Every year, more than 32,000 Americans die from gunshot wounds. A significant proportion of these deaths involve head wounds. Despite this massive public health burden, researchers know little about the variables that determine whether a victim of these injuries will live or die.
Now, for the first time ever, researchers at the University of Maryland School of Medicine (UM SOM) have developed a system to help answer this question. The system has created a way to better understand the variables involved in survival from these wounds. The paper appears in the latest issue of the journal Neurology.
“This kind of analysis has never been done before,” said one of the study’s principal authors, Thomas M. Scalea, MD, FACS, MCCM, the Honorable Francis X. Kelly Distinguished Professor of Trauma Surgery, Director, Program in Trauma, and Physician-in-Chief, R Adams Cowley Shock Trauma Center. “Using this knowledge, we can improve treatments and focus our care to maximize survival chances.”
The study was a partnership between scientists at UM SOM and researchers at the University of Massachusetts Medical School, Massachusetts General Hospital and Brigham & Women’s Hospital, Harvard Medical School and Yale University. Besides Dr. Scalea, the other UM SOM researcher was Deborah M. Stein, MD, MPH, FACS, FCCM, R Adams Cowley Professor in Shock & Trauma, University of Maryland School of Medicine, Chief of Trauma and Director of Neurotrauma Critical Care.
The researchers looked at 413 patients, most whom were treated at the Shock Trauma Center. All of the patients had penetrating brain injuries, 93 percent of them from gunshot wounds. Of the overall group, 42 percent, 175 in total, survived. The researchers looked at a range of variables to see which seemed to correlate with survival.
One key variable appears to be the level of consciousness upon arrival. The researchers used a measure known as the Glasgow Coma Scale (GCS), which tracks patient awareness after injury. The higher the score, the more aware the person is. The study found that patients with a lower GCS score were significantly less likely to survive. This was particularly true for movement – patients who were not moving after injury had a higher risk of death.
Another key measure appears to be pupillary reactivity, the ability of the eye’s pupils to change diameter in response to light. This is a measure of the nervous system’s basic functioning. In patients with low or absent pupillary reactivity, survival rates were significantly lower. Also crucial was Injury Severity Score (ISS), a measure of overall bodily trauma. The higher the ISS, the lower the survival rate.
The study also found that having only a single penetrating brain injury, rather than multiple penetrating brain injuries, was associated with 87 percent higher odds for survival.
Interestingly, female patients had 76 percent higher odds for survival than men. The reason for this is not clear. The researchers note that progesterone, a hormone that tends to be higher in women than in men, may have a protective effect in these injuries. The overwhelming majority of the subjects in the study, however, were men: women made up only 13 percent of the subjects in the study.
“Gunshot wounds and other penetrating brain injuries are a severe public health problem,” said UM SOM Dean E. Albert Reece, MD, PhD, MBA, who is also vice president for medical affairs at the University of Maryland and the John Z. and Akiko K. Bowers Distinguished Professor. “This groundbreaking research points the way to better understanding who is most at risk of death from these events, and how we can improve our treatment.”
About the University of Maryland School of Medicine
The University of Maryland School of Medicine was chartered in 1807 and is the first public medical school in the United States and continues today as an innovative leader in accelerating innovation and discovery in medicine. The School of Medicine is the founding school of the University of Maryland and is an integral part of the 11-campus University System of Maryland. Located on the University of Maryland’s Baltimore campus, the School of Medicine works closely with the University of Maryland Medical Center and Medical System to provide a research-intensive, academic and clinically based education. With 43 academic departments, centers and institutes and a faculty of more than 3,000 physicians and research scientists plus more than $400 million in extramural funding, the School is regarded as one of the leading biomedical research institutions in the U.S. with top-tier faculty and programs in cancer, brain science, surgery and transplantation, trauma and emergency medicine, vaccine development and human genomics, among other centers of excellence. The School is not only concerned with the health of the citizens of Maryland and the nation, but also has a global presence, with research and treatment facilities in more than 35 countries around the world. http://medschool.umaryland.edu/
University of Maryland School of Medicine