Really poor taste, to put this in the clinic, when the guy is really ill.
Here is the breakdown:
1. Trauma, a leading cause of deep venous thrombosis, particularly in the lower extremity
2. We know he had a huge hematoma in his calf by his and others accounts--which would have compressed the venous return (and hid the swelling from the DVT) rendering that leg much more prone to DVT
3. Dehydration: from the bike race
4. Immobilization--because of the head injury, he wasnt allowed to move for a couple of days. After release, he was too sore to move much
5. Followed immediately by Trans-Atlantic flight
<<The causes for pulmonary embolism are multifactorial and are not readily apparent in many cases. The causes described in the literature include the following:
<<Venous stasis
Hypercoagulable states
<<Immobilization
<<Surgery and trauma
Pregnancy
Oral contraceptives and estrogen replacement
Malignancy
<<Hereditary factors
Acute medical illness
Venous stasis
Venous stasis leads to accumulation of platelets and thrombin in veins. Increased viscosity may occur due to polycythemia and dehydration, immobility, raised venous pressure in cardiac failure, or compression of a vein by a tumor.
Hypercoagulable states
The complex and delicate balance between coagulation and anticoagulation is altered by many diseases, by obesity, or by trauma. It can also occur after surgery.
Concomitant hypercoagulability may be present in disease states where prolonged venous stasis or injury to veins occurs.
Immobilization
Immobilization leads to local venous stasis by accumulation of clotting factors and fibrin, resulting in thrombus formation. The risk of pulmonary embolism increases with prolonged bed rest or immobilization of a limb in a cast.
In the Prospective Investigation of Pulmonary Embolism Diagnosis II (PIOPED II) study, immobilization (usually because of surgery) was the risk factor most commonly found in patients with pulmonary embolism.
Surgery and trauma
A prospective study by Geerts and colleagues indicated that major trauma was associated with a 58% incidence of DVT in the lower extremities and an 18% incidence in proximal veins.[7]
Surgical and accidental traumas predispose patients to venous thromboembolism by activating clotting factors and causing immobility. Pulmonary embolism may account for 15% of all postoperative deaths. Leg amputations and hip, pelvic, and spinal surgery are associated with the highest risk.
Fractures of the femur and tibia are associated with the highest risk of fracture-related pulmonary embolism, followed by pelvic, spinal, and other fractures. Severe burns also carry a high risk of DVT or pulmonary embolism.