Air travel associated with blood clot risk

According to a recent study air travel has been linked with the risk of pulmonary embolism. Pulmonary embolism is a condition when a clot passes to and obstructs the arteries of the lungs and it requires immediate medical care. It most often complicates the course of sick, hospitalised patients but may also affect ambulatory and otherwise healthy persons.

The study was done from November 1993 to December 2000. The researchers analysed records from the ambulance unit at the Charles de Gaulle airport in France, which showed that nearly 135 million passengers had arrived during that time. Fifty-six of these required the airport ambulance because of pulmonary embolism.

The incidence of pulmonary embolism was much higher among passengers travelling more than 5000 km - 1.5 cases per million, as compared with 0.01 case per million among those travelling less than 5000 km. The incidence of pulmonary embolism rose to 4.8 cases per million for those travelling more than 10,000 km.

The vast majority of the patients said that they had not moved during the flight. However the risk of embolism rose significantly in people travelling a greater distance. It was established that the farther people fly, the more likely they are to suffer a potentially fatal blood clot in their lungs. This study underlines the importance of in-flight exercises to maintain the blood circulation and prevent embolism.