appendicitis and other acute abdominal conditions that could be treated conservatively, by using data routinely recorded in the emergency department. Since our results indicated that rebound tenderness was a statistically significant predictor to aid in this differential diagnosis, it was included in the scoring system. Several tests have been suggested as being helpful for the diagnosis of acute appendicitis. However, since none of them is in widespread use it is difficult to know their real reliability. We selected a scoring system, albeit one far from perfect, to aid decision making in acute appendicitis because of its simple design and application. With all reservations taken into account, the usefulness of the system was demonstrated; it reduced by nearly 15 per cent the rate of unnecessary Iaparotomies in the prospective trial.
Cirugia General CME 'Inocencio Jimenez ' 50 010 Zaragoza Spain
J. M. Ramirez
Inappropriate neutrophil activation in venous disease
Sir I was intrigued by the paper of Mr Whiston and colleagues (Br J Surg 1994; 81: 695-8), given that the data presented do not substantiate the conclusions. First, the authors fail to establish satisfactorily that their patients suffered from venous disease and have given no exclusion criteria to suggest that they suffered only from such disease. They used a protocol that was said to cause white cell trapping but presented no evidence to show that this occurred. Given the ease of performing a full blood count at the beginning and end of the experiment, one can only assume that no white cell trapping was observed. The paper then claims to measure oxygen free radical production but uses an assay to detect hypochlorous acid. This assay is extremely sensitive to myeloperoxidase and several authors have shown degranulation of neutrophils during venous hypertension, which suggests that Mr Whiston and coworkers may have indirectly measured neutrophil degranulation, not oxygen free radical production. There are several perfectly good assays for oxygen free radical production, such as the spectrophotometric method of measuring superoxide by reduction of cytochrome c or lucinogen-enhanced chemiluminescence.