Deep Vein Thrombosis And Long-Haul Flights
The Lonflit Studies

At the American Heart Association scientific meeting on November 13th, it was pointed out that the incidence of leg blood clots on long-haul flights is common and life threatening: 4 to 5 percent of individuals may suffer deep vein thrombosis (DVT).

The LONFLIT 2 study evaluated whether compression stockings could effectively prevent or minimise DVT. 833 subjects were recruited. Half wore "flight socks" (below-the-knee stockings); the control group wore none. "In the control group, 4.5% of the subjects developed DVT, while only 0.24% of subjects wearing stockings developed DVT." The incidence of DVT observed when subjects were wearing stockings was 18.75 times lower than in controls.

The LONFLIT 3 study showed that, in high risk subjects, aspirin was not effective in preventing DVT, but in those given heparin (a powerful anticoagulant) there was no incidence of DVT.

The findings of the LONFLIT studies bear out the hypothesis that a simple expedient such as wearing flight socks, minimises DVT, and, in high risk patients, pre-flight heparin medication eliminates the risk.