Risk factors for multidrug resistant bacteria and optimization of empirical antibiotic therapy in postoperative peritonitis

Intra-abdominal infection and sepsis in immunocompromised intensive care unit patients: Disease expression, microbial aetiology, and clinical outcomes

We compared epidemiology of intra-abdominal infection (IAI) between immunocompromised and non-immunocompromised ICU patients and identified risk factors for mortality. We performed a secondary analysis on the "AbSeS" database, a prospective, observational study with IAI patients from 309 ICUs in 42 countries. Immunocompromised status was defined as either neutropenia or prolonged corticosteroids use, chemotherapy or radiotherapy in the past year, bone marrow or solid organ transplantation, congenital immunodeficiency, or immunosuppressive drugs use. Mortality was defined as ICU mortality at any time or 28-day mortality for those discharged earlier. Associations with mortality were assessed by logistic regression. The cohort included 2589 patients of which 239 immunocompromised (9.2 %), most with secondary peritonitis. Among immunocompromised patients, biliary tract infections were less frequent, typhlitis more frequent, and IAIs were more frequently healthcare-associated or early-onset hospital-acquired compared with immunocompetent patients. No difference existed in grade of anatomical disruption, disease severity, organ failure, pathogens, and resistance patterns. Septic shock was significantly more frequent in the immunocompromised population. Mortality was similar in both groups (31.1% vs. 28.9 %; p = 0.468). Immunocompromise was not a risk factor for mortality (OR 0.98, 95 % CI 0.66-1.43). Independent risk factors for mortality among immunocompromised patients included septic shock at presentation (OR 6.64, 95 % CI 1.27-55.72), and unsuccessful source control with persistent inflammation (OR 5.48, 95 % CI 2.29-12.57). In immunocompromised ICU patients with IAI, short-term mortality was similar to immunocompetent patients, despite the former presented more frequently with septic shock, and septic shock and persistent inflammation after source control were independent risk factors for death.

Establishment of epidemiological cut-off values for eravacycline, against Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Acinetobacter baumannii and Staphylococcus aureus

OBJECTIVES

To establish the epidemiology cut-off (ECOFF) values of eravacycline against Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Acinetobacter baumannii and Staphylococcus aureus, from a multi-centre study in China.

METHODS

We collected 2500 clinical isolates from five hospitals in China from 2017 to 2020. The MICs of eravacycline were determined using broth microdilution. The ECOFF values of eravacycline against the five species commonly causing cIAIs were calculated using visual estimation and ECOFFinder following the EUCAST guideline.

RESULTS

The MICs of eravacycline against all the strains were in the range of 0.004-16 mg/L. The ECOFF values of eravacycline were 0.5 mg/L for E. coli, 2 mg/L for K. pneumonia and E. cloacae, and 0.25 mg/L for A. baumannii and S. aureus, consistent with the newest EUCAST publication of eravacycline ECOFF values for the populations. No discrepancy was found between the visually estimated and 99.00% ECOFF values calculated using ECOFFinder.

CONCLUSIONS

The determined ECOFF values of eravacycline against the five species can assist in distinguishing wild-type from non-wild-type strains. Given its promising activity, eravacycline may represent a member of the tetracycline class in treating cIAIs caused by commonly encountered Gram-negative and Gram-positive pathogens.

Source Control and Antibiotics in Intra-Abdominal Infections

Intra-abdominal infections (IAIs) account for a major cause of morbidity and mortality, representing the second most common sepsis-related death with a hospital mortality of 23-38%. Prompt identification of sepsis source, appropriate resuscitation, and early treatment with the shortest delay possible are the cornerstones of management of IAIs and are associated with a more favorable clinical outcome. The aim of source control is to reduce microbial load by removing the infection source and it is achievable by using a wide range of procedures, such as definitive surgical removal of anatomic infectious foci, percutaneous drainage and toilette of infected collections, decompression, and debridement of infected and necrotic tissue or device removal, providing for the restoration of anatomy and function. Damage control surgery may be an option in selected septic patients. Intra-abdominal infections can be classified as uncomplicated or complicated causing localized or diffuse peritonitis. Early clinical evaluation is mandatory in order to optimize diagnostic testing and establish a therapeutic plan. Prognostic scores could serve as helpful tools in medical settings for evaluating both the seriousness and future outlook of a condition. The patient's conditions and the potential progression of the disease determine when to initiate source control. Patients can be classified into three groups based on disease severity, the origin of infection, and the patient's overall physical health, as well as any existing comorbidities. In recent decades, antibiotic resistance has become a global health threat caused by inappropriate antibiotic regimens, inadequate control measures, and infection prevention. The sepsis prevention and infection control protocols combined with optimizing antibiotic administration are crucial to improve outcome and should be encouraged in surgical departments. Antibiotic and antifungal regimens in patients with IAIs should be based on the resistance epidemiology, clinical conditions, and risk for multidrug resistance (MDR) and Candida spp. infections. Several challenges still exist regarding the effectiveness, timing, and patient stratification, as well as the procedures for source control. Antibiotic choice, optimal dosing, and duration of therapy are essential to achieve the best treatment. Promoting standard of care in the management of IAIs improves clinical outcomes worldwide. Further trials and stronger evidence are required to achieve optimal management with the least morbidity in the clinical care of critically ill patients with intra-abdominal sepsis.

Management of intra-abdominal infections: recommendations by the Italian council for the optimization of antimicrobial use

Intra-abdominal infections (IAIs) are common surgical emergencies and are an important cause of morbidity and mortality in hospital settings, particularly if poorly managed. The cornerstones of effective IAIs management include early diagnosis, adequate source control, appropriate antimicrobial therapy, and early physiologic stabilization using intravenous fluids and vasopressor agents in critically ill patients. Adequate empiric antimicrobial therapy in patients with IAIs is of paramount importance because inappropriate antimicrobial therapy is associated with poor outcomes. Optimizing antimicrobial prescriptions improves treatment effectiveness, increases patients' safety, and minimizes the risk of opportunistic infections (such as Clostridioides difficile) and antimicrobial resistance selection. The growing emergence of multi-drug resistant organisms has caused an impending crisis with alarming implications, especially regarding Gram-negative bacteria. The Multidisciplinary and Intersociety Italian Council for the Optimization of Antimicrobial Use promoted a consensus conference on the antimicrobial management of IAIs, including emergency medicine specialists, radiologists, surgeons, intensivists, infectious disease specialists, clinical pharmacologists, hospital pharmacists, microbiologists and public health specialists. Relevant clinical questions were constructed by the Organizational Committee in order to investigate the topic. The expert panel produced recommendation statements based on the best scientific evidence from PubMed and EMBASE Library and experts' opinions. The statements were planned and graded according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) hierarchy of evidence. On November 10, 2023, the experts met in Mestre (Italy) to debate the statements. After the approval of the statements, the expert panel met via email and virtual meetings to prepare and revise the definitive document. This document represents the executive summary of the consensus conference and comprises three sections. The first section focuses on the general principles of diagnosis and treatment of IAIs. The second section provides twenty-three evidence-based recommendations for the antimicrobial therapy of IAIs. The third section presents eight clinical diagnostic-therapeutic pathways for the most common IAIs. The document has been endorsed by the Italian Society of Surgery.

Microbiological profile of patients treated for postoperative peritonitis: temporal trends 1999-2019

BACKGROUND

Temporal changes in the microbiological resistance profile have been reported in several life-threatening infections. However, no data have ever assessed this issue in postoperative peritonitis (POP). Our purpose was to assess the rate of multidrug-resistant organisms (MDROs) in POP over a two-decade period and to analyse their influence on the adequacy of empirical antibiotic therapy (EAT).

METHODS

This retrospective monocentric analysis (1999-2019) addressed the changes over time in microbiologic data, including the emergence of MDROs and the adequacy of EAT for all intensive care unit adult patients treated for POP. The in vitro activities of 10 antibiotics were assessed to determine the most adequate EAT in the largest number of cases among 17 antibiotic regimens in patients with/without MDRO isolates. Our primary endpoint was to determine the frequency of MDRO and their temporal changes. Our second endpoint assessed the impact of MDROs on the adequacy of EAT per patient and their temporal changes based on susceptibility testing. In this analysis, the subgroup of patients with MDRO was compared with the subgroup of patients free of MDRO.

RESULTS

A total of 1,318 microorganisms were cultured from 422 patients, including 188 (45%) patients harbouring MDROs. The growing proportions of MDR Enterobacterales were observed over time (p = 0.016), including ESBL-producing strains (p = 0.0013), mainly related to Klebsiella spp (p < 0.001). Adequacy of EAT was achieved in 305 (73%) patients. Decreased adequacy rates were observed when MDROs were cultured [p = 0.0001 vs. MDRO-free patients]. Over the study period, decreased adequacy rates were reported for patients receiving piperacillin/tazobactam in monotherapy or combined with vancomycin and imipenem/cilastatin combined with vancomycin (p < 0.01 in the three cases). In patients with MDROs, the combination of imipenem/cilastatin + vancomycin + amikacin or ciprofloxacin reached the highest adequacy rates (95% and 91%, respectively) and remained unchanged over time.

CONCLUSIONS

We observed high proportions of MDRO in patients treated for POP associated with increasing proportions of MDR Enterobacterales over time. High adequacy rates were only achieved in antibiotic combinations involving carbapenems and vancomycin, while piperacillin/tazobactam is no longer a drug of choice for EAT in POP in infections involving MDRO.

Optimized Treatment of Nosocomial Peritonitis

This comprehensive review aims to provide a practical guide for intensivists, focusing on enhancing patient care associated with nosocomial peritonitis (NP). It explores the epidemiology, diagnosis, and management of NP, a significant contributor to the mortality of surgical patients worldwide. NP is, per definition, a hospital-acquired condition and a consequence of gastrointestinal surgery or a complication of other diseases. NP, one of the most prevalent causes of sepsis in surgical Intensive Care Units (ICUs), is often associated with multi-drug resistant (MDR) bacteria and high mortality rates. Early clinical suspicion and the utilization of various diagnostic tools like biomarkers and imaging are of great importance. Microbiology is often complex, with antimicrobial resistance escalating in many parts of the world. Fungal peritonitis and its risk factors, diagnostic hurdles, and effective management approaches are particularly relevant in patients with NP. Contemporary antimicrobial strategies for treating NP are discussed, including drug resistance challenges and empirical antibiotic regimens. The importance of source control in intra-abdominal infection management, including surgical and non-surgical interventions, is also emphasized. A deeper exploration into the role of open abdomen treatment as a potential option for selected patients is proposed, indicating an area for further investigation. This review underscores the need for more research to advance the best treatment strategies for NP.

Establishment of a risk prediction model for multidrug-resistant bacteria in deceased organ donors: a retrospective cohort study in China

Background

Multidrug resistance in bacteria is a serious problem in organ transplantations. This study aimed to identify risk factors and establish a predictive model for screening deceased organ donors for multidrug-resistant (MDR) bacteria.

Methods

A retrospective cohort study was conducted at the First Affiliated Hospital of Zhejiang University School of Medicine from July 1, 2019 to December 31, 2022. The univariate and multivariate logistic regression analysis was used to determine independent risk factors associated with MDR bacteria in organ donors. A nomogram was established based on these risk factors. A calibration plot, receiver operating characteristic (ROC) curve, and decision curve analysis (DCA) were used to estimated the model.

Results

In 164 organ donors, the incidence of MDR bacteria in culture was 29.9%. The duration of antibiotic use ≥3 days (odds ratio [OR] 3.78, 95% confidence interval [CI] 1.62-8.81, p=0.002), length of intensive care unit (ICU) stay per day(OR 1.06, 95% CI 1.02-1.11, p=0.005) and neurosurgery (OR 3.31, 95% CI 1.44-7.58, p=0.005) were significant independent predictive factors for MDR bacteria. The nomogram constructed using these three predictors displayed good predictive ability, with an area under the ROC curve value of 0.79. The calibration curve showed a high consistency between the probabilities and observed values. DCA also revealed the potential clinical usefulness of this nomogram.

Conclusions

The duration of antibiotic use ≥3 days, length of ICU stay and neurosurgery are independent risk factors for MDR bacteria in organ donors. The nomogram can be used to monitor MDR bacteria acquisition risk in organ donors.

Outcomes of Beta-Lactam Allergic and Non-Beta-Lactam Allergic Patients with Intra-Abdominal Infection: A Case-Control Study

Background: In the case of intra-abdominal infections (IAI) in beta-lactam (BL) allergic patients, empiric antimicrobial therapy without BL is recommended; however, data regarding the outcome with alternative regimens are scarce. This study aimed to compare the outcomes of BL allergic (BLA) patients with IAI to those who were non-BLA (NBLA). Method: We conducted a case−control study in a French teaching hospital, between 1 January 2016 and 31 August 2021. BLA patients with IAI treated with fluoroquinolone or aztreonam and metronidazole were matched with controls treated with BL, on age, sex, disease severity, IAI localization, and healthcare-associated infection (HAI) status. We compared rates of therapeutic failures, adverse events, and HAI, and then assessed factors associated with therapeutic failure using a logistic regression model. Results: The therapeutic failure rate was 14% (p > 0.99) in both groups of 43 patients, and there was no significant difference in the adverse events rate (p > 0.99) and HAI rate (p = 0.154). Factors independently associated with therapeutic failure were higher BMI (OR 1.16; 95%CI [1.00−1.36]; p = 0.041), longer hospital length of stay (OR 1,20; 95%CI [1.08−1.41]; p = 0.006), and inadequate empiric antimicrobial therapy (OR 11.71; 95%CI [1.43−132.46]; p = 0.025). Conclusion: The outcomes of BLA patients with IAI treated without BL were the same as those for NBLA patients treated with BL.

A Proposal for a Classification Guiding the Selection of Appropriate Antibiotic Therapy for Intra-Abdominal Infections

Adequately controlling the source of infection and prescribing appropriately antibiotic therapy are the cornerstones of the management of patients with intra-abdominal infections (IAIs). Correctly classifying patients with IAIs is crucial to assessing the severity of their clinical condition and deciding the strategy of the treatment, including a correct empiric antibiotic therapy. Best practices in prescribing antibiotics may impact patient outcomes and the cost of treatment, as well as the risk of “opportunistic” infections such as Clostridioides difficile infection and the development and spread of antimicrobial resistance. This review aims to identify a correct classification of IAIs, guiding clinicians in the selection of the best antibiotic therapy in patients with IAIs.

Is ß-d-glucan Relevant for the Diagnosis and Follow-Up of Intensive Care Patients with Yeast-Complicated Intra-Abdominal Infection?

The usefulness of (1,3)-ß-d-glucan (BDG) detection for the diagnosis of intra-abdominal candidiasis and treatment monitoring is unknown. A prospective, single-center study of consecutive patients admitted to an ICU with complicated intra-abdominal infection (IAI) over a 2-year period was conducted. BDG was measured in the peritoneal fluid and serum between day 1 (D1) and D10. Patients with a positive peritoneal fluid yeast culture (YP) were compared to those with a negative yeast culture (YN). The evolution of serum BDG was compared in the two groups. Seventy patients were included (sixty-five analyzed): YP group (n = 19) and YN group (n = 46). Median peritoneal BDG concentration during surgery was 2890 pg.mL⁻¹ [IQR: 942–12,326] in the YP group vs. 1202 pg.mL⁻¹ [IQR: 317–4223] in the YN group (p = 0.13). Initial serum BDG concentration was 130 pg.mL⁻¹ [IQR: 55–259] in the YP group vs. 88 pg.mL⁻¹ [IQR: 44–296] in the YN group (p = 0.78). No difference in evolution of serum BDG concentrations was observed between the groups (p = 0.18). In conclusion, neither peritoneal BDG nor serum BDG appear to be good discriminating markers for the diagnosis of yeast IAI. In addition, monitoring the evolution of serum BDG in yeast IAI did not appear to be of any diagnostic value.

Surgical site infections caused by multi-drug resistant organisms: a case-control study in general surgery

Multi-drug resistant organisms (MDR-Os) are emerging as a significant cause of surgical site infections (SSI), but clinical outcomes and risk factors associated to MDR-Os-SSI have been poorly investigated in general surgery. Aims were to investigate risk factors, clinical outcomes and costs of care of multi-drug resistant organisms (MDR-Os-SSI) in general surgery. From January 2018 to December 2019, all the consecutive, unselected patients affected by MDR-O SSI were prospectively evaluated. In the same period, patients with non-MDR-O SSI and without SSI, matched for clinical and surgical data were used as control groups. Risk factors for infection, clinical outcome, and costs of care were compared by univariate and multivariate analysis. Among 3494 patients operated on during the study period, 47 presented an MDR-O SSI. Two control groups of 47 patients with non-MDR-O SSI and without SSI were identified. MDR-Os SSI were caused by poly-microbial etiology, meanly related to Gram negative Enterobacteriales. MDR-Os-SSI were related to major postoperative complications. At univariate analysis, iterative surgery, open abdomen, intensive care, hospital stay, and use of aggressive and expensive therapies were associated to MDR-Os-SSI. At multivariate analysis, only iterative surgery and the need of total parenteral and immune-nutrition were significantly associated to MDR-Os-SSI. The extra-cost of MDR-Os-SSI treatment was 150% in comparison to uncomplicated patients. MDR-Os SSI seems to be associated with major postoperative complications and reoperative surgery, they are demanding in terms of clinical workload and costs of care, they are rare but increasing, and difficult to prevent with current strategies.

Risk Factors for Intra-Abdominal Candidiasis in Intensive Care Units: Results from EUCANDICU Study

INTRODUCTION

Intra-abdominal infections represent the second most frequently acquired infection in the intensive care unit (ICU), with mortality rates ranging from 20% to 50%. Candida spp. may be responsible for up to 10-30% of cases. This study assesses risk factors for development of intra-abdominal candidiasis (IAC) among patients admitted to ICU.

METHODS

We performed a case-control study in 26 European ICUs during the period January 2015-December 2016. Patients at least 18 years old who developed an episode of microbiologically documented IAC during their stay in the ICU (at least 48 h after admission) served as the case cohort. The control group consisted of adult patients who did not develop episodes of IAC during ICU admission. Matching was performed at a ratio of 1:1 according to time at risk (i.e. controls had to have at least the same length of ICU stay as their matched cases prior to IAC onset), ICU ward and period of study.

RESULTS

During the study period, 101 case patients with a diagnosis of IAC were included in the study. On univariate analysis, severe hepatic failure, prior receipt of antibiotics, prior receipt of parenteral nutrition, abdominal drain, prior bacterial infection, anastomotic leakage, recurrent gastrointestinal perforation, prior receipt of antifungal drugs and higher median number of abdominal surgical interventions were associated with IAC development. On multivariate analysis, recurrent gastrointestinal perforation (OR 13.90; 95% CI 2.65-72.82, p = 0.002), anastomotic leakage (OR 6.61; 95% CI 1.98-21.99, p = 0.002), abdominal drain (OR 6.58; 95% CI 1.73-25.06, p = 0.006), prior receipt of antifungal drugs (OR 4.26; 95% CI 1.04-17.46, p = 0.04) or antibiotics (OR 3.78; 95% CI 1.32-10.52, p = 0.01) were independently associated with IAC.

CONCLUSIONS

Gastrointestinal perforation, anastomotic leakage, abdominal drain and prior receipt of antifungals or antibiotics may help to identify critically ill patients with higher probability of developing IAC. Prospective studies are needed to identify which patients will benefit from early antifungal treatment.

Severe secondary peritonitis: impact of inappropriate initial antimicrobial therapy on prognosis and potential carbapenem-sparing

BACKGROUND

Initiation of antimicrobial therapy (IAT) with broad-spectrum antibiotics is usual in Intensive Care Unit (ICU) patients with secondary peritonitis. Carbapenems are widely proposed by recent guidelines contrasting with current antibiotic stewardship policies of carbapenem-sparing. However, prognosis of inappropriate IAT remains unclear in these patients and broad-spectrum antibiotics are probably overused. We aimed to assess the role of inappropriate IAT in ICU patients with secondary peritonitis and the use of carbapenems in our IAT regimens.

METHODS

We performed a retrospective analysis during a six-year period including 131 ICU patients with secondary peritonitis. We collected data concerning comorbidities, source and severity of peritonitis, management of IAT, peritoneal samples and outcome.

RESULTS

Forty-one patients presented with community acquired peritonitis (CAP) and 90 with postoperative peritonitis (POP). Thirty-seven (28.2%) patients died during ICU stay. IAT was inappropriate in 35 (26.7%) patients. Inappropriate IAT was not associated with reduced survival with respectively 26 (27%) deaths when IAT was adequate and 11 (31.4%) deaths when IAT was inadequate (P=0.87). Inappropriate IAT was not associated with the need of re-operation and duration of ICU stay. Carbapenems were delivered in 29 patients but were only necessary for eight patients without alternative treatment.

CONCLUSIONS

In our study, inappropriate IAT was not associated with a worse prognosis and carbapenems were overused. Extensive delivery of carbapenems proposed by recent guidelines could be reconsidered in the management of these patients.

Advances in the pharmacological management of bacterial peritonitis

Introduction: Bacterial peritonitis is an infection with high mortality if not treated immediately. In the absence of an intraabdominal source of infection, bacterial peritonitis may arise in patients with liver cirrhosis, in patients on peritoneal dialysis (PD) for end-stage renal disease or in patients with tuberculosis. In patients with cirrhosis, bacterial peritonitis may trigger acute on chronic liver failure with substantial mortality despite optimal treatment. In patients on PD, peritonitis may make continuation of PD impossible, necessitating the switch to hemodialysis.Areas covered: Recovery from peritonitis and prevention of complications depend on timely pharmacological management. Challenges are the broad microbiological spectrum with growing rates of antimicrobial resistance, the underlying chronic liver or kidney failure and high rates of relapse. The authors provide a review of predisposing conditions, diagnosis, and prevention of bacterial peritonitis with a particular focus on the pharmacological management.Expert opinion: Diagnosis of the type of bacterial peritonitis is essential to pharmacological management. In patients with spontaneous bacterial peritonitis, broad-spectrum antibiotics should be given intravenously in conjunction with albumin. In patients on PD, antibiotic therapy should be preferably applied intraperitoneally with empirical coverage of gram-positive and gram-negative bacteria. Secondary peritonitis usually requires surgical or interventional treatment.

Antimicrobial Lessons From a Large Observational Cohort on Intra-abdominal Infections in Intensive Care Units

Severe intra-abdominal infection commonly requires intensive care. Mortality is high and is mainly determined by disease-specific characteristics, i.e. setting of infection onset, anatomical barrier disruption, and severity of disease expression. Recent observations revealed that antimicrobial resistance appears equally common in community-acquired and late-onset hospital-acquired infection. This challenges basic principles in anti-infective therapy guidelines, including the paradigm that pathogens involved in community-acquired infection are covered by standard empiric antimicrobial regimens, and second, the concept of nosocomial acquisition as the main driver for resistance involvement. In this study, we report on resistance profiles of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterococcus faecalis and Enterococcus faecium in distinct European geographic regions based on an observational cohort study on intra-abdominal infections in intensive care unit (ICU) patients. Resistance against aminopenicillins, fluoroquinolones, and third-generation cephalosporins in E. coli, K. pneumoniae and P. aeruginosa is problematic, as is carbapenem-resistance in the latter pathogen. For E. coli and K. pneumoniae, resistance is mainly an issue in Central Europe, Eastern and South-East Europe, and Southern Europe, while resistance in P. aeruginosa is additionally problematic in Western Europe. Vancomycin-resistance in E. faecalis is of lesser concern but requires vigilance in E. faecium in Central and Eastern and South-East Europe. In the subcohort of patients with secondary peritonitis presenting with either sepsis or septic shock, the appropriateness of empiric antimicrobial therapy was not associated with mortality. In contrast, failure of source control was strongly associated with mortality. The relevance of these new insights for future recommendations regarding empiric antimicrobial therapy in intra-abdominal infections is discussed.

Review of Colonic Anastomotic Leakage and Prevention Methods

Although surgeries involving anastomosis are relatively common, anastomotic leakages are potentially deadly complications of colorectal surgeries due to increased risk of morbidity and mortality. As a result of the potentially fatal effects of anastomotic leakages, a myriad of techniques and treatments have been developed to treat these unfortunate cases. In order to better understand the steps taken to treat this complication, we have created a composite review involving some of the current and best treatments for colonic anastomotic leakage that are available. The aim of this article is to present a background review of colonic anastomotic leakage, as well as current strategies to prevent and treat this condition, for a broader audience, including scientist, engineers, and especially biomedical engineers.

Hydrophilic polymer-based anti-biofouling coatings: Preparation, mechanism, and durability

Anti-biofouling materials that combat microorganism attachment have been intensively studied due to the ever-growing demand on smart and durable coatings. Although various hydrophilic polymer surfaces demonstrated superior anti-biofouling properties, their practical application was hampered by the undesired mechanical vulnerability and complicated fabrication process. In this review, we summarized the mechanically and chemically robust anti-biofouling coatings into six strategies namely (i) 3D-grafted coatings, (ii) hierarchical spheres-based coatings, (iii) inorganic nanomaterials-reinforced coatings, (iv) hydrolysis-based coating, (v) semi-interpenetrating structure-based coatings, and (vi) layer-by-layer (LbL) assembled coatings. The anti-biofouling efficacy and durability of these coatings over a series of challenges were also comprehensively presented. The purpose of this review is to inspire researchers to develop novel anti-biofouling coatings for future practical applications.

In Vitro Activity of Eravacycline against Gram-Negative Bacilli Isolated in Clinical Laboratories Worldwide from 2013 to 2017

Eravacycline is a novel, fully synthetic fluorocycline antibiotic developed for the treatment of serious infections, including those caused by multidrug-resistant (MDR) pathogens. Here, we evaluated the in vitro activities of eravacycline and comparator antimicrobial agents against a global collection of frequently encountered clinical isolates of Gram-negative bacilli. The CLSI broth microdilution method was used to determine MIC data for isolates of Enterobacterales (n = 13,983), Acinetobacter baumannii (n = 2,097), Pseudomonas aeruginosa (n = 1,647), and Stenotrophomonas maltophilia (n = 1,210) isolated primarily from respiratory, intra-abdominal, and urinary specimens by clinical laboratories in 36 countries from 2013 to 2017. Susceptibilities were interpreted using both CLSI and EUCAST breakpoints. Multidrug-resistant (MDR) isolates were defined by resistance to agents from ≥3 different antimicrobial classes. The MIC₉₀s ranged from 0.25 to 1 μg/ml for Enterobacteriaceae and were 1 μg/ml for A. baumannii and 2 μg/ml for S. maltophilia, Proteus mirabilis, and Serratia marcescens Eravacycline's potency was up to 4-fold greater than that of tigecycline against genera/species of Enterobacterales, A. baumannii, and S. maltophilia The MIC₉₀s for five of six individual genera/species of Enterobacterales and A. baumannii were within 2-fold of the MIC₉₀s for their respective subsets of MDR isolates, while the MDR subpopulation of Klebsiella spp. demonstrated 4-fold higher MIC₉₀s. Eravacycline demonstrated potent in vitro activity against the majority of clinical isolates of Gram-negative bacilli, including MDR isolates, collected over a 5-year period. This study further underscores the potential benefit of eravacycline in the treatment of infections caused by MDR Gram-negative pathogens.

Management of anastomotic leakage after rectal surgery: a review article

Anastomotic leaks (ALs) are associated with increased perioperative morbidity and mortality, prolonged length of stay, higher readmission rates, the potential need for further operative interventions, and unintended permanent stomas; resulting in increased hospital costs and resource use, and decreased quality of life. This review article is to present definition, diagnosis and management strategies for AL after rectal surgery.

Outcome and Adequacy of Empirical Antibiotherapy in Post-Operative Peritonitis: A Retrospective Study

Background: Empirical antibiotherapy (EA) should target all bacteria in post-operative peritonitis (PP). Nevertheless, recent studies failed to prove a link between adequacy of EA and prognosis of PP. We sought to confirm this loss of association between adequate EA and prognosis and to analyze the evolution of patients' characteristics and antimicrobial strategies. Methods: This is was retrospective study. Patients with a positive fungal culture were excluded. The cohort was divided into two time periods. Data of survivors and non-survivors were compared within each time period. Differences between the two periods were assessed. A multivariable analysis searched for parameters associated with a higher hospital mortality rate. Results: Two hundred fifty-one patients were included, with 92 patients in the first period (P1) and 152 patients in the second period (P2). Inadequate EA was associated with a worse outcome only in P1. The multivariable analysis in the whole cohort showed that inadequate EA was associated with a higher mortality rate. When the differences noticed between the two periods were entered in the model (presence of resistant gram-positive cocci and EA comprising glycopeptides), inadequate EA was no longer associated with worse outcome. In P1, the most severe patients had more resistant bacteria, hence, had a higher rate of inadequate EA. This artifact disappeared in P2, during which broader antibiotherapies with triple EA were more often prescribed for the most severe patients. Conclusion: This study showed that the link between inadequate EA and outcome of patients with PP was at least partly artifactual in older studies.

Post-operative abdominal infections: epidemiology, operational definitions, and outcomes

Postoperative abdominal infections are an important and heterogeneous health challenge in intensive care units (ICU) and encompass postoperative infectious processes developing within the abdominal cavity that may be caused by either bacterial or fungal pathogens. In this narrative review, we discuss postoperative bacterial and fungal abdominal infections, covering also multidrug-resistant (MDR) pathogens. We also cover clinically preeminent aspects such as the definition of postoperative abdominal infections, which still remains difficult owing to their heterogeneity in patient characteristics, clinical presentation, ecology and antimicrobial treatment. With regard to treatment, modifiable factors such as source control and antimicrobial therapy play a key role in influencing the prognosis of postoperative abdominal infections, but several conditions may hamper their correct application; thus efforts should necessarily be devoted towards improving their appropriateness and timing. Hot topics regarding the characteristics and management of postoperative abdominal infections are discussed in this narrative review.

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.

Vancomycin in the treatment of adult intra-abdominal infections: do we have strong evidences?

The management of intra-abdominal infections (IAIs) primarily includes adequate antimicrobial therapy and appropriate source control. Vancomycin is a fundamental and most effective antimicrobial agent. The aim of this study is to search and evaluate the quality of clinical evidences regarding the exclusive use of vancomycin for the management of adult IAIs. For this purpose, we first summarized the recommendations on exclusive use of vancomycin in adult IAIs from six leading guidelines and excavated the relevant supporting references. We subsequently conducted a literature search to screen eligible clinical studies in this field for possible systematic review. Our investigation demonstrates that the exclusive use of vancomycin is recommended in restricted indications, that is, IAIs caused by Enterococcus spp. or methicillin-resistant Staphylococcus aureus. However, the supporting references in the guidelines are more subjective instead of objective, which mainly originate from experts’ personal experiences or from the therapeutic efficacy of vancomycin in other types of infections rather than in IAIs. Furthermore, our literature search fails to find high-level evidence. In conclusion, current low-level evidences are inadequate to elicit strong recommendations on the exclusive use of vancomycin in the treatment of adult IAIs. Our study would be helpful for the rational use of vancomycin and deceleration of the emerging vancomycin resistance rates.

Colorectal Surgical Site Infections and Their Causative Pathogens: Differences between Left- and Right-Side Resections

BACKGROUND

Surgical site infections (SSIs), after colorectal resection, pose a significant burden. Recognition of the spectrum of potentially involved pathogens is crucial for determining correct antibiotic prophylaxis. This study aimed to determine whether the distribution of SSI-associated pathogens depends on the location of the colorectal resection.

METHODS

We retrospectively categorized 2713 consecutive colon resections as left- or right-side operations, identified patients having concurrent peritonitis or development of postoperative SSIs and peritonitis, and assigned all subcutaneously and intra-abdominally isolated pathogens according to the location of the resection.

RESULTS

Gram-positive cocci (especially enterococci) and gram-negative bacilli (especially Pseudomonas aeruginosa) were isolated more frequently from patients in whom SSIs developed after left-side resections than after right-side resections (52.5% vs. 32.6%, p < 0.01 and 15.9% vs. 6.7%, p < 0.01, respectively); enterococci were the causative organisms in a large percentage of SSIs (46.3%). Moreover, intra-abdominal P. aeruginosa and Candida spp. were isolated more frequently during left-side resections than during right-side operations in patients with peritonitis (15.8% vs. 6.3%, p = 0.02 and 14.3% vs. 5.3%, p = 0.02, respectively).

CONCLUSIONS

Our results indicate that differences exist in the distribution of pathogens after left- or right-side colorectal resections. Our data further suggest that gram-positive cocci play an important role in SSIs occurring after colorectal resections; therefore, antibiotic prophylaxis should emphasize their coverage. Further, enterococcal coverage may be especially advantageous during left-side resections.

[Spectrum of pathogens in postoperative complications of visceral surgery : The problem of multidrug resistance]

In general surgery the etiology of surgical site infections has not significantly changed over the last 30 years. Gram-positive bacteria, e.g. coagulase negative staphylococci (CNS), Staphylococcus aureus and Enterococcus spp. as well as Gram-negative bacteria, e.g. Escherichia coli, Enterobacter spp., Klebsiella spp. and Pseudomonas aeruginosa, are the most common findings. Although in general surgery 10% of the S. aureus causing postoperative wound infections were methicillin resistant (MRSA), no cases of multidrug-resistant Gram-negative (MRGN) bacteria were reported. Yeasts (particularly Candida spp.) are rarely the pathogen causing surgical site infections (≤3%) and concomitant risk factors are typical (e.g. diabetes, chemotherapy, immunosuppression and malnutrition). Viruses are rarely the cause of surgical site infections. Transmission can occur by HBV, HCV or HIV positive surgical staff or in organ transplantations and postoperative reactivation of persistent infections is possible (especially for HBV, HCV, CMV, EBV and HIV). The principles for prevention of surgical site infections are dealt with as consequences of preoperative colonization by MRSA, methicillin-sensitive S. aureus (MSSA) and MRGN and reviewed with respect to screening, perioperative antibiotic prophylaxis and decolonization. In nosocomial peritonitis, the selection of antibiotics should consider previous antibiotic treatment. A single intra-abdominal detection of Candida spp. usually does not require antimycotic treatment in postoperatively stable and immunocompetent patients but is recommended in severe community-acquired or nosocomial peritonitis. Viral infections can be avoided by screening of organ donors and serological surveillance of surgery personnel.

[Not Available]

Bacterial resistance is a major concern and the proper use of antibiotics is a global public health priority. Inappropriate use of antibiotic therapy can have serious ecological and pharmaco-economic consequences. The objective of our work was to study the reevaluation of probabilistic antibiotherapy in the burns intensive care unit. A prospective study concerning the clinical-biological reassessment of antibiotic therapy was set up in the burns intensive care unit at the Military Hospital Instruction Mohammed V of Rabat. The data was collected over a period of 6 months, from June 1, 2017 to November 30, 2017. During the study period, 142 patients received an antibiotic prescription. Only 68 serious hospitalized septic patients were included in our study. The population was predominantly male (75%). The average age of our patients was 36 years, ranging from 15 to 56 years old. The average length of hospitalization in intensive care was 10 days. Of the 68 antibiotic regimens implemented, the reassessment rate was 72.06%, with 75% justified treatment rates, and 25% not justified. Therapeutic de-escalation was performed in 8 cases (11.76%), when it could have been performed 25 times (36.76%). This is justified by the nosocomial context of the burns intensive care unit with a bacterial ecosystem of BMR type (Klebsiella pneumoniae, Acinetobacter baumanii, Escherichia coli and Staphylococcus coagulase negative), which restricts the choice of antibiotic therapy to some molecules. Clinico-biological re-evaluation of antibiotic therapy is essential to fight the misuse of antibiotics. This study allowed us to evaluate the re-evaluation practices of antibiotic therapy at 48-72h in burns resuscitation. Subsequently, several actions were carried out: the appointment of a pharmacist in antibiotherapy within the Pole Pharmacy of the Mohammed V Military Hospital in Rabat, the activation of an Anti-Infectious Committee and the dispensing of antibiotics via Pyxis MedStation.

Epidemiology and Risk Factors for Isolation of Multi-Drug-Resistant Organisms in Patients with Complicated Intra-Abdominal Infections

BACKGROUND

Patients with complicated intra-abdominal infections (cIAIs) caused by multi-drug-resistant organisms (MDROs) have been identified as being at increased risk for adverse outcomes. Prompt identification and stratification of these patients is essential in the clinical management, allowing the physician timely optimization of empiric antimicrobial therapy while awaiting results of intra-operative cultures to streamline antibiotic treatment.

METHODS

The study is a secondary analysis from two prospective multi-center color surveillance studies. It included all consecutively hospitalized adult patients undergoing surgical procedures, interventional drainage, or conservative treatment with cIAIs, with positive cultures performer on intra-operative samples of peritoneal fluid or purulent exudate/discrete abscesses. Patients with pancreatitis and primary peritonitis were excluded. A case-control approach has been used to evaluate the factors associated with the isolation of a MDRO in enrolled patients.

RESULTS

Among 1986 patients included in the study, a total of 3534 micro-organisms were isolated from intra-peritoneal fluid samples; in 46.5% of cultures, two or more pathogens were identified. The MDROs represented 9.8% of the total of isolated micro-organisms. The overall incidence rate of MDROs was 13.9%. The MDROs were more frequently isolated in patients with health-care-associated cIAIs (25.4%). Multi-nomial logistic regression analysis of risk factors demonstrated that statistically significant risk factors independently associated with the occurrence of MDROs were previous antimicrobial therapy administered within seven days before operation, presence of severe cardiovascular disease, white blood cell count <4000/mL or >12,000/mL, cIAI acquired in a healthcare setting, and inadequate source control.

CONCLUSIONS

The study showed that knowledge of five easily recognizable variables-assessable on hospital admission or as soon as the surgical intervention is concluded-might guide the surgeon to identify patients with cIAIs caused by MDROs, and therefore to choose the most adequate empiric antimicrobial therapy for them.

MICROBIOLOGICAL SPECTRE OF TERTIARY PERITONITIS AS A COMPONENT OF ITS DIAGNOSTICS AND TREATMENT

The aim of the research was to investigate the microbial spectre of tertiary peritonits (TP) and its antibiotic resistance as the way to improve the diagnostics and treatment of TP. Materials and methods. Prospective research enrolled 109 patients with secondary peritonitis. Tertiary peritonitis developed in 18,3 % of cases. Samples of peritoneal exudate had been drawn upon index operation, relaparotomy and on the day of diagnosis of TP. Blood sampling was performed in patients with persistent fever, impaired consciousness, prolonged (>4 days) discharge from drainage tubes and on the 1st day of diagnosis of TP. Antibacterial susceptibility was evaluated using Hinton-Müller media. Results and discussion. Patients were divided into 2 groups: with secondary peritonitis (89) and with TP (20). In TP group, cultivation of 76,2 % of primary specimens resulted in replantable and identifiable growth, presenting a shift towards Gram-negative flora and higher incidence of Candida albicans. Following the development of TP, hemocultures were positive in 15,1 %, presented mainly by Proteus spp. and non-albicans Candida spp. Second-group carbapenems, tigecycline and piperacillin-tazobactam had shown the highest activity in pathogens of TP. Caspofungin proved to be the most potent antifungal agent, especially towards non-albicans Candida spp. Antibiotic resistance in TP group was marked in 63,8 %. Conclusions. Tertiary peritonitis is one of the most severe forms of abdominal sepsis with highest mortality. Causing pathogenic flora in case of TP is mainly Gram-negative and coccal with high rates of antibiotic resistance both in vitro and in vivo. Fungi, presented predominantly by Candida non-albicans substrains, show an increasing content in peritoneal exudate and major effect upon mortality in TP. In case of TP, a significant percent of peritoneal specimens do not provide any culture growth despite of observing stringent sampling, transportation and cultivation rules. Antimicrobial therapy of TP can never be standardized and should always be thoroughly based upon regular and proper peritoneal and blood sampling.

The Surgical Infection Society Revised Guidelines on the Management of Intra-Abdominal Infection

BACKGROUND

Previous evidence-based guidelines on the management of intra-abdominal infection (IAI) were published by the Surgical Infection Society (SIS) in 1992, 2002, and 2010. At the time the most recent guideline was released, the plan was to update the guideline every five years to ensure the timeliness and appropriateness of the recommendations.

METHODS

Based on the previous guidelines, the task force outlined a number of topics related to the treatment of patients with IAI and then developed key questions on these various topics. All questions were approached using general and specific literature searches, focusing on articles and other information published since 2008. These publications and additional materials published before 2008 were reviewed by the task force as a whole or by individual subgroups as to relevance to individual questions. Recommendations were developed by a process of iterative consensus, with all task force members voting to accept or reject each recommendation. Grading was based on the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) system; the quality of the evidence was graded as high, moderate, or weak, and the strength of the recommendation was graded as strong or weak. Review of the document was performed by members of the SIS who were not on the task force. After responses were made to all critiques, the document was approved as an official guideline of the SIS by the Executive Council.

RESULTS

This guideline summarizes the current recommendations developed by the task force on the treatment of patients who have IAI. Evidence-based recommendations have been made regarding risk assessment in individual patients; source control; the timing, selection, and duration of antimicrobial therapy; and suggested approaches to patients who fail initial therapy. Additional recommendations related to the treatment of pediatric patients with IAI have been included.

SUMMARY

The current recommendations of the SIS regarding the treatment of patients with IAI are provided in this guideline.

Specific Clinical Profile and Risk Factors for Mortality in General Surgery Patients with Infections by Multi-Drug-Resistant Gram-Negative Bacteria

BACKGROUND

The incidence of gram-negative multi-drug-resistant (MDR) infections is increasing worldwide. This study sought to determine the incidence, clinical profiles, risk factors, and mortality of these infections in general surgery patients.

PATIENTS AND METHODS

All general surgery patients with a clinical infection by gram-negative MDR bacteria were studied prospectively for a period of five years (2007-2011). Clinical, surgical, and microbiologic parameters were recorded, with a focus on the identification of risk factors for MDR infection and mortality.

RESULTS

Incidence of MDR infections increased (5.6% to 15.2%) during the study period; 106 patients were included, 69.8% presented nosocomial infections. Mean age was 65 ± 15 years, 61% male. Extended-spectrum β-lactamases (ESBL) Escherichia coli was the most frequent MDR bacteria. Surgical site infections and abscesses were the most common culture locations. The patients presented multiple pre-admission risk factors and invasive measures during hospitalization. Mortality was 15%, and related to older age (odds ratio [OR] 1.07), malnutrition (OR 13.5), chronic digestive conditions (OR 4.7), chronic obstructive pulmonary disease (OR 3.9), and surgical re-intervention (OR 9.2).

CONCLUSION

Multi-drug resistant infections in the surgical population are increasing. The most common clinical profile is a 65-year-old male, with previous comorbidities, who has undergone a surgical intervention, intensive care unit (ICU) admission, and invasive procedures and who has acquired the MDR infection in the nosocomial setting.

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.

Current outcomes and predictors of treatment failure in patients with surgical site infection after elective colorectal surgery. A multicentre prospective cohort study

OBJECTIVE

To determine current outcomes and predictors of treatment failure among patients with surgical site infection (SSI) after colorectal surgery.

METHODS

A multicentre observational prospective cohort study of adults undergoing elective colorectal surgery in 10 Spanish hospitals (2011-2014). Treatment failure was defined as persistence of signs/symptoms of SSI or death at 30 days post-surgery.

RESULTS

Of 3701 patients, 669 (18.1%) developed SSI; 336 (9.1%) were organ-space infections. Among patients with organ-space SSI, 81.2% required source control: 60.4% reoperation and 20.8% percutaneous/transrectal drainage. Overall treatment failure rate was 21.7%: 9% in incisional SSIs and 34.2% in organ-space SSIs (p < 0.001). Median length of stay was 15 days (IQR 9-22) for incisional SSIs and 24 days (IQR 17-35) for organ-space SSIs (p < 0.001). One hundred and twenty-seven patients (19%) required readmission and 35 patients died (5.2%). Risk factors for treatment failure among patients with organ-space SSI were age ≥65 years (OR 1.83, 95% CI: 1.07-1.83), laparoscopy (OR 1.7, 95% CI: 1.06-2.77), and reoperation (OR 2.8, 95% CI: 1.7-4.6).

CONCLUSIONS

Rates of SSI and treatment failure in organ-space SSI after elective colorectal surgery are notably high. Careful attention should be paid to older patients with previous laparoscopy requiring reoperation for organ-space SSI, so that treatment failure can be identified early.

Risk factors for mortality in postoperative peritonitis in critically ill patients

AIM

To identify the risk factors for mortality in intensive care patients with postoperative peritonitis (POP).

METHODS

This was a retrospective analysis using a prospective database that includes all patients hospitalized in a surgical intensive care unit for POP from September 2006 to August 2011. The data collected included demographics, comorbidities, postoperative severity parameters, bacteriological findings, adequacy of antimicrobial therapy and surgical treatments. Adequate source control was defined based on a midline laparotomy, infection source control and intraoperative peritoneal lavage. The number of reoperations needed was also recorded.

RESULTS

A total of 201 patients were included. The overall mortality rate was 31%. Three independent risk factors for mortality were identified: The Simplified Acute Physiological II Score (OR = 1.03; 95%CI: 1.02-1.05, P < 0.001), postoperative medical complications (OR = 6.02; 95%CI: 1.95-18.55, P < 0.001) and the number of reoperations (OR = 2.45; 95%CI: 1.16-5.17, P = 0.015). Surgery was considered as optimal in 69% of the cases, but without any significant effect on mortality.

CONCLUSION

The results from the large cohort in this study emphasize the role of the initial postoperative severity parameters in the prognosis of POP. No predefined criteria for optimal surgery were significantly associated with increased mortality, although the number of reoperations appeared as an independent risk factor of mortality.

The management of intra-abdominal infections from a global perspective: 2017 WSES guidelines for management of intra-abdominal infections

Intra-abdominal infections (IAIs) are common surgical emergencies and have been reported as major contributors to non-trauma deaths in the emergency departments worldwide. The cornerstones of effective treatment of IAIs are early recognition, adequate source control, and appropriate antimicrobial therapy. Prompt resuscitation of patients with ongoing sepsis is of utmost important. In hospitals worldwide, non-acceptance of, or lack of access to, accessible evidence-based practices and guidelines result in overall poorer outcome of patients suffering IAIs. The aim of this paper is to promote global standards of care in IAIs and update the 2013 WSES guidelines for management of intra-abdominal infections.

Characteristics and outcomes of anti-infective de-escalation during health care-associated intra-abdominal infections

Background

De-escalation is strongly recommended for antibiotic stewardship. No studies have addressed this issue in the context of health care-associated intra-abdominal infections (HCIAI). We analyzed the factors that could interfere with this process and their clinical consequences in intensive care unit (ICU) patients with HCIAI.

Methods

All consecutive patients admitted for the management of HCIAI who survived more than 3 days following their diagnosis, who remained in the ICU for more than 3 days, and who did not undergo early reoperation during the first 3 days were analyzed prospectively in an observational, single-center study in a tertiary care university hospital.

Results

Overall, 311 patients with HCIAI were admitted to the ICU. De-escalation was applied in 110 patients (53 %), and no de-escalation was reported in 96 patients (47 %) (escalation in 65 [32 %] and unchanged regimen in 31 [15 %]). Lower proportions of Enterococcus faecium, nonfermenting Gram-negative bacilli (NFGNB), and multidrug-resistant (MDR) strains were cultured in the de-escalation group. No clinical difference was observed at day 7 between patients who were de-escalated and those who were not. Determinants of de-escalation in multivariate analysis were adequate empiric therapy (OR 9.60, 95 % CI 4.02–22.97) and empiric use of vancomycin (OR 3.39, 95 % CI 1.46–7.87), carbapenems (OR 2.64, 95 % CI 1.01–6.91), and aminoglycosides (OR 2.31 95 % CI 1.08–4.94). The presence of NFGNB (OR 0.28, 95 % CI 0.09–0.89) and the presence of MDR bacteria (OR 0.21, 95 % CI 0.09–0.52) were risk factors for non-de-escalation. De-escalation did not change the overall duration of therapy. The risk factors for death at day 28 were presence of fungi (HR 2.64, 95 % CI 1.34–5.17), Sequential Organ Failure Assessment score on admission (HR 1.29, 95 % CI 1.16–1.42), and age (HR 1.03, 95 % CI 1.01–1.05). The survival rate expressed by a Kaplan-Meier curve was similar between groups (log-rank test p value 0.176).

Conclusions

De-escalation is a feasible option in patients with polymicrobial infections such as HCIAI, but MDR organisms and NFGNB limit its implementation.

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.

Basis for selecting optimum antibiotic regimens for secondary peritonitis

Adequate management of severely ill patients with secondary peritonitis requires supportive therapy of organ dysfunction, source control of infection and antimicrobial therapy. Since secondary peritonitis is polymicrobial, appropriate empiric therapy requires combination therapy in order to achieve the needed coverage for both common and more unusual organisms. This article reviews etiological agents, resistance mechanisms and their prevalence, how and when to cover them and guidelines for treatment in the literature. Local surveillances are the basis for the selection of compounds in antibiotic regimens, which should be further adapted to the increasing number of patients with risk factors for resistance (clinical setting, comorbidities, previous antibiotic treatments, previous colonization, severity…). Inadequate antimicrobial regimens are strongly associated with unfavorable outcomes. Awareness of resistance epidemiology and of clinical consequences of inadequate therapy against resistant bacteria is crucial for clinicians treating secondary peritonitis, with delicate balance between optimization of empirical therapy (improving outcomes) and antimicrobial overuse (increasing resistance emergence).

Positive peritoneal fluid fungal cultures in postoperative peritonitis after bariatric surgery

Postoperative peritonitis (POP) is a common surgical complication after bariatric surgery (BS). We assessed the importance of positive fungal cultures in these cases of POP admitted to the intensive care unit. Clinical features and outcome were compared in 25 (41%) Candida-positive patients (6 (22%) fluconazole-resistant Candida glabrata) and 36 patients without Candida infection. Candida infections were more commonly isolated in late-onset peritonitis and were often associated with multidrug-resistant bacteria. Risk factors for intensive care unit mortality (19.6%) were diabetes and superobesity. Candida infections, including fluconazole-resistant strains, are common in POP after BS. These data encourage the empirical use of a broad-spectrum antifungal agent.

Guidelines for management of intra-abdominal infections

Intra-abdominal infections are one of the most common gastrointestinal emergencies and a leading cause of septic shock. A consensus conference on the management of community-acquired peritonitis was published in 2000. A new consensus as well as new guidelines for less common situations such as peritonitis in paediatrics and healthcare-associated infections had become necessary. The objectives of these Clinical Practice Guidelines (CPGs) were therefore to define the medical and surgical management of community-acquired intra-abdominal infections, define the specificities of intra-abdominal infections in children and describe the management of healthcare-associated infections. The literature review was divided into six main themes: diagnostic approach, infection source control, microbiological data, paediatric specificities, medical treatment of peritonitis, and management of complications. The GRADE(®) methodology was applied to determine the level of evidence and the strength of recommendations. After summarising the work of the experts and application of the GRADE(®) method, 62 recommendations were formally defined by the organisation committee. Recommendations were then submitted to and amended by a review committee. After 2 rounds of Delphi scoring and various amendments, a strong agreement was obtained for 44 (100%) recommendations. The CPGs for peritonitis are therefore based on a consensus between the various disciplines involved in the management of these patients concerning a number of themes such as: diagnostic strategy and the place of imaging; time to management; the place of microbiological specimens; targets of empirical anti-infective therapy; duration of anti-infective therapy. The CPGs also specified the value and the place of certain practices such as: the place of laparoscopy; the indications for image-guided percutaneous drainage; indications for the treatment of enterococci and fungi. The CPGs also confirmed the futility of certain practices such as: the use of diagnostic biomarkers; systematic relaparotomies; prolonged anti-infective therapy, especially in children.

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.

Dynamic changes of microbial flora and therapeutic consequences in persistent peritonitis

Introduction

Persistent peritonitis is a frequent complication of secondary peritonitis requiring additional reoperations and antibiotic therapy. This situation raises specific concerns due to microbiological changes in peritoneal samples, especially the emergence of multidrug-resistant (MDR) strains. Although this complication has been extensively studied, the rate and dynamics of MDR strains have rarely been analysed.

Methods

We compared the clinical, microbiological and therapeutic data of consecutive ICU patients admitted for postoperative peritonitis either without subsequent reoperation (n = 122) or who underwent repeated surgery for persistent peritonitis with positive peritoneal fluid cultures (n = 98). Data collected on index surgery for the treatment of postoperative peritonitis were compared between these two groups. In the patients with persistent peritonitis, the data obtained at the first, second and third reoperations were compared with those of index surgery. Risk factors for emergence of MDR strains were assessed.

Results

At the time of index surgery, no parameters were able to differentiate patients with or without persistent peritonitis except for increased severity and high proportions of fungal isolates in the persistent peritonitis group. The mean time to reoperation was similar from the first to the third reoperation (range: 5 to 6 days). Septic shock was the main clinical expression of persistent peritonitis. A progressive shift of peritoneal flora was observed with the number of reoperations, comprising extinction of susceptible strains and emergence of 85 MDR strains. The proportion of patients harbouring MDR strains increased from 41% at index surgery, to 49% at the first, 54% at the second (P = 0.037) and 76% at the third reoperation (P = 0.003 versus index surgery). In multivariate analysis, the only risk factor for emergence of MDR strains was time to reoperation (OR 1.19 per day, 95%CI (1.08 to 1.33), P = 0.0006).

Conclusions

Initial severity, presence of Candida in surgical samples and inadequate source control are the major risk factors for persistent peritonitis. Emergence of MDR bacteria is frequent and increases progressively with the number of reoperations. No link was demonstrated between emergence of MDR strains and antibiotic regimens, while source control and its timing appeared to be major determinants of emergence of MDR strains.

Respiratory infections in patients undergoing mechanical ventilation

Lower respiratory tract infections in mechanically ventilated patients are a frequent cause of antibiotic treatment in intensive-care units. These infections present as severe sepsis or septic shock with respiratory dysfunction in intubated patients. Purulent respiratory secretions are needed for diagnosis, but distinguishing between pneumonia and tracheobronchitis is not easy. Both presentations are associated with longlasting mechanical ventilation and extended intensive-care unit stay, providing a rationale for antibiotic treatment initiation. Differentiation of colonisers from true pathogens is difficult, and microbiological data show Staphylococcus aureus and Pseudomonas aeruginosa to be of great concern because of clinical outcomes and therapeutic challenges. Key management issues include identification of the pathogen, choice of initial empirical antibiotic, and decisions with regard to the resolution pattern.

Strategies to improve the outcome of emergency surgery for perforated peptic ulcer

BACKGROUND

Perforated peptic ulcer (PPU) is a common surgical emergency that carries high mortality and morbidity rates. Globally, one-quarter of a million people die from peptic ulcer disease each year. Strategies to improve outcomes are needed.

METHODS

PubMed was searched for evidence related to the surgical treatment of patients with PPU. The clinical registries of trials were examined for other available or ongoing studies. Randomized clinical trials (RCTs), systematic reviews and meta-analyses were preferred.

RESULTS

Deaths from peptic ulcer disease eclipse those of several other common emergencies. The reported incidence of PPU is 3.8-14 per 100,000 and the mortality rate is 10-25 per cent. The possibility of non-operative management has been assessed in one small RCT of 83 patients, with success in 29 (73 per cent) of 40, and only in patients aged less than 70 years. Adherence to a perioperative sepsis protocol decreased mortality in a cohort study, with a relative risk (RR) reduction of 0.63 (95 per cent confidence interval (c.i.) 0.41 to 0.97). Based on meta-analysis of three RCTs (315 patients), laparoscopic and open surgery for PPU are equivalent, but patient selection remains a challenge. Eradication of Helicobacter pylori after surgical repair of PPI reduces both the short-term (RR 2.97, 95 per cent c.i. 1.06 to 8.29) and 1-year (RR 1.49, 1.10 to 2.03) risk of ulcer recurrence.

CONCLUSION

Mortality and morbidity from PPU can be reduced by adherence to perioperative strategies.