Venous Ch 24-33 Flashcards
Difference between the pressure within the vein (intramluminal pressure) and from outside the veins (interstitial pressure)
transmural pressure
the venous system holds _____ of total blood volume
two-thirds
veins can distend ____ times that of the coresponding artery.
3-4
The greater resistance occurs when the vein is ________ and the least resistance exists when the vein is _________
elliptical, distended
supine = \_\_\_\_\_ transmural pressure Standing = \_\_\_\_\_ transmural pressure
low
high
is caused by the weight of a column of blood extended from the heart to the level where the pressure is being measured
hydrostatic pressure
hydrostatic pressure = _ x _x _
p,g,h
p= blood density (specific gravity of blood)
g= acceleration due to gravity
h= height of the column of blood (distance from the heart)
hp at the ankles
100mmHg (ankle P = circulatory + 100mg)
arm pressure =
venous P - 50mmHg
during inspiration…
- pressure decreases in chest
- increased abdominal pressure
- IVC collapses and venous return from the legs is impeded
during expiration…
- abdominal pressure decreases
- pressure increases in chest
- flow increases from legs into abdomen
- blood flow is decreased into the thorax
valsalva maneuver causes the intrathoracic and intraabdominal pressure to ….
increase significantly
all venous return is halted
the maneuver equates with proximal compression while preforming doppler assessment of the lower extremities
Normal time when testing for venous reflux*
Normal 1 sec
In the past, the clinical diagnosis of acute DVT based on pt medical history and physical exam was considered _________ (___%)
very unreliable, less than or equal to 50%
most common clinical findings of ACUTE DVT
- swelling
- pain
- redness, or erythema
- warmth
nonspecific test for deep venous disease since any inflammation of muscle will elicit the same result
Homan’s sign
symptoms of CHRONIC DVT…
- swelling
- erythema
- heaviness/aching
- discoloration or ulcerations
- varicosities
CEAP is the international standard for describing clinical manifestations and pathologic features of chronic venous disease
C = Clinical disease E= Etiology A= Anatomic distribution of reflux P= underlying Pathology
the development of venous thrombosis is based on three factors know as __________
VIRCHOW’S TRIAD***
what are the three factors in Virchow’s Triad?***
- trauma to the vessel
- venous stasis
- hypercoagulability
thrombosis usually occurs at the most _______ portion of the PICC line
proximal
what can cause venous stasis?
- bed rest or immobility
- CHF
- obesity
- COPD
- pregnancy
- previous DVT
- extrinsic compression
- surgery-associated condition
what can cause hypercoagulability?
- cigarette smoking
- brith control pills
- estrogen intake
- cancer
- pregnancy
- inherited states, e.g. factor V leiden etc.
also known as stress or effort thrombosis
-usually involves thrombosis of the subclavian or axillary vein secondary to intense, repetitive activity
-venous component of TOS
Ex. heavy lifting or strenuous throwing of base ball or football
Paget-Schroetter Syndrome***
left common iliac vein compression by the right common iliac artery as the artery crosses over it.
May-Thurner Syndrome***
what is Nutcracker syndrome?
compression of the left renal vein between the aorta and the SMA
hypoplatic or complete absence of the deep veins (absent iliacs with varicosities of the superfical system resulting in a enlarged limb
Klippel-Trenaunay
in klippel-Trenaunay severe varicose veins, widely dispersed, are commonly seen on the _______ aspect of the thigh and calf.
lateral
causes of portal hypertension
- chronic liver disease such as cirrhosis
- severe CHF
- proximal venous occlusion
most common symptom of Superior Vena Cava Syndrome
- dysonea (difficulty breathing) is most common
- facial and extremity swelling may also be evident
most common solid renal mass in adults that can result in thrombosis of the renal vein.
Renal Cell Carcinoma
most common cause of IVC tumor
Renal Cell Carcinoma
secondary varicose veins are a result of …
constructive conditions
value damage from DVT, pregnancy, obesity
thickening or hardening of the skin and can be found in pt with chronic venous insufficiency
lipodermatosclerosis
What is “bottle-neck-deficiency” ?
over time tissue becomes depressed, changing the contour of the ankle area
limb threatening condition that results from arterial spasms that occur secondary to extensive, acute ilio-femoral vein thrombosis; Limb is very swollen, pale, and painful
whiteness (pallor)
phegmasia alba dolens
complications of an acure iliofemoral vein thrombosis severely reduced venous outflow causes marked reduction in arterial inflow
tissue hypoxia can develop, leading to venous gangrene
limb is very swollen, dark blue, and painful
limb threatening!
plegmasia cerulea dolens
1st stage- phegmasia alba dolens and
2nd stage- plegmasia cerula dolens
are both examples of an ______
acute DVT
the formation of local defects on the surface of skin that occurs with the sloughing of inflammatory necrotic tissue - can be associated with venous disease
ulceration
where do venous ulcers usually occur?
around the medial malleolus where the posterior tibial (formerly Cockett’s I, II, and III) perforators are located
one of the most consistent signs of elevated venous pressure
edema
documents capillary blood volume, evaluates the presence and severity of venous insufficiency
(microcirculation)
PPG
how is the pt positioned for a PPG?
seated with legs dangling, i.e. nonweight bearing
sensor is placed on the lower leg, 5-10cm above the medial mallelous
speed of the strip chart recorder for PPGs
5mm/sec
technique used for PPGs
- pt is instructed to dorsiflex the foot 5 times to empty veins
- tracing is recorded after dorsiflexions to record venous refill time or venous reactive time (VRT)
normal venous reactive time…
greater than or equal to 20 sec***
If VRT is less than ______ sec the study is repeated with a tourniquet test to determine if the incompetence is coming from the superficial or deep system
20
VRT of less than 20 sec without the tourniquet that normalizes to greater than 20 sec with the touriquet ABOVE THE KNEE is consistant with reflux in the ….
great saphenous
VRT of less than 20 sec without the torniquet that normalizes to greater than 20 sec only when the tourniquet is applied BELOW THE KNEE is consistant with reflux in the …..
small saphenous
a VRT of less than 20 sec with and without tourniquet application is consistent with….
reflux in the deep system
Normal VFT is _____, minor to moderate reflux is _____, and severe reflux is _____
less than or equal to 2, greater than 2-10, greater than 10
normally want the ejection fraction a high percentage, Normally the calf expels _____ with one toe up
greater than 60%
a residual volume fraction of _____ is considered normal
less than 35%
reverese trendelenbury is approx. ____ degrees
30
continuous wave doppler ___MHz at _____ degrees
5, 45-60
continuous wave interpretation
-spontaniety, patency, respiration/phasicity
continuous flow patterns of veins of the upper or lower extremity are usually consistent with ______ venous obstruction
proximal
most common duplications
-femoral and popliteal vein
when identifying venous insufficiency a _____cm cuff is is applied to the high thigh portion of the leg
the cuff is then inflated to ____mmHg and maintained for ____ seconds
12x40
80
1-2
the cuff is inflated to ____mmHg for the popliteal vein and placed on the calf
100
for the posterior tibial vein the cuff is inflated to _____mmHg
120
how can you optimize the system for low velocity flow detection
- decrease scale
- decrease wall filter
- increase color gain
- largest vein in the upper arm
- medial and superficially without an companion artery
basilic vein
if a perforator vein has a diameter of ____mm, many think its probably normal regardless of flow direction
less than 3
if a pt has a dialysis accsess graft what should be expected
- increased velocity and volume flow
- pulsatile flow
- no response to distal compression
- incompressible vessel
- collateral channels evident
sluggish flow seen as heterogenous material moving with respirations and augmentation maneuvers
-red blood cells arrange like a roll of coins or roleau
roleau formation
a compressible vessel with evidence of roleau formation on b-mode suggest ______ obstruction
proximal
if the perforator measures greater than 3,5mm reflux has been found to be present about ____ of the time
90%
two alternative diagnostic tests related to venous diseases
- D-dimer
- contrast venography (used to evaluate pulmonary embolism)
proteins produces when a blot clot dissolves in the body and normally is undetectable in the blood.
D-dimer
considered the “gold standard”
the number has decreased due to the accuracy of duplex scanning
contrast venography
the most common cause of varicose veins is imcompentence of the _______ vein
great saphenous
used to treat small varicosities such as spider veins
sclerotherapy
primary treatment of non healing ulcers
unna boots
- fistula in the non dominate arm
- radial artery to cephalic vein fistula is most common
Brescia-Cimino Fistula
grafts are usually made of _____ commercially known as _____
teflon , Gore Tex
requirments for AVF and grafts
- venous diameter is greater than or equal to 2.5mm
- for a graft the vein should be greater than or equal to 4mm
- within 1cm of the skin surface
