A simple scoring system to reduce the negative appendicectomy rate

In a controlled, prospective study the following five criteria were used for the diagnosis and management of acute appendicitis: abdominal pain; vomiting; right lower quadrant tenderness; low grade fever (< or = 38.8 degrees C); and polymorphonuclear leucocytosis (TC > or = 10,000 with polymorphs > or = 75%). The aim of the study was to reduce the negative appendicectomy rate. If four out of five or five out of five criteria were present on admission, appendicectomy was carried out. On the other hand, if three out of five criteria were present on admission, the patient was subjected to active inpatient observation until either the development of the fourth criterion, when appendicectomy was performed, or until the patient recovered and the condition did not progress beyond the third criterion. Generalised peritonitis due to a perforated appendix was excluded from the study. Over a 1-year period, 58 patients (M:F = 45:13) were entered into the study. Appendicectomy was carried out in 46 (80%) of patients; of these, 32 patients (70%) were operated on soon after admission. The remaining 14 (30%) were operated on after a period of inpatient observation decided the development of the fourth criterion. A total of 12 patients (12/58 = 20%) did not undergo operation. The control group consisted of 59 patients upon whom appendicectomy was carried out by another surgical unit over the same 1-year period. The negative appendicectomy rate in the trial group was 6.5% (3/46), whereas in the control group it was 17% (10/59) (P < 0.05). We conclude that the use of a simple scoring system can significantly reduce the negative appendicectomy rate.