An Animal Model of Sepsis in Appendicitis: Assessment of the Microcirculation

Acute appendicitis is one of the most common causes of inflammation in the abdomen. Appendicitis, characterized by inflammation of the appendix, is an urgent clinical illness with significant morbidity, which increases with diagnostic delay. Perforation and peritonitis are associated with increased morbidity and mortality, especially in the very young, the elderly and immune-suppressed patients. The diagnosis is based on the patient’s history by the classic signs and symptoms of appendicitis (abdominal pain in the right iliac fossa, fever, anorexia, nausea, and vomiting) and physical examination. Children and the elderly have fewer signs and symptoms, or cannot adequate describe them. In pregnant women, particularly during the second and third trimester, the diagnosis of acute appendicitis is often delayed because of the nonspecific clinical abdominal presentation. In these conditions, diagnosis often requires imaging methods (ultrasound and/or CT scanning), and the incidence of complications is more frequent. Most patients usually recover well after surgical treatment, but complications can occur if treatment is delayed or if perforation that results in peritonitis or sepsis is present. Sepsis and septic shock are clinical syndromes that result from complex interactions between the host and infectious agents. These events are characterized by hemodynamic derangements, widespread microcirculatory disturbances and cellular alterations leading to heterogeneous flow distribution, capillary obstruction and, therefore, to an uncoupling between cellular oxygen need and oxygen supply (De Backer et al., 2002; Hinshaw, 1996; Sakr et al., 2004). Despite improvements in treatments for sepsis, there are still gaps in our knowledge of the physiopathology and therapeutic interventions.