Venous Review ch. 26-28 Flashcards
Which vein has the most valves in the lower extremity?
Greater saphenous vein
What is pitting edema?
Indention or impression made in an extremity when compressed.
nonpitting edema: a result of Lymphedema, not a venous disease.
What is brawny discoloration caused by?
The breakdown of RBCs creates a hemosiderin deposit that gives off a brownish discoloration caused by increased pressure.
Virchow’s Triad
hypercoagulability, endothelial injury or trauma, venous stasis
How is a patient tested for hypercoagulability?
blood test, labs and treatment would be blood thinners
If a patient does not have a family history of DVT, no injuries or recent surgeries and their labs are normal, what could be the cause of them being positive for DVT?
Trousseau’s sign- hypercoagulability associated with cancer and is based on the finding of spontaneous venous thrombosis in patients with underlying malignancy
examples of hypercoagulability
pregnancy, birth control, cancer, dehydration, hormone replacement therapy, Factor V Leiden, antithrombin III deficiency
which patients should not preform the valsalva maneuver?
difficulty breathing, severe CAD, acute MI, or moderate to severe hypovolemia
what are the venous sinuses in the cranium?
right and left transverse sinuses drain into the IJV
Veins from distal to proximal
deep digital veins- metatarsal veins- deep venous arches peroneal veins(lateral leg) and PTV (posterior) join to form the tibioperoneal trunk joins the ATV (anterior) to form the popliteal just below the knee at the adductor canal the popliteal becomes the femoral which joins the deep femoral and becomes the common femoral becomes the external iliac just above the inguinal ligament which joins the internal iliac to become the common iliac. The left common iliac travels under the right common iliac artery to become the IVC.
Muscular veins
soleal veins empty into the peroneal and PTV and the gastroc empties into the popliteal
the confluence of the common iliac vein and the IVC forms at what level
the 5th lumbar vertebrae
perforating veins form communications between
the superficial to deep veins
perforating veins
posterior arch vein, cockett’s (calf), boyd’s (knee) and dodd’s (distal thigh)
have at least one valve
What percentage of femoral veins are bifed?
30%
posterior arch vein importance
communication with three of the perforators in the ankle, important fact in the development of venous ulcers
inner layer of a vein
tunica intima, a single layer of endothelial cells
middle layer of a vein
tunica media, a thick layer of smooth muscles and collagenous fiber
outer layer of a vein
tunica adventitia, a thin fibrous layer surrounding elastic tissue containing the vasa vasorum
number of valves: GSV
12, mostly below the knee
of valves: SSV
6-12
of valves: perforators
each contain 1 sometimes up to 3
of valves: infrapopliteal
7-12
of valves: popliteal and femoral veins
1-3 valves
of valves: external iliac vein
contains valves approximately 25% of the time
of valves: CFV
1
of valves: IJV
1
of valves: axillary vein
1
of valves: cephalic
variable in distal segment
of valves: basilic vein
variable in distal segment
veins without valves
soleal sinuses, external iliac (contains valves 25% of the time), internal iliac veins, CIV, IVC, subclavian, innominate, SVC
GSV carries what percentage of venous blood in the leg?
15%, 8% double systems and 25% noncontinous
what percentage of the population has SSV that enter above the popliteal vein or join the giacomini vein?
20-30%
What type of pressure determines the cross sectional shape of a vein?
transmural pressure
dumbbell shape vs. circular cross sectional shape
relationship of pressure vs. resistance
high transmural pressure with less resistance occurs in the circular cross sectional shape
low transmural pressure with more resistance occurs in the dumbbell shape
Hydrostatic pressure
in a supine individual HP is 0mmhg, standing HP at the ankles is 100mmhg
weight of a column of blood
if standing for a long period of time, what affect does it have on lower veins?
increase transmural pressure distally, increase venous distention, increase venous pooling, decrease in capillary perfusion, decrease in venous return and decrease in cardiac output, hypotension
Normal effects of muscle pump
with competent valves there will be a decrease in venous pressure and pooling and an increase in venous return and cardiac output
effects of muscle pump with incompetent valves
increase in venous pressure and pooling and decrease in venous return and cardiac output
During muscle contraction
contraction of the calf muscles forces blood cephalad toward the heart when it relaxes blood moves from the superficial veins to the deep system
what happens during valvular incompetence?
control of blood flow is deficient, blood travels both antegrade and retrograde
during muscle relaxation
very low pressure is created in the deep system and blood flows from the superficial to deep system
this process reduces peripheral venous pressure
What occurs during inspiration?
diaphragm descends during inspiration, intrathoracic pressure decreases and intraabdominal pressure increases minimizing blood flow to the lower extremities but increasing blood flow to the head, neck, and arms
What occurs during expiration?
intrathoracic pressure increases and intraabdominal pressure decreases
increasing blood flow to the lower extremities but decreasing blood flow to the upper extremities
acute signs and symptoms of a DVT
swelling, pain, warmth, erythema (redness)
scoring for probability of a DVT
active cancer within 6 months 1
paralysis, paresis or immobilization of lower extremities 1
recently bedridden for > 3 days or major surgery within 4 weeks 1
localized tenderness along the distribution of the deep veins 1
entire leg swollen 1
calf swelling > 3 cm compared to contralateral leg 1
pitting edema 1
collateral superficial veins 1
alternative diagnosis as likely or more likely than DVT -2
differential diagnosis in patients with a suspected DVT
muscle strain, direct injury to the leg, muscle tear, baker’s cyst, cellulitis, lymphangitis, heart failure, extrinsic compression, or complications of chronic venous insufficieny
patients with chronic venous insufficiency represent with
swelling, heaviness, discoloration or ulcerations, varicosities
Venous stasis
bedrest or immobility, hypotension, extrinsic compression, MI, congestive heart failure, COPD, obesity, pregnancy, previous DVT, paraplegia, surgery
congenital venous disease
avalvular (valveless vein), incompetent valves, arteriovenous malformations
venous ulcers
near medial and lateral malleolus mild to severe pain shallow, irregular appearance venous ooze stasis changes: brawny discoloration, varicosities present, or lipodermatosclerosis
arterial ulcers
location is near the tibial area or toes, bony prominences
severe pain
deep regular shape
little bleeding
Trophic changes: shiny skin, thickened toenails, loss of hair
