Computers may be an unrecognized source of the same deep vein thrombosis associated with long-distance air travel, New Zealand researchers report (Eur Respir J 2003;21[2]:374-6). Internist Richard Beasley and colleagues recently diagnosed a pulmonary embolism in a 32-year-old man. After studying his sedentary lifestyle and learning that he had been spending up to 18 hours a day seated at his computer, the doctors coined a new phrase for his condition — “eThrombosis.”
Beasley, a professor at the Medical Research Institute of New Zealand, recently completed the largest study ever conducted on venous thromboembolism (VTE) associated with air travel — it involved 1000 New Zealanders who took long-haul flights.
He says the link between prolonged sitting and VTE was first reported in 1940 after British researchers observed cases of fatal pulmonary embolism among people who had sat in air-raid shelters for prolonged periods during the Blitz (Lancet 1940;2:744).
Beasley says the eThrombosis case proved intriguing because he and his colleagues could not find any risk factors for VTE until the patient told them about his working conditions. “That was one of the learning points for us, actually taking a work history in terms of mobility,” he told CMAJ. “[Physicians] are now getting pretty good about checking for long-distance air travel, and we have known for many years about mobility [problems] associated with surgery, but we often haven't thought of asking about mobility associated with lifestyle.”
Was this an isolated case? To find out, Beasley's team began a retrospective chart review at the Wellington Hospital involving patients with significant VTE but without apparent risk factors. That second look revealed that many patients had spent long periods working at a computer or sitting for long periods in other work situations.
Beasley says he has learned “how common it is for people to spend such huge amounts of time in front of their computers. I never realized the very prolonged periods that are [often] involved, and I would not be surprised if this is a very significant problem.”
Beasley likens knowledge of eThrombosis to awareness of traveller's thrombosis 5 years ago, before prospective studies on that phenomenon began appearing. “It wasn't until the first case reports [had prompted] proper prospective studies that we were able to identify how common it was.”
Beasley, who plans to conduct a larger study of eThrombosis later this year, says it is easy to prevent the problem: simply get up from the computer every hour and exercise your feet while working. — Heather Kent, Vancouver