From the Guidelines
Aspirin is not recommended as the primary method for deep vein thrombosis (DVT) prophylaxis during flights. For most travelers, non-pharmacological measures are sufficient, including staying hydrated, avoiding alcohol and caffeine, performing regular leg exercises, walking around the cabin every 1-2 hours, and wearing compression stockings (15-30 mmHg) for flights longer than 4 hours. Some key points to consider for DVT prophylaxis during flights include:
- Staying hydrated and avoiding dehydration
- Performing regular leg exercises, such as calf muscle exercises, to improve popliteal venous flow during prolonged immobility in seated individuals 1
- Wearing compression stockings (15-30 mmHg) to reduce the incidence of asymptomatic DVT and leg oedema 1
- Walking around the cabin every 1-2 hours to reduce immobility For high-risk individuals with previous DVT/PE, recent surgery, active cancer, or multiple risk factors, low molecular weight heparin (such as enoxaparin 40mg subcutaneously 2-12 hours before flight) or direct oral anticoagulants may be considered after consultation with a healthcare provider. Aspirin has shown minimal benefit in preventing travel-related DVT compared to these more effective methods, as seen in the LONFLIT-3 study, where enoxaparine was found to be more effective than aspirin in preventing asymptomatic DVT 1. Additionally, guidelines from the American College of Chest Physicians suggest against the use of aspirin or anticoagulants to prevent VTE in long-distance travelers, with a Grade 2C recommendation 1. The reason aspirin is not recommended is that it only affects platelet aggregation, while DVT formation primarily involves the coagulation cascade. Flight-related DVT risk increases with flight duration (particularly over 4 hours), immobility, dehydration, and personal risk factors such as obesity, advanced age, hormone therapy, and inherited thrombophilias.
From the Research
Aspirin for DVT Prophylaxis During Long Flights
- The use of aspirin for Deep Vein Thrombosis (DVT) prophylaxis during long flights has been investigated in several studies 2, 3, 4, 5.
- A randomized trial, the LONFLIT3 study, found that aspirin (400 mg daily for 3 days, starting 12 hours before the flight) reduced the incidence of DVT from 4.82% in the control group to 3.6% in the aspirin treatment group 2.
- However, another study found that aspirin did not prevent travel-related DVT, while graduated compression stockings and low-molecular-weight heparin (LMWH) showed efficacy in preventing DVT 3.
- A model simulating factors of "long haul" flight found that aspirin, combined with compression stockings, may provide prophylaxis against DVT, although no subject developed a DVT in the study 4.
- The potential benefit of aspirin in preventing travel-related DVT has been estimated, suggesting that a large number of people would need to be treated with aspirin to prevent one additional DVT 5.
Comparison with Other Prophylactic Measures
- The LONFLIT3 study found that LMWH was more effective than aspirin in preventing DVT, with no cases of DVT reported in the LMWH group 2.
- Graduated compression stockings have been shown to prevent travel-related DVT in several studies, and are recommended for travelers with one or more risk factors for VTE 3.
- Other prophylactic measures, such as exercise programs and oral profibrinolytic agents (e.g. Flite Tabs), have also been investigated, with some studies showing efficacy in reducing thrombotic events and edema 6.