Module 5: Acute Venous pathophysiology Flashcards
What is a D-Dimer Positive?
Blood test that detects a certain protein in the presence of some sort of blood clot.
DVT occurs in about how many Canadians each year?
200,000
Pulmonary embolism is the leading cause of what death associated with which demographic of patients?
Maternal women with child birth
A women’s risk of developing Venous thromboembolism (VTE) is how much greater if pregnant?
Six times
Pulmonary embolism causes more deaths annually in North America than what? 3
- Breast cancer
- AIDs
- Highway fatalities
Fetal Pulmonary embolism may be the most common preventative cause of ________ in ____________?
Hospital death in North America
Approximately how many patients are hospitalized each year for DVT in Canada each year?
60,000
What is the most common reason we scan extremity veins?
DVT
How much DVT is clinically diagnosed diagnose?
50%
What are some complications of DVT? 2
- Pulmonary embolism
- Chronic venous insufficiency (CVI)
How much pulmonary embolism originate in LE?
80%
If untreated what is the mortality rate of pulmonary embolism?
30%
Venous diseases can be what two things?
acute or chronic
Venous disease can effect what systems?
Both deep or superficial systems
The venous system can also be effected by what?
Non- venous pathologies
What are some underlying risk factors DVTs? 2
- Genetics
- Acquired - more common
What are some genetic factors for DVTs? 4
- Gender
- Race
- Antithrombin deficiency
- Fact V Leiden mutation
Acquired factors can be categorized into what system?
Virchow’s Triad
What is Virchow’s Triad?
- Stasis
- Injury
- Hypercoagulability
What is the most common factor for LE DVT?
Venous stasis
What are some reasons for Venous stasis? 5
- Immobility
- Congestive heart failure
- Obesity
- Pregnancy (vein compression L>R)
- Surgery (leg or hip example)
How would we get DVT from injuries?
Trauma to vessels, Like infection or HTN
What is the most common factor for UE DVT?
Central lines like peripherally inserted central catheter (PICC)
What is hypercoagulability?
The clotting ability of blood is increased
What are some reasons for Hypercoagulability? 4
- Pregnancy
- Cancer
- Estrogen intake (BCP, HRT)
- Genetic blood factors
What are some questions we ask for patient history for DVT? 5
- Previous DVT or family history
- Trauma?
- Surgery?
- Bed rest > 4 days
- Medications (BCP/HRT)
What is the difference between signs and symptoms?
Symptoms are patient recorded and signs are things we can see
Symptom could be something like pain, we can’t see pain
What are some common acute signs of onset for DVT? 5
- Pain
- Swelling (edema)
- Redness/ erythema
- Skin warm/ hot to touch
- Persistent pain (positive Homans sign)
What are some Symptoms of Pulmonary embolism? 4
- SOB
- Chest pain
- Hemoptysis
- Increased heart rate/ respiratory rate
C his
What are less common signs and symptoms for DVT? 6
- Ulceration (gaiter area, medical malleoulus) , shallow and round
- Discoloration in the gaiter area
- Varicose veins
- Pallor (phegmasia alba dolens) or getting white
- Cyanosis (phlegmasia cerulea dolens) or getting blue
- Positive D-timer test result
C pup VD
D-dimer test looks for what?
The presence of breakdown products of linked fibrin
D-dimers are very how sensitive to clots, and is it specific to DVTs?
Very sensitive 95%, but not specific to DVTs
For DVTs false positives occur due to what? 6
- Trauma
- Surgeries
- Pregnancy
- Malignancy
- Liver
- Kidney disease
PMS TLK
If there is a negative D-dimer test how likely is a DVT?
Unlikely
What is Well’s score?
Clinical assessment that estimates the DVT probabilities
What is the reported scores for Well’s score?
Low - 0
Intermediate - 1 or 2
High - 3
How is the Well’s score used for PE? 2
- Clinical assessment
- Positive criterion is a given number value
What is the PE well’s scoring system?
Low probability (<2)
Intermediate (2 to 6)
High (>6)
For thrombus formation where does it usually begin?
Soleal calf veins or the valve cusps due to stasis
What is thrombus formation?
- Red blood cells aggregate and cause fibrin formation and adheres to vessels walls
this induces further thrombosis which propagates along the vessel lumen
Acute stage of thrombus formation is within what time frame?
First 14 days after thrombus forms
What are other sites for thrombus? 5
- Muscular veins (gastrocnemius or soleal sinus)
- Valves sites
- Venous confluence
- Perforators
- Deep venous system or superficial system
Vm Vpd
What is the most common site for Calf vein DVT?
Soleal sinus
What is the current approaches to treatment for DVT? 2
- Surveillance with duplex US to check for propagation to larger veins
- Therapeutic anticoagulation for 6 weeks
Between a fem pop DVT and a calf DVT which is more serious? why?
Fem- pop DVT because of the higher risk of PE
For fem-pop DVTs what initial test is performed?
Duplex sonography initial test
What is the most common treatment for Fem-Pop DVT?
Anticoagulation therapy
Imaging the Iliac veins can be challenging and success is dependent on what?
Patients body habitus
For Iliac DVTs doppler signals can give what?
Indirect information
For iliac DVT we should compare what things and assess what?
We should compare bilateral CFV waveforms and assess the IVC
How do we confirm Iliac DVT?
Venography
What are UE DVTs a result of?
Central venous catheters
Besides Central venous catheters, what can UE DVT be a result of? 3
- Mediastinal lymphoma
- Previous radiation therapy
- Trauma or surgery to the area
When can an acute DVT be first seen?
First 14 days
Acute thrombus can look how?
Anechoic to hypoechoic and enlarges the vessel slightly
There will be incomplete compression of the lumen with the transducer
For a sub-acute DVT when would it present and what would it look like?
1 to 2 months old and can be slightly more echogenic and retracts in size
When the DVT is distal to where you scan the waveform can show what?
Reduced or absent augment
Collateralization is another sign of what?
DVT
Collaterals are what?
Accessory vessels that reroute flow around an obstruction.
Collaterals may occur rapidly in the presence of what?
DVT and may be readily seen
What are some Rare DVT conditions? 4
- May-Thurber syndrome
- Pages- Schreotter syndrome
- Phlegmasia Alba Dolens
- Phlegmasia cerulean dolens
What a some rare conditions of DVT?
- May- Thurner syndrome
- Page- Schroetter Syndrome
- Phlegmasia Alba Dolens
- Phlegmasia Cerulean Dolens
What is another name for May- Thurber Sydrome?
Iliac vein compression syndrome
What is May-Thurner syndrome?
Result of an anatomical variant of an overriding RT CIA compressing the LT CIV against the 5th Lumbar vertebra