Immunology of Septic Shock and Traumatic Injury: A Review

Sepsis remains a major worldwide cause of morbidity and mortality and remains amongst the leading causes of death in medical Intensive Care Units (ICUs). Increasing injury severity associated with trauma is a significant independent risk factor for sepsis and many of these patients require intensive care unit resource utilization with increased rates of mortality. There are many postulated theories regarding the mechanism surrounding the correlation between trauma and shock. One such theory evaluated the deterioration of the immune system after trauma with the activation of Damage Associated Molecular Proteins (DAMPs) and the potential role of mitochondrial release into the bloodstream following physical injury leading to the onset of the Systemic Inflammatory Response Syndrome (SIRS). Despite these proposed theories, a breach of cellular integrity seems to unravel a multitude of immunologic responses that in essence account for the deleterious symptoms associated with sepsis. The association between traumatic injury and sepsis is very complex. This review explores the multifaceted immunoinflammatory response and gives an in depth immunologic explanation of the fundamental mediators in the initiation and continuation of the inflammatory response following the loss of cellular integrity.