Flying and thromboembolism

Editor, – I refer to the article 'Flying and thromboembolism' (Aust Prescr 2009;32:148-50) and the patient's perspective on the same topic (Aust Prescr 2009;32:150-1).

I recall with relish the media exposure the 'economy class syndrome' had at the turn of the millennium and the impact this had on the airline industry in terms of seating standards and raising consumer awareness. The article revisited the relevance of both mechanical and chemical prophylaxis in different at-risk groups. However, it failed to address the more controversial issues about practical management of patients with treated venous thromboembolism particularly with advice on mobilisation and flying which was elegantly illustrated by the patient's perspective article.

Even with available research showing the benefits of early mobilisation in deep vein thrombosis with no significant risk in pulmonary embolism, there is still hesitation in the medical community in recommending continuing mobilisation in massive deep vein thrombosis, particularly those proximal to the femoral veins. Practical advice on flying and other activities after deep vein thrombosis should be addressed early in conjunction with patient handouts.

Ms Hannah Baird should be congratulated for her remarkable ability to manage her deep vein thrombosis in spite of the limited support she received. I wonder what would be the outcome if she was neither well-informed nor motivated to take charge of her condition.

Shyan Lii Goh
Orthopaedic registrar
Dubbo Base Hospital, NSW

Associate Professor Frank Firkin and Associate Professor Harshal Nandurkar, authors of the article, comment:

The purpose of the article was to discuss the relative degrees of risk conferred by in-flight and pre-existing medical factors. Prophylactic measures for patients at high risk, including those with a history of venous thrombosis, were discussed in the article.

The question of management of a patient with newly diagnosed venous thrombosis on therapy in relation to taking flights is a different issue. Dr Goh raises the issue of the extent to which early mobilisation confers risk despite administration of standard therapy for deep vein thrombosis. Various factors may play a part, including physical limitations imposed by the impact of the thrombus on venous return, sequelae of pulmonary emboli and imaging results that raise concerns about thrombus stability.

More pertinent issues relate to the period in which there is an increased risk of venous thrombosis following the onset of deep vein thrombosis, amounting to many weeks, and thus delayed diagnosis and suboptimal therapy are disadvantageous. This enhanced risk is normally suppressed by appropriate treatment with low molecular weight heparin and warfarin, and regular monitoring to ensure the INR is maintained.