Diagnostic Accuracy Of Radiological Investigations In Acute Abdomen

Abstract

Background: The term ‘acute abdomen’ refers to signs and symptoms of abdominal pain and tenderness- a clinical presentation that often requires emergency surgical therapy. Acute surgical emergencies constitute 50% of all general surgical admissions and 50% of them are for ‘acute abdomen’, 50% of which requires surgical intervention. Pre-operative diagnosis of acute abdomen with limited facilities is very crucial to minimize the morbidity and mortality in the developing countries like ours, where the facilities of diagnosis are limited, and clinical acumen play a pivotal role in the diagnosis of acute abdomen. Pre-operative knowledge of cause of acute abdomen has the advantage of enabling formation of detailed operative plan including- incision, operative procedures, instrument preparation, and pre-operative instructions to patients and their family members. Since acute abdomen is the most common surgical emergency, present study intended to find out the accuracy of clinical methods and radiological investigations in diagnosing the cause for it. Objectives: 1. To find out the diagnostic accuracy of clinical methods and radiological investigations to achieve definitive diagnosis in patients with acute abdomen.

Method: This study “DIAGMOSTIC ACCURACY OF RADIOLOGICAL INVESTIGATIONS IN ACUTE ABDOMEN” was carried out at BLDE x

UNIVERSITY SHRI B.M.PATIL MEDICAL COLLEGE HOSPITAL, BIJAPUR. from October 2008 to May 2010. The 100 patients who form the basis of this study were randomly selected, fulfilling the inclusion and exclusion criteria. These comprised of patients who presented with acute abdominal pain (of non-traumatic origin) at the emergency department, surgical out patient department, surgical wards and patients referred from other departments. Only those cases that underwent surgery have been included in this study, as the correct diagnosis could be established only then. Each case was assessed with the help of a specially designed proforma. All cases were subjected to a detailed history and a thorough physical examination to arrive at a clinical diagnosis. The details recorded in the proforma and analysed. The radiological investigations comprised of plain abdominal x-ray, ultrasonography and CT scan for which no ordering protocol was followed. It was left to the discretion of the treating unit to order the investigation which they felt most appropriate for each case. Radiologic diagnosis was made after the official report by the radiologist. The radiologic investigations were divided into two categories, ones with positive findings were considered diagnostic and the others considered inconsistent. All the final diagnoses were operative. In all cases the operative findings and post-operative diagnosis were recorded. As soon as possible after admission routine investigations namely: - Hb%, TC, DC, ESR, Urine routine were carried out. A relevant procedure like four quadrant xi

aspiration was carried out in some cases. A Widal test was done in suspected cases of enteric fever. The pre-operative preparation essentially consisted of treating shock, correction of dehydration, gastric aspiration and antibiotic administration. Treatment was instituted according to the cause of acute abdomen. Complications if any were noted and managed accordingly.

Results: We found 80% of the x-rays to have positive findings and thus helpful in confirming the suspected diagnosis. In other words, positive x-rays outnumbered the inconsistent ones. In the present study the overall diagnostic accuracy for ultrasonography was 68.6%, compared to a clinical diagnostic accuracy of 81.18%. However, if only cases of acute appendicitis and acute cholecystitis were considered, the ultrasonographic accuracy rises to 75%. Failure to visualize an inflammed appendix was probably due to dilated bowel loops obstructing the field of study, in these cases. Thus from our study we can conclude that ultrasonography to be the initial radiologic investigation for acute appendicitis, especially in clinically doubtful cases and also in acute cholecystitis. In our study, CT scan was called for only in three cases. In two cases it helped to diagnose the cause of acute abdomen. In one case it confirmed the clinical diagnosis of acute cholecystitis, where ultrasonography was normal. In the other case, it picked up a growth in the descending colon. However, CT scan was helpful to diagnose infected pancreatic necrosis in the third case. xii

Conclusion: In majority of the cases, it was possible to make an accurate clinical diagnosis after a proper history and physical examination and analyzing the clinical pattern. The clinical diagnostic accuracy was superior to the diagnostic accuracy obtained by radiological investigations. The diagnosis of acute abdominal pain depends on optimal clinical assessment. There is no substitute for skill in interviewing patients and eliciting physical signs. While further imaging is usually not necessary for patients presenting with classic signs and symptoms of various acute abdominal pathologies, it is the atypical patients that require careful, appropriately tailored diagnostic imaging