Diagnostic Efficacy of Diagnostic Scoring System and Ultrasonographic Examination in Acute Appendicitis: Retrospective and Prospective Study

Oh, Chang Hwan; Sung, Chun Ki; Kim, Kon Hong

Abstract

BACKGROUND: As preoperative diagnosis of acute appendicitis is sometimes difficult, various diagnostic modalities are used for accurate diagnosis. The aims of this study were to define the diagnostic parameters of ultrasonographic (USG) examination and to evaluate the diagnostic efficacy of clinical scoring system in the patients with suspected acute appendicitis.
METHODS
A consecutive 130 patients, admitted under impression of acute appendicitis, were underwent routine ultrasonographic examination (from December 1994 to July 1995), and analyzed the accuracy rate of ultrasonographic examination. Already applied diagnostic score (age> or =50 yrs; 1.5, steady pain in right low quadrant; 2, pain relocation to RLQ; 2, tenderness in RLQ; 2.5, rebound tenderness; 2.5, rigidity; 1, Rovsing sign; 2, Rosenstein sign; 2, and leukocyte> or =10,000/mm3; 1.5) in these same patients also analyzed for correlation with final diagnosis and ultrasonographic examination retrospectively. In the second prospective study (from August 1995 to December 1995), 102 patients were enrolled, and diagnostic scoring system was evaluated for the applicability in diagnosis of appendicitis.
RESULTS
Of ninety-nine operated patients (clinical and sonography suggested appendicitis), 93 patients (94%) were confirmed as a acute appendicitis, and remaining 6 patients (6%) revealed mesenteric lymphadenitis and 31 patients were discharged without operation. Accuracy of the ultrasonographic examination was 91% of sensitivity, 86% of specificity, and 90% of accuracy rate, respectively. Diagnostic score (>10 point) of these patients revealed also a sensitive parameter in diagnosis of acute appendicitis with 94% of sensitivity, 71% of specificity, and 86% of accuracy rate. In the second prospective study, 85 patients (97% of 88 cases) with diagnostic score over 10 points had been confirmed as a acute appendicitis and only two cases (14% of 14 cases) having below 10 points in diagnostic score needed appendectomy. Over 10 ponits of diagnostic score in diagnosis of appendicitis revealed 98% of sensitivity, 80% of specificity, 96.5% of positive predict value, 85.7% of negative predict value, and 95% of accuracy rate, and relative risk 4.89 (p=0.000). Using multivariate analysis, age (> or =50 years),diagnostic score (> or =10), diameter of appendix (> or =6 mm) in USG, and Rovosing sign were significant independent factors in the diagnosis of acute appendicitis.
CONCLUSION
Our results suggest that ultrasonographic examination is necessary in patients with low diagnostic score (<10) to avoid negative laparatomy, but patients with high diagnostic score (>10) can be operated without ultrasonographic examination.