Page 13 - Volume 11 Number 7

Dehydration also increases the chance of a DVT. But most important for pilots, prolonged sitting can increase the risk of DVT significantly. Not only are your leg muscles not contracting while you are sitting, you are often putting pressure on the leg in the lower thigh which can help compress the veins and decrease flow; pilots tend to sit for a long time in one position.
It’s important to try to prevent DVTs. Pilots can lower their risk by staying hydrated and exercising their leg muscles at frequent (every 15-30 minute) intervals. This is done by pushing down first with the toes and then with the ball of the feet to contract the muscles of the calf. Walking every half hour is ideal and while this can be done in an airliner, it’s impossible to do in most light GA aircraft. Additionally, the use of properly fitting compression hose (flight socks) may help. These socks are graduated in their compression and must go up to the knee for maximum effectiveness.
Many pilots take low dose aspirin for prophylaxis against heart attacks and wonder if the anticoagulant effects of aspirin will help with DVT prevention. The short answer is probably not. Aspirin inhibits the action of platelets which are important in arterial clotting but have little to do with clots forming in veins. There are prescription anticoagulants that do decrease the risk of DVT, but these must be taken continuously and there are
significant potential side effects. Their use is reserved for persons at high risk such as those with a previous history of DVT, pulmonary embolism, certain cancers and postop of certain surgeries. Pilots using these drugs must have FAA approval via the Special Issuance process and require frequent monitoring. Furthermore, flying is prohibited until at least six weeks after the initiation of therapy, so they are not a reasonable choice for routine DVT prophylaxis.
Finally, be aware of the potential for deep vein thrombosis. If you notice swelling of one leg, or pain in the calf after a flight, consult a physician as soon as you can. Untreated DVT can be fatal. KA
Dr. Jerrold Seckler is retired after practicing medicine (urology) for over 40 years and as an active AME for 25 years. He has over 6,000 total hours, 2,200 of those in his 2001 Cirrus SR22. He is an ATP, CFII, former COPA Board Member and a ground instructor at Cirrus Pilot Proficiency Programs.
The items discussed in this column are related to experiences by Dr. Seckler in his many years as an AME, and made hypothetical for the article. Any information given is general in nature and does not constitute medical advice.
JULY 2017
KING AIR MAGAZINE • 11