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What is TOWAR?

The Type O whole blood and assessment of AGE during prehospital resuscitation trial, or simply TOWAR, is a research study that will look at whether giving whole blood transfusion early in the course of treatment would help severely injured patients that lose a lot of blood survive their injuries.

Normally when a person loses a lot of blood, they may receive whole blood as part of standard medical care, but not until they arrive at the hospital. For this study, some people who have injuries that caused them to lose a lot of blood will be randomly picked to get whole blood before coming to the hospital. The other people will get the usual care, which could include whole blood. Information from health records for both groups will also be collected as part of the study.  Researchers will look at both groups of people and see if one group did better than the other.

Who will be included?

TOWAR will enroll adults who are over 15 years old and less than 90 years old who are:

  • Severely injured patients that lose a lot of blood (hemorrhagic shock)
  • Being transported to a research site participating in TOWAR

Why Whole Blood?

There is information that suggests that severely injured people who are given whole blood before coming to the hospital need fewer transfusions and have fewer complications in the hospital.

Whole blood is normally stored for up to 35 days. We are also trying to see if giving younger whole blood (less than 14 days old) or older whole blood (older than 14 days old) will change some patient labs like clotting times and markers of inflammation.

What are the risks? Are there any benefits?

Risks of receiving whole blood are rare and include respiratory distress (shortness of breath) or lung injury; kidney damage; systemic infection; exposure to blood borne micro-organisms (bacteria and parasites) that could result in an infection; or allergic reaction with possible side effects on the immune system, which may decrease the body’s ability to fight infection; shock; death.  Women with Rh-negative blood types are at risk of Rh incompatibility with future pregnancies if receiving Type O positive whole blood, but this risk is very low.

We are conducting this study because we anticipate that the benefits of getting whole blood may reduce bleeding in some patients, and possibly reduce overall blood transfusion requirements during the first day after injury.  

How are people enrolled in the study?

People who have traumatic injuries and lose a lot of blood (hemorrhagic shock) who are being transported to a research site participating in TOWAR may be included in this study.

Normally, researchers must ask a person for their consent before they can be in a study. Because traumatic injuries must be treated right away, there may not be time to get consent. Giving consent for medical research usually means reading information, talking with doctors and nurses, and having time to think about whether to join. A person with traumatic injury is often not able to do these things. Sometimes researchers can talk to the patient’s family to ask for consent. However, in the emergency of traumatic injury, the family is often not around or can’t be found before the injured person must be treated. This study could not be done without special permission to include people before getting consent. This permission is called Exception from Informed Consent, or EFIC. Once the enrolled person is better and can consent or their family arrives at the hospital, the researchers will ask for consent to continue with the study. For more information regarding EFIC, please visit Planned Emergency Research

How do I opt out of the study?

You can opt-out of the study by contacting us using any of the methods below and letting us know that you do not want to participate. Please make sure to give us your name and contact information so that we can get in touch with you. We can provide you with a hypoallergenic silicone bracelet to wear that indicates that you should not be enrolled into the study. Please note that opting out of the study only means that you will not receive whole blood as part of the study. Opting out will not prevent you from getting blood products at part of your normal care. To request an opt-out bracelet for TOWAR, email

For questions or to learn more about this study, visit NCT04684719 please call the study team at 1-800-664-0557 or email us at .