Material and Method: A consecutive series of adult patients with acute appendicitis who underwent appendectomy at Songklanagarind Hospital between 2005 and 2010 were retrospectively analyzed.

Results: Nine hundred twenty four patients were evaluated. Median (interquartile range) age was 34.9 (22.4, 50.1) years. There were 669 (72.4%) simple acute appendicitis and 255 (27.6%) complicated acute appendicitis. Multivariate analyses showed that age >60 years (OR 1.93, 95% CI 1.23-3.02), duration of symptoms >12 hours (OR 3.29, 95% CI 2.25-4.8), anorexia (OR 1.69, 95% CI 1.2-2.37), body temperature >38°C (OR 2.38, 95% CI 1.59-3.58), generalized tenderness (OR 5.36, 95% CI 2.4-11.95), guarding (OR 1.5 95% CI 1.08-2.08), bandemia (OR 1.65, 95% CI 1.16-2.34), pyuria (OR 1.66, 95% CI 1.07-2.57), urine specific gravity ≥1.020 (OR 1.66, 95% CI 1.18-2.33), and duration from visit to surgery >12 hours (OR 1.82, 95% CI 1.18-2.82) were related to complicated acute appendicitis.

Conclusion: Ten clinical features can be used to predict the risk of complicated acute appendicitis. However, the strong factors are duration of symptoms, body temperature, and generalized tenderness. They should be the useful tools for acute appendicitis management, especially in limited resources situation.

Keywords: Clinical features, Complicated appendicitis, Acute appendicitis, Ruptured appendicitis, Gangrenous appendicitis