The natural inflammatory response to major trauma may be associated with the development of a systemic inflammatory state, remote multiorgan failure, and death. Although a controlled inflammatory response is beneficial, an exaggerated response can cause serious adverse systemic effects. Early identification of high-risk patients, based on inflammatory markers and genomic predisposition, should help direct intervention in terms of surgical stabilization and biologic response modification. Currently, two markers of immune reactivity, interleukin-6 and human leukocyte antigen-DR class II molecules, appear to have the most potential for regular use in predicting the clinical course and outcome in trauma patients; however, the ability to measure markers of inflammation is still limited at many hospitals. With improving technology and increasing research interest, understanding of the significance of the immunoinflammatory response system in injured patients will continue to evolve.Inflammation is not itself considered to be a disease but a salutary operation … but when it cannot accomplish that salutary purpose … it does mischief.
John Hunter 1For decades, the inflammatory response has been recognized as a physiologic reaction to injury. This complex response arises from the interplay between various mediators produced at the site of injury, including cytokines, growth factors, nitric oxide, and platelet-activating factors, and the activation of local and systemic polymorphonuclear neutrophils (PMNs), lymphocytes, and macrophages. In the acute period following major trauma, this endogenous response system mobilizes to initiate healing and acts as a barrier to injury propagation. Cytokines operate as the main regulators of the postinjury immune response. These mediators, which are produced by diverse cell types, exert their effects by binding to specific cellular receptors, regulating gene transcription, and modifying intracellular signaling pathways 2 (Figure 1).Typically, the amplitude of the inflammatory response is related to the severity of injury. When injury is dramatic, the local inflammatory response may propagate systemically, resulting in serious systemic disease, including acute respiratory distress syndrome and multiorgan failure. 3 In addition to the initial injury, surgical reduction and fixation of fractures also stimulate the immunoinflammatory response. 4 This may result in a second-hit phenomenon, in which a