Fewer warfighters have died from bleeding complications in forward-based hospitals since 2006, when the military changed its protocol of blood transfusions used for such cases, according to a study published Wednesday in the Journal of the American Medical Association.
Eight years ago, forward-based hospitals that treated wounded from Iraq and Afghanistan implemented a protocol known as “damage control resuscitation,” which called for a change in the ratios of blood components given to hemorrhaging patients, such as red-blood cells, plasma and platelets.
The study found that patients who died in the hospital after the DCR protocol was put into place were more likely to be severely injured and to have severe brain injuries, as compared to less seriously wounded patients who died before the new protocol.
The findings indicate “potentially preventable” deaths from bleeding complications were reduced after 2006, said Dr. Matthew J. Martin, a co-author of the study who is the trauma medical director and chief of surgical critical care at Madigan Army Medical Center in Tacoma, Washington.
Bleeding is a leading cause of combat deaths.
Severe bleeding can trigger what’s known as the “trauma triad of death,” a lethal spiral of hypothermia, toxic acidity and impaired coagulation. Heavy bleeding decreases the oxygen being delivered throughout the body, which leads to a lowering of the body temperature. That in turn retards blood clotting. The absence of oxygen and other nutrients in the blood causes the body to burn glucose, releasing acids into the blood stream, which can be fatal. Each element continually exacerbates the others.
“On a bleeding patient, the focus had always been that they were losing red blood cells, which carries the oxygen to your tissues,” Martin said of the approach early in the wars in Iraq and Afghanistan.
“It used to be thought that if a healthy young patient gets wounded they have enough clotting factors on their own to get them through – for a long time.”
But during the first years of the two wars, doctors in forward hospitals began to realize that despite youth and good health, patients could have failed clotting function within an hour.
“We used to think it could take days to develop that bad of a clotting deficiency,” Martin said.
Before 2006, patients were usually given large quantities of cold, concentrated red blood cells, Martin said.
“So what we were probably doing was giving them back a cold fluid that didn’t help them clot blood much, and so they were getting even colder and their clotting system was becoming even more dysfunctional,” he said.
The study analyzed details of the 2,565 patients who died at forward hospitals from 2002 to early 2011.
“When we look at deaths now and compare them to the beginning of the war, patients who die now are patients you’d look at and say, ‘That patient was probably going to die no matter what we did,’” Martin said.
On average these post-2006 patients are much more severely injured and have a much higher percentage of severe head injuries, for which there is no therapy at present, he said.
“We would consider those non-preventable deaths,” he said.
The DCR protocol is now widely used in civilian trauma centers, said Dr. John B. Holcomb, a surgeon with the University of Texas Health Science Center in Houston who retired from the Army in 2008 after serving 23 years.
“Everybody says that the silver lining that comes out war is improved trauma care, and I think this war is no exception,” Holcomb said.
“Trauma care has improved for soldiers, sailors and Marines and also for the civilians that have benefited as well from improved care at civilian trauma centers.”
Holcolmb contributed a brief commentary in JAMA urging the Pentagon and researchers to make further use of the vast amount of medical data collected during the decade-long wars to “implement the lessons learned.”
“If you step back and look at what’s happening right now, we’re still in the war, and it’s going to continue,” he said. “Casualties are still occurring. The Department of Defense is engaged around the world, actively, and we still have problems we need to work on. Those problems aren’t solved, and the tension needs to be kept on them.”