April 25, 1997

Trauma center to test synthetic blood product

Trauma center to test synthetic blood product

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Dr. John Morris Jr., talks with nurse Jan Dahlke in the emergency room. Morris is overseeing VUMC's study of a new synthetic blood product

Vanderbilt University Medical Center's trauma center is gearing up to test a new synthetic blood product on severely injured patients.

The new product will be administered to patients who are in shock due to excessive blood loss. VUMC is one of 35 health care centers across the country testing the new product to determine if it is a viable alternative to saline infusion, the standard treatment.

The upcoming trial falls under recently adopted federal regulations giving research institutions the authority to treat gravely ill patients with investigational drugs or devices in some emergency situations without their consent (see VUMC Reporter, March 14).

The synthetic blood product, called Diaspirin Cross-Linked Hemoglobin (DCLHb), is a purified human hemoglobin solution. Hemoglobin is the protein in red blood cells that carries oxygen. The synthetic blood product, which has already been proven safe and effective in prior studies, is prepared from units of human red blood cells from volunteer donors who have been tested negative for the viruses that cause hepatitis and AIDS. Unlike blood, it does not need to be cross-matched and is easily stored in the emergency department so that it is available as soon as the patient arrives.

The multi-center study will compare the use of the synthetic blood product to saline, the current standard of treatment when blood is not readily available.

"This study is designed to try to identify the very sickest people who can benefit from the administration of a blood substitute when blood is not available," said Dr. John A. Morris Jr., professor of Surgery, and the principal investigator of the Vanderbilt portion of the study. Also participating in the study will be Judy Jenkins, R.N., M.S.N., clinical nurse specialist and case manager in the division of Trauma.

Before blood can be given to a patient, the patient must be cross-matched so that the correct type of blood is given, Morris explained. Giving a patient the wrong type blood can be a "fatal mistake," Morris said.

Cross-matching can take up to 45 minutes, time that is not available when an injured patient is in shock, he said.

When a patient is in shock the body is unable to deliver enough blood and oxygen to all of the vital organs and tissues, Morris explained. Because of this, the vital organs may no longer be able to function and the patient may die. About 150,000 people die each year due to trauma injuries.

"The ravages of shock are dependent upon two things – the magnitude of the injury and the length of time before the patient gets therapy for that injury," Morris said. "The most important therapy we can give people is the ability to get oxygen to the tissues," Morris said.

A breathing tube can deliver oxygen from the air to the blood, Morris said. But within the blood there has to be a method by which oxygen is carried to the tissues. That is the importance of hemoglobin.

"In a normal situation, the boxcar that delivers oxygen is called hemoglobin," Morris explained. "Hemoglobin is the business end of what a blood transfusion is all about."

But blood transfusions take time to prepare.

"If we had something to give patients in the first 45 minutes that would carry oxygen, i.e. a boxcar, we could shorten the time they are without enough oxygen to the tissues. And that's good," Morris said.

Currently, when it is not feasible to wait for blood to be given, the treatment of choice is the rapid infusion of large volumes of saline to replace fluid loss due to injury, followed by the transfusion of blood to replace the fluid and blood loss.

The nationwide study will involve approximately 850 severely injured patients at the 35 trauma centers. About 20 to 30 patients will be involved at each institution.

Only those at the greatest risk of death can be considered for the study. Patients can be either male or female and must be at least 18. Patients with severe head injuries or whose heart has stopped in the hospital will not be entered into the study.

The study participants will be randomized. Some will receive the new synthetic blood product. Some will receive an equal amount of saline. The order of assignment will be determined before the patients are entered into the study so neither the patients nor the patients' physician can choose which solution is given.

Morris said the implications of the study are important for several reasons.

"It's important to the people of Tennessee for several reasons. This is a rural state and the transport time to definitive care is relatively long. Consequently the risks of shock are relatively high," he said.

The product may also have military applications.

In the Gulf War, for example, the job of preparing for American casualties of up to 10,000 men was "profound," Morris said.

Blood products, with a shelf life of 30 days, had to be shipped at a point where they wouldn't expire before the hostilities took place.

"It put a significant drain on the civilian blood supply. It was costly. And it was a logistical nightmare," Morris said.

"Imagine the logistics of 10,000 casualties over a week, having to type and cross all of these casualties, needing the logistical support to be able to administer all this blood without killing people by making mistakes, and doing the whole thing in a combat environment," Morris said.

The new synthetic blood product has a shelf life of more than a year, and can be reconstituted for use after it is frozen.

"All you'd have to do is manufacture it, ship it over on one airplane and reconstitute it when you need it," Morris said. "If this product is proven to work, it may have tremendous implications for the military not far down the road."

Morris said it is believed that the earlier the synthetic blood product is used the better it may work. If the product is proven effective, it will more than likely be of best use before the patients actually get to the hospital, administered while they are en route, either in a ground or air ambulance.

"The next step will be to get this product into the pre-hospital environment," Morris said.

For now, the question of whether the product works better than saline is all that this project attempts to answer.

"It's not a question of whether this product serves as a boxcar. We know it does. It's not a question of whether it's safe. We know it is. The question is can we give it, can we give it early enough and can we give it in volumes sufficient enough to save lives," Morris said.

"We're confident we're not going to make anyone worse. The question is can we make a significant number of people better."