Chances are, by the time you finish reading this sentence, someone in the U.S. will need a blood transfusion, likely due to blood loss from a serious injury or a health condition.

Blood is the highway of the body. It’s the route by which oxygen, nutrients, carbon dioxide, immune cells, platelets and hormones circulate. In the event of a significant blood loss, your organs can’t get much-needed oxygen. As a result, organs fail. If you don’t get the treatment you need (i.e., more blood), you could even die.

Problems with the blood supply

Transfusions with donor-supplied blood are lifesaving, but there a few problems that can sometimes make it tricky for people to get the blood they need.

• Availability. According to America’s Blood Centers, only 3% of the U.S. population donates blood.
• Compatibility. Unless the donated blood is O negative, not everyone can receive it. People with this blood type are called “universal donors.”
• Logistics. Getting blood to recipients who aren’t in a hospital can be a challenge.
• Shelf life. Blood components usually expire before volunteers can donate again. For example, whole blood can last 21–35 days, but you can only donate every 56 days.
• Safety. Testing methods for donated blood can’t detect new diseases.

Enter a solution?

The problematic issues that can occur with donor-based blood transfusions have compelled scientists to develop alternatives to blood. Rather than replace every component in your blood, these “blood substitutes” are mostly designed to fill in for red blood cells, which carry oxygen throughout the body.

There aren’t any oxygen-carrying blood substitutes that are approved for use in humans in the U.S. Significant issues with developing these substitutes include safety concerns, availability of funding and manufacturing challenges.

Researchers are debating whether some level of toxicity is acceptable if these oxygen-carrying substitutes are only used as a short-term solution for stabilizing a patient until they can receive a transfusion. Adjusting the goals for these blood substitutes may be a compromise between minimizing the dangers while giving patients the support they need during an episode of major blood loss.

Future directions

Research continues for blood substitutes, and maybe they will make it to the bedside one day. There is still a long road ahead, and scientists continue to make progress. While donating blood may no longer be necessary in the future, for now, we can still roll up our sleeves and head to the nearest blood drive.