**3. Appendicitis**

Appendicitis is defined as inflammation of the vermiform appendix and represents the most common cause of acute abdomen and emergency surgical indication in the world [1]. As common to all kinds of inflammation and precisely to the gut, appendicitis was commonly related to biochemical, histological, and physiological changes to the vermiform appendix itself. Inflammatory mediators regardless of factors precipitating lead to common manifest of inflammatory signs of a fluid shift, size changes (enlargement), increased blood flow and perfusion, inflammatory cell infiltrations, and also tissue remodeling, especially to the lymphoid tissues of the appendix. The inflammatory process as occur in all tissue may be reversible and some tend to be permanent remodeling or end with tissue damage and causes complication of appendicitis [11].

Presentation of appendicitis occurs by luminal obstruction of the appendix lumen that may be precipitated by a variety of etiologies, whether due to mass, faecolith or appendicolith, mucosal inflammation, lymphoid tissue hyperplasia, parasite infestations, or other mechanism leading to disruption of the passage of fluid and any luminal contents in the appendix to be propelled away to the cecum, and causing maladaptive mechanism that started certain cascade of pathophysiological events of inflammation that would be manifested clinically [12].

Clinical manifestation of appendicitis may be challenging. Most common symptom that occurs and causes patients to seek medical care is abdominal pain, although other symptoms such as fever, constipation, diarrhea, anorexia, and nausea are also reported as the main symptom. Pain in appendicitis starts in periumbilical and epigastric region at the beginning of the onset, and later migrates to the lower right

#### *Endothelial Dysfunction in Appendicitis DOI: http://dx.doi.org/10.5772/intechopen.107480*

quadrant where classic McBurney sign of classic lower right quadrant pain occurs. However, the history of migratory pain from one to another abdominal region occurs only in 50–60% of patients with acute appendicitis. Symptoms of nausea and vomiting start as the effect of abdominal pain, and fever starts about 6 hours after the onset of pain where an inflammatory process in the appendix had been established. The history of symptoms may be different from one patient to another, related to the anatomical variation of the appendix. Anteriorly located appendix commonly causes more marked and localized pain in the right lower quadrant, and the variation of retro-cecal one commonly has a dull abdominal pain manifestation or may be interpreted as a lower lumbar region pain. Furthermore, as appendicitis occurs with inflammation not restricted only to the appendix itself but may affect surrounding organs, other symptoms such as urinary urgency, dysuria, or rectal symptoms may appear but some cases [13, 14].

Physical examinations of patients with appendicitis include basic vital sign findings followed by an appendicitis-specific examination. Patients with appendicitis mostly present as febrile with a temperature greater than 38°C, tachycardia, and tachypnea may be found. Most early clinical manifestation of appendicitis are mostly non-specific and mimics other gastrointestinal disturbances. Obvious manifestation would present when inflammation progresses when inflammation had involved the parietal peritoneum in the serosa of the appendix which causes localized right lower quadrant tenderness that further exacerbates by specific physical examination such as McBurney sign, Rovsig sign, or other signs of appendicitis. However, the pain would progress more to be exacerbated by movement or cough causing an increase in intraabdominal pressure. Routine laboratory test usually provides an increase in leukocytes, especially neutrophil as an acute reaction to the inflammatory process presents a shifting to the left in leukocyte differential count. C-reactive protein indicates that systemic inflammation with greater than 1.5 mg/l may be one of the likely diagnostic indicators of appendicitis [15].

Further complicated and severe appendicitis usually has leukocytosis counts more than 20,000/μl and commonly related to perforation dan peritonitis and high level of C-reactive protein or even Procalcitonin. However, perforation and complicated appendicitis were also reported in about 10% of appendicitis with normal to mild increase in leukocyte count and C-reactive protein. This could not exclude the possibility of perforation in normal laboratory values in appendicitis. This because low sensitivity of leukocyte count in the diagnosis of appendicitis with only 65–75% while only 57–87% for C-reactive protein. Therefore, many studies had been conducted on early specific diagnosis; such as procalcitonin, as it is a good biomarker in sepsis and appendicitis may lead to sepsis but is still limited in appendicitis with no sepsis [15].
