Definition of the role of enterococcus in intraabdominal infection: analysis of a prospective randomized trial

Association of the origin of contamination and species of microorganisms with short-term survival in dogs with septic peritonitis

OBJECTIVE

To assess the association between anatomical location of contamination and mortality in dogs with gastrointestinal and biliary origin of septic peritonitis.

METHODS

Medical records at two private referral hospitals between 2003 and 2020 were retrospectively reviewed. Cases were included if the origin of contamination was confirmed intraoperatively within the gastrointestinal or biliary tract. Cases were excluded if the dog died or was euthanized intraoperatively or where the data regarding the origin of contamination were not available. The association of anatomical origin with survival was assessed specifying the locations as stomach, small intestine, large intestine and biliary tract. The gastrointestinal tract origin was further subdivided into pylorus, nonpylorus, duodenum, jejunum, ileum, caecum and colon.

RESULTS

The overall survival rate was 75.9% (n = 44/58). There were no significant differences in survival among different anatomical origins of contaminations before or after subdivision (P = 0.349 and 0.832, respectively). Also, there was no association between isolated microorganism species in microbiological culture and the anatomical origin (P = 0.951) and the microorganism species was not associated with survival (P = 0.674).

CONCLUSIONS

There was no association between anatomical location of leakage, microorganism species and survival although further studies are warranted to analyse the relationships between anatomical leakage site and microorganism species as well as microorganism species and mortality.

Korean Guidelines for Use of Antibiotics for Intra-abdominal Infections in Adults

The guidelines are intended to provide practical information for the correct use of antibiotics for intra-abdominal infections in Korea. With the aim of realizing evidence-based treatment, these guidelines for the use of antibiotics were written to help clinicians find answers to key clinical questions that arise in the course of patient care, using the latest research results based on systematic literature review. The guidelines were prepared in consideration of the data on the causative pathogens of intra-abdominal infections in Korea, the antibiotic susceptibility of the causative pathogens, and the antibiotics available in Korea.

Diagnosis and Management of Intraabdominal Infection: Guidelines by the Chinese Society of Surgical Infection and Intensive Care and the Chinese College of Gastrointestinal Fistula Surgeons

The Chinese guidelines for IAI presented here were developed by a panel that included experts from the fields of surgery, critical care, microbiology, infection control, pharmacology, and evidence-based medicine. All questions were structured in population, intervention, comparison, and outcomes format, and evidence profiles were generated. Recommendations were generated following the principles of the Grading of Recommendations Assessment, Development, and Evaluation system or Best Practice Statement (BPS), when applicable. The final guidelines include 45 graded recommendations and 17 BPSs, including the classification of disease severity, diagnosis, source control, antimicrobial therapy, microbiologic evaluation, nutritional therapy, other supportive therapies, diagnosis and management of specific IAIs, and recognition and management of source control failure. Recommendations on fluid resuscitation and organ support therapy could not be formulated and thus were not included. Accordingly, additional high-quality clinical studies should be performed in the future to address the clinicians' concerns.

Risk Factors for Enterococcal Intra-Abdominal Infections and Outcomes in Intensive Care Unit Patients

Background: To investigate the risk factors for enterococcal intra-abdominal infections (EIAIs) and the association between EIAIs and outcomes in intensive care unit (ICU) patients. Methods: We reviewed retrospectively the records of patients with intra-abdominal infections admitted to the Department of Critical Care Medicine at Nanfang Hospital, Southern Medical University, China, from January 2011 to December 2018. Patients with intra-abdominal infections were divided into enterococcal and non-enterococcal groups based on whether enterococci were isolated from intra-abdominal specimens. Results: A total of 431 patients with intra-abdominal infections were included, of whom 119 were infected with enterococci and 312 were infected with non-enterococci. Enterococci were isolated in 27.6% of patients, accounting for 24.5% (129/527) of all clinical bacterial isolates. Post-operative abdominal infection (adjusted odds ratio [OR], 2.361; p = 0.004), intestinal infection (adjusted OR, 2.703; p < 0.001), Mannheim Peritonitis Index score (MPI; adjusted OR, 1.052; p = 0.015), and use of antibiotic agents within the previous 90 days (adjusted OR, 1.880; p = 0.025) were associated with an increased risk of EIAIs. Compared with patients without enterococcal infection, ICU patients with enterococcal infection had a higher risk of failure of initial clinical therapy (49.6% vs. 24.2%; p < 0.001) and longer hospital stays (33 days [19, 48] vs. 18 days [12, 29]; p < 0.001). Enterococcal infection was associated with increased 28-day mortality, in-hospital mortality, and ICU mortality. However, no difference was found in length of ICU stay between the two groups. Additionally, there was no difference in ICU mortality, hospital mortality, or 28-day mortality in patients infected with enterococcus who did or did not receive empirical anti-enterococcal therapy. Conclusion: Post-operative abdominal infection, intestinal infection, MPI score, and use of antibiotic agents within the previous 90 days were independent risk factors for enterococcal infection. Enterococcal infection was associated with reduced short-term survival in ICU patients.

Systematic Review and Meta-Analysis of the Efficacy of Appropriate Empiric Anti-Enterococcal Therapy for Intra-Abdominal Infection

Background: Delayed treatment of seriously infected patients results in increased mortality. However, antimicrobial therapy for the initial 24 to 48 hours is mostly empirically provided, without evidence regarding the causative pathogen. Whether empiric anti-enterococcal therapy should be administered to treat intra-abdominal infection (IAI) before obtaining culture results remains unknown. We performed a meta-analysis to explore the effects of empiric enterococci covered antibiotic therapy in IAI and the risk factors for enterococcal infection in IAI. Methods: We searched multiple databases systematically and included 23 randomized controlled trials (RCTs) and 13 observational studies. The quality of included studies was assessed, and the reporting bias was evaluated. Meta-analysis was performed using random effects or fixed effects models according to the heterogeneity. The risk ratio (RR), odds ratio (OR), and 95% confidence interval (CI) were calculated. Results: Enterococci-covered antibiotic regimens provided no improvement in treatment success compared with control regimens (RR, 0.99; 95% CI, 0.97-1.00; p = 0.15), with similar mortality and adverse effects in both arms. Basic characteristic analysis revealed that most of the enrolled patients with IAI in RCTs were young, lower risk community-acquired intra-abdominal infection (CA-IAI) patients with a relatively low APACHE II score. Interestingly, risk factor screening revealed that malignancy, corticosteroid use, operation, any antibiotic treatment, admission to intensive care unit (ICU), and indwelling urinary catheter could predispose the patients with IAI to a substantially higher risk of enterococcal infection. "Hospital acquired" itself was a risk factor (OR, 2.81; 95% CI, 2.34-3.39; p < 0.001). Conclusion: It is unnecessary to use additional agents empirically to specifically provide anti-enterococcal coverage for the management of CA-IAI in lower risk patients without evidence of causative pathogen, and risk factors can increase the risk of enterococcal infection. Thus, there is a rationale for providing empiric anti-enterococcal coverage for severely ill patients with CA-IAI with high risk factors and patients with hospital-acquired intra-abdominal infection (HA-IAI).

Antimicrobial Susceptibility of Microorganisms Isolated from Patients with Intraabdominal Infection in Korea: a Multicenter Study

BACKGROUND

This study evaluated the antimicrobial susceptibility of pathogens isolated from Korean patients with intraabdominal infections (IAIs).

METHODS

This multicenter study was conducted at 6 university-affiliated hospitals in Korea between 2016 and 2018. All patients with microbiologically proven IAIs were retrospectively included, while patients with spontaneous bacterial peritonitis or continuous ambulatory peritoneal dialysis peritonitis were excluded. Identification and antimicrobial susceptibility testing were performed using automated microbiology systems.

RESULTS

A total of 2,114 non-duplicated clinical isolates were collected from 1,571 patients. Among these pathogens, 510 (24.1%) were isolated from nosocomial infections, and 848 isolates (40.1%) were associated with complicated IAIs. The distribution of the microorganisms included aerobic gram-negative (62.6% of isolates), aerobic gram-positive (33.7%), anaerobic (0.9%), and fungal (2.8%) pathogens. The most common pathogens were Escherichia coli (23.8%), followed by Enterococcus spp. (23.1%) and Klebsiella spp. (19.8%). The susceptibility rates of E. coli and Klebsiella spp. to major antibiotics were as follows: amoxicillin/clavulanate (62.5%, 83.0%), cefotaxime (61.4%, 80.7%), ceftazidime (63.7%, 83.1%), cefepime (65.3%, 84.3%), ciprofloxacin (56.4%, 86.3%), piperacillin/tazobactam (99.0%, 84.8%), amikacin (97.4%, 98.3%), and imipenem (99.8%, 98.8%). The susceptibility rates of Enterococcus spp. to ampicillin were 61.0%, amoxicillin/clavulanate, 63.6%; ciprofloxacin, 49.7%; imipenem, 65.2%; and vancomycin, 78.2%. The susceptibility rates of Pseudomonas aeruginosa and Acinetobacter spp. to imipenem were 77.4% and 36.7%, respectively.

CONCLUSION

Enterococcus spp. with susceptibility to limited antibiotics was one of the main pathogens in Korean IAIs, along with E. coli and Klebsiella spp., which were highly susceptible to imipenem, amikacin, and piperacillin/tazobactam. Meanwhile, the low susceptibilities of E. coli or Klebsiella spp. to amoxicillin/clavulanate, advanced-generation cephalosporins, and ciprofloxacin should be considered when determining empirical antibiotic therapy in clinical practice.

Clinical implications of multidrug-resistant microorganisms and fungi isolated from patients with intra-abdominal infections in the Republic of Korea: a multicenter study

The purpose of this study was to evaluate the clinical significance of fungi and multidrug-resistant organisms (MDROs) isolated from patients with intra-abdominal infections (IAIs). This multicenter study included consecutive patients admitted for microbiologically proven IAIs at 6 university-affiliated hospitals in South Korea between 2016 and 2018. A total of 1571 patients were enrolled. Multivariable logistic regression analysis revealed that the isolation of MDROs, isolation of Candida spp., underlying renal diseases, Charlson comorbidity score ≥ 3, septic shock, failure to receive a required surgery or invasive intervention, secondary bacteremia due to IAIs, and lower body mass index were found to be independent predictors for 28-day mortality. However, the isolation of Enterococcus spp. was not identified as a significant risk factor. MDROs and Candida spp. were found in 42 (2.7%) and 395 (25.1%), patients respectively. The isolation of MDROs or Candida spp. was a surrogate marker of 28-day mortality.

Impact of species and antibiotic therapy of enterococcal peritonitis on 30-day mortality in critical care-an analysis of the OUTCOMEREA database

Introduction

Enterococcus species are associated with an increased morbidity in intraabdominal infections (IAI). However, their impact on mortality remains uncertain. Moreover, the influence on outcome of the appropriate or inappropriate status of initial antimicrobial therapy (IAT) is subjected to debate, except in septic shock. The aim of our study was to evaluate whether an IAT that did not cover Enterococcus spp. was associated with 30-day mortality in ICU patients presenting with IAI growing with Enterococcus spp.

Material and methods

Retrospective analysis of French database OutcomeRea from 1997 to 2016. We included all patients with IAI with a peritoneal sample growing with Enterococcus. Primary endpoint was 30-day mortality.

Results

Of the 1017 patients with IAI, 76 (8%) patients were included. Thirty-day mortality in patients with inadequate IAT against Enterococcus was higher (7/18 (39%) vs 10/58 (17%), p = 0.05); however, the incidence of postoperative complications was similar. Presence of Enterococcus spp. other than E. faecalis alone was associated with a significantly higher mortality, even greater when IAT was inadequate. Main risk factors for having an Enterococcus other than E. faecalis alone were as follows: SAPS score on day 0, ICU-acquired IAI, and antimicrobial therapy within 3 months prior to IAI especially with third-generation cephalosporins. Univariate analysis found a higher hazard ratio of death with an Enterococcus other than E. faecalis alone that had an inadequate IAT (HR = 4.4 [1.3–15.3], p = 0.019) versus an adequate IAT (HR = 3.1 [1.0–10.0], p = 0.053). However, after adjusting for confounders (i.e., SAPS II and septic shock at IAI diagnosis, ICU-acquired peritonitis, and adequacy of IAT for other germs), the impact of the adequacy of IAT was no longer significant in multivariate analysis. Septic shock at diagnosis and ICU-acquired IAI were prognostic factors.

Conclusion

An IAT which does not cover Enterococcus is associated with an increased 30-day mortality in ICU patients presenting with an IAI growing with Enterococcus, especially when it is not an E. faecalis alone. It seems reasonable to use an IAT active against Enterococcus in severe postoperative ICU-acquired IAI, especially when a third-generation cephalosporin has been used within 3 months.

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2581-8) contains supplementary material, which is available to authorized users.

Usefulness of Gram stain examination of peritoneal fluid in postoperative peritonitis to guide empirical antibiotherapy

PURPOSE

In postoperative peritonitis, Gram stain examination (GSE) of peritoneal fluid has been proposed as a guide for the prescription of glycopeptides and antifungal therapy in empirical antibiotherapy. No data support this approach for Gram-positive cocci. We aimed to evaluate the performance of GSE in predicting the results of the culture of peritoneal fluid.

METHODS

In this retrospective single-center study, concordance between GSE and culture of peritoneal fluid was assessed for different types of microorganisms. Factors associated with concordance of the two tests were evaluated in the subpopulation of Gram-positive cocci peritonitis.

RESULTS

Among the 152 episodes, the GSE was negative in 57 cases. The negative predictive value and the positive predictive value were 41% and 87% for Gram-positive cocci (GPC), 31% and 86% for Gram-negative bacilli, and 78% and 94% for fungi. GSE is not a reliable guide for the choice of empirical antibiotherapy and cannot reliably rule out the presence of GPC at culture. If we aim to achieve a high rate of adequacy, the systematic use of glycopeptide in the empirical antibiotherapy may be considered.

CONCLUSION

GSE shows poor performance to predict the results of culture of peritoneal fluid in postoperative peritonitis. Avoiding covering resistant GPC cannot be based on the result of GSE.

Model systems for the study of Enterococcal colonization and infection

Enterococcus faecalis and Enterococcus faecium are common inhabitants of the human gastrointestinal tract, as well as frequent opportunistic pathogens. Enterococci cause a range of infections including, most frequently, infections of the urinary tract, catheterized urinary tract, bloodstream, wounds and surgical sites, and heart valves in endocarditis. Enterococcal infections are often biofilm-associated, polymicrobial in nature, and resistant to antibiotics of last resort. Understanding Enterococcal mechanisms of colonization and pathogenesis are important for identifying new ways to manage and intervene with these infections. We review vertebrate and invertebrate model systems applied to study the most common E. faecalis and E. faecium infections, with emphasis on recent findings examining Enterococcal-host interactions using these models. We discuss strengths and shortcomings of each model, propose future animal models not yet applied to study mono- and polymicrobial infections involving E. faecalis and E. faecium, and comment on the significance of anti-virulence strategies derived from a fundamental understanding of host-pathogen interactions in model systems.

Bad bacteria in acute appendicitis: rare but relevant

PURPOSE

Bacterial infections are a factor for morbidity in patients with acute appendicitis (AA). The spreading of multidrug-resistant (MDR) bacteria is a significant problem in surgery, and the most relevant MDR pathogens are summarized as Enterobacteriaceae, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterococci (ESKAPE) bacteria. Data regarding the species and distribution of bacteria in AA are available, but information about the resistances and their relevance is deficient.

METHODS

In this retrospective study, we analyzed microbiological swabs of patients with AA. The outcome parameters of patients after laparoscopic appendectomy were analyzed against microbiological results, including antibiotic resistance testing. Positive swabs were compared with bacteria cultivated after alternative abdominal emergency surgery (AES).

RESULTS

In total, 584 patients with AA were included and had a mean age of 35.5 years. In 216 patients (36.9%), a swab was taken, and in 128 (59.3%) swabs, bacteria could be cultivated. The most frequent organisms were Escherichia coli, Bacteroides species, and Pseudomonas. In 9.4% of the positive AA swabs, MDR germs were cultivated, and all of them were ESKAPE pathogens. Patients with MDR bacteria in AA suffered more infectious complications (p = 0.006) and needed longer hospitalizations (p < 0.009). In AES, aside from appendicitis, a different spectrum containing more MDR bacteria was cultivated (5.9 vs. 20.9%; p < 0.0001).

CONCLUSIONS

Although they occur less frequently in appendectomy compared to emergency surgeries for other abdominal diseases, MDR bacteria are traceable in this common disease and contribute to additional morbidity.

Antimicrobial Monotherapy versus Combination Therapy for the Treatment of Complicated Intra-Abdominal Infections

STUDY OBJECTIVE

It is unknown if β-lactam monotherapy is sufficient for complicated intra-abdominal infections or if broader coverage is required, such as with vancomycin. This study sought to determine the clinical outcomes of piperacillin/tazobactam (PIP/TAZ) monotherapy compared to combination therapy with vancomycin and PIP/TAZ for complicated intra-abdominal infections among patients within a surgical intensive care unit (ICU).

DESIGN

Retrospective cohort study.

SETTING

Three surgical ICUs at a tertiary academic medical center.

PATIENTS

Four hundred seventeen patients with a secondary peritonitis identified by International Classification of Diseases, Ninth Revision codes who received either PIP/TAZ monotherapy (228 patients) or PIP/TAZ and vancomycin combination therapy (189 patients).

MEASUREMENTS AND MAIN RESULTS

The primary outcome was day 28 clinical cure; secondary outcomes included day 7 clinical cure, length of stay (LOS), and mortality. There were no statistically significant differences between the monotherapy and combination therapy groups with respect to day 28 clinical cure (33.9% vs 25.5%, p=0.064), day 7 clinical cure (23.6% vs 17.6%, p=0.14), or 28-day mortality (7% vs 7.9%, p=0.72). LOS in the ICU was significantly shorter in the monotherapy group (6 days) compared with the combination therapy group (7 days; p=0.04); however, hospital LOS was not significantly different.

CONCLUSIONS

No difference was observed in clinical cure rates at day 28 or day 7 between those who received PIP/TAZ monotherapy compared to PIP/TAZ and vancomycin combination therapy.

Management of intra-abdominal infections: recommendations by the WSES 2016 consensus conference

This paper reports on the consensus conference on the management of intra-abdominal infections (IAIs) which was held on July 23, 2016, in Dublin, Ireland, as a part of the annual World Society of Emergency Surgery (WSES) meeting. This document covers all aspects of the management of IAIs. The Grading of Recommendations Assessment, Development and Evaluation recommendation is used, and this document represents the executive summary of the consensus conference findings.

Inclusion of Vancomycin as Part of Broad-Spectrum Coverage Does Not Improve Outcomes in Patients with Intra-Abdominal Infections: A Post Hoc Analysis

BACKGROUND

Management of complicated intra-abdominal infections (cIAIs) includes broad-spectrum antimicrobial coverage and commonly includes vancomycin for the empiric coverage of methicillin-resistant Staphylococcus aureus (MRSA). Ideally, culture-guided de-escalation follows to promote robust antimicrobial stewardship. This study assessed the impact and necessity of vancomycin in cIAI treatment regimens.

PATIENTS AND METHODS

A post hoc analysis of the Study to Optimize Peritoneal Infection Therapy (STOP-IT) trial was performed. Patients receiving piperacillin-tazobactam (P/T) and/or a carbapenem were included with categorization based on use of vancomycin. Univariate and multivariable analyses evaluated effects of including vancomycin on individual and the composite of undesirable outcomes (recurrent IAI, surgical site infection [SSI], or death).

RESULTS

The study cohort included 344 patients with 110 (32%) patients receiving vancomycin. Isolation of MRSA occurred in only eight (2.3%) patients. Vancomycin use was associated with a similar composite outcome, 29.1%, vs. no vancomycin, 22.2% (p = 0.17). Patients receiving vancomycin had (mean [standard deviation]) higher Acute Physiology and Chronic Health Evaluation II scores (13.1 [6.6] vs. 9.4 [5.7], p < 0.0001), extended length of stay (12.6 [10.2] vs. 8.6 [8.0] d, p < 0.001), and prolonged antibiotic courses (9.1 [8.0] vs. 7.1 [4.9] d, p = 0.02). After risk adjustment in a multivariate model, no significant difference existed for the measured outcomes.

CONCLUSIONS

This post hoc analysis reveals that addition of vancomycin occurred in nearly one third of patients and more often in sicker patients. Despite this selection bias, no appreciable differences in undesired outcomes were demonstrated, suggesting limited utility for adding vancomycin to cIAI treatment regimens.

Antimicrobials: a global alliance for optimizing their rational use in intra-abdominal infections (AGORA)

Intra-abdominal infections (IAI) are an important cause of morbidity and are frequently associated with poor prognosis, particularly in high-risk patients. The cornerstones in the management of complicated IAIs are timely effective source control with appropriate antimicrobial therapy. Empiric antimicrobial therapy is important in the management of intra-abdominal infections and must be broad enough to cover all likely organisms because inappropriate initial antimicrobial therapy is associated with poor patient outcomes and the development of bacterial resistance. The overuse of antimicrobials is widely accepted as a major driver of some emerging infections (such as C. difficile), the selection of resistant pathogens in individual patients, and for the continued development of antimicrobial resistance globally. The growing emergence of multi-drug resistant organisms and the limited development of new agents available to counteract them have caused an impending crisis with alarming implications, especially with regards to Gram-negative bacteria. An international task force from 79 different countries has joined this project by sharing a document on the rational use of antimicrobials for patients with IAIs. The project has been termed AGORA (Antimicrobials: A Global Alliance for Optimizing their Rational Use in Intra-Abdominal Infections). The authors hope that AGORA, involving many of the world's leading experts, can actively raise awareness in health workers and can improve prescribing behavior in treating IAIs.

Microbial colonization of open abdomen in critically ill surgical patients

Introduction

This study was designed to describe the time-course and microbiology of colonization of open abdomen in critically ill surgical patients and to study its association with morbidity, mortality and specific complications of open abdomen. A retrospective cohort analysis was done.

Methods

One hundred eleven consecutive patients undergoing vacuum-assisted closure with mesh as temporary abdominal closure method for open abdomen were analyzed. Microbiological samples from the open abdomen were collected. Statistical analyses were performed using Fisher’s exact test for categorical variables. Mann-Whitney U test was used when comparing number of temporary abdominal closure changes between colonized and sterile patients. Kaplan-Meier analysis was done to calculate cumulative estimates for colonization. Cox regression analyses were performed to analyze risk factors for colonization.

Results

Microbiological samples were obtained from 97 patients. Of these 76 (78 %) were positive. Sixty-one (80 %) patients were colonized with multiple micro-organisms and 27 (36 %) were cultured positive for candida species. The duration of open abdomen treatment adversely affected the colonization rate. Thirty-three (34 %) patients were colonized at the time of laparostomy. After one week of open abdomen treatment 69, and after two weeks 76 patients were colonized with cumulative colonization estimates of 74 % and 89 %, respectively. Primary fascial closure rate was 80 % (61/76) and 86 % (18/21) for the colonized and sterile patients, respectively. The rate of wound complications did not significantly differ between these groups.

Conclusions

Microbial colonization of open abdomen is associated with the duration of open abdomen treatment. Wound complications are common after open abdomen, but colonization does not seem to have significant effect on these. The high colonization rate described herein should be taken into account when primarily sterile conditions like acute pancreatitis and aortic aneurysmal rupture are treated with open abdomen.

Risk factors for acquisition of multidrug-resistant bacteria in patients with anastomotic leakage after colorectal cancer surgery

PURPOSE

The risk factors for acquiring an infection with multidrug-resistant (MDR) bacteria in patients with anastomotic leakage after colorectal cancer surgery are poorly understood. We evaluated the risk factors associated with the initial acquisition of MDR pathogens in patients with anastomotic leakage after colorectal cancer surgery.

METHODS

This study was a retrospective review of prospectively collected data at a university affiliated-tertiary referral hospital in South Korea. From January 2009 to April 2013, a total of 6767 consecutive patients with colorectal cancer who underwent surgery were registered. Of these patients, 190 (2.8%) were diagnosed with anastomotic leakage. Finally, 143 (2.1%) patients with culture test results were included in this study.

RESULTS

Of the 143 enrolled patients, 46 (32.2%) were classified in the MDR group. The use of antibiotics for more than 5 days before diagnosis of anastomosis site leakage (p = 0.016) and diabetes mellitus (p = 0.028) was identified as independent risk factors for MDR acquisition by multivariate analysis. The rate of adequate initial empirical antibiotic therapy in the MDR group was lower than in the non-MDR group (35 vs. 75%, p < 0.001). Furthermore, the duration of antibiotic administration after the leak was longer in the MDR group (p = 0.013). Patients in the MDR group also had a longer hospital stay (p = 0.012).

CONCLUSIONS

The length of antibiotic administration before the diagnosis of anastomotic leakage and diabetes mellitus were risk factors associated with the acquisition of MDR bacteria in patients with anastomotic leakage after colorectal cancer surgery.

The Challenge of Antimicrobial Resistance in Managing Intra-Abdominal Infections

BACKGROUND

In recent years, there has been a worldwide increase in infections caused by microorganisms resistant to multiple antimicrobial agents.

METHODS

In the past few decades, an increased prevalence of infections caused by antibiotic-resistant pathogens, including Enterococcus spp., carbapenem-resistant Pseudomonas aeruginosa and Acinetobacter baumannii, extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella spp., carbapenemase-producing Klebsiella pneumoniae, and resistant Candida spp., also has been observed among intra-abdominal infections (IAIs).

RESULTS

The increasing prevalence of multi-drug resistance is responsible for a substantial increase in morbidity and mortality rates associated with IAIs.

CONCLUSIONS

It is necessary for every surgeon treating IAIs to understand the underlying epidemiology and clinical consequences of antimicrobial resistance. Emergence of drug resistance, combined with the lack of new agents in the drug development pipeline, indicates that judicious antimicrobial management will be necessary to preserve the utility of the drugs available currently.

Management of Complicated Appendicitis and Comparison of Outcome with Other Primary Sites of Intra-abdominal Infection: Results of a Trial Comparing Ertapenem and Piperacillin-Tazobactam

A post-hoc analysis of data from a trial of complicated intra-abdominal infection was performed to compare the demographic and disease characteristics of patients with complicated appendicitis to those whose primary infection involved other intra-abdominal sites, assess the impact of site of primary infection on outcome, and compare the efficacy and safety of ertapenem 1 g daily with piperacillin-tazobactam 3.375 g every 6 h for treatment of complicated appendicitis. Compared with patients who had primary infection of the colon or another site in the abdomen, patients with complicated appendicitis were younger, had less severe disease (based on lower APACHE II score and lower proportion with generalized peritonitis), and were less likely to be managed by percutaneous drainage of an abscess or to have a postoperative infection. Patients with complicated appendicitis were more likely to have a favorable outcome than were patients with infection of the colon (OR, 3.02; 95% CI, [1.54-5.901; P = .001). At the test-of-cure assessment, 109/123 (88.6%) microbiologically evaluable patients with complicated appendicitis who received ertapenem and 102/113 (90.3%) who received piperacillin-tazobactam had a favorable combined clinical and microbiologic outcome. The frequency and severity of drug-related adverse events were similar in the two treatment groups.

Are enterococci playing a role in postoperative peritonitis in critically ill patients?

This prospective non-interventional study is aimed at evaluating the role of enterococci in the postoperative course of postoperative peritonitis (POP) and the predictive factors for isolating Enterococcus spp. All adult patients, hospitalized in intensive care, who had POP between September 2006 and February 2010 were analysed. The patients' baseline clinical characteristics and microbiological and surgical characteristics of the first episode of POP were recorded. The rates of surgical and non-surgical complications and mortality were studied. A total of 139 patients were analysed and Enterococcus spp. were recovered in 61 patients (43%). The presence of enterococci was associated with significantly more intra-abdominal abscesses (26% vs 12%, p=0.025), but did not affect the rate of reoperation or mortality. Antibiotic use before reoperation was the only independent predictive factor for isolating enterococci (OR=2.19, CI95%: 1.02-4.70, p<0.043). Although mortality was not affected by the presence of Enterococcus spp., a higher rate of intra-abdominal abscess was found, suggesting that enterococci play a significant role in postoperative peritonitis, but the need to treat them remains to be determined. Previous antibiotic use before reoperation was a key factor in predicting the subsequent recovery of enterococci.

Enterococci increase the morbidity and mortality associated with severe intra-abdominal infections in elderly patients hospitalized in the intensive care unit

OBJECTIVES

Enterococci may increase morbidity and mortality in elderly patients with intra-abdominal infections (IAIs) hospitalized in the intensive care unit (ICU).

PATIENTS AND METHODS

A single-centre, retrospective evaluation of an ICU database (1997-2007) of elderly ICU patients (≥75 years) with a severe IAI was performed. Demographics, severity scores, underlying diseases, microbiology and outcomes were recorded. Patients with enterococci isolated in peritoneal fluid (E+ group) were compared with those lacking enterococci in peritoneal fluid (E- group). Stepwise multivariate logistic regression was used to identify independent factors associated with mortality.

RESULTS

One hundred and sixty patients were included (mean ± SD age 82 ± 5 years; n = 72 in the E+ group). The E+ group was more severely ill than the E- group, with higher Simplified Acute Physiologic Score 2 (61 ± 20 versus 48 ± 16, P = 0.0001) and Sequential Organ Failure Assessment scores (8 ± 3 versus 5 ± 3, P = 0.0001), a greater postoperative infection rate (58.3% versus 34.1%, P = 0.01), a higher incidence of inappropriate empirical antimicrobial therapies (33.3% versus 19.3%, P = 0.04), a longer duration of mechanical ventilation (11.8 ± 10.9 versus 7.8 ± 10.2 days, P = 0.02) and greater vasopressor use (7.2 ± 7.1 versus 3.3 ± 4.1 days, P = 0.001). ICU mortality was higher in the E+ group than in the E- group (54.2% versus 38.6%, P = 0.05). In the multivariate analysis, E+ status was independently associated with mortality (odds ratio 2.24; 95% confidence interval 1.06-4.75; P = 0.03).

CONCLUSIONS

In severely ill, elderly patients in the ICU for an IAI, the isolation of enterococci was associated with increased disease severity and morbidity and was an independent risk factor for mortality.

Critical care issues in managing complex open abdominal wound

Over the past 30 years, surgical specialties have introduced and expanded the role of open abdominal management in complicated operative cases, necessitating an intensivist's understanding of the indications and unique intensive care unit (ICU) issues related to the open abdomen. When presented with the open abdomen, resuscitation to correct shock is of primary concern. This is accomplished by correction of hypothermia, acidosis, and coagulopathy in trauma and adequate resolution of intra-abdominal hypertension or source control in general surgery. These patients typically require deep sedation and often paralysis and benefit from low-volume ventilatory strategies to prevent and treat acute lung injury. Antibiotics must be tailored to the clinical situation, but in most cases, 24 hours of perioperative treatment is all that is required. In cases of gross contamination and peritonitis, a 5- to 7-day course of broad-spectrum antibiotics may be of benefit.Adequate source control has been demonstrated to have the greatest impact on outcome and when the patient's clinical milieu dictates, bedside washouts. Enteral nutrition should be instituted as early as possible after intestinal continuity has been reestablished. Additional protein is required to account for losses from the open abdomen. Reconstruction may require staging, but in general, should proceed following resolution of shock and control of sepsis. Elevated multiorgan dysfunction score, Acute Physiology And Chronic Health Evaluation II (APACHE II), and a rise in peak inspiratory pressure portend poor source control and could result in failure of fascial closure. If unable to proceed to fascial closure, then considerations should be made for planned ventral hernia and subsequent abdominal wall reconstruction.

[What should and should not be covered in intraabdominal infection]

Despite improvements in our knowledge of the physiopathology of severe infection, diagnostic methods, antibiotic therapy, postoperative care and surgical techniques, a substantial number of patients with intraabdominal infection (IAI) will develop advanced stages of septic insult requiring admission to the intensive care unit. The success of treatment of IAI is multifactorial and the best antibiotic protocol may be insufficient unless adequate control of the focus of infection has been achieved. The present article discusses the appropriacy of empirical antibiotic therapy and the main pathogens associated with treatment failure. We also analyze the patients at risk of infection with microorganisms requiring broad-spectrum antimicrobial coverage. However, excessive antibiotic treatment, in terms of either spectrum or duration, could jeopardize future patients in an environment already threatened by the scarcity of research and development into new molecules required for the emergence of pathogens resistant to current antibiotics.

Treatment of complicated intra-abdominal infections in the era of multi-drug resistant bacteria

The management of severe intra-abdominal infections remains a major challenge facing surgeons and intensive care physicians, because of its association with high morbidity and mortality. Surgical management and intensive care medicine have constantly improved, but in the recent years a rapidly continuing emergence of resistant pathogens led to treatment failure secondary to infections with multi-drug resistant bacteria. In secondary peritonitis the rate of resistant germs at the initial operation is already 30%. The lack of effective antibiotics against these pathogens resulted in the development of new broad-spectrum compounds and antibiotics directed against resistant germs. But so far no "super-drug" with efficacy against all resistant bacteria exists. Even more, soon after their approval, reports on resistance against these novel drugs have been reported, or the drugs were withdrawn from the market due to severe side effects. Since pharmaceutical companies reduced their investigations on antibiotic research, only few new antimicrobial derivates are available.

In abdominal surgery you may be in fear that in the future more and more patients with tertiary peritonitis secondary to multi-drug resistant species are seen with an increase of mortality after secondary peritonitis.

This article reviews the current treatment modalities for complicated intra-abdominal infections with special reference to the antibiotic treatment of complicated intra-abdominal infections with multi-drug resistant species.

Perioperative use of antibiotics in intra-abdominal surgical infections

BACKGROUND

We created a questionnaire with the aim of evaluating surgeon compliance with the guidelines for antibiotic use in the perioperative period in intra-abdominal surgical infections. We discuss the problems emerging from non-adherence to these guidelines.

METHODS

In the questionnaire, we tried to correlate the type of intra-abdominal infection with: (1) Time of antibiotic administration commencement; (2) type of antibiotic(s) administered; (c) duration of antibiotic administration; and (4) modification of antibiotic type/duration of administration in the presence of factors increasing the risk of treatment failure. In order to collect and process the data more easily, the patients were divided into four groups-Group A: Community patients with intra-abdominal surgical infections and simple contamination of the peritoneal cavity according to the Surgical Infection Society (SIS) guidelines; Group B: Community patients with an intra-abdominal surgical infection evolving to secondary peritonitis per SIS guidelines; Group C: Community patients with an intra-abdominal surgical infection with a high risk of surgical site infection; and Group D: Patients with recent hospitalization or nosocomial or postoperative intra-abdominal infection.

RESULTS

The questionnaire was sent to the directors of 43 surgical clinics in northern Greece, and 27 answered (63%). In 81.5% of the clinics (median 22; range 15-24), depending on the type of infection, empirical antibiotic treatment commenced preoperatively. In Group A, on average, 29.6% of the clinics (median 8; range 5-16) administer antibiotics for as long as 24 h, and 11.1% (median 3; range 1-10) use antibiotics not recommended in the SIS guidelines (e.g., third- and fourth-generation cephalosporins, ciprofloxacin, imipenem-cilastatin, meropenem, or piperacillin/tazobactam). In Group B, 22.2% of clinics (median 6; range 2-15) administer antibiotics for three to five days, and 14.8% (median 4; range 1-11) use antibiotics outside SIS guidelines. In Group C, 40.7% of clinics (median 11; range 1-14) administer antibiotics for more than five days, and 14.8% (median 4; range 1-14) use antibiotics that are outside the SIS guidelines. In Group D, 11.1% of clinics (median 3; range 2-5) do not cover Enterococcus with the antibiotics administered.

CONCLUSIONS

There seems to be confusion in determining the situations with simple contamination of the peritoneal cavity, whose treatment requires short-duration antibiotic administration, and in the type of antibiotics administered to various patient groups, elements that lead to prolonged or erroneous administration of antibiotic drugs. Continuous discussion and surgeon training is imperative and may be the best choice to ensure familiarity with antibiotics and their proper use and thus to minimize serious adverse events and treatment failure.

Preventing surgical site infections after bariatric surgery: value of perioperative antibiotic regimens

Bariatric surgery for obesity has emerged as an effective and commonly used treatment modality. This paper reviews the surgical site infections (SSIs) that occur post bariatric surgery and SSI prevention. The benefit of bariatric surgery resulting in profound weight loss brings with it consequences in the form of postoperative complications that can have profound effects on morbidity and mortality in these patients. This paper sets out to define different types of SSIs that occur following bariatric surgery and to discuss existing literature on the critical aspects of SSI prevention and the appropriate use of surgical antimicrobial prophylaxis for bariatric surgery.

Microbiological profile and antimicrobial susceptibility in surgical site infections following hollow viscus injury

INTRODUCTION

The purpose of this study was to assess the microbiological profile, antimicrobial susceptibility, and adequacy of the empiric antibiotic therapy in surgical site infections (SSI) following traumatic hollow viscus injury (HVI).

METHODS

This is a retrospective study of patients admitted with an HVI from March 2003 to July 2009. SSI was defined as a wound infection or intra-abdominal collection confirmed by positive cultures and requiring percutaneous or surgical drainage.

RESULTS

A total of 91 of 667 (13.6%) patients with an HVI developed an SSI confirmed by positive culture. Mean age was 33.0 +/- 14.1 years, mean Injury Severity Score (ISS) was 17.7 +/- 9.6, 91.2% were male, and 80.2% had sustained penetrating injuries. The SSI consisted of 65 intra-abdominal collections and 26 wound infections requiring intervention. The most commonly isolated species in the presence of a colonic injury was Escherichia coli (64.7%), Enterococcus spp. (41.2%), and Bacteroides (29.4%), and in the absence of a colonic perforation, Enterococcus spp. and Enterobacter cloacae (both 38.9%). Susceptibility rates of E. coli and E. cloacae, respectively, were 38% and 8% for ampicillin/sulbactam, 82% and 4% for cefazolin, 96% and 92% for cefoxitin, with both 92% to piperacillin/tazobactam, and 100% to ertapenem. The initial empirical antibiotic therapy adequately targeted the pathogens in 51.6% of patients who developed an SSI.

CONCLUSION

The distribution of the microorganisms isolated from SSIs differed significantly according to whether or not a colonic injury was present. Empiric antibiotic treatment was inadequate in upwards of 50% of patients who developed an SSI. Further investigation is warranted to determine the optimal empiric antibiotic regimen for reducing the rate of postoperative SSI.

Diagnosis and management of complicated intra-abdominal infection in adults and children: guidelines by the Surgical Infection Society and the Infectious Diseases Society of America

Evidence-based guidelines for managing patients with intra-abdominal infection were prepared by an Expert Panel of the Surgical Infection Society and the Infectious Diseases Society of America. These updated guidelines replace those previously published in 2002 and 2003. The guidelines are intended for treating patients who either have these infections or may be at risk for them. New information, based on publications from the period 2003-2008, is incorporated into this guideline document. The panel has also added recommendations for managing intra-abdominal infection in children, particularly where such management differs from that of adults; for appendicitis in patients of all ages; and for necrotizing enterocolitis in neonates.

Diagnosis and Management of Complicated Intra-abdominal Infection in Adults and Children: Guidelines by the Surgical Infection Society and the Infectious Diseases Society of America

Evidence-based guidelines for managing patients with intra-abdominal infection were prepared by an Expert Panel of the Surgical Infection Society and the Infectious Diseases Society of America. These updated guidelines replace those previously published in 2002 and 2003. The guidelines are intended for treating patients who either have these infections or may be at risk for them. New information, based on publications from the period 2003–2008, is incorporated into this guideline document. The panel has also added recommendations for managing intra-abdominal infection in children, particularly where such management differs from that of adults; for appendicitis in patients of all ages; and for necrotizing enterocolitis in neonates.

Epidemiology, management, and prognosis of secondary non-postoperative peritonitis: a French prospective observational multicenter study

BACKGROUND

Despite improvements in treatment, secondary peritonitis still is associated with high morbidity and mortality rates. Better knowledge of real-life clinical practice might improve management.

METHODS

Prospective, observational study (January-June 2005) of 841 patients with non-postoperative secondary peritonitis.

RESULTS

Peritonitis originated in the colon (32% of patients), appendix (31%), stomach/duodenum (18%), small bowel (13%), or biliary tract (6%). Most patients (78%) presented with generalized peritonitis and 26% with severe peritonitis (Simplified Acute Physiology Score [SAPS] II score>38). Among the 841 patients, 27.3% underwent laparoscopy alone; 11% underwent repeat surgery, percutaneous drainage, or both. A SAPS II score>38 and the presence of Enterococcus spp. were predictive of abdominal and non-surgical infections (odds ratio [OR]=1.84; p=0.013 and OR=2.93; p<0.0001, respectively). A SAPS II score>38 also was predictive of death (OR=10.5; p<0.0001). The overall mortality rate was high (15%). Patients receiving inappropriate initial antimicrobial therapy had significantly higher morbidity and mortality rates than patients receiving appropriate therapy (44 vs. 30%; p=0.004 and 23% vs. 14%; p=0.015, respectively). The SAPS II score and rates of severe peritonitis, morbidity, and mortality were significantly lower in patients with appendiceal peritonitis.

CONCLUSIONS

Patients with non-postoperative peritonitis should be considered high risk and should receive appropriate initial therapy. The presence of Enterococcus spp. in peritoneal cultures significantly increased morbidity but not the mortality rate. Appendiceal peritonitis that was less severe and had a better prognosis than peritonitis originating in other sites should be considered a special case in future studies.

Clinical and microbiological profiles of community-acquired and nosocomial intra-abdominal infections: results of the French prospective, observational EBIIA study

OBJECTIVES

The EBIIA (Etude épidémiologique Bactério-clinique des Infections Intra-Abdominales) study was designed to describe the clinical, microbiological and resistance profiles of community-acquired and nosocomial intra-abdominal infections (IAIs).

PATIENTS AND METHODS

From January to July 2005, patients undergoing surgery/interventional drainage for IAIs with a positive microbiological culture were included by 25 French centres. The primary endpoint was the epidemiology of the microorganisms and their resistance to antibiotics. Multivariate analysis was carried out using stepwise logistic regression to assess the factors predictive of death during hospitalization.

RESULTS

Three hundred and thirty-one patients (234 community-acquired and 97 nosocomial) were included. The distribution of the microorganisms differed according to the type of infection. Carbapenems and amikacin were the most active agents in vitro against Enterobacteriaceae in both community-acquired and nosocomial infections. Against Pseudomonas aeruginosa, amikacin, imipenem, ceftazidime and ciprofloxacin were the most active agents in community-acquired infections, while imipenem, cefepime and amikacin were the most active in nosocomial cases. Against the Gram-positive bacteria, vancomycin and teicoplanin were the most active in both infections. Against anaerobic bacteria, the most active agents were metronidazole and carbapenems in both groups. Empirical antibiotic therapy adequately targeted the pathogens for 63% of community-acquired and 64% of nosocomial peritonitis. The presence of one or more co-morbidities [odds ratio (OR) = 3.17; P = 0.007], one or more severity criteria (OR = 4.90; P < 0.001) and generalized peritonitis (OR = 3.17; P = 0.006) were predictive of death.

CONCLUSIONS

The principal results of EBIIA are a higher diversity of microorganisms isolated in nosocomial infections and decreased susceptibility among these strains. Despite this, the adequacy of treatment is comparable in the two groups.

Antibiotic management of sepsis: current concepts

BACKGROUND

The development of guidelines for sepsis management has improved disease survival and reduced treatment costs. Adequate antibiotic therapy is the cornerstone of sepsis treatment. Specific rules should be established in every institution according to its profiles.

OBJECTIVES

To review the current knowledge about the best drugs to be used as empiric treatment for sepsis based on their clinical efficacy and costs.

METHODS

Medline 1950 - 2008 was searched using the following terms: sepsis, organ failure, system failure, SIRS, septic shock, antibiotic, pneumonia, urinary tract infection, urosepsis, catheter-related infection, bloodstream, abdominal infection, and surgical wound.

RESULTS/CONCLUSION

For most septic shock patients, monotherapy is adequate and treatment should be initiated in the first hour after first sepsis-induced organ dysfunction. The drug of choice varies in different situations and choosing the right antibiotic enables better survival, fewer complications and shorter stays in intensive care.

[Bacterial cultures and empirical antimicrobial therapy for community-acquired secondary peritonitis]

Surgeons and anesthetists are frequently confronted with community-acquired secondary peritonitis. We summarize literature results and consensus conferences concerning the types of bacteriologic sampling and cultures and the empiric choice of an antibiotic regimen based on the probable pathogens encountered in community-acquired secondary peritonitis. These studies leave some doubt as to the necessity for routine blood cultures and the need for anaerobic cultures of peritoneal fluid. No one disputes the need for broad spectrum antibiotic therapy, but there is no consensus regarding one, two, or three drug antibiotic regimens or whether an aminoglycoside is an essential part of the recipe. Duration of antibiotic therapy is still a subject of controversy with recommendations varying from 24 hours to 10 days. The need for antibiotics with activity against enterococcus and the need for systematic antifungal therapy when fungal growth is noted in the peritoneal fluid remain undefined. These uncertainties underline the need for treating physicians within each establishment to elaborate a written consensus of antibiotic therapy.