Frequency of Venous Thromboembolism in Low to Moderate Risk Long Distance Air Travellers: the New Zealand Air Traveller's Thrombosis (NZATT) Study

Abstract

The authors studied the frequency of venous thromboembolism in long-distance air travel and investigated the role of risk factors. One thousand Individuals between 18 and 70 years old were recruited into a prospective study, and 878 met the inclusion criteria and completed the study. Participants traveled at least 10 hours (mean total duration 39 hours). Measurements of D-dimer were taken before and after travel and those with a D-dimer of less than 500 ng/L were included. One-hundred twelve patients underwent radiologic assessment on return. Any subject who developed high clinical probability symptoms or became D-dimer positive within 3 months after travel was investigated, Clinical and thrombophilic risk factors were assessed by bilateral compression ultrasonography and computed tomographic pulmonary angiography. Nine of the 878 patients developed venous thromboembolism, including 4 cases of pulmonary embolism and 5 of deep venous thrombosis. Six patients with venous thromboembolism had preexisting risk factors. The authors concluded that there was an association between multiple long-distance air flights and venous thromboembolism.

Keywords

venous thromboembolism air travel D-dimer

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