Flashcards in Venous testing Deck (45):
most common findings of DVT?
swelling, pain, redness, warmth
differential diagnoses of DVT?
Most common findings of chronic DVT?
swelling, heaviness, discoloration, ulcers, varicosities
what does erythema indicate?
inflammatory process, cellulitis
what does brawny (brown) color indicate?
venous stasis usually lower leg to ankle area
what does pallor indicate?
arterial spasms secondary to extensive, acute iliofemoral thrombosis; limb threatening; called phelgmasia alba dolens
what does cyanosis indicate?
severely reduced venous outflow from iliofemoral thrombosis markedly reduces arterial inflow; limb threatening; called phlegmasia cerulea dolens (venous gangrene)
characteristics of venous ulcers?
often near medial malleolus, shallow and irregular
stasis changes: inflammation, infection, brawny, presence of varicos
characteristics of arterial ulcers?
-tibial, toes, and bony prominences are common areas
-deep, regular shape, punch-out appearence
-trophic changes: dryness, scaly, atrophy, shiny skin, loss of hair, thickened toenails
What are the characteristics of pitting edema?
-fluid in subcutaneous tissue
-depression of skin surface with manual pressure
-can be related to CHF, fluid retention, elevated venous pressure
What is lymph edema?
when fluid accumulates after lymph nodes and/or lymph vessels are removed or damaged
frequency seen after many types of cancer surgery
What is virchow's triad made up of?
trauma to the vessel/ endothelial damage
Why might surgery be a risk factor for DVt?
may be due to alteration in endothelial cell funciton
What can cause hypercoagulability?
certain protein deficiencies
What are the components of Paget-Schroetter syndrome?
- stress/effort thrombosis
-involves axillary or subclavian vein
-venous component of TOS
What are signs of superior vena cava syndrome?
-obstruction by neoplasm
-edema and engorgement of vessels evident
-patient may have cough and/or difficulty breathing
-flow in UE remains the same during inspiration (continuous)
Acute intraluminal thrombi frequently begin where?
at valve cusps or in soleal sinuses secondary to stagnation
Where do thrombi resulting from trauma occur?
at any site
Stretching of walls results in damage to valves and increased venous pressure causes flow changes, this is what?
chronic venous insufficiency
What is post-phlebitic syndrome?
-chronic flow changes result in persistent edema, stasis changes, and pain
-may also lead to ulceration
What are the most definitive diagnostic tools for diagnosing a PE?
CTA chest and pulmonary angiography
Primary varicose veins are what?
dilated veins secondary to valvular incompetence of superficial system
deep system is intact
What are secondary varicose veins?
dilated veins caused by incompetence of the superficial system resulting from deep venous obstruction
deep system is not intact
what are congenital venous diseases
Klippel-trenaunay: can include multiple varicosities of superficial system and hypoplastic or absent deep veins
What is portal hypertension?
elevated venous pressure results from obstruction of blood flow, may result in reverse flow in the portal vein and increased portal venous pressure that impedes blood flow into the liver
What is DC coupling for PPG's?
-electric voltage that is either positive or negative
-current flows in only one direction
-batteries are DC
-detects slow changes in blood content
-used for venous studies
What is AC coupling for PPG's
-electric voltage that reverses polarity 60 times a second
-current flows in both directions
-wall plugs deliver 120 volts of AC
-detects fast changes in blood content
-used for arterial studies
Where is the PPG sensor applied for veins?
lower leg, approx 5-10cm above medial malleolus
What is a normal venous refill time/venous reactive time?
> 20 sec without tourniquet
What is the result of the VRT for superficial system incompetence?
VRT 20 sec with tourniquet
What is the result of the VRT for deep system incompetence?
What are the PPG capable of documenting for venous?
insufficiency/quantitate venous reflux in patients with chronic swelling, venous ulcers and/or varicose veins
What is the patient positioning for venous PPG's?
seated with feet dangling
measures volume changes
What is air-plethysmography used to evaluate?
document venous insufficiency and quantitate venous reflux
What are limitations of air-plethysmography?
- inability of patient to maintain positions or perform exercise
- casts, traction, or heavy non-removable bandages
- will not diagnose incompetent perforators or isolated incompetent distal veins
What are the physical principles of air-plethysmography?
- plethysmography measures volume changes
- pneumatic cuff connected to pressure transducer; volume changes amplified and converted to analog display
-documents volume changes secondary to position changes/ exercise
What does the air-plethysmography test involve?
a) patient supine, cuff applied to lower leg, manual calibration of cuff
b) leg elevated to empty veins to zero volume
c) patient quickly stands of bearing weight on contralateral leg; increase in venous volume
d) patient stands equally on both feet; performs one 1 toe raise to document a decrease in calf vv; 10 toe raises completed
e) patient resumes supine position; test leg elevated
f) if abnormal repeat after tourniquet applied to eliminate influence of superficial system
venous filling index shows rate of venous refilling and is calculated venous volume and venous filling time. Is a high or low number normal?
a low number
What does the ejection fraction measure?
calf muscle pump function
ejection volume and functional venous volume
want to be a high % (>60%)
Residual volume fraction is equivalent to what?
ambulatory venous pressure in mmHg
calculated as the % of VV remaining after 10 toe raises
normal is a low %
What are the capabilities of continuous-wave doppler for venous testing?
evaluation of deep venous obstruction and venous incompetence
What are sources of false positive studies with continuous -wave doppler?
- Extrinsic compression; tight clothing, tumors, ascities, pregnancy, obesity, improper positioning, pain causing muscle contraction
-peripheral arterial disease: decreased venous filling
-chronic obstructive pulmonary disease: elevated central venous pressure
-improper doppler angle or probe position
What are sources of false positive studies with continuous doppler?
presence of bifed system (multiple deep veins)
What is the patients position when evaluating the venous system with continuous wave doppler?
-supine with body shifted to side being examined
-leg externally rotated with hip and knee flexed
-reversed trendelenburg position for venous filling