Certified Wound Care Nurse (CWCN) Practice Exam

At what Ankle-Brachial Index (ABI) value should a toe brachial pressure assessment be conducted before starting compression therapy?

1. 1.0

2. 1.3

3. 3.0

4. 3.5

The correct answer is: 1.3

The Ankle-Brachial Index (ABI) is a crucial assessment tool in evaluating peripheral arterial disease and determining the appropriateness of compression therapy in patients with venous leg ulcers. An ABI value of 1.3 indicates that the arteries might be calcified, which can lead to overestimating the blood flow to the lower extremities. In such cases, the toe brachial pressure index (TBPI) is warranted to assess blood flow more accurately in the toes, where vascular status can be determined with less influence from calcification. Conducting a toe brachial pressure assessment when the ABI is 1.3 helps ensure that the patient can tolerate compression therapy without risking complications such as critical limb ischemia. Compression therapy enhances venous return and decreases edema, but it must be applied safely, particularly in patients with vascular insufficiency. Therefore, an ABI of 1.3 serves as a threshold indicating the necessity for further assessment through TBPI before commencing compression therapy.