Perforating appendicitis: is it a separate disease? Acute Abdominal Pain Study Group.

OBJECTIVE

To find out whether perforated and unperforated appendicitis are separate diseases and can be distinguished clinically.

DESIGN

Prospective multicentre study.

SETTING

11 departments of surgery in Germany and Austria.

SUBJECTS

519 patients over 6 years old who had histologically confirmed acute appendicitis between October 1994 and March 1996.

MAIN OUTCOME MEASURES

Differences in history, clinical findings, lab results, clinical course and outcome.

RESULTS

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: rigidity, 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 > or =10(9)/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.

CONCLUSIONS

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.