The systemic inflammatory response syndrome

Severe burn injuries induce a systemic response that is characterized by cardiopulmonary, immunological, and metabolic perturbations and is described as the systemic inflammatory response syndrome (SIRS). The initial inflammatory response to burn injury results from activation of signaling pathways in predominantly immune cells by intracellular molecules that are released from damaged cells. These molecules, known as damage-associated molecular patterns (DAMPs), cause the release of cytokine and noncytokine mediators of inflammation. A compensatory response, known as the counter anti-inflammatory response syndrome (CARS), is mounted and, if persistent, can lead to immunosuppression and susceptibility to infections. A prolonged existence of SIRS and CARS can lead to severe muscle protein catabolism, described as persistent inflammation, immunosuppression, and catabolism syndrome (PICS), and is associated with an increased risk of multiorgan failure and death. This chapter reviews our knowledge of this systemic response and the associated perturbations in immunological, cardiovascular, and pulmonary function.