Leg swelling

Five days after major surgery, your patient complains of pain and swelling in the right leg. Discuss your initial assessment of the problem.

Of prime concern is whether this patient has a DVT. Before you examine the patient, determine if there is a past history of venous thromboembolic disorders and establish the risk factors for DVT. See exactly what type of surgery was performed and what, if any, prophylactic measures were taken to minimise the risk of clot formation. Remembering Virchow's triad, consider the changes that may bring about DVT:

• change in flow

• change in the vessel wall

• change in the constituents of the blood.

Apart from DVT, other conditions to consider include congestive cardiac failure, dependent oedema and cellulitis. Remember that clinical assessment for the presence of DVT is, at best, unreliable. A tender, swollen calf suggests that the patient may have a DVT.

The patient is 63 years old and had an unremarkable past history. In particular, he had no history of thromboembolic problems or cardiac disease. He was not overweight and had been mobile before the operation. The patient had been classified as having a low risk for DVT and immediately before the operation had been given a dose of an unfractionated heparin preparation. A calf vein compression device had been used during the procedure. He had undergone an anterior resection of the rectum for carcinoma. The procedure had been uncomplicated.

From your assessment you suspect the patient may have a DVT. What do you do next?

An ultrasonographic examination of the deep veins of the thigh and leg should confirm or refute the diagnosis. If the patient has a DVT, it will be important to document the extent of the clot and the degree of luminal occlusion. Extension of the clot into the femoral vein increases the risk of detachment and pulmonary embolism.

If clot is present and extends into the popliteal vein or beyond, heparin should be started and graded compression stockings applied. If conventional heparin is to be used, a typical regimen is a loading dose of 5000 IU followed by 1000 IU per hour. The patient will require monitoring with serial activated partial thromboplastin time (APTT) measurements. Alternatively, a lowmolecular- weight heparin can be given. This does not require APTT estimations and can therefore be used on an outpatient basis.

The patient will probably be anticoagulated with warfarin for 3–6 months.