New clinical study to examine safety and outcomes of body cooling in cardiac arrest patients

The R Adams Cowley Shock Trauma Center at the University of Maryland has opened a clinical trial to study whether rapidly cooling the body temperature of patients whose hearts stop due to massive blood loss will give surgeons extra time to find and repair injuries, and in turn, help save their lives. The trial, funded by the U.S. Department of Defense, builds on previous findings that therapeutic hypothermia improves survival in non-trauma cardiac arrest patients.

Few patients -- less than 5 percent -- typically survive cardiac arrest due to massive blood loss. The Emergency Preservation and Resuscitation for Cardiac Arrest from Trauma (EPR-CAT) study will test whether cooling patients' body temperatures to 50 degrees Fahrenheit is safe and can improve outcomes.

"If we can increase the odds so that just 10 percent of these patients survive, that would be a significant achievement," says Thomas M. Scalea, MD, FACS, the Honorable Francis X. Kelly Distinguished Professor of Trauma Surgery at the University of Maryland School of Medicine (UM SOM), Physician-in-Chief of the R Adams Cowley Shock Trauma Center, and one of the study's investigators at the University of Maryland. "It's incredibly frustrating because these patients are usually young and otherwise healthy, and we can't save them."

Why Use Therapeutic Hypothermia?

While cardiopulmonary resuscitation (CPR) can save the lives of patients who suffer a non-traumatic cardiac arrest, CPR does little good if bleeding cannot be stopped and there is little to no blood to circulate. Cooling patients to 50 degrees Fahrenheit may buy surgeons extra time to find and repair injuries while protecting the brain and other vital organs from permanent damage.

Organs like the heart and brain need oxygen and blood flow to function. Rapid cooling can decrease the need for oxygen, explains Samuel A. Tisherman, MD, Professor of Surgery and Director of the Division of Critical Care and Trauma Education at UM SOM, and the principal investigator of the multi-center study. Dr. Tisherman is internationally-recognized for developing innovative ways to treat hemorrhagic shock and cardiac arrest using therapeutic hypothermia. EPR-CAT is a continuation of the pioneering work of his mentor Dr. Peter Safar, the father of cardiopulmonary resuscitation.

"With its extensive history and expertise in trauma and critical care research, Shock Trauma is a natural institution to conduct this important trial," Dr. Tisherman says. He adds that while the overall percentage of patients whom Shock Trauma is able to save is very high -- around 96 percent -- this trial seeks to improve the survival rate of a patient population whose odds are much more dismal.

"Our dedicated faculty are motivated every day to find innovative ways to save lives and advance trauma research," says UM SOM Dean E. Albert Reece, MD, PhD, MBA, Vice President for Medical Affairs at the University of Maryland and the John Z. and Akiko Bowers Distinguished Professor at UM SOM. "With this trial, we are hopeful to improve the outcomes for patients who now have little chance at survival."

How EPR-CAT Works

Patients who experience cardiac arrest after a penetrating trauma, such as a gunshot or stab wound, will be eligible to be enrolled in the study once standard resuscitation techniques have failed. A large volume of cold fluid will be administered through a tube placed directly into the bloodstream. Once the source of the bleeding has been found and repaired, a heart-lung bypass machine will be used to restore blood circulation and warm the body back up.

Due to the severity of injuries required to be eligible for the study and the need for immediate treatment, eligible patients are unable to provide consent to participate. As such, the EPR-CAT study is being conducted under federal guidelines for exception from informed consent. In October 2015, the research team began what is known as community consultation, during which members of the research team discussed the study and fielded questions at several venues throughout Baltimore. Community members are able to provide feedback as well as opt out of the study by obtaining a bracelet.

Upon completion of the community consultation process, the research team reported back to the University of Maryland's Institutional Review Board to seek regulatory approval to begin enrolling patients. The required regulatory approval has now been granted, and treatment teams may begin enrolling eligible patients. Results will be reported only upon the trial's conclusion.