A new blood substitute could revolutionize emergency care.
By Kristian Smock | Feb - March 2006
Blood substitutes are an innovation that has been around for quite a while. The technology is vital in saving patients worldwide, as well as soldiers in the battlefield. Substitutes for whole blood include many blood components such as serum albumin, plasma, and other fluids that are not derived from blood, but are used as plasma volume expanders, including crystalloid intravenous solutions.
Illustration by Brian Haeger
In comparison to blood far more of these solutions are used intravenously, and a thorough knowledge of plasma volume expanders is vital when implementing them. In 1915, doctors began experimenting with colloidal gelatin on shock patients, noticing a significant drop in blood pressure on their subjects.
In our current world climate blood substitutes are essential in saving lives. According to the “U.S. Armed Forces Blood Program;” hemorrhage is the leading cause of death for soldiers on the battlefield. Early intervention with blood expanders can save up to 30 percent of soldiers killed in action, and many that later die of combat wounds. Rapid volume expansion and hemorrhage control in combat casualties are the main priorities of medics in the pre-hospital resuscitation of battlefield victims.
Plasma expanders have a longer storage life than actual blood, and it is easier to implement in combat without fear of outdated contamination. Oxygen-carrying fluids in the initial treatment of military injuries are undefined, but erythrocyte substitutes could easily reduce the logistic requirements for whole blood in military hospitals.
According to research done at the “Letterman Army Institute of Research,” at the Presidio in San Francisco, the loss of contaminated stored blood supplies has been catastrophic during wartime conflicts.
In recent wars, 60-95 percent of units were discarded as a result of outdated blood supplies; 60 percent of 1.3 million units during the Vietnam War, and 95 percent of 120,000 units in the Persian Gulf Conflict. Light unit weight, long storage life, and tolerance to environmental extremes are all positive characteristics of erythrocyte substitutes to extend or replace the use of stored blood in treating wartime casualties.
In Texas, army doctors at “Fort Sam Houston” are presently testing a new blood substitute called, “PolyHeme.” “University Hospital” and “Brooke Army Medical Center” will both be participating in a national clinical trial to evaluate the usefulness and safety of PolyHeme; an oxygen-carrying blood substitute created to increase the survival rates of critically injured patients.
PolyHene is a universally capable resuscitative fluid designed for use in urgent blood loss when whole blood is unavailable. According to “The Journal of the American College of Surgeons,” PolyHeme has been previously studied on trauma patients in a hospital setting, demonstrating a significantly improved survival rate on test subjects.
PolyHeme is manufactured by “Northfield Laboratories Inc.,” in Evanston, Illinois. The blood substitute has an extended shelf-life of more than 12 months, and it requires no cross-matching, making it immediately compatible with all blood types.
The treatment study will begin on patients at the scene of injury or in an airborne ambulance, during a 12 hour “post-injury” period at the hospital. The study will compare the survival rates of those receiving PolyHeme to those receiving saline solution, which is the current standard of care among patients.
In a recent interview with “The Army News,” principal study investigator and trauma surgeon, Col. Toney Baskin said, “We are excited to be included in this groundbreaking clinical trial.”
According to “The National Center for Injury Prevention and Control” and “The Centers for Disease Control and Prevention,” trauma related injuries are the leading cause of death among Americans under the age of 45.
“Almost one in five trauma patients die from their injuries,” Baskin said. “If we can begin to treat these patients very early with oxygen-carrying solution and keep their hemoglobin levels up, we might have more survivors.”
Since patients eligible for this study are unlikely to provide consent due to the nature of their injuries, the study will be conducted under federal regulations, allowing doctors to use clinical research in emergency settings without the requirements of consent releases.
PolyHeme looks similar to real blood, but it only stays in the patient’s system for about 24 hours, allowing time for doctors to harvest the whole blood needed to permanently sustain a patient’s life. Research indicates that the product is very safe, and there have been no known adverse effects on patients already tested.
“It can buy you time in a trauma situation, but it will not eliminate the need for blood banks,” Baskin said.
If you are injured or sick, this century is the greatest time in history to find proper treatment. Doctors and scientists are working around the clock to ensure people have the longest life-expectancy possible, and technological advances are only getting better and more effective.