Combined radiation and burn injuries are likely to occur after nuclear events, such as a meltdown accident at a nuclear energy plant or a nuclear attack. Little is known about the mechanisms by which combined injuries result in higher mortality than by either insult alone, and few animal models exist for combined radiation and burn injury. Herein, the authors developed a murine model of radiation and scald burn injury. Mice were given a single dose of 0, 2, 4, 5, 6, or 9 Gray (Gy) alone, followed by a 15% TBSA scald burn. All mice receiving ≤4 Gy of radiation with burn survived combined injury. Higher doses of radiation (5, 6, and 9 Gy) followed by scald injury had a dose-dependent increase in mortality (34, 67, and 100%, respectively). Five Gy was determined to be the ideal dose to use in conjunction with burn injury for this model. There was a decrease in circulating white blood cells in burn, irradiated, and combined injury (5 Gy and burn) mice by 48 hours postinjury compared with sham (49.7, 11.6, and 57.3%, respectively). Circulating interleukin-6 and tumor necrosis factor-α were increased in combined injury at 48 hours postinjury compared with all other treatment groups. Prolonged overproduction of proinflammatory cytokines could contribute to subsequent organ damage. Decreased leukocytes might exacerbate immune impairment and susceptibility to infections. Future studies will determine whether there are long lasting consequences of this early proinflammatory response and extended decrease in leukocytes. (J Burn Care Res 2011;32:317-323) After nuclear accidents or attacks, radiation exposure is often coupled with other forms of injury, such as burns, blunt trauma, and infectious complications. Projected casualty estimates predict that 65 to 70% of affected people will have some kind of traumatic injury in addition to radiation exposure, whereas only 15 to 20% will be affected by radiation alone. 1 In accordance with these estimates, reports from the nuclear explosions in Hiroshima and Nagasaki, and the Chernobyl nuclear accident, showed that more than 60% of radiation victims also sustained a traumatic injury of some kind, most often burn injury. 1,2 Clinical data from these incidents show that victims of combined injury suffer worse postinjury complications than those patients with a single type of injury. The pathology of combined injuries is extremely complex; individuals who died shortly after these incidents sustained injuries to nearly every organ system, in addition to infectious complications. 3 It is known that combined radiation and burn causes aberrant wound healing and severe hematopoietic impairment. 4,5 Little is known about the mechanisms by which combined injuries result in higher morbidity and mortality than either injury alone, and few animal models exist for the combined insult of radiation and burn injury.
NIH-PA Author ManuscriptNIH-PA Author Manuscript
NIH-PA Author ManuscriptTo examine the mechanisms of tissue and organ damage and failure after this complex combined insult...
