Perforating Appendicitis: is it a Separate Disease?

To find out whether perforated and unperforated appendicitis are separate diseases and can be distinguished clinically. Prospective multicentre study. 11 departments of surgery in Germany and Austria. 519 patients over 6 years old who had histologically confirmed acute appendicitis between October 1994 and March 1996. Differences in history, clinical findings, lab results, clinical course and outcome. 92 of the 519 patients (18%) had perforated appendicitis. The following variables were shown by univariate analysis to be significantly more common in the group with perforated appendicitis: rigiditiy, reduced abdominal wall movement, abdominal distension, reduced bowel sounds (all p < 0.001), pale skin (p < 0.005), generalised abdominal tenderness, severe abdominal tenderness (both p < 0.01), WCC ≥ 109/L (p < 0.05). By multivariate analysis the following variables were significantly more common in the group with perforated appendicitis: age over 50 years (p < 0.0001); change in bowel habit and rigidity of the abdominal wall (both p = 0.001); generalised tenderness (p < 0.01); male sex (p < 0.01); and distended abdomen (p < 0.05). Rectal examination failed to make the distinction. Perforated and unperforated appendicitis behave clinically like two different diseases. They can in most cases reliably be distinguished using clinical criteria alone. Although greater diagnostic accuracy may result in a higher rate of perforation, close observation and timely intervention will only marginally affect the outcome.