Internal Medicine

P1: RLJ/OZN P2: KUF

0521779407-D-01 CUNY1086/Karliner 0 521 77940 7 June 13, 2007 7:41

464 Deep Venous Thrombosis

tests

Blood

■Hypercoagulable workup only in pts without predisposing

condition; so-called “idiopathic DVT”; blood for w/u must be drawn

BEFORE heparin is started

➣D-dimer levels

➣Very sensitive; not very specific

➣Can be used to rule out DVT but not diagnose it

Specific Diagnostic Studies

■Duplex study

➣Highly sensitive and specific

➣Study of choice for DVT

■Contrast venography

➣Currently used only if duplex is nondiagnostic or to separate prior

chronic DVT from acute DVT

differential diagnosis

■Cellulitis

➣Warm, red skin

➣Normal duplex study

■Trauma

➣Distinguish by history

➣Duplex to r/o DVT (common in trauma)

■Arterial occlusion

➣Distinguish by history, pulses

➣Duplex may be needed (DVT can occur after arterial thrombo-

sis)

management

What to Do First

■Immediate anticoagulation

➣Low molecular weight heparin

➣Unfractionated (standard) heparin

General Measures

■Prevent DVT in surgical and bedridden patients with low-dose hep-

arin

■Initial elevation

■Ambulation with elastic stockings