Chapter 14: Miscellaneous Conditions/ Tests (2%) Flashcards
What is an AV fistula
abnormal connection between high pressure arterial system and low pressure venous system
AV fistulas can be
congenital or traumatic
If a fistula is close to the heart what increases
potential for cardiac failure
a fistula located peripherally is more likely to cause
ischemia
AVF may involve
prx and dst arteries/veins as well as collaterals
Proximal arterial flow (prox to AV fistula)
increase diastolic flow because fistula reduces resistance
Depending on size of fistula, arterial flow distal to AV fistula may
resume its normal triphasic pattern or be somewhat reduced
Flow throughout the AV fistula
higher velocities
low resistance
Venous outflow of AV fistula
takes on flow quality of fistulas low resistant pulsatile flow
Compartment syndrome
compression of tibial arteries due to swelling
leads to necrosis of muscle
compartment syndrome can be caused by
repair of tibial artery (from trauma or occlusion)
compartment is bound by bone, fascia and interosseous membrane that does not allow for expansion
pts with compartment syndrome present with
severe pain
tenderness
foot drop
treatment for anterior compartment syndrome
fasciotomy (cutting of fascia to relieve pressure)
Treatment for Pseudoaneurysms
US guided compression
US guided thrombin injection
US guided compression for pseudos technique
compression of 10-15 min with short rest period performed with MD present
monitoring of distal perfusion necessary
length of time varies