[Significance of anamnesis and clinical findings for diagnosis of acute appendicitis. Acute Abdominal Pain Study Group]

Abstract

Acute appendicitis raises considerable diagnostic difficulties. This is proven by rates of negative appendectomies that sometimes extent 30%. In order to find reasons for this we tested 211 patients findings for diagnostic relevance.

Method: Within the European Community--Acute Abdominal Pain Survey, a study to support diagnosis in acute abdominal pain, 1254 patients were seen in the six participating German hospitals. 16.8% had appendicitis. History data and physical findings were tested for positive and negative predictive value (PPV/NPV), sensitivity and specificity (SEN/SPE).

Results: We had 15% negative appendectomies and 16% perforated appendicies. Only few of the parameters tested show a PPW significantly higher than the prior probability of appendicitis: (PPV/NPV/SEN/SPE in %) rebound tenderness 39/63/91/80, tenderness in the right lower quadrant 36/82/95/70, pain right lower quadrant at presentation 34/77/94/70, onset of pain right lower quadrant 29/49/88/75, rigidity 28/9/84/95, guarding 26/43/87/76. All other parameters had a lower PPV. The combination of three parameters leads to maximal PPV of 85%.

Conclusion: Very few symptoms are helpful in diagnosing appendicitis: the pain related symptoms (spontaneous pain, tenderness and rebound tenderness, guarding) and the history of the pain hint at an appendicitis. A structured and complete medical history and physical examination focussing on these few symptoms, a systematic combination of these and possibly ultrasonography will improve diagnostic accuracy.