Wound, Ostomy and Continence Nurses Society (WOCN) Practice Exam

Which sequence describes reactive hyperemia?

1. Occlusion, hypoxia, reduced blood flow, pressure increase

2. Increased pressure, vasodilation, occlusion, redness

3. Capillary occlusion, hypoxia, vasodilation, blood rush

4. Hypoxia, increased pressure, blood rush, tissue damage

The correct answer is: Capillary occlusion, hypoxia, vasodilation, blood rush

Reactive hyperemia is a physiological response that occurs when an area of tissue experiences a temporary reduction in blood flow, often due to pressure or obstruction. The sequence of events that leads to reactive hyperemia begins with capillary occlusion, which causes hypoxia (a deficiency in the amount of oxygen reaching the tissues) due to the lack of blood flow. In response to this hypoxia, the tissues initiate a series of compensatory mechanisms, including vasodilation, which is the widening of blood vessels. This reaction aims to increase blood flow and deliver more oxygen to the affected tissue. Once the occlusion is released, a significant rush of blood occurs, carrying oxygen and nutrients back into the previously deprived area. This results in a flushing or reddening of the skin, which is a hallmark sign of reactive hyperemia. The correct answer captures all these critical steps: it starts with capillary occlusion, followed by hypoxia, leading to vasodilation and finally resulting in increased blood flow or a "blood rush" to the area. This sequence accurately reflects the body's natural response to restore blood supply and rectify the imbalances caused by the initial reduction in circulation.