Review Note

A 65 year old man is admitted as a medical emergency. A diagnosis of pulmonary embolism is made. Which of the following features in his clinical history is most likely to have contributed most to his thrombosis risk?

• He had a total knee replacement (TKR) 9 months previously
  He had just flown back to the UK from a weekend break in Paris
  He has recently started quinine for night cramps
  His 64 year old cousin has recently suffered from a pulmonary embolism following bowel surgery
  He was discharged from hospital 4 weeks ago following treatment for congestive cardiac failure (CCF)
  

The TKR is too remote in time to be relevant; however, it is a strong risk factor for VTE in the 35 days postsurgery. Quinine can result in the development of thrombocytopenia and a systemic reaction but is not associated with VTE. Travel is a common but weak risk factor for thrombosis and only journeys of >3 hours of continuous travel are relevant. A cousin is not a first-degree relative and the event suffered by this man's cousin was provoked. CCF, or indeed any significant hospitalisation, is a strong risk factor for subsequent VTE - The Million Women Study suggests the period of attributable risk is about 12 weeks.

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