Chapter 26: venous continuous wave doppler

Question 1

CW of venous system is used for

Answer 1

evaluation of DVT and venous incompetence

Question 2

limitations of CW of venous system

Answer 2

unable to differentiate abnormal flow from DVT vs extrinsic compression
normal flow can be evident with partial or well collateralized thrombus

Question 3

sources of false positive CW studies

Answer 3

extrinsic compression (tumors, pregnancy, ect)
peripheral arterial disease (PAD)
COPD

Question 4

PAD can cause

Answer 4

decreased venous filling

Question 5

COPD can cause

Answer 5

elevated central venous pressure

Question 6

Sources of false negatives

Answer 6

collateral development
bifed system (multiple deep veins)

Question 7

patient positioning for CW venous doppler exam

Answer 7

supine
leg externally rotated
hip and knee flex
position should facilitate venous filling (reverse trendelenburg extremities 30 degrees lower than heart)

Question 8

what vessels do you image

Answer 8

CFV femoral popliteal and posterior tibial veins

from assymptomatic side to symptomatic side

Question 9

venous flow patters

Answer 9

spontaneous
phasic
augment with distal compression
augment with proximal release