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Clinical Trials Resource Center


Informed consent is the process where the researchers share key facts about a research study with a person to help them decide whether or not to take part in the research study. Taking part in research is voluntary and people have the right to refuse to take part in a research study. In some emergency situations, people who are taking part in a research study are not able to give their consent due to their condition. Cryostat-2 is a research study in which patients may be included in the study without their consent.

What is the purpose of this research study?

Worldwide, injury accounts for 5.8 million deaths every year, equivalent to one death every nine minutes and it is the leading cause of death in people under the age of 44.

One of the most common causes of death in trauma patients is uncontrolled bleeding. At present, standard treatment for severe bleeding involves rapid infusion of red blood cells and blood components e.g. plasma and platelets, in large volumes. Until recently, one in two people who received a massive blood transfusion (more than 10 pints) would die from their injuries.

Two important studies involving bleeding trauma patients have been conducted in the last five years showing that early intervention is more effective after injury and may help save lives. Patients who have severe bleeding after injury develop a problem with their clotting system which means that they tend to bleed more. One of the main problems is due to low levels of fibrinogen, a clotting protein normally circulating in the bloodstream. Fibrinogen acts as the ‘glue’ which holds a blood clot together and at low levels, blood clots don’t form properly and bleeding can continue.

Cryoprecipitate is a frozen blood component prepared from plasma and rich in fibrinogen. By transfusing cryoprecipitate early to replace fibrinogen levels in bleeding trauma patients, we believe blood clots will be more stable, reducing bleeding and consequently the number of deaths.

Cryostat 2 is an international, pragmatic, multi-center, parallel group, randomized controlled trial, which will run at all major trauma centers in England and at 8 international centers. At least 4 United States Level 1 trauma center sites will participate, including Memorial Herman Hospital Texas medical Center and University of Texas Health Science Center at Houston.  

Cryostat 2 is designed to answer a simple research question of whether the addition of early cryoprecipitate to the current standard of care Major Hemorrhage Protocol improves survival from major trauma hemorrhage

What will happen in the research study?

The trauma physician on call in the emergency department will use information obtained when a patient (>16 yrs old) first arrives to predict if he/she will require a significant amount of blood products.  The information includes blood pressure, pulse, type of injury, and an ultrasound test to see if there is bleeding in the abdomen (FAST exam). For patients who are eligible for this study, the blood bank will be notified to randomize (a process like flipping a coin) the patient to receive one of the two groups (cryoprecipitate with blood products or blood products only). The knowledge gained will likely impact the way in which massively bleeding patients are transfused and lower the amount of otherwise preventable deaths resulting from hemorrhagic shock.

What are the risks of taking part in the study?

Any severely injured patient requiring massive transfusion of blood products is at risk for a number of complications, such as infection, bleeding, respiratory distress, and organ failure.  The patients in the early cryoprecipitate group may have a slight increased risk of clotting complications such as deep vein thrombosis (DVT), blood clot in the lung, heart attack and stroke.

A committee composed of physicians, a statistician, and a former patient will meet every 3 months to review preliminary data from the study to assess for the potential of harm.  If this committee feels that patients are being harmed by the study, the study will be halted at their recommendation.

Why is it not possible to get the patients’ consent before including them in the study?

For patients requiring massive transfusion, the median time of before a patient receives blood products in the emergency department is 26 minutes.  There simply isn’t enough time to both provide the timely care necessary and to obtain informed consent from family.  This study will be done under emergency exception from informed consent regulations. Patients or their loved ones will be approached after the fact to seek their permission to continue in the study.

How many patients will be included in this study?

This study will enroll approximately 1500 patients and around 400 in the US.

When will this study start?

The Cryostat-2 trial has already begun enrolling patients in England sites. The projected start date of the trial in Houston is March, 2020.  The study is to run for 2 years and complete by June 2022.

If I do not wish to be included in this research study, how can make my wish known?

If you wish to not participate in this trial, please request an “opt out” bracelet.  As many of the patients who will be enrolled in this study will be unconscious or otherwise unable to communicate with the team of surgeons treating them, the bracelet must be worn to indicate that you do not wish to be enrolled in the stud.  To request an opt-out bracelet, email to request for a Cryostat-2 Opt Out Bracelet.

More about the study:

For more information about emergency exception from informed consent visit planned emergency research without consent.