A COMPARATIVE STUDY OF THE DIAGNOSTIC ACCURACY OF PLAIN FILM AND ULTRASONOGRAPHY IN NONTRAUMATIC ACUTE ABDOMEN

ABSTRACT

Acute abdomen might indicate a progressive intra-abdominal condition that is threatening to life or capable of causing severe morbidity.  A good history, thorough clinical examination, laboratory investigations and imaging studies are necessary in order to arrive at a correct diagnosis. A comparative study of the diagnostic accuracy of plain x-ray film abdomen and ultrasound was done on 173 cases of non traumatic acute abdomen in Federal Teaching Hospital Abakaliki, (FETHA), Ebonyi state from November 2012 – April, 2013.  Retrospective design was adopted for this study.  Convenient sampling was used to select the 173 cases of acute abdomen.  Data were collected from the archives of the radiology department of the above named hospital and information obtained from the folders which were relevant to this study included patients age, clinical history/indication for the examination and the radiologists reports.  The results were grouped into two main blocks “True positive” and “false negative” results.  The major findings were that ultrasound is best used in gynaecological pathologies and cases of appendicitis, while plain x-ray film is best preferred in the diagnosis of GIT obstruction, abdominal pain, and perforation.

TABLE OF CONTENTS

Title page---------i
Approval page--------ii
Certification --------iii
Dedication--------iv
Acknowledgements-------v
Table of contents-------vii
List of Table --------ix
Abstract---------x
CHAPTER ONE:  INTRODUCTION
1.1 Background of the Study-----1
1.2 Statement of Problem-----4
1.3 Main Objective-------4
1.4 Specific Objectives------5
1.5 Significance of the Study-----5
1.6 Scope of the Study------5
1.7 Research Hypothesis -----6
CHAPTER TWO: LITERATURE REVIEW
2.1 Literature Review ------7
    Theoretical background -----12
2.2 Anatomy of the Abdomen-----12
2.3 Causes and Pathophysiology of Acute Abdomen23
2.4 The Physiology of Acute Abdomen---30
2.5 Clinical Characteristics of Acute Abdomen -33
2.6 Physical Examination of Acute Abdomen--37
2.7 Laboratory Tests of Acute Abdomen---43
2.8 Plain X-ray Examination of Acute Abdomen-45
2.9 Sonographic Examination of Acute Abdomen (Non-Traumatic)-------47
2.10 Evaluation and Management of the Acute Abdomen (Non Traumatic)------49
2.11 Diagnosis and Treatment of Acute Abdomen (Non-Traumatic)-------53
CHAPTER THREE:  RESEARCH METHODOLOGY
3.1 Design of the Study------54
3.2 Population-------54
3.2.1 Subject selection Criteria-----54
3.3 Sampling size -------55
3.4 Sampling Technique Adopted----55
3.5 Data Collection-------55
3.6 Hypothesis -------56
CHAPTER FOUR
Data Presentation and Analysis ----58
CHAPTER FIVE:  DISCUSSION OF FINDING 
5.1 Discussion -------65
5.2 Summary of Findings -----66
5.3 Recommendations------66
5.4 Conclusion -------67
5.5 Areas  for further Studies -----67
5.6 Limitation of the Study-----67
References --------69
Appendix I--------72
Appendix II--------77
Appendix III--------79

LIST OF TABLES

Table 4.1: Sex Distributions of patients by Disease (Male)----58
Table 4.2: Sex Distributions of Patients by disease (female ------59
Table 4.3: Age distribution of patients by diseases60
Table 4.4: True positive and false negative cases with ultrasonography----62
Table 4.5: True positive and false negative cases with plain film radiography---63
Table 4.6: Comparison of the sensitivity of ultrasound and plain film radiography--64

INTRODUCTION 

The term acute abdomen refers to a sudden, severe abdominal pain of unclear etiology that is less than 24 hours in duration1. It is in many cases a medical emergency, requiring urgent and specific diagnosis. 
An acute abdomen is also an acute intra abdominal condition of abrupt onset, usually associated with severe pain due to inflammation, perforation, obstruction, infarction, or rupture of abdominal organs, and usually requiring emergency surgical intervention. An acute abdomen can also be defined as any serious acute intra-abdominal condition (for example, appendicitis) attended by pain, tenderness, and muscular rigidity and for which emergency surgery must be considered. 
The differential diagnosis of acute abdomen include but not limited to: acute appendicitis, acute peptic ulcer and its complications, acute cholecystitis, acute pancreatitis, acute intestinal ischaemia, diabetic ketoacidosis, acute diverticulitis, ectopic pregnancy with tubal rupture, acute peritonitis (including hollow viscus perforation), acute ureteric colic, bowel volvulus, acute pyelonephritis, adrenal crisis, biliary colic, abdominal aortic aneurysm, hemoperitoneum and ruptured spleen1 
Clinically the patient presents with pain (therefore, there is need to explore the nature of the pain, site, quality, timing and aggravating /alleviating factors of the pain), nausea and vomiting, fever, diarrhoea, constipation, palpitation, dizziness, syncope, breathlessness. Clinically, patients can also present with haemoptysis (coughing up blood), haematemesis (vomiting of blood), haematochezia (blood per rectum), melaena (tarry blood stool containing altered blood) and haematuria (blood in urine). Other clinical presentations of acute abdomen include anorexia and weight loss.
Diagnostically erect chest-rays are necessary to exclude a perforated bowel, air under the diaphragm, especially the right hemi-diaphragm. Abdominal x-rays may show bowel dilation suggestive of obstruction or in the case of inflammatory bowel disease (IBD) a toxic megacolon. Faecal loading may be suggestive of constipation. Ultrasound of the abdomen can reveal, gallstones, evidence of acute cholecystitis, dilated chronic bowel disease (CBD) suggestive of downstream obstruction e.g.  Gallstones or neoplasm, abdominal aortic aneurysm(AAA), right iliac fossa(RIF) inflammation suggestive of acute appendicitis, gynaecological pathology e.g. ovarian cysts or ectopic pregnancies and renal tract pathology e.g. structural abnormalities, hydronephrosis, calculi.
Abdominal radiography in acute abdomen will show many air-fluid levels, as well as wide- spread edema. Sonography (for children with right upper quadrant pain) demonstrates gallbladder wall thickening and tenderness when scanning is performed over the gallbladder. For midabdominal pain, ultrasound can reveal thick- walled bowel loops and small bowel intussusception from bleeding disorder that produce hemorrhage into the bowel wall. 
Patients presenting to the accident and emergency (A and E) or the emergency radiology(ER) with severe abdominal pain will almost always have an abdominal x-rays and ultrasound scan and /0r a CT scan. These tests can provide a differential diagnosis between simple and complex pathologies. It can also provide evidence to the doctor whether surgical intervention is necessary. 
Patients will also most likely receive a complete blood count, looking for characteristic findings such as neutrophilia in appendicitis.
Traditionally, the use of opiates or other pain killers in patients with an acute abdomen has been discouraged before the clinical examination, because these would alter the examination. 2, 3