The utility of the speed bump sign for diagnosing acute appendicitis

Acute appendicitis is the most common abdominal complaint in the emergency department. This study was made in order to determine whether there is any evidence to support the practice of inquiring about pain over speed bumps in patient suspected to have acute appendicitis and to discover its predictive power as a diagnostic sign.

A prospective study was conducted in the emergency department of Al Ain Hospital over one year. A convenient sample of 100 consecutive adult patients over the age of 15 years who presented with an abdominal pain and symptoms suggestive of acute appendicitis were recruited over the study period. They all underwent questionnaire of whether they had pain, or their pain increased while they travelled over speed bumps.

The study shows that 80 of the 90 participants were "speed bump positive." Eighty-five had a confirmed diagnosis of appendicitis, 77 of whom had worsened pain over speed bumps, giving a sensitivity of 90.5% and a specificity of 40%. The positive predictive value was 96.25% and the negative predictive value was 20%. The likelihood ratios were 1.5 for a positive test result and 0.23 for a negative result.

The pain over speed bump can be considered as a significant "rule out" criterion of appendicitis due to the high sensitivity observed in this study. However, with its low specificity, many patients with this sign would not undoubtedly have appendicitis, meaning it is a poor "rule-in" test.