[A prospective study of 776 cases of acute non-traumatic abdominal pain. Acute appendicitis and its diagnosis].

776 patients seen in our emergency ward with abdominal pain for less than one week duration were prospectively analysed. In 49% of these patients no cause was found and 19% had acute appendicitis. Among 180 appendectomized patients, 147 (82%) had acute appendicitis whereas 33 (18%) had no inflammation of the appendix. Clinical presentation with a pain duration of less than 36 hours, steady abdominal pain, guarding in the right iliac fossa and a white cell count above 12,000/mm3 (12 g/l) were the best criteria for prediction of acute appendicitis versus a normal appendix. Perforated appendicitis was found in 18% of the patients with acute appendicitis but in only one patient for whom appendectomy had been deferred on the grounds of atypical presentation. Thus, in most cases, the perforation was preexistent to admission. We therefore recommended a 24-48-hour observation period for patients with uncertain diagnosis. Rates of normal appendices and perforated appendices of about 20% seem to be difficult to improve upon.