Understanding Sickle Cell Pain Crisis

What is a vaso-occlusive crisis?

Sickle cell pain crises, also called vaso-occlusive crises (VOCs) are extremely painful episodes due to our sickle-shaped blood cells trouble flowing through blood vessels easily and clogging the vessels. If this happens, blood and oxygen can’t get through, and parts of the body (like the heart, lungs, and kidneys) can’t work the way they should. The blockage also can cause severe pain.

VOCs can be sudden and unpredictable and can last for a few hours up to several weeks often requiring visits to the hospital. Outside factors in our lives may help trigger a pain crisis, but within our bodies, our sickled blood cells cause issues within our blood vessels that lead to these painful events.

Stickiness

• Blood vessels are damaged by sickled red blood cells and breaking apart of RBC. This creates inflammation and irritation that activates molecules in the blood, causing blood cells to stick together like glue

Clusters

• This stickiness is turned on by “selectins” in the blood, such as P-selectin, and can cause certain blood cells (including red blood cells, white blood cells, and platelets) to stick to blood vessel walls and to each other. P-selectin can be thought of as a sticky factor

Blockages

• Clusters can build up like a traffic jam in the blood vessels and form blockages, making it difficult for blood and oxygen to flow normally
• This process of clusters forming and becoming blockages in the blood vessel can happen throughout the body at any time. Your doctor may refer to these blockages as “vaso-occlusion”

Prevention of these painful crises is critical to sickle cell patients daily care.