Although the presence of SIRS has been described in patients with appendicitis, its progressive response related and together with progression of symptomatology from the onset of symptoms to diagnostic has not been characterized. Continuation of the systemic inflammation in patients with injury and infectious processes may result in multiple organ dysfunction and ultimately failure. As with any acute inflammatory condition, the patients' systemic inflammatory response to appendicitis will progress and become more intense with the passing of time. The purpose of this study is to characterize the systemic inflammatory response to appendicitis from the beginning of symptoms to diagnostic in patients with appendicitis submitted to emergency surgery.