New challenges to military medicine

Better body armor and rapid aeromedical evacuations enable American service members to survive blasts that would have proved fatal in Vietnam or even the first Gulf War, but they pose new challenges to military medicine - how to deal with the excruciating pain of injuries, especially severe burns from IED blasts that body armor can't protect.

In fact, U.S. military doctors say the wars are inflicting injuries among the most painful known to medicine. Department of Defense scientists working at the U.S Army Institute of Surgical Research (USAISR) at Joint Base San Antonio-Fort Sam Houston, Texas, spoke at the American Pain Society's annual scientific meeting and reported on progress in addressing pain management challenges for treating service members returning from the war front with severe burns.

"Soldiers with severe burns, such as those on 20 percent of their bodies or more, are often hospitalized for months and they endure agonizing pain every day - not just from the first wound but also from repeated washings, dressing changes and multiple skin graft surgeries," said DOD Scientist Marcie Fowler, Ph.D. "Many also have polytraumatic injuries and have received several levels of treatment from the battlefield to the hospital, and brain trauma adds a cognitive impairment component to the rehabilitation of burns and polytraumatic injuries."

Opioids have been a mainstay for treating pain in badly burned warfighters, but extended use increases the risk for respiratory side effects and possible addiction. "There aren't many great alternatives to opioids but they do work and we have to deal with the side effects," said Fowler. "However, we are exploring several alternatives that might help reduce opioid use."

Dayna Loyd Averitt, Ph.D., a researcher at the USAISR, reported that the Army is conducting extensive research with novel therapeutic options for treating pain, such as using complementary drug therapy regimens, multidisciplinary pain management strategies, and even virtual reality to help decrease pain during procedures. She reviewed current projects evaluating the potential benefits of the synthetic analgesic tramadol to treat pain with a reduced emphasis on opioids and in using an injectable agent, resiniferatoxin (RTX), to temporarily deactivate nerve endings. The RTX project is in collaboration with the National Institutes of Health.

"In our research with tramadol, we are evaluating the potential of using dual mechanism therapeutics that act on both opiate and neurotransmitter receptors," explained Averitt. "The drug's activity with neurotransmitters involved in pain modulation, such as serotonin and norepinephrine, could be helpful in treating pain while decreasing opioid use and lowering risk for addiction. The anti-depressive mode of action also can help treat burn patients who are dealing with PTSD and mood disorders.

Averitt said that preclinical studies with RTX show that treatment significantly reduced pain sensitivity from burns.