Certified Wound Ostomy Nurse (CWON) Practice Test

What is the most accurate description of the ABI measurement technique?

1. Measure only the brachial BP

2. Rest, measure brachial BP, then ankle BP, and calculate

3. Perform an ultrasound to evaluate blood flow

4. Only measure ankle pressures

The correct answer is: Rest, measure brachial BP, then ankle BP, and calculate

The most accurate description of the Ankle-Brachial Index (ABI) measurement technique involves measuring both the brachial blood pressure and the ankle blood pressure after allowing the patient to rest. This method is critical because it provides a comparison of the blood flow in the ankle arteries relative to the brachial arteries, which helps in assessing peripheral vascular disease. The process begins with the patient resting in a supine position, which allows blood flow to stabilize. Brachial blood pressure is measured first, typically in both arms, to ensure accuracy and select the higher reading. Following this, the ankle blood pressure is then measured at the posterior tibial and dorsalis pedis arteries. The ABI is calculated by taking the higher of the two ankle pressures and dividing it by the highest brachial pressure. This technique's thoroughness is essential for accurate diagnosis. Simply measuring the brachial blood pressure alone would not provide sufficient information about potential vascular issues in the lower extremities. Similarly, performing an ultrasound to evaluate blood flow, while useful in some contexts, does not constitute the ABI measurement method. Likewise, only measuring ankle pressures without considering the brachial pressures would neglect the comparative aspect that the ABI is designed to represent. Thus, the comprehensive approach