The initial management of left lower quadrant peritonitis

Imaging Inflammation and Infection in the Gastrointestinal Tract

A variety of seemingly non-specific symptoms manifest within the gastrointestinal (GI) tract, particularly in the colon, in response to inflammation, infection, or a combination thereof. Differentiation between symptom sources can often be achieved using various radiologic studies. Although it is not possible to provide a comprehensive survey of imaging gastrointestinal GI tract infections in a single article, the purpose of this review is to survey several topics on imaging of GI tract inflammation and infections. The review discusses such modalities as computed tomography, positron emission tomography, ultrasound, endoscopy, and magnetic resonance imaging while looking at up-an-coming technologies that could improve diagnoses and patient comfort. The discussion is accomplished through examining a combination of organ-based and organism-based approaches, with accompanying selected case examples. Specific focus is placed on the bacterial infections caused by Shigella spp., Escherichia coli, Clostridium difficile, Salmonella, and inflammatory conditions of diverticulitis and irritable bowel disease. These infectious and inflammatory diseases and their detection via molecular imaging will be compared including the appropriate differential diagnostic considerations.

Emergency Presentations of Diverticulitis

Acute diverticulitis is a common condition that has been increasing in incidence in the United States. It is associated with increasing age, but the pathophysiology of acute diverticulitis is still being elucidated. It is now believed to have a significant contribution from inflammatory processes rather than being a strictly infectious process. There are still many questions to be answered regarding the optimal management of acute diverticulitis because recent studies have challenged traditional practices, such as the routine use of antibiotics, surgical technique, and dietary restrictions for prevention of recurrence.

Anorectal pathology amongst HIV infected patients attending the Douala General Hospital: a cross-sectional study

While gastrointestinal disease is common among HIV infected individuals, the prevalence and distribution of ano-rectal pathology has not been well studied in our setting. The objective of this study therefore was to determine the prevalence and determinants of ano-rectal pathology in HIV infected patients attending the Douala General Hospital HIV treatment centre. A hospital-based cross-sectional study was undertaken. We collected socio-demographic, clinical and laboratory data using a structured questionnaire and patients' files. Each study participant had a full physical and ano-rectal examination. We further studied factors associated with having at least one ano-rectal lesion by logistic regression reporting odds ratios (ORs) and their 95% confidence intervals (CI). We included 390 HIV infected patients. The mean age was 41 (SD: 8) years and 48% were men. Median duration since HIV diagnosis was 3 (interquartile range: 2-5) years and median CD4 cell count was 411 (interquartile range: 234-601) cells/mm³. Prevalence of ano-rectal pathology was 22.8% (95% CI: 18.7-27.3). Hemorrhoids and proctitis were most common lesions found; each in 10% of patients. From multivariate logistic regression, factors associated with ano-rectal pathology were CD4 < 350 cells/ml (OR: 2.1, 95% CI: 1.1-4.2), not on highly active antiretroviral therapy (OR: 2.2, 95% CI: 1.1-4.6), inpatient (OR: 2.3, 95% CI: 1.2-4.3), ano-rectal intercourse (OR: 5.0, 95% CI: 1.7-15.1), and more than one sexual partner (OR: 2.4, 95% CI: 1.3-4.2). Ano-rectal pathology is common amongst HIV infected patients. Care givers should actively investigate and treat them as this will improve the quality of life of people living with HIV/AIDS.

External validation of two tools for the clinical diagnosis of acute diverticulitis without imaging

AIM

External validation and comparison of the diagnostic accuracy of two predictive tools, the emergency department triad and the clinical scoring tool in diagnosing acute diverticulitis.

METHODS

Two derivation datasets were used crosswise for external validation. In addition, both tools were validated in a third independent cohort. Predictive values were reassessed and the Area Under the Curve expressed discriminatory capacity. Performance was compared by calculating positive predictive values of the emergency department triad in the validation cohorts and with a cut-off analysis for the clinical scoring tool at a positive predictive value of 90%.

RESULTS

Predictive value of the emergency department triad was comparable to the clinical scoring tool. The positive predictive value of the emergency department triad (97%) decreased in the clinical scoring tool cohort (81%) and was excellent in the independent cohort (100%), identifying 24%, 20% and 14% of the patients. A smaller proportion of patients with diverticulitis could be identified with the clinical scoring tool (6%, 19% and 9%).

CONCLUSION

The emergency department triad as well as the clinical scoring tool have significant predictive value in external cohorts of patients suspected of diverticulitis. These tools can be used to select patients in whom additional imaging to diagnose acute diverticulitis may be omitted.

The gastroenterologist's view

The traditional view that recurrent episodes of diverticulitis lead to progressively complicated disease resulting in a disadvantageous course, more difficult, complicated operations and lethal outcomes did not stand the test of evidence. Only a minority of patients with acute diverticulitis will ever require surgery, and if so, this occurs during or early after the first episode. Complications and recurrence of disease after surgery are enumerable. Strong indicators favoring sigmoid colectomy are major abscess, free air, and fistula, i.e. perforating disease. This occurs predominantly at the initial presentation, frequently in younger or immunosuppressed patients. Important differential diagnoses must be considered both for initial diagnosis of diverticulitis and for recurrent episodes. Conservative management of recurrent diverticulitis is safe and best guided by gastroenterological expertise. Sophisticated ultrasound experience as a part of this competence allows detailed evaluation of the local status and the best evidence in the literature for diagnosing diverticulitis is on US. In practice, however, the question of perforating diverticulitis is adequately answered by subtle CT scan. Medical therapy is usually the treatment of choice for recurrent diverticulitis. Avoidance of drugs bearing the hazard of perforation (e.g. NSAIDs) is emphasized, and smoking is strongly discouraged. A mathematical model based on published data shows that patients with recurrent diverticulitis overall (only) profit from surgery if they are hit by four episodes during the course of disease. This is where theory and reality (should) meet.

How to diagnose acute left-sided colonic diverticulitis: proposal for a clinical scoring system

OBJECTIVE

The aim of this study was to assess and compare the diagnostic value of elements of the disease history, physical examination, and routine laboratory tests in patients with suspected acute left-sided colonic diverticulitis (ALCD).

BACKGROUND

Misdiagnosis rates for diverticulitis vary in literature between 34% and 68% which needs improvement. Because of the frequent misdiagnosis, liberal use of imaging has been recommended. Before making a plea for routine imaging, the diagnostic accuracy of different variables of disease history, physical examination, and routine laboratory tests needs to be specified.

METHODS

All patients seen on the emergency department because of acute abdominal pain suspected of ALCD in whom an abdominal computed tomography was performed, between January 2002 and March 2006, were studied. Univariate logistic regression was used to study differences in patients' characteristics and symptoms, findings at physical examination and routine laboratory tests between patients with and without ALCD. Independent predictors to the risk of ALCD were identified using multivariate logistic regression and used to create a clinical scoring system.

RESULTS

Of 1290 patients with acute abdominal pain, 287 patients were eligible for analysis. Acute left-sided colonic diverticulitis was the final diagnosis in 124 patients (43%). Age, 1 or more previous episodes, localization of symptoms in the lower left abdomen, aggravation of pain on movement, the absence of vomiting, localization of abdominal tenderness in the lower left abdomen, and C-reactive protein 50 or more were found to be independent predictors of ALCD. A nomogram was constructed based on these independent predictors with a diagnostic accuracy of 86%.

CONCLUSIONS

This study showed that the clinical diagnosis of diverticulitis is difficult to make but can be improved using a clinical scoring system. In case of a high chance of ALCD based on the nomogram, additional imaging may not be needed.

Colonic diverticulitis: a prospective analysis of diagnostic accuracy and clinical decision-making

OBJECTIVE

To evaluate the diagnostic accuracy of clinical evaluation and cross-sectional imaging modalities such as ultrasound and computed tomography for patients with suspected colonic diverticulitis and to determine the value of these examinations in clinical decision-making.

METHOD

A prospective analysis was conducted of 802 consecutive patients that presented with abdominal pain at the emergency department. Initial clinical diagnoses and management proposals were compared to the final diagnoses and therapeutic strategies for all patients.

RESULTS

Fifty-seven patients were identified with colonic diverticulitis as the final diagnosis. The positive and negative predictive values for the clinical diagnosis of colonic diverticulitis were 0.65 and 0.98 respectively. Additional cross-sectional imaging had a positive and negative predictive value of respectively 0.95 and 0.99 or higher. These additional examinations led to a correct change of the initial clinical diagnosis in 37% of the patients, and a change in management in only 7%.

CONCLUSION

The accuracy of the clinical diagnosis for colonic diverticulitis is low. Ultrasound and computed tomography have superior diagnostic accuracy but these examinations rarely change the initial management proposal.

Does a 48-hour rule predict outcomes in patients with acute sigmoid diverticulitis?

INTRODUCTION

Sigmoid diverticulitis is an infection that resolves with conservative management in 70-85% of patients. Some patients require prolonged hospitalization or surgery during their admission. It has been taught that one should expect clinical improvement within 48 h. In this study, we examined whether basic clinical parameters (the maximum temperature and leukocyte count) of patients would predict improvement and discharge as expected, or prolonged hospitalization.

MATERIALS AND METHODS

Data was acquired from 198 patients admitted with acute sigmoid diverticulitis as confirmed by computed tomography (CT) scanning and physical exam. One hundred sixty-five patients recovered without surgery with an average hospital stay of 4 days: 120 were discharged within 4 days, whereas 45 patients required longer stays. Nineteen patients underwent surgery early during their admission (within 48 h). Fourteen patients did not improve over time and required surgery later during their hospital stay. The daily maximum temperature and leukocyte count of patients with prolonged stays was compared to the patients who were discharged within 4 days using analysis of variance analysis.

RESULTS

The average maximum temperature and leukocyte count on admission were not statistically different between the groups; therefore, maximum temperature and leukocyte count on admission alone are not predictive. After the first 24 h, however, one could see a statistically significant difference in maximum temperature (p=0.004). The leukocyte count responded significantly by hospital day 2 (p=0.003). Both trends were significant through hospital day 4.

DISCUSSION

Patients with a noticeable drop in leukocyte count and maximum temperature over the first 48 h of medical management were predictably discharged early on oral antibiotics. Patients failing to improve at 48 h required prolonged stays or surgery.

CONCLUSION

By observing early trends in leukocyte count and maximum temperature of patients with diverticulitis, one can predict whether they will recover quickly as expected or if they will likely require prolonged IV antibiotics and/or surgery.

Management of acute diverticulitis in the East Anglian region: results of a United Kingdom regional survey

PURPOSE

Acute diverticulitis is the most common presentation of diverticular disease; however, no published guidelines for management are available in the United Kingdom. This survey was designed to assess the current United Kingdom regional practice compared with the guidelines published by The American Society of Colon and Rectal Surgeons.

METHODS

A questionnaire survey focused on the management of acute diverticulitis was sent to all consultants, specialist registrars, and staff-grade surgeons in general surgery in one United Kingdom region.

RESULTS

Eighty-two questionnaires were returned (80 percent). A majority (80 percent) would request routine blood tests, abdominal, and erect chest x-rays on arrival. Pethidine (56 percent) was the preferred analgesic, followed by morphine (40 percent). Ninety-four percent used an antibiotic combination of second/third-generation cephalosporin and metronidazole. Computerized tomography was the most commonly used initial investigation (42 percent). Forty percent use barium enema and 31 percent use a combination of barium enema and sigmoidoscopy as follow-up investigations. In patients older than aged 50 years, elective resection would be considered by a majority (51 percent) only when complications arose. In those aged 50 years or younger, 35 percent would resect only if complications arose with only 6 percent after a single episode of acute diverticulitis.

CONCLUSIONS

There are major differences in the management of patients with acute diverticulitis in our current practice in one United Kingdom region compared with the guidelines published by The American Society of Colon and Rectal Surgeons, which are based on published literature. There is an urgent need to establish similar guidelines in the United Kingdom to improve the clinical outcome of patients with such a common condition.

Multi-detector computed tomography of acute abdomen

Acute abdominal pain is one of the most common causes for referrals to the emergency department. The sudden onset of severe abdominal pain characterising the "acute abdomen" requires rapid and accurate identification of a potentially life-threatening abdominal pathology to provide a timely referral to the appropriate physician. While the physical examination and laboratory investigations are often non-specific, computed tomography (CT) has evolved as the first-line imaging modality in patients with an acute abdomen. Because the new multi-detector CT (MDCT) scanner generations provide increased speed, greater volume coverage and thinner slices, the acceptance of CT for abdominal imaging has increased rapidly. The goal of this article is to discuss the role of MDCT in the diagnostic work-up of acute abdominal pain.

Dark-lumen magnetic resonance colonography in patients with suspected sigmoid diverticulitis: a feasibility study

To assess dark-lumen magnetic resonance colonography (MRC) for the evaluation of patients with suspected sigmoid diverticulitis. Forty patients with suspected sigmoid diverticulitis underwent MRC within 72 h prior to conventional colonoscopy (CC). A three-dimensional T1-weighted volumetric interpolated breath-hold examination sequence was acquired after an aqueous enema and intravenous administration of gadolinium-based contrast agents. All MRC data were evaluated by two radiologists. Based on wall thickness and focal uptake of contrast material and pericolic reaction including mesenteric infiltration on T1-weighted sequence the sigmoid colon was assessed for the presence of diverticulitis. MRC classified 17 of the 40 patients as normal with regard to sigmoid diverticulitis. However, CC confirmed the presence of light inflammatory signs in four patients which were missed in MRC. MRC correctly identified wall thickness and contrast uptake of the sigmoid colon in the other 23 patients. In three of these patients false-positive findings were observed, and MRC classified the inflammation of the sigmoid colon as diverticulitis whereas CC and histopathology confirmed invasive carcinoma. MRC detected additionally relevant pathologies of the entire colon and could be performed in cases where CC was incomplete. MRC may be considered a promising alternative to CC for the detection of sigmoid diverticulitis.

Computed tomography evaluation of diverticulitis

Acute diverticulitis is a frequent and important diagnosis in gastrointestinal disease, most commonly involving the colon. It is estimated that approximately 15% to 30% of patients with diverticulosis develop symptomatic diverticulitis at some point in the natural history of the condition, often requiring medical and/or surgical therapy. The clinical diagnosis is often difficult to make, and several radiological studies have been used over the past decades to assist in the diagnosis of acute diverticulitis. These include barium enema, ultrasound, and computed tomography (CT). A number of studies over the past decade have shown CT to be the preferable initial examination because of its ability to demonstrate not only the extent of intramural inflammation but also the degree of pericolic disease, including intraperitoneal inflammation, perforation, and abscess formation. Additional benefits of CT imaging include guiding therapeutic interventions in complicated forms of diverticular disease and providing an alternative diagnosis in patients without diverticulitis. The accuracy, techniques, criteria for diagnosis, and staging and applications of CT imaging in acute diverticulitis are discussed.

Imaging of colonic diverticular disease

Diverticular disease affects approximately two thirds of the population over the age of 70. While only a small fraction of these patients will develop diverticulitis, adequate radiological evaluation of diverticulitis and its complications is imperative in determining proper medical and surgical treatment. Clinical examination and laboratory tests alone have been found to be inaccurate in defining many aspects of the disease in up to 60% of cases. Over the past 30 years, contrast enema, computed tomography, and ultrasound have all been used extensively to diagnose the complications of diverticular disease. More recently, magnetic resonance imaging has been studied in patients with complicated diverticulitis. This article reviews the use of these different radiological modalities in diagnosing acute colonic diverticulitis and its complications.

Practice parameters for the treatment of sigmoid diverticulitis--supporting documentation. The Standards Task Force. The American Society of Colon and Rectal Surgeons

It should be recognized that these guidelines should not be deemed inclusive of all proper methods of care or exclusive of methods of care reasonably directed to obtaining the same results. The ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of all of the circumstances presented by the individual patient.

Helical CT in emergency radiology

Today, a wide range of traumatic and nontraumatic emergency conditions are quickly and accurately diagnosed with helical computed tomography (CT). Many traditional emergency imaging procedures have been replaced with newer helical CT techniques that can be performed in less time and with greater accuracy, less patient discomfort, and decreased cost. The speed of helical technology permits CT examination of seriously ill patients in the emergency department, as well as patients who might not have been taken to CT previously because of the length of the examinations of the past. Also, helical technology permits multiple, sequential CT scans to be quickly obtained in the same patient, a great advance for the multiple-trauma patient. Higher quality CT examinations result from decreased respiratory misregistration, enhanced intravenous contrast material opacification of vascular structures and parenchymal organs, greater flexibility in image reconstruction, and improved multiplanar and three-dimensional reformations. This report summarizes the role and recommended protocols for the helical CT diagnosis of thoracic aortic trauma; aortic dissection; pulmonary embolism; acute conditions of the neck soft tissues; abdominal trauma; urinary tract stones; appendicitis; diverticulitis; abdominal aortic aneurysm; fractures of the face, spine, and extremities; and acute stroke.

Helical CT of appendicitis and diverticulitis

The clinical diagnosis of appendicitis and diverticulitis remains challenging. Clinical diagnosis alone can lead to unnecessary hospitalizations and surgeries, prolonged periods of hospital observation, and delays prior to necessary medical or surgical treatment. Helical CT combined with recently reported techniques for imaging appendicitis and diverticulitis offers rapid and accurate confirmation or exclusion of these entities as well as identification of alternative conditions that can clinically mimic them. More routine use of helical CT holds great promise for improving patient care and lowering hospital resource use in patients with clinically suspected appendicitis and diverticulitis.

CT of diverticulitis and alternative conditions

The clinical diagnosis of diverticulitis is often uncertain and frequently incorrect. Diagnostic imaging such as with helical CT offers a rapid and accurate diagnosis of diverticulitis and its complications as well as alternative conditions. In particular, helical CT combined with contrast material administered through the colon is highly accurate and can be obtained quickly. CT signs of diverticulitis include focal inflammatory wall thickening and paracolic inflammation superimposed on diverticular disease (diverticula, muscular wall hypertrophy). Common alternative conditions that can clinically mimic diverticulitis include small bowel obstruction, primary epiploic appendagitis, acute cholecystitis, appendicitis, ileitis, ovarian cystic disease, and ureteral stone disease. Early and frequent use of diverticular CT promises to improve diagnosis and treatment of patients with clinically suspected diverticulitis.

Surgery for complicated diverticulitis

The surgical treatment of acute, complicated diverticulitis remains controversial. No randomized studies have been performed to clarify which operative procedure best fits each situation. As a result, the surgeon must use accumulated knowledge and judgment to make the correct decisions for an individual patient. The morbidity and mortality of patients with complicated diverticular disease in 1993 depend, not so much on the operative procedure, but on the severity of the disease and the associated comorbid conditions, namely the presence of fecal or purulent peritonitis, past medical problems, immune status, and nutritional status. However, adherence to the several principles detailed in this report will minimize morbidity and mortality. The surgeon should always attempt to convert the patient from an emergency to an urgent or elective operative status. In the absence of free perforation, this goal usually can be achieved. Rushing into surgery in patients with a normal immune system is generally ill advised. It is far preferable to stabilize the patient, percutaneously drain abscesses if possible, prepare the bowel before exploration, and thus keep the option of primary anastomosis open. A primary anastomosis done first thing in the morning is far preferable to an end-stoma created in the middle of the night in an emergency situation. The algorithm displayed in Figure 1 provides a useful guideline for treating patients with complicated diverticulitis.

Radiological investigation in acute diverticulitis

Optimal management of acute sigmoid diverticulitis depends on evaluation of the severity of the inflammatory process, in which radiological investigation is a useful but probably underutilized adjunct to clinical assessment. Plain abdominal radiography shows abnormalities in 30-50 per cent of patients but these tend to be non-specific and more accurate information is obtainable from a contrast enema. Although the quality of images produced by a water-soluble contrast agent is inferior to that with barium, the former is less hazardous in the presence of perforation and provides sufficient information to permit rational management decisions to be made. Ultrasonography and computed tomography (CT) are particularly useful in visualizing abscesses. They may be helpful in following the progression or resolution of suppuration and in guiding percutaneous aspiration when appropriate. Despite early reports to the contrary, CT is no more specific than a contrast enema in the diagnosis of acute diverticulitis. Radionuclide scans have little role in the routine assessment of acute diverticulitis and magnetic resonance imaging has not been adequately evaluated. Water-soluble contrast enema is safe, widely available and probably the most useful early supplementary investigation.

Acute diverticulitis: diagnosis and management

A high index of suspicion is required for early detection of complications, most commonly diverticular abscess and colovesical fistula. Appropriate antibiotic therapy should cover a wide range of potential pathogens.