this time my leg was pretty sore, but, as most medics would, I continued to ignore it. I managed two days of a pretty windy regatta before admitting that I really couldn’t walk.

At this point my leg ached with a high pressure feeling every time I stood up and it was swollen and tense compared to the other leg. So, a week after my symptoms started, I took myself to A+E in Torquay - the waiting room can be an entertaining place on a Friday evening! After a short time I was diagnosed with a deep vein thrombosis, which is what I, and a number other medical experts in the J-Cup fleet, had suspected.

A deep vein thrombosis (DVT) is a condition where a clot forms in one of the deep veins, most commonly in the calf. It causes a blockage which leads to pain and swelling. It is a relatively common condition and becomes more common with increasing age. So, why did I, a healthy 23 year old, end up with one?

There are a number of well recognised factors that increase your risk, the most well recognised is a period of immobility, such as a long journey, a period in hospital, or possibly lots of time on the weather rail of yacht competing in an offshore race. Other known risk factors include smoking, taking certain oral contraceptives or HRT, blood disorders and pregnancy.


Less comfortable than an economy class flight...

The main symptoms of a DVT are pain and swelling of the affected limb. As a medical student I am always told that the reason we have two legs is so we can compare them, if one suddenly becomes fatter than the other then it’s worth getting it checked out, either in A+E or by your GP, especially if it is also painful.

To diagnose a DVT the first test is a blood test, known as a d-dimer, if the result of this test is high, a diagnosis of DVT is likely, if it’s low a DVT can usually be excluded. Mine was high, very high. As by this point it was 2200 on a Friday night and the drunks were starting to roll into A+E, I was given some treatment and sent back to the hotel.

Initial treatment for DVT is injections of Heparin into the stomach; these were started at the hospital and then I was given a pack of syringes to give myself every day at home. It takes a lot of willpower to give yourself an injection and I now have great sympathy for people with diabetes who do it every single day. The following day I returned to Torbay hospital for an ultrasound scan of my leg – this leads to a definite diagnosis as the clot can be seen.

The The self-administered Heparin injections fortunately ceased after a week, giving time for the other main treatment – Warfarin to start working.

Warfarin (well known as ‘rat poison’) is an anticoagulant, which means it thins the blood and reduces the risk of further clots. I will be taking it for at least three months.

While on the Warfarin regular blood tests are needed to ensure the dosage is correct, too much and the side effects are worse and too little and it’s not doing its job. The main side effects are a higher chance of bruising and longer bleeding times if you cut yourself.

Sailing while on Warfarin is also more dangerous as any injury may bleed more, so a bump on the head from the boom could have a significantly worse outcome. The drug also interacts with a number of foods, including green vegetables, cranberry juice and alcohol. So Christmas could be interesting, no brussel sprouts but also no booze.

Another aspect of treatment is compression stockings, up to two years of wearing those highly attractive knee-high stockings that your nan wore when she had her hip done, sure they’ll go great with a miniskirt!

As you may be able to tell from the long list of treatments DVTs have complications. Immediate complications are associated with the clot moving, either further up the affected limb, or to the lungs. When the lungs are affected it is known as a pulmonary embolism (PE) which can be a serious complication. In the long term, over 25% of DVTs recur and many people develop post thrombotic syndrome, a long lasting condition where the affected limb is persistently swollen and painful with recurrent ulcers.

So how can we reduce the risk? The general advice is to stay mobile, which may be difficult offshore. My clot was behind the knee, an area where a lot of pressure passes through when on the rail, worse on boat with a toe rail. Another important piece of advice is to stay well hydrated, not only does this maintain a higher performance but it will also reduce the risk of a clot.

The most important piece of advice I can give is don’t panic but be aware. DVT is an important condition to be aware of.

Toni would like to her from anyone who also has experience of DVT while sailing as she is considering writing a medical paper. She can be contacted via email: toni_bull@hotmail.com

Further advice:
http://www.nhs.uk/Conditions/Deep-vein-thrombosis/Pages/Introduction.aspx
http://www.patient.co.uk/health/Deep-Vein-Thrombosis-Prevention-When-Travelling.htm

References:
McManus RA, Fitzmaurice D. 2007 April 1. Thromboembolism. In: Clinical evidence. BMJ Publishing group, London. Available from URL: http://clinicalevidence.bmj.com/ceweb/conditions/cvd/cvd.jsp

EBM guidelines, 2006 April 24. Deep venous thrombosis. In: Evidence Based Medicine. Wiley Intmerscience. Available from URL: http://ebmg.wiley.com/ebmg/ltk.koti