Chapter 27

Question 1

what are capabilites of CW doppler?

Answer 1

evaluation of deep venous obstruction

evaluate venous incompetence

Question 2

what are some limitations of CW doppler?

Answer 2

unable to differentiate abnormal flow patterns from DVT versus extrinsic compression i.e tumor, ascites, pregnancy
normal flow patterns may be evident with parital or well- collateralized thrombosis
paired deep veins in calf limit diagnosis of an isolated calf clot

Question 3

what are some false positive for CW?

Answer 3

• extrinsic compression ie. tight clothing, tumors, ascites. pregnancy, obesity, improper patient positioning , or pain causing muscle contraction
• PAD. decreased venous filing
• chronic obstructive pulmonary disease: elevated central venous pressure
• improper doppler angle or probe pressure

Question 4

what are some false negative for CW?

Answer 4

collateral development

presence of bifed system (multiple deep veins)

Question 5

what is patient positioning for CW?

Answer 5

supine with body shifted to side being examined
leg externally rotated with hip and knee flexed
position should faciliate venous filing (extremities lower than heart) reversed trendeleburg (apprx 30 degrees)

Question 6

what may an extreme side laying position do?

Answer 6

an extreme side lying position may diminish extrinsic compresson on IVC from pregnancy, ascites, or tumor formation

Question 7

what are some reminders to do with CW?

Answer 7

use 5MHz probe at 45-60 degree to skin surface
deep veins found with artery
correct vessel id requires hearing accompaning arterial signal
exam based on audible venous signal

Question 8

t/f start with the symptomatic side

Answer 8

FALSE

asymtomatic

Question 9

what should venous flow patterns look like?

Answer 9

spontaneous
phasic
augment with distal compression
augment with proximal release

Question 10

T/F you want to evaluate the vessel from multiple angles before making a final conclusion

Answer 10

true