Journal of Evaluation in Clinical Practice, 11, 5, 507–508 © 2005 Blackwell Publishing Ltd 507 Blackwell Science, LtdOxford, UKJEPJournal of Evaluation in Clinical Practice1356-1294Blackwell Publishing Ltd 2004 2004115507508MiscellaneousResearch letterA. Tiwari et al. *The abstract was presented as a poster at the Royal College of Surgeons of Edinburgh Clinical and Scientific meeting in 2003. RESEARCH LETTER Can surgical registrars identify an acutely inflamed appendix? A prospective audit* Alok Tiwari MS MRCSEd, Yogesh Kumar MBBS, Ganesh Walkay MBBS, Steven Ross BSc MBBS and Joseph L. Peters BSc FRCS Department of Surgery, Princess Alexandra Hospital, Harlow, Essex, UK Accepted for publication: 9 August 2004 To the Editor Appendicectomy remains the most common emer- gency surgical procedure. However, histologically confirmed acute appendicitis may only be seen in 60–83% of patients (Izbicki et al. 1992; Charitou et al. 2001). This may lead to other intra-abdominal pathology being missed because the operating sur- geon believes they are removing an acutely inflamed appendix as the cause of the abdominal pain (Nord- back & Matikainen 1985). In this audit we looked at the ability of surgical registrars to identify an acutely inflamed appendix and to see whether intra- operative features may increase the likelihood of a histological diagnosis of acute appendicitis. Patients and methods A prospective audit was undertaken in patients undergoing appendicectomy for suspected acute appendicitis. The operating surgical registrar was asked to fill in a pro forma on whether they thought that the appendix was normal, mildly inflamed or grossly inflamed (suppurative, perforated or gangre- nous appendix). They were also asked to comment on the presence of and colour of any intra-peritoneal fluid. These findings were then correlated with the histological diagnosis. An acutely inflamed appendix was defined when there was evidence of acute inflam- mation in the histology report. Results The results are summarized in Table 1. There were 30 male and 20 female patients. The total number of his- tologically inflamed appendices in males was 24/30 (80%) and females 14/20 (70%). Other pathological features included lymphocytic inflammation/ hyperplasia (4 patients), fibrosis of the appendix (2 patients) and enterobius vermicularis (1 patient). When the operating surgeons thought that the appendix was mildly inflamed the positive predictive value was 69%, whilst this was 100% when the appendix was thought to be grossly inflamed giving an overall positive predictive value of 79%. In the presence of any type of fluid (clear, serous, purulent) the positive predictive value in males was 83%, though if the fluid was purulent then the positive pre- dictive value was 100%. However, the lack of intra- peritoneal fluid did not exclude acute appendicitis. Discussion This study emphasizes the difficulty in recognizing a pathologically inflamed appendix on the operating table if there is no gross inflammation. Other tech- niques to predict an acutely inflamed appendix such as looking at the mucosa have also not been success- ful (Charitou et al. 2001). We therefore looked at the presence of other factors including the colour and presence of intra-peritoneal fluid and by classifying the appendix into normal, mildly inflamed and grossly inflamed to see whether this may make it easier to identify any pathology in the appendix. A previous study by Grunewald and Keating (1993) on 175 patients showed a histologically inflamed appendix in 75% of patients. When they looked at the positive predictive value of an inflamed- looking appendix this was 91%. However, in their study they subdivided their appendices to either nor-