Certified Wound Ostomy Nurse (CWON) Practice Test

What can lead to reactive hyperemia following ischemia?

1. Chronic venous insufficiency

2. Vasodilation after pressure relief

3. Permanent capillary occlusion

4. Low blood oxygen levels

The correct answer is: Vasodilation after pressure relief

Reactive hyperemia occurs as a physiological response when blood supply returns to an area that has experienced temporary ischemia, typically following a period of pressure relief. When there is a temporary restriction of blood flow, a buildup of metabolites occurs, leading to vasodilation when the pressure is released. This response aims to restore oxygen and nutrients to the affected tissue quickly. The sudden influx of blood, which can be greater than normal, causes the area to appear reddened—this is the phenomenon known as reactive hyperemia. Chronic venous insufficiency, permanent capillary occlusion, and low blood oxygen levels do not typically cause reactive hyperemia in the same way. Chronic venous insufficiency may lead to poor blood flow but does not produce the same transient hyperemic response once pressure is released. Permanent capillary occlusion prevents blood flow entirely, thus eliminating the possibility of reactive hyperemia in the affected area. Low blood oxygen levels indicate a lack of oxygen availability rather than the restoration of blood flow, which does not lead to the hyperemic response seen after ischemic episodes.