Yersinia enterocolitica infection and toxic megacolon

CT features of toxic megacolon: A systematic review

INTRODUCTION

Toxic megacolon is a rare but life-threatening condition. Diagnosis is made when both systemic toxicity and an enlarged colon are present. We undertook a systematic review of the literature to provide a list of toxic megacolon findings on computed tomography (CT) imaging along with the prevalence rate for each finding.

METHODS

PubMed, Embase, and Cochrane library were searched. After eligibility screening and quality assessment, the reported CT findings of toxic megacolon with their respective prevalence rates were extracted from the included studies. Pooled prevalence rates were calculated for each finding using random-effects model and inverse variance method. I² statistics were used to estimate the heterogeneity. All statistical analyses were performed using R software. P-values less than 0.05 were considered significant.

RESULTS

Database search yielded a total of 122 records. Only 2 of these studies were finally selected following two-step eligibility screening. Most common CT features of toxic megacolon and their pooled prevalence rates [95% CI] were: colonic distension (reported in 100% of patients), abnormal haustration 96% [0.75-0.99], peri-colonic fat stranding 87% [0.29-0.99], nodular pseudo polyps 76% [0.52-0.91], multilayered appearance of colonic wall 58% [0.38-0.76], and ascites 57% [0.21-0.87]. Other reported CT features: colonic wall thickening, pleural effusion, accordion sign, small bowel/gastric distension, and segmental colonic wall thinning.

CONCLUSION

and implication for practice: Colonic distension can be accompanied by 10 other findings in CT images of patients with toxic megacolon. Although these findings are not specific, toxic megacolon should be included in the list of differential diagnoses when these findings are present.

Factors associated with intestinal perforation in children's non-typhi Salmonella toxic megacolon

BACKGROUND

To evaluate the risk factors for intestinal perforation in children with toxic megacolon caused by non-typhi Salmonella infection.

METHODS

During an 11-year period we reviewed the records of children treated for non-typhi Salmonella infection. All of the subjects had positive stool culture for non-typhi Salmonella and were treated with intravenous ceftriaxone during hospitalization. Clinical data reviewed included demographic features, clinical manifestations, laboratory findings, radiologic findings, microbiology, therapeutic effect of hydration and rectal tube placement and the operative findings. Patients with toxic megacolon were defined as those having toxic appearance, diarrhea, high fever (>39 degrees C) and marked colon dilatation with maximal diameter > 1.5 times the width of the vertebra body of the first lumbar spine (L1-VB). To define the risk factors for patients with toxic megacolon complicated by intestinal perforation, patients were divided into two groups for analysis: P group, those complicated with intestinal perforation; and NP group, those without intestinal perforation. Differences in age, sex, severity of diarrhea, duration of fever, hemogram and its differential, culture, stool analysis, serum C-reactive protein (CRP), electrolytes, maximal colon diameter, medical therapy and timing of rectal tube insertion between the two groups were analyzed. Statistical analyses were conducted with chi square tests and multiple logistic regression.

RESULTS

A total of 75 patients (P group, 27 patients; NP group, 48 patients) ages 4 months to 6 years were evaluated. With chi square analysis 7 variables were found to be significantly associated with intestinal perforation: age >1 year; fever >5 days; ratio of immature to total neutrophils >20%; serum CRP >200 mg/l; colon diameter >2.5 times the width of L1-VB; inadequate early hydration; and delay in rectal tube insertion. With multivariate analysis age >1 year, serum CRP >200 mg/l and colon diameter >2.5 times of width of L1-VB, inadequate early hydration and delay in rectal tube insertion were the most significant factors associated with intestinal perforation.

CONCLUSION

Identification of patients with toxic megacolon associated with non-typhi Salmonella infection at risk for further intestinal perforation is possible. Early effective fluid resuscitation and rectal tube insertion may be helpful to prevent the occurrence of intestinal perforation.

Etiology and management of toxic megacolon in patients with human immunodeficiency virus infection

We report six cases of toxic megacolon in patients with human immunodeficiency virus (HIV). One case, at an early stage of HIV infection, mimicked a severe attack of Crohn's disease, with a negative search for infectious agents. Subtotal colectomy was successfully performed with an uneventful postoperative course. The five other cases concerned patients with acquired immunodeficiency syndrome at a late stage of immunodeficiency. They were related to Clostridium difficile or cytomegalovirus (CMV) intestinal infection in two and three patients, respectively. One case of CMV colitis presented macroscopically and histologically as pseudomembranous colitis. Emergency subtotal colectomy, performed in the first four patients with acquired immunodeficiency syndrome was followed by a fatal postoperative outcome. The last patient treated conservatively by colonoscopic decompression, in association with anti-CMV therapy, had a favorable short-term outcome. From the experience of our series and data from the literature, we discuss the best diagnostic and therapeutic approach to toxic megacolon in patients with HIV.

Toxic dilatation of the colon in shigellosis

Images

Yersinia infections in surgical practice

This article reviews the clinical manifestations of Yersinia bacteria emphasizing their recent rise in incidence and describing how Yersinia infection presents to the general surgeon. Geographical variations, patterns of disease, pathogenicity and the problems in diagnosis and management are discussed. This common but often unrecognized infection is usually self-limiting but the very young, the very old and the immunocompromised are at greater risk and prompt treatment is required to save lives.