Hypothermia - Treatment for Victims of Cardiac Arrest
The HYPOTHERMIA study is being conducted under the U. S. Food and Drug Administration (FDA) “emergency waiver of consent” guidelines. This means subjects are enrolled in the study without their prior consent. Federal regulations usually do not allow patients to be enrolled in a study without their informed consent or without the consent of their next of kin. However, in certain limited situations, such as emergency medicine research, the U. S. Food and Drug Administration (FDA) does allow some studies to be conducted without prior consent. In order to be able to do a study using “waiver of consent” requirements established by the FDA must be met.
Cardiac arrest is a commonplace medical problem with major adverse health impacts. In the United States 225,000 people per year will die from cardiac arrest before reaching the hospital. Many more may never leave the hospital, or will do so severely disabled.
Following cardiac arrest, the brain is often injured due to a lack of blood and oxygen. Some patients will recover and wake up. However, a majority of patients resuscitated from cardiac arrest never awaken, despite the excellent care they receive. In other words, these patients never regain enough neurologic function to allow them to follow commands or to have comprehensible speech.
Effective treatments to protect the brain from the damage that accompanies cardiac arrest would allow more patients to awaken after cardiac arrest. To date, studies using various drugs have failed to improve neurological outcome after cardiac arrest. Researchers continue to look for new therapies that may improve the patient’s chance of awakening. Based on studies on patients who are admitted to the hospital following cardiac arrest, induced hypothermia (cooling the body) has been shown to improve the chances that a patient will wake up. In fact, in some hospitals, such as Harborview Medical Center, it is standard of care to cool these patients as soon as they are admitted to the hospital. Typically, patients who are unconscious following cardiac arrest are cooled to 33
°-34
°C (91.4
°-93.2
°F for 24 hours).
Animal studies have shown that the greatest benefits of cooling occur if it is started as soon as possible after the cardiac arrest. Researchers at the University of Washington based at Harborview Medical Center are planning to conduct a large study of induced hypothermia in patients who have out of hospital cardiac arrest. It is thought that starting hypothermia outside the hospital may improve neurologic outcome and survival in this group of patients.
These same investigators recently completed a small pilot study of 125 subjects to test whether starting cold fluids in the field is safe and effective. The study showed that Seattle Fire Department paramedics could identify appropriate patients and begin the infusion of cold IV fluids in patients with out of hospital cardiac arrest. Patients arrived at the hospital with temperatures lower than those patients who did not receive any cold fluid. In this preliminary study there were no adverse effects. A study involving a larger number of subjects would allow more safety data to be obtained.
The purpose of the larger Hypothermia study is to test whether starting cooling, using cold IV fluids, as soon as possible
before someone arrives at the hospital improves their condition and survival. This type of cooling is considered experimental. It is allowed by the United States Food and Drug Administration (FDA) in research studies only. This larger study will enroll 1,364 subjects and will involved Seattle Fire Department and King County Emergency Services paramedics.
The potential risks involved in this trial include the following: discomfort or pain, too large of a temperature drop and fluid overload. There are safety measures built into the plan to minimize any of these risks. In the studies cited above there have not been any of these complications reported. However there may be unknown or unexpected risks.
The study also includes a neurological assessment performed three months following discharge from the hospital. If the patient agrees to participate in the follow up part of the study he/she or their legally authorized representative will be asked a series of questions over the phone. These questions involve how the patient is doing and feeling since his/her cardiac arrest.
The trial was initiated in three phases. The first phase began in Seattle (December 2007); the second phase began in South King County (July 2008) and the third phase began in North and East King County (October 2008). Prior to the start of the study the King County emergency room doctors, cardiologists, neurologists, and critical care physicians were notified by mail. As of mid December 2008 there have been 200 patients enrolled into the trial.
Some of the information provided in this website might be difficult to understand. If this is the case please view the consent form located under the "consent form" tab or contact us at 206-521-1588 where you will be able to leave a voice message. The voicemails are checked daily and you can expect to receive a reply within two days.
Patients who do not want to participate in this study can request an opt-out bracelet to wear. The opt-out bracelets may be obtained by calling the research coordinator.
UPDATE June 2011: Data safety and monitoring of this clinical trial is the responsibility of an independent data monitoring and safety board. The members consist of physicians, fire department representatives, statisticians and community representatives, all of whom have no involvement with the study or its outcome. The Data and Safety Monitoring Board (DSMB) met on May 18, 2011 and reviewed the data of the first 50% - 702 patients - enrolled into the study, and recommended continuing the study. It is anticipated that approximately 1364 patients will be enrolled by December 2012. The DSMB will review the data every 6 months and at 25% intervals until completion of enrollment. This Web Site will be updated periodically to reflect each new review by the DSMB.
Community Consultation
Research and Consent
Contact Us
Michele Olsufka RN, Research Coordinator – Seattle
Phone: 206.521.1588
Joan Tupper, PhD, Research Coordinator – King County
Karen Dong, RN, Research Coordinator – King County
Phone: 206.521.1783
Mailing address:
Harborview Medical Center
Department of Medicine/Division of Cardiology
325 Ninth Avenue
Box 359748
Seattle, WA 98104-2499