DVT Flashcards
What is a venous thrombus?
formation of semi-solid coagulum within flowing blood in venous system
What are the types of superficial thrombophlebitis?
- simple (traumatic) thrombophlebitis
- Mondor’s disease
- Thrombophlebitis Migrans
What is simple thrombophlebitis?
localized inflammation of the vein wall + thrombus formation in the lumen
What are the causes of simple thrombophlebitis?
- Direct trauma
- Venous intimal damage
- infusion of hypertonic solutions, antibiotics & chemo & drug abuse
- cannula insertion
- on top of varicose vein “stasis”
What is the clinical picture of simple thrombophlebitis?
- vein becomes tender, painful, firm, & cord-like
- overlying skin is dusky & edematous
- rare embolization cause its firmly attached to the wall
How should simple thrombophlebitis be treated?
PREVENTION
- rotate IV sites every 3 days
- diluting irritating infusions
CONSERVATIVE
- rest & elevation + elastic bandage
- warm compresses + NSAIDS or aspirin +- antibiotics
SURGICAL (only if extensive)
- if thrombus propagates –> ligation of sapheno-femoral junction under local anesthesia
- excision in cases on top of varicose veins & recurrent symptomizing phlebitis
What is Mondor’s disease?
String Phlebitis
- spontaneous thrombophlebitis of the superficial veins over the breast & anterior chest wall towards the axilla
- usually lateral thoracic vein, thoracoepigastric vein, & superficial epigastric vein
What characterizes Thrombophlebitis Migrans?
recurrent attacks of thrombophlebitis involving segments of previously normal superficial veins
What are the causes of thrombophlebitis migrans?
- early stages of Burger’s disease
- polyarteritis nodusa
- visceral carcinoma (trousseau’s sign)
How should thrombophlebitis migrans be treated?
- treat symptoms
- smoking should be stopped & prohibited (in BURGER’S)
- if persistently active: long term anti-coagulant therapy
- if no obvious cause: search for underlying pathological process (intra-abdominal & GI malignancies or hypercoagulable states)
What are the common sites for DVT?
UPPER LIMB
- axillary vein thrombosis
LOWER LIMB
- Soleal venous plexus calf vein thrombosis
- ilio-femoral thrombosis -> phlegmasia alba dolens PAD
- ilio-femoral thrombosis + deep pelvic vein thrombosis -> phegmasia cerulae dolans PCD
which side is more common to be affected in case of ilio-femoral thrombosis?
left side
- more liable to be compressed by overlying right common iliac artery against L5
- left iliac vein is longer
What are the causes leading to DVT?
VIRCHOW TRIAD
- vessel wall (VASCULAR WALL INJURY)
- velocity (HYPERCOAGULABLE STATE)
- viscosity (CIRCULATORY STASIS)
What are examples of hypercoagulable states?
- malignancy
- pregnancy & peripartum period
- estrogen therapy
- trauma or surgery of lower extremity, hip, abdomen, or pelvis
- inflammatory bowel disease
- nephrotic syndrome
- sepsis
- thrombophilia
What are examples of circulatory stasis?
- atrial fibrillation
- left ventricular dysfunction
- immobility or paralysis
- venous insufficiency or VV
- venous obstruction from tumor, obesity, or pregnancy
What are the risk factors for DVT?
PATIENT
- > 60 yrs
- obesity
- varicose veins
- immobility
- pregnancy
- puerperium
- high-dose estrogen therapy
- previous DVT or pulmonary embolism
What diseases of surgical procedures are a risk for developing DVT?
- trauma or surgery, esp in pelvis, hip, & lower limb
- malignancy esp pelvic & abdominal
- heart failure
- recent MI
- paralysis of lower limb
- inflammatory bowel disease
- polcycthaemia
What is the pathogenesis of DVT?
- primary platelet thrombus
- mural coralline thrombus
- occluding thrombus
- consecutive clot
- propagated clot
What is the difference between thrombophlebitis & phlebothrombosis?
THROMBOPHLEBITIS PHLEBOTHROMBOSIS
- inflammation of vein wall - stasis & hypercoagulability
- pain + signs of inflammation - silent + few signs
- short & fixed propagated clot - large & easily detachable
- less liable to embolization - more liable to embolization
What are the local consequences of thrombosis?
- lysis
- organization & fibrosis (CVI due to valve destruction)
- calcification & ossification
- extension (propagation)
What are the distal & proximal consequences of thrombosis?
DISTAL
- edema after venous collaterals open up
- phlegmasia alba & cerula
- post-phlebetic syndrome -> 2ndry VV -> CVI
PROXIMALLY
- detachement -> pulmonary embolism
What is the clinical picture of DVT?
- asymptomatic in 30-50%
- detectable pulmonary embolism -> fatal
- low grade fever that fails to settle after operation
What are the local signs of DVT?
- swelling (FROG-LEG POSITION)
- leg is externally rotated
- knee is flexed
- calf is stiff
- aching pain & heaviness on moving calf & thigh
- tenderness on pressure on instep of sole of foot
What are the complications of DVT?
- CVI
- VV
- venous gangrene
- pulmonary embolism
What investigation should be preformed for DVT?
- doppler US
- D-dimer (breakdown products of complexed fibrin)
What are the pre-op measures that should be done?
MECHANICAL PROPHYLAXIS
- elastic compression stockings
- intermittent pneumatic compression device
PHARMA PROPHYLAXIS
- low-dose unfractioned heparin injection 2 hours pre-op & every 8-12 hours after (requires monitoring)
- LMWH
What operative measures should be done to prevent DVT?
- reduction of trauma to calf muscle in surgery
- elevation & massage of leg at the end of operation
What post-op measures should be taken post-op to avoid DVT?
- early ambulation
- maintenance of adequate hydration
- pharmacological prophylaxis
- daily examination of calf & feet
How should an established DVT be treated?
CONSERVATIVE
- bed rest & foot elevation
- anti coagulants
- thrombolytic & defibrinating agents (urokinase & streptokinase)
- post treatment compression to control leg edema
How is DVT treated operatively?
VENOUS THROMBECTOMY
- extraction with a balloon Fogarty catheter
CAVAL FILTER
- use if there are contraindications, complications or failure of anticoagulants & prophylaxis
When should heparin be given?
5000-100 000units/6hrs for 7 days in CALF THROMBOSIS
and for 14 days in ILIOFEMORAL THROMBOSIS
LMWH = 1mg/kg/12hrs
- DRIP INFUSION
- monitor PTT
- protamine sulfate is the antidote
- dont give in HYPERTENSION
When should warfarin be given?
10mg on day 1
10 mg on day 2
5mg on day 3 for 6 months
start before we stop heparin by 3 days
- ORALLY
- PT monitoring
- fresh blood transfusions & VIT K are the antidotes
- could cause bleeding & is teratogenic
- DONT GIVE IN PREGNANCY
