section name header

Introduction ⬇

Peripheral arterial Doppler studies visualize and document the arterial blood flow in the extremities. Arterial duplex ultrasound scans can determine the presence, amount, and location of plaques in arteries and are helpful in assessing the cause of claudication. Graft patency and condition may also be evaluated. Ultrasound analysis is used to evaluate the area of concern in the lower or upper extremity or the site of a prior surgical or percutaneous intervention.

Procedure ⬆ ⬇

  1. Ask the patient to lie on the examining table with the leg or arm turned out slightly and the knee or elbow partially bent.

  2. Apply a couplant (ultrasound gel) to the leg from groin down or to the arm from shoulder down to enhance the transmission of sound. During Doppler evaluation, an audible signal, representing blood flow, can be heard.

  3. Move a handheld transducer gently up and down the limb while images of appropriate blood vessels are made.

  4. Tell the patient that the examination time is about 60 minutes.

  5. See Chapter 1 guidelines for intratest care.

Clinical Implications ⬆ ⬇

Abnormal tracings (see Figure 13.2) and Doppler signals may provide evidence of the following:

  1. Plaque or calcification (particularly in the diabetic patient)

  2. Stenosis

  3. Occlusion

  4. Arteritis

  5. Aneurysm

  6. Pseudoaneurysm

  7. Graft diameter reduction

  8. Abnormal communication between artery and vein

Interventions ⬆ ⬇

Pretest Patient Care

  1. Explain the test purpose, benefits, and procedure. Instruct the patient to refrain from smoking or consuming caffeine for at least 2 hours before the test. Assure the patient that no radiation is employed, typically no contrast medium is injected, and no pain is involved. Some slight discomfort may be experienced from lying with the extremity extended or if segmental blood pressures are taken.

  2. Advise the patient that a liberal coating of coupling gel must be applied to the skin to promote sound transmission. A sensation of warmth or wetness may be felt during application.

  3. Follow guidelines in Chapter 1 for safe, effective, informed pretest care.

Posttest Patient Care

  1. Remind the patient to remove any residual gel from the skin.

  2. Review test results; report and record findings. Modify the nursing care plan as needed.

  3. Provide support and counsel appropriately should an abnormality be detected. Monitor and counsel for arterial disease and possible further testing (arteriogram or venogram) and treatment (surgery).

  4. Follow guidelines in Chapter 1 for safe, effective, informed posttest care.

Interfering Factors ⬆ ⬇

  1. Severe obesity compromises examination quality.

  2. Cardiac arrhythmias and disease may cause changes in hemodynamic patterns.

Reference Values ⬆

Normal