Thrombosis, Pulmonary Embolus and Air Flights
There have been individual
case reports of deep vein thrombosis and deaths from pulmonary emboli following
airflights but the problem has also been noted following prolonged travel
by train or car and even after sitting cramped up in air raid shelters
during the London blitz. Aggravating factors could be pressure from the
edge of seats on the back of the leg, dehydration aggravated by caffeine,
alcohol and sedation which may encourage immobility.
Suggestions on preventing deep vein thrombosis and pulmonary embolus during
Be aware predisposing and risk factors
Predisposing factors for DVT (in addition
to the possible effects of prolonged immobility while travelling) are endothelial
vascular lesions, hypercoagulabiltity of the blood and thrombophilia (including
hereditary forms such as factor V Leiden)
These factors may specifically include
those over 60 years of age, smokers, previous (especially recent) DVT or
pulmonary embolus, recent surgery or injury, pregnancy or less than 2 months
post-partum, malignancy, cardio-respiratory disease, other chronic illnesses,
oestrogen medication (contraceptive and hormone replacement), varicose
veins. Symptoms can be delayed for several weeks after the flight. Cases
of DVT may have an average of 3 factors.
Advice for those at minimal risk (nil
or one predisposing factor)
While further studies are undertaken preliminary
advice for those at low risk could be to exercise the legs when possible,
maintain hydration and limit alcohol consumption.
Advice for those at low or moderate
risk (e.g. 2 or 3 predisposing factors)
Exercise in the aircraft cabin wherever
possible, maintain hydration and limit alcohol consumption, consider using
below knee compression stockings. Possibly consider taking a daily dose
of aspirin while at risk (so long as aspirin is not contra-indicated).
The effective dose is unclear – perhaps 75-300mg.
Advice for those at high-risk (e.g.
more than 3 predisposing factors)
Exercise, compression pantyhose / stockings,
maintain hydration and limit alcohol consumption. Possibly consider a subcutaneous
injections of Minihep (sodium heparin 5000 IU twice daily) or low molecular
weight heparin (e.g. dalteparin 2500 daily or enoxaparin 40mg daily) while
at risk (so long as anticoagulation is not contra-indicated).
source: Scottish NHS www.fitfortravel.scot.nhs.uk/General/