ANATOMY OF A DIVER
Anticoagulants
Dr Rosie Stokes of DDRC Healthcare sets out the issues facing divers who have been prescribed anticoagulant meds
Why do some people need to take anticoagulants ?
Some people can develop blood clots which block blood vessels , interrupting blood flow . This can lead to damage in the tissue , depending on where the clot has formed . When people develop these clots in the veins in their legs , this is called a DVT ( deep vein thrombosis ), and when these clots develop in the lungs , this is called a PE ( pulmonary embolism ).
If such a clotting event occurs , then an anticoagulant medication must be taken to break up the clot and prevent further clot formation . They work by interrupting the clot-making process in the blood . This is slightly different to anti-platelet medications such as Aspirin or Clopidogrel , which are given to patients who have had heart attacks or strokes .
Sometimes , as you age , your heart rhythm may become irregular . This is called atrial fibrillation and it is known to increase the risk of stroke due to the turbulent blood flow in the heart . An anticoagulant may also be taken in this instance , as a preventative measure .
Traditionally , Warfarin was the main choice of anticoagulant . However , it requires close monitoring with regular blood tests ( INR ), and the dose taken often varies day-to-day . Now , we have other medications such as Apixaban , Rivaroxaban , Edoxaban and Dabigatran . These medications have set doses and do not require blood test monitoring , so patients find them easier to manage .
What are the issues with taking anticoagulants ?
Any medication that interrupts the clotmaking process will make people more prone to bleeding . This means that if a trauma occurs or a bleed develops , then the blood loss may be heavier and last for longer . If the blood loss is significant then this may lead to shock and even death . However , if an anticoagulant has been recommended by your doctor , then often the benefit gained will outweigh any risk of a major bleed .
Sometimes , the medication can be stopped after a period of treatment . However , if the risks of clotting are too high , then anticoagulants must be taken lifelong . Your GP or haematologist ( blood specialist ) will discuss this with you .
How risky is diving while on an anticoagulant ?
Firstly , you must consider why you have been given an anticoagulant treatment . If you are receiving it as a treatment for a large pulmonary embolism in the lungs then this has , more than likely , compromised your lung function and breathing in some way . It is recommended that you discuss this with a dive doctor .
Secondly , you must consider the risk of bleeding underwater . Anticoagulants are designed to stop blood clotting , resulting in a great deal of risk if an incident occurs underwater . Any trauma or injury sustained will result in more significant and prolonged blood loss , especially underwater where it would be difficult to control . Even on an uneventful dive , anticoagulants increase risk of nosebleeds which may obscure vision in a
Anticoagulant Essentials
Anyone taking an anticoagulant should contact a dive doctor to discuss their fitness to dive . If you are able to continue , then restrictions will be put in place to try and mitigate some of the risks involved :
This page is produced with DDRC Healthcare , specialists in diving and hyperbaric medicine
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mask or cause anxiety and distress .
Diving is an extreme sport and involves risk of injury ; either through a physical trauma , barotrauma or a decompression illness . If a diver sustained a ‘ simple ’ injury such as a mild ear barotrauma , the injury sustained due to blood loss may be much more significant and impact on their fitness to dive for a long period of time . If a diver sustained a significant decompression illness , for example a spinal bend , then small microvascular bleeds would occur . This would be made worse by anticoagulants , making it harder to treat and more likely to lead to long term disability . There is no evidence to suggest that diving alters how anticoagulants work in the body , but studies have shown that decompression can use up some of the platelets in the blood . This , on top of an anticoagulant , would be an additional risk factor for prolonged bleeding .
Overall , there is a significant increased risk of injury , which is why your diving doctor will advise you to be as conservative as possible if you decide that you would like to continue to dive . �
n Maximum depth limit of 20m n No stop diving using tables rather than a computer
For those on Warfarin : nFrequent INR blood tests , with a test within 7 days of diving n Do not dive if your INR blood test result is greater than 3 n Use INR self-monitoring devices where possible
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