Blood Substitute Appropriate for Trauma Cases

Thursday, October 02, 2008

The blood substitute Polyheme® is appropriate for use in emergency situations when no other blood products are available. That's the conclusion of researchers in a national clinical trial that included Mayo Clinic and the Rochester community.

The objective of the study was to determine the effectiveness and safety of the blood substitute produced by Northfield Laboratories of Evanston, Ill., which sponsored the trial. The Rochester portion of the trial was conducted between January 2004 and May 2006.

"Many trauma patients are at risk of dying because lost oxygen-carrying capacity is not replaced in a timely manner," says Andy Boggust, M.D., Mayo Clinic emergency physician and lead investigator for Rochester on the study. "Ambulances don't carry blood, and the normal saline treatment delivers no oxygen. This is especially a concern in rural areas, where 60 percent of trauma deaths occur."

How the study was conducted

A total of 714 trauma patients were treated in the study, which involved 31 level 1 trauma centers across the country. Seventeen patients were located at Mayo Clinic in Rochester. Treatment began at the scene of an accident or in the ambulance. Participants received either Polyheme (which is made from human hemoglobin) or saline. Polyheme carries the same amount of oxygen as blood, but is compatible across all blood types. Patients continued to receive Polyheme as needed for up to 12 hours, for a total of six units, and were then switched to blood. Those in the control group received saline in the field and blood as needed upon reaching the hospital.

Because trauma patients cannot participate in the normal informed consent process, Mayo Clinic, in coordination with its Institutional Review Board, conducted a program of community notification before the study began, in accordance with federal requirements. This news release is part of the required follow-up information to the community.

Results

Findings showed that Polyheme was "not inferior" to the control, saline, which is normally used by ambulance crews. The researchers found it was as effective and safe as saline, with the additional benefit of adding oxygen to the patient's bloodstream. As in any trauma cases, not all patients survived their experience and not all were without some complications. However, none of the adverse events among participants could be directly related to the study treatment. Mortality rates in the study were the same in the Polyheme and control groups. The most frequent adverse events in the study were typical of trauma cases: pneumonia, multiple organ failure and respiratory failure. The percentage of those adverse events was not statistically significant. An exception was the number of heart attacks in the Polyheme group. Again, however, none of those heart attacks were considered related to the study treatment.

Study leaders concluded that in cases of high-risk trauma where no red blood components are available, Polyheme is appropriate for use. They say it can be especially appropriate in battlefield situations, natural disasters and cases where compatible blood is not immediately available.

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