DVT Flashcards
(23 cards)
virchows triad
vascular endothelial damage
venous stasis
hyper coagulability
symptoms
edema, warmth, and dull pain of the affected extremity
What D-dimer level allows DVT to be ruled out?
Levels < 500 ng/mL
A negative D-dimer assay is used to rule out DVT.
What does a positive D-dimer level (≥ 500 ng/mL) indicate?
It is nonspecific and requires a venous ultrasound to confirm the diagnosis.
A positive D-dimer does not confirm DVT but suggests further investigation.
What is the most important sonographic feature of DVT?
Noncompressibility of the affected vein
This feature is crucial for diagnosing DVT via ultrasound.
What is the recommended duration of anticoagulation for patients with DVT?
3–6 months
This recommendation applies to all patients with DVT, except for isolated asymptomatic distal DVT.
What management may be considered for isolated asymptomatic distal DVT?
Expectant management with serial ultrasound
The risk of postthrombotic sequelae is low in these cases.
In what cases may catheter-directed thrombolysis or thrombectomy be considered?
Limb-threatening ischemia, acute iliofemoral DVT, and patients with contraindications to anticoagulation
These interventions are used for severe cases of DVT.
what can be used to determine pre test probability of DVT
Wells criteria
Homans sign
calf pain on dorsal flexion of the foot
false positives are common
Meyer sign
Compression of the calf causes pain.
Payr sign
pain when pressure is applied over the medial part of the sole of the foot
Proximal UEDVT
thrombosis of the axillary or subclavian vein
Distal UEDVT
thrombosis of the brachial, radial, ulnar, or interosseus veins
aetiology of primary UEDVT
Venous thoracic outlet syndrome due to increased muscle bulk, fibrotic connective tissue, abnormal ligamentous insertion, or osseous abnormalities (e.g., cervical rib)
Effort-induced thrombosis: repetitive strenuous activity involving the upper extremities (e.g., weight-lifting, gymnastics, operation of a jackhammer)
aetiology of secondary UEDVT
Venous devices
Central venous catheters and port systems (difficult insertion, long duration of use, presence of catheter associated infection)
Pacemaker leads
Hypercoagulable states
Malignancy
Hereditary thrombophilia
Pregnancy
Oral contraceptive use
Prolonged upper extremity immobilisation
Phlegmasia cerulea dolens
a severe form of phlebothrombosis characterized by obstruction of all veins of one extremity, with subsequent restriction of arterial flow; associated with high mortality
symptoms of Phlegmasia cerulea dolens
Severe swelling, edema, and pain
Coldness, cyanosis, and pulselessness
treatment for Phlegmasia cerulea dolens
Emergency surgery: venous thrombectomy, fasciotomy
Fibrinolysis if surgery fails
Amputation as last resort
Complications: shock, gangrene, acute renal failure (due to rhabdomyolysis)
red flags in DVT
Severe swelling and edema with concomitant coldness, cyanosis, and pulselessness should raise concern for phlegmasia cerulea dolens, which requires emergency surgery.
Catheter-directed thrombolysis (CDT)
If thrombolysis is selected, CDT is preferred over systemic thrombolysis for DVT.
Indications:
Limb-threatening ischemia (phlegmasia cerulea dolens)
Consider in acute (< 14 days) iliofemoral DVT in patients with low risk of bleeding and life expectancy ≥ 1 year
Agents: streptokinase, urokinase, rtPA
Thrombectomy
Catheter-directed or surgical
Indications: same as for CDT; consider as an alternative to CDT in patients with absolute contraindications to thrombolysis
