An audit to assess the usefulness of investigations for patients with acute appendicitis.

Abstract

The NICE guidelines recommend that acute appendicitis should be diagnosed clinically. In our hospital, many patients initially have an ultrasound or a CT scan before being taken to theatre. We aimed to assess the usefulness of investigations in diagnosing acute appendicitis. The objective will be to look at the clinical, radiological, operative, and histological diagnosis and identify if these are coherent. A single centre retrospective study was carried out on all patients who underwent an appendicectomy between December 2022 and May 2023. Data was collected about the patient demographics, their presenting symptoms, clinical examination findings, blood test results, and whether they had radiological investigations and the respective results. This was then compared to the operative diagnosis and histological diagnosis. 169 patients were taken to theatre for an appendicectomy with a median age of 24 (IQR 15-43) and 51.5% were male. Blood tests were done in all patients and imaging was done in 50.9% patients. Amongst the investigations, CT scans were the most accurate in diagnosing appendicitis (91.5% accurate), followed by bloods (65.5% accurate). US scans were the least reliable as it only accurately picked up 57.1% of the histologically proven appendicitis and reported 52% of appendicitis on histology as normal. History, clinical examination, blood tests, and CT scans are reliable tools for diagnosing appendicitis pre-operatively. Investigations such as US Abdomen are not suggested for diagnosing appendicitis. Patients with clinically suspected appendicitis with raised inflammatory markers should be taken to theatre regardless of normal US Abdomen results.