Cardiac arrest is the abrupt loss of heart function in a person who may or may not have been diagnosed with an underlying heart condition. It is neither a specific disease nor a heart attack, but the final step before death. It is caused by any disease or condition that can cause someone to die, such as an infection, accident, or heart attack. In the end, every person will potentially die through a cardiac arrest.

Cardiopulmonary resuscitation (CPR) is the current standard of treatment for cardiac arrest. It uses chest compressions (pushing hard and fast at the center of the chest) and mouth-to-mouth breathing to keep the flow of oxygen and blood active when the heart has stopped. Most patients who respond to CPR do so within the first five minutes. The rate of survival drops quickly when a person requires more than ten minutes of CPR. Of the roughly one million people who receive CPR in and out of American hospitals every year, only about 10 percent who require more than 10 to 15 minutes of CPR survive without brain injury, compared to about 70 percent for those who are able to have their heart restarted within five minutes.

Red Blood Cells and Oxygen in the Body

The heart is responsible for pumping oxygen-rich blood from the lungs to all of the body’s organs, including itself. Our organs must receive a constant supply of oxygen to function normally, which does not happen when the heart has stopped during a cardiac arrest. Without oxygen, the heart cannot generate the energy to start pumping blood again. As the length of time of cardiac arrest increases, the amount of oxygen debt in the body adds up, making it increasingly more difficult to restart the heart.

When a person remains in cardiac arrest after five minutes of CPR, it is important to provide them with more oxygen to help restart the heart. Our body carries oxygen using a protein called hemoglobin, which is found in red blood cells (RBCs). RBC transfusions are commonly given in hospitals to people with anemia (a condition where the body does not have enough healthy RBCs) to increase the amount of hemoglobin in the body and improve oxygen delivery to the organs.

Study Design

Previous research carried out by our study team and others have shown that people who have more hemoglobin at the time of cardiac arrest are more likely to survive. It is assumed that this is due to the increased ability to deliver oxygen to the body’s vital organs. For this study, we plan on giving RBC transfusions to patients who experience cardiac arrests lasting longer than five minutes to increase the delivery of oxygen. By delivering more oxygen to the body during this critical time, we hope to improve the likelihood of restarting the heart when traditional CPR methods have not been successful.

Visit Community Consultations & Interviews for information about how to get involved in this study.