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

Antimicrobial de-escalation strategies in hospitalized patients with pneumonia, intra-abdominal infections, and bacteremia

Increasing numbers of serious hospital/healthcare- or community-acquired infections are caused by resistant (often multi-drug resistant) bacterial pathogens. Because delayed or ineffective initial therapy can have severe negative consequences, patients at risk for these types of infections typically receive initial empiric antibiotic therapy with a broad-spectrum regimen covering the most likely pathogens, based on local surveillance data and risk factors for infection with a resistant microorganism. While improving the likelihood of a successful outcome, use of broad-spectrum, often high-dose, empiric antimicrobial therapy also creates pressure for the selection or development of resistant microorganisms, as well as increasing costs and possibly exposing patients to adverse events or collateral damage such as Clostridium difficile-associated disease. De-escalation is a strategy that attempts to balance the competing aims of providing initial empiric therapy that is appropriate and covers the likely pathogens, and limiting antimicrobial exposure and increased risk for emergence of resistant pathogens. More specifically, the de-escalation strategy involves collection of cultures for later microbiological assessment before initiating broad-spectrum empiric therapy covering the most likely pathogens, with the intention of streamlining or de-escalating to a more narrow-spectrum antimicrobial regimen 2-3 days later if warranted by clinical status and culture results. In some cases, negative culture results and subsequent clinical review may allow for termination of initial empiric therapy. In this manner, de-escalation enables more effective targeting of the causative pathogen(s), elimination of redundant therapy, a decrease in antimicrobial pressure for emergence of resistance, and cost savings. This article examines application of the de-escalation strategy to 3 case patients, one with healthcare-associated pneumonia, another with complicated intra-abdominal infection, and a third with central line-associated bacteremia.

Compendium of national guidelines for imaging of the pediatric patient

BACKGROUND

Diagnostic imaging plays an integral role in diagnosing and managing many pediatric disorders, but there is growing concern in both the medical community and the general public about the long-term health effects of ionizing radiation in children, as well as utilization of imaging evaluation. These concerns, coupled with increasing pressure to reduce national health care spending, underscore the need for an assessment of readily available guidelines, especially evidence-based guidelines, for imaging in children.

OBJECTIVE

To generate a list of national medical organization-endorsed guidelines with provisions for imaging the pediatric patient.

MATERIALS AND METHODS

Several resources, including the National Guideline Clearinghouse (NGC) and the Web sites of major medical organizations, were searched for documents that contained specific recommendations for imaging in the pediatric population.

RESULTS

A total of 155 guidelines from 40 medical organizations met inclusion criteria and are represented in our compendium.

CONCLUSIONS

The compendium generated in this study can be used to direct clinical care, inform policy development and improve education of health care personnel. Additionally, the compendium can be used to identify areas of redundancy or deficiency, which may stimulate the reassessment of existing recommendations as well as the creation of new guidelines.

Antimicrobial prescribing in the USA for adult acute pharyngitis in relation to treatment guidelines

RATIONALE, AIMS AND OBJECTIVES

American College of Physicians (ACP) published guidelines for the diagnosis and treatment of acute pharyngitis in adults in 2001. The objective of this study is to characterize antibiotic prescribing patterns in the USA for acute pharyngitis and evaluate concordance with the 2001 ACP pharyngitis treatment guidelines.

METHODS

Patients aged ≥18 years identified with acute pharyngitis via diagnosis codes (ICD-9 CM) were identified from data collected annually (1996-2006) by the National Center for Health Statistics and Centers for Disease Control and Prevention from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey. Total US office visits for acute pharyngitis were estimated. Logistic regression was performed to determine whether antibiotic prescribing was associated with the publishing of the ACP guidelines.

RESULTS

A total of 3791 office visits met study criteria. We extrapolated 78.0 million visits for acute pharyngitis from 1996 to 2006. Antibiotics were prescribed in 62.6% of cases and 7.5% of cases received ACP-recommended antibiotics. There was a significant decrease in the rate of antibiotic prescriptions from 66.5% to 59.1% after publication of ACP guidelines. Univariate analysis showed that antibiotic prescribing decreased by 27% (OR = 0.73, 95% CI 0.55-0.95, P = 0.021). Multivariate analyses confirmed this finding (OR = 0.72, 95% CI 0.56-0.94, P = 0.014). The prescribing of ACP-recommended antibiotics did not significantly change (8.5% to 6.6%, P = 0.519).

CONCLUSIONS

Publishing of ACP guidelines for the diagnosis and treatment of pharyngitis was associated with a decrease in the overall prescribing of antibiotics but not the prescribing of ACP-recommended antibiotics.

Duration of antibiotic therapy for bacteremia: a systematic review and meta-analysis

Introduction

The optimal duration of antibiotic therapy for bloodstream infections is unknown. Shorter durations of therapy have been demonstrated to be as effective as longer durations for many common infections; similar findings in bacteremia could enable hospitals to reduce antibiotic utilization, adverse events, resistance and costs.

Methods

A search of the MEDLINE, EMBASE and COCHRANE databases was conducted for the years 1947-2010. Controlled trials were identified that randomized patients to shorter versus longer durations of treatment for bacteremia, or the infectious foci most commonly causing bacteremia in critically ill patients (catheter-related bloodstream infections (CRBSI), intra-abdominal infections, pneumonia, pyelonephritis and skin and soft-tissue infections (SSTI)).

Results

Twenty-four eligible trials were identified, including one trial focusing exclusively on bacteremia, zero in catheter related bloodstream infection, three in intra-abdominal infection, six in pyelonephritis, thirteen in pneumonia and one in skin and soft tissue infection. Thirteen studies reported on 227 patients with bacteremia allocated to 'shorter' or 'longer' durations of treatment. Outcome data were available for 155 bacteremic patients: neonatal bacteremia (n = 66); intra-abdominal infection (40); pyelonephritis (9); and pneumonia (40). Among bacteremic patients receiving shorter (5-7 days) versus longer (7-21 days) antibiotic therapy, no significant difference was detected with respect to rates of clinical cure (45/52 versus 47/49, risk ratio 0.88, 95% confidence interval [CI] 0.77-1.01), microbiologic cure (28/28 versus 30/32, risk ratio 1.05, 95% CI 0.91-1.21), and survival (15/17 versus 26/29, risk ratio 0.97, 95% CI 0.76-1.23).

Conclusions

No significant differences in clinical cure, microbiologic cure and survival were detected among bacteremic patients receiving shorter versus longer duration antibiotic therapy. An adequately powered randomized trial of bacteremic patients is needed to confirm these findings.

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.

Prevention of infections associated with combat-related thoracic and abdominal cavity injuries

Trauma-associated injuries of the thorax and abdomen account for the majority of combat trauma-associated deaths, and infectious complications are common in those who survive the initial injury. This review focuses on the initial surgical and medical management of torso injuries intended to diminish the occurrence of infection. The evidence for recommendations is drawn from published military and civilian data in case reports, clinical trials, meta-analyses, and previously published guidelines, in the interval since publication of the 2008 guidelines. The emphasis of these recommendations is on actions that can be taken in the forward-deployed setting within hours to days of injury. This evidence-based medicine review was produced to support the Guidelines for the Prevention of Infections Associated With Combat-Related Injuries: 2011 Update contained in this supplement of Journal of Trauma.

Cumulative antibiotic exposures over time and the risk of Clostridium difficile infection

BACKGROUND

Clostridium difficile infection (CDI) is a major cause of hospital-acquired diarrhea and is most commonly associated with changes in normal intestinal flora caused by administration of antibiotics. Few studies have examined the risk of CDI associated with total dose, duration, or number of antibiotics while taking into account the complex changes in exposures over time.

METHODS

A retrospective cohort study conducted from 1 January to 31 December 2005 among hospitalized patients 18 years or older receiving 2 or more days of antibiotics.

RESULTS

The study identified 10,154 hospitalizations for 7,792 unique patients and 241 cases of CDI, defined as the detection of C. difficile toxin in a diarrheal stool sample within 60 days of discharge. We observed dose-dependent increases in the risk of CDI associated with increasing cumulative dose, number of antibiotics, and days of antibiotic exposure. Compared to patients who received only 1 antibiotic, the adjusted hazard ratios (HRs) for those who received 2, 3 or 4, or 5 or more antibiotics were 2.5 (95% confidence interval [CI] 1.6-4.0), 3.3 (CI 2.2-5.2), and 9.6 (CI 6.1-15.1), respectively. The receipt of fluoroquinolones was associated with an increased risk of CDI, while metronidazole was associated with reduced risk.

CONCLUSIONS

Cumulative antibiotic exposures appear to be associated with the risk of CDI. Antimicrobial stewardship programs that focus on the overall reduction of total dose as well as number and days of antibiotic exposure and the substitution of high-risk antibiotic classes for lower-risk alternatives may reduce the incidence of hospital-acquired CDI.

Use of antibiotics alone for treatment of uncomplicated acute appendicitis: a systematic review and meta-analysis

BACKGROUND

The use of antibiotics alone in the treatment of uncomplicated acute appendicitis has been controversial. The present report is based on a systematic review and meta-analysis of existing studies that compared antibiotics treatment to appendectomy in patients with uncomplicated acute appendicitis.

METHODS

A Medline search was performed for studies published between 1970 and 2009. Studies were selected based on specific inclusion and exclusion criteria. Six reports comprised of 1,201 patients were analyzed.

RESULTS

In patients treated with antibiotics alone, 6.9 ± 4.4% failed to respond and required appendectomy, and acute appendicitis recurred in 14.2 ± 10.6%. One appendectomy patient had a recurrence. A normal appendix was found in 7.3 ± 5.1% of patients at appendectomy. Complications were considerably less likely to occur with antibiotic treatment than with appendectomy. Major surgical complications included enterocutaneous fistula and reoperation.

CONCLUSION

In some cases, antibiotic treatment may fail, and there is a risk of recurrence. However, surgically treated patients, including those with the potential for spontaneous resolution and those with a normal appendix, are subjected to the risks of operative morbidity and mortality. Antibiotic therapy incurs significantly fewer complications. Prospective randomized studies are urgently needed to conclusively define the roles of appendectomy and antibiotic treatment in the management of uncomplicated acute appendicitis.

Current strategies in the management of intra-abdominal abscesses in Crohn's disease

Crohn's disease is characterized by inflammation that involves the full thickness of the bowel wall, which can lead to serious complications including intra-abdominal and pelvic abscesses. The combination of an intra-abdominal abscess with active Crohn's disease poses a particular dilemma for the treating physician, who must weigh the benefits of using immunosuppressive therapies for the inflammatory bowel disease against the risks of immunosuppression in the presence of serious abdominal infection. Traditionally, Crohn's-related abscesses were managed with early surgery, which often involved external drainage procedures, bowel resection, and the creation of diverting ostomies in acutely ill patients. Today such abscesses often can be managed initially with antibiotics and percutaneous drainage, with evaluation for the need for delayed surgery in selected patients. With delayed surgery performed electively, the surgeon frequently can resect the diseased bowel and create a primary anastomosis, thus avoiding emergency operations and multistage procedures. In highly selected cases, surgery might be avoided entirely. This report reviews the literature on the pathophysiology and management of intra-abdominal abscesses in Crohn's disease (including the roles of percutaneous drainage, immunosuppressive therapy, and surgery), and provides a suggested approach to the management of patients with this difficult problem.

Outcomes in severe sepsis and patients with septic shock: pathogen species and infection sites are not associated with mortality

OBJECTIVES

We evaluated the respective influence of the causative pathogen and infection site on hospital mortality from severe sepsis related to community-, hospital-, and intensive care unit-acquired infections.

DESIGN

We used a prospective observational cohort 10-yr database. We built a subdistribution hazards model with corrections for competing risks and adjustment for potential confounders including early appropriate antimicrobial therapy.

SETTING

Twelve intensive care units.

PATIENTS

We included 4,006 first episodes of acquisition-site-specific severe sepsis in 3,588 patients. INTEVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS

We included 1562 community-acquired, 1432 hospital-acquired, and 1012 intensive care unit-acquired episodes of severe sepsis. After adjustment, we found no independent associations of the causative organism, multidrug resistance of the causative organism, infection site, or presence of bacteremia with mortality. Early appropriate antimicrobial therapy was consistently associated with better survival in the community-acquired (0.64 [0.51-0.8], p = .0001), hospital-acquired (0.72 [0.58-0.88], p = .0011), and intensive care unit-acquired (0.79 [0.64-0.97], p = .0272) groups.

CONCLUSION

The infectious process may not exert as strong a prognostic effect when severity, organ dysfunction and, above all, appropriateness of early antimicrobials are taken into account. Our findings emphasize the importance of developing valid recommendations for early antimicrobial therapy.

Strategies for reduction in duration of antibiotic use in hospitalized patients

There is a global crisis of antibiotic resistance in part because of the collateral damage of antibiotic use. Reduction in antibiotic consumption is clearly important to minimize this problem. Limiting treatment duration may be the most clinically palatable means of reducing antibiotic consumption. Antimicrobial stewardship programs play an important role in this process. Their effectiveness may be increased by drawing on evidence from randomized controlled trials regarding optimal antibiotic duration. However, in most clinical scenarios, the recommended duration of therapy in published guidelines is based on expert opinion. Biological markers, such as procalcitonin, have been shown to reduce antimicrobial consumption with no adverse outcome in 11 randomized controlled trials. Although procalcitonin may not be the perfect biomarker, the concept of procalcitonin-guided antibiotic discontinuation after clinical stabilization, in conjunction with antimicrobial stewardship programs, appears to be ready for introduction into clinical practice.

Human microbial ecology: lactobacilli, probiotics, selective decontamination

Health care-associated infections are closely associated with different medical interventions which interrupt the balance of human microbiota. The occasional predominance of opportunistic pathogens may lead to their translocation into the lymph nodes and bloodstream, causing endogenous (primary or secondary) hospital infections. The question is raised as to if there is a possibility for prevention of the imbalance of GI microbiota during medical interventions in critically ill patients. Prophylactic selective decontamination of the digestive tract (SDD) simultaneously applies three to four different antimicrobials for the suppression of enteric aerobic microbes, which are potentially pathogenic microorganisms. However, there is no convincing evidence that the indigenous beneficial intestinal microbiota are preserved, resulting in reduced mortality of high-risk patients. In this overview, we have evaluated the antimicrobial treatment guidelines of the Infectious Diseases Society of America (IDSA) for intra-abdominal infections in adults and seniors according to their safety for different Lactobacillus spp. The data from our group and in the literature have shown that all tested lactobacilli strains (nearly one hundred) were insusceptible to metronidazole while different species of lactobacilli of the three fermentation groups expressed particular antibiotic susceptibility to vancomycin, cefoxitin, ciprofloxacin and some new tetracyclines. We have relied on microbial ecology data showing that the GI tracts of adults and the elderly are simultaneously colonised at least with several (four to a maximum of 12) Lactobacillus species expressing variable intrinsic insusceptibility to the aforementioned antimicrobials, according to the provided data in table. This finding offers the possibility of preserving the colonisation of the intestine with some beneficial lactobacilli during antimicrobial treatment in critically ill patients with health care-associated infections. Several probiotic Lactobacillus spp. strains are intrinsically resistant to antimicrobials and can be used during antibacterial therapy, however, their application as an additive to antimicrobial treatment in critically ill patients needs to be investigated in well-designed clinical trials.

Early Diagnosis and Evidence-Based Care of Surgical Sepsis

Sepsis continues to be a common and serious problem among surgical patients. It is a leading cause of both morbidity and mortality in the perioperative period. The early identification of sepsis and the early implementation of evidence-based care can improve outcomes. This focused review will identify ways to improve the early identification of sepsis and discuss the current evidence-based guidelines for the early management of sepsis, severe sepsis, and septic shock in the surgical patients.

Susceptibility of Klebsiella pneumoniae isolates from intra-abdominal infections and molecular characterization of ertapenem-resistant isolates

A total of 2,841 clinical isolates of Klebsiella pneumoniae from intra-abdominal infections worldwide were collected in the Study for Monitoring Antimicrobial Resistance Trends (SMART) during 2008 and 2009. Overall, 22.4% of isolates had extended-spectrum β-lactamases (ESBLs). The most active antibiotics among the 11 tested were imipenem, amikacin, and ertapenem, though even these, like all other comparators, were less consistently active against ESBL-positive isolates than against ESBL-negative isolates. Globally, 6.5% of isolates were ertapenem resistant based on the June 2010 clinical breakpoints published by the Clinical and Laboratory Standards Institute, with MICs of ≥1 μg/ml. Molecular characterization of 43 isolates with ertapenem MICs of ≥4 μg/ml showed that they variously produced CTX-M or SHV ESBLs combined with altered impermeability and/or had KPC (n = 28), OXA-48 (n = 3), or VIM (n = 1) carbapenemases. Further monitoring of ertapenem susceptibility and molecular characterization of ertapenem-resistant isolates are needed.

Characteristics of clinical sepsis reflected in a reliable and reproducible rodent sepsis model

BACKGROUND

Sepsis models are frequently based on induction of peritonitis, with cecal ligation and puncture reflecting the prototypical model. However, there is an ongoing discussion about the limitations of these models due to their variability in progression and outcome. Since standardization is a cornerstone of experimental models, we aimed to develop a reliable and reproducible procedure for induction of peritonitis.

MATERIALS AND METHODS

A human stool batch was processed for -80° storage. For induction of peritonitis in fluid-resuscitated rats, a defined volume of stool suspension from this batch was injected intraperitoneally. For characterization of the model, physiologic and inflammatory changes were evaluated after sepsis induction. Survival analyses with the same batch were repeated in four independent experiments over a time period of 16 mo.

RESULTS

The polymicrobial infection resulted in severe peritoneal inflammation with a systemic increase in cytokines. The mortality rate at 15 h was 29% and this was reproducible over a 16 mo time period. If antibiotic treatment was applied, a 50% survival was achieved. Laboratory markers indicated a progressive multi-organ dysfunction, while blood gas analysis showed respiratory compensation of a metabolic acidosis, and maintenance of PaO(2). Intravital microscopy of the liver revealed an impaired microcirculation. A decreased hemostatic potential was demonstrated by rotational thromboelastometry. Despite clinical recovery within 3 d, surviving animals showed laboratory and histologic signs of persisting inflammation even after 2 wk.

CONCLUSIONS

This model reflects many features of human sepsis. Application of an infectious focus that is both quantitatively and qualitatively defined assures high reproducibility. Moreover, the procedure is simple and can be easily standardized.

Epidemiological characteristics of infections caused by Bacteroides, Prevotella and Fusobacterium species: a prospective observational study

In order to investigate differences among infections due to Gram-negative anaerobic bacteria (Bacteroides, Prevotella and Fusobacterium spp.), clinical, epidemiological, and microbiological data were collected and evaluated from 206 anaerobic infections. The most frequently isolated species was Bacteroides fragilis. The majority of the cases were intra-abdominal infections (49%) followed by skin and soft tissue infections (24.7%). Logistic regression analysis showed that Bacteroides spp. strains were more often isolated from intra-abdominal infections (p = 0.002), whereas Prevotella spp. were isolated more frequently from cases with shorter duration of hospitalization (p = 0.026), and less frequently from bloodstream infections (p = 0.049). In addition, Bacteroides spp. were associated with coinfection due to Enterobacteriaceae species (p = 0.007), whereas Prevotella spp. were associated with coinfection due to Staphylococcus spp. (p = 0.002). Patients with an infection due to B. fragilis, were more frequently admitted in a general surgical ward (p = 0.017), or have been treated with a 2nd generation cephalosporin before anaerobic infection onset (p = 0.05). Total mortality was 10.9% and was associated with bacteremia (p = 0.026), and hematological (p = 0.028), or solid organ malignancy (p = 0.007). Metronidazole resistance was detected only among Prevotella spp. (16.2%) and B. fragilis group (0.8%) isolates. In conclusion, this study indicated differences between infections due to the most frequently isolated Gram-negative anaerobic species, differences that may affect the design and implementation of empirical antimicrobial chemotherapy guidelines.

Antimicrobial treatment of "complicated" intra-abdominal infections and the new IDSA guidelines ? a commentary and an alternative European approach according to clinical definitions

Recently, an update of the IDSA guidelines for the treatment of complicated intraabdominal infections has been published. No guideline can cater for all variations in ecology, antimicrobial resistance patterns, patient characteristics and presentation, health care and reimbursement systems in many different countries. In the short time the IDSA guidelines have been available, a number of practical clinical issues have been raised by physicians regarding interpretation of the guidelines. The main debatable issues of the new IDSA guidelines are described as follows: The authors of the IDSA guidelines present recommendations for the following subgroups of "complicated" IAI: community-acquired intra-abdominal infections of mild-to-moderate and high severity and health care-associated intra-abdominal infections (no general treatment recommendations, only information about antimicrobial therapy of specific resistant bacterial isolates). From a clinical point of view, "complicated" IAI are better differentiated into primary, secondary (community-acquired and postoperative) and tertiary peritonitis. Those are the clinical presentations of IAI as seen in the emergency room, the general ward and on ICU. Future antibiotic treatment studies of IAI would be more clinically relevant if they included patients in studies for the efficacy and safety of antibiotics for the treatment of the above mentioned forms of IAI, rather than conducting studies based on the vague term "complicated" intra-abdominal infections. - The new IDSA guidelines for the treatment of resistant bacteria fail to mention many of new available drugs, although clinical data for the treatment of "complicated IAI" with new substances exist. Furthermore, treatment recommendations for cIAI caused by VRE are not included. This group of diseases comprises enough patients (i.e. the entire group of postoperative and tertiary peritonitis, recurrent interventions in bile duct surgery or necrotizing pancreatitis) to provide specific recommendations for such antimicrobial treatment. - A panel of European colleagues from surgery, intensive care, clinical microbiology and infectious diseases has developed recommendations based on the above mentioned clinical entities with the aim of providing clear therapeutic recommendations for specific clinical diagnoses. An individual patient-centered approach for this very important group of diseases with a substantial morbidity and mortality is essential for optimal antimicrobial treatment.

Current challenges in the management of the infected patient

PURPOSE OF REVIEW

Management of hospital-associated infections (HAIs) has been made more challenging by the increasing proportion of immunocompromised or otherwise severely ill patients and increasing prevalence of antibiotic-resistant pathogens in this environment. This review examines strategies to optimize clinical outcomes and lower healthcare costs for patients with HAIs by focusing on patient-related, pathogen-related, and drug-related factors.

RECENT FINDINGS

Factors have converged to increase the risk of infection with antibiotic-resistant pathogens in the current hospital environment, including the increasing prevalence of resistant species and number of hospitalized patients with conditions increasingly susceptible to infection with drug-resistant bacteria. Although the list of bacterial pathogens associated with HAIs has been fairly constant over time, the prevalence and resistance profile of these individual species continues to evolve. Periodic antibiograms should be utilized to access local patterns of resistance within the different hospital wards. Outcomes for patients with HAIs are optimized with early empiric treatment with an appropriate regimen, selected on the basis of patient characteristics and local resistance patterns. Dosing strategies should be utilized to ensure that the efficacy of an appropriate antibiotic is optimized, by achieving the pharmacodynamic target predictive of its efficacy. Using these strategies improves quality of care and is associated with lower overall healthcare costs.

SUMMARY

Bacterial resistance is an increasing problem in the hospital environment, and has been associated with poorer clinical outcomes and elevated healthcare costs. By using patient characteristics, local antibiograms, and dosing strategies to achieve an optimal pharmacodynamic profile, early appropriate empiric therapy can be utilized to improve clinical outcomes, minimize the development of resistance, and reduce healthcare costs.

Antimicrobial stewardship: bridging the gap between quality care and cost

PURPOSE OF REVIEW

Antibiotic resistance continues to rise, whereas development of new agents to counter it has slowed. A heightened need exists to maintain the effectiveness of currently available agents. This review focuses on the need for better antimicrobial stewardship, expected benefits of well designed antimicrobial stewardship programs (ASPs), and provides suggestions for development of an effective ASP.

RECENT FINDINGS

Healthcare-associated infections (HAIs) are a significant cause of poor treatment outcomes and elevated healthcare and societal costs worldwide. HAIs are often caused by antibiotic-resistant pathogens; overuse of antibiotics has been linked with antibiotic resistance. Benefits of improved antimicrobial stewardship include reduced emergence of antibiotic resistance, limitation of drug-related adverse events, minimization of other consequences of antibiotic use (e.g., superinfection), and reduction of societal and healthcare-related costs. In 2007, the Infectious Diseases Society of America (IDSA) and the Society for Healthcare Epidemiology of America (SHEA) provided guidelines for the development of institutional programs to enhance antimicrobial stewardship. Experiences at The Ohio State University Medical Center (OSUMC) reinforce this message, while providing specific examples of ways to optimize ASP development and implementation. The focus of an ASP should be on improving quality of care, reducing drug resistance, and cost savings. When implementing an ASP, it is important to identify those most likely to resist the ASP, understand their concerns, and develop easy-to-understand messages that address these concerns and highlight the benefits of the proposed changes. Antibiograms play a key role in identifying local and interdepartmental trends in antibiotic susceptibility or resistance. These data are important not only in devising best-treatment practices for the institution, but also in evaluating the impact of a recently implemented ASP. Other measures of the impact of an ASP should include patient outcomes and overall costs or savings.

SUMMARY

Better antimicrobial stewardship is needed to limit the emergence of antibiotic resistance, prolong the effectiveness of currently available agents, improve patient outcomes, and reduce healthcare and societal costs associated with HAIs. Guidelines from the IDSA/SHEA and experiences at OSUMC provide examples of how best to develop an institutional ASP to accomplish these goals.

The Microbiology of Community-acquired Peritonitis in Children

BACKGROUND

microbiologic data are lacking regarding pediatric community-acquired peritonitis (CAP).

METHODS

we conducted a 2-year retrospective single center study. Consecutive children undergoing CAP surgery were included. Microbiology and antimicrobial susceptibility of peritoneal isolates were analyzed.

RESULTS

a total of 70 children from 3 months to 14 years of age were included. A total of 123 bacterial isolates were analyzed. Escherichia coli was the predominant aerobic organism (51% of isolates); 54.8% were susceptible to amoxicillin whereas 90.3% were susceptible to amoxicillin-clavulanate. Anaerobes accounted for 29% of isolates, and 94.3% of strains were susceptible to amoxicillin-clavulanate and 68.5% were susceptible to clindamycin. Pseudomonas aeruginosa was present in 6% of isolates and in 10% of children. The presence of E. coli resistant to amoxicillin or to amoxicillin-clavulanate was the only independent risk factor associated with postoperative peritonitis.

CONCLUSION

microbiology of pediatric CAP is similar to adult CAP with a predominancy of E. coli and anaerobes. P. aeruginosa in peritoneal samples had no apparent influence on the outcome.

WSES consensus conference: Guidelines for first-line management of intra-abdominal infections

Intra-abdominal infections are still associated with high rate of morbidity and mortality.A multidisciplinary approach to the management of patients with intra-abdominal infections may be an important factor in the quality of care. The presence of a team of health professionals from various disciplines, working in concert, may improve efficiency, outcome, and the cost of care.A World Society of Emergency Surgery (WSES) Consensus Conference was held in Bologna on July 2010, during the 1st congress of the WSES, involving surgeons, infectious disease specialists, pharmacologists, radiologists and intensivists with the goal of defining recommendations for the early management of intra-abdominal infections.This document represents the executive summary of the final guidelines approved by the consensus conference.

High rates of quinolone resistance among urinary tract infections in the ED

OBJECTIVES

The objectives of this study are to examine antibiotic resistance rates and to determine appropriate empiric oral antibiotic for patients with urinary tract infections (UTIs) evaluated and discharged from the ED.

METHODS

A retrospective, single-institution chart review study from August 2008 to March 2009 was conducted. Adult patients seen in the ED with UTI were identified for study inclusion from review of microbiology records. Hospitalized or asymptomatic bacteriuria cases were excluded. Health care-associated (HA)-UTI was defined as UTI with indwelling urinary catheters, health care exposure, or urologic procedures within 3 months. Prevalence of causative bacteria, antibiotic resistance rates, and risk factors for quinolone resistance were determined.

RESULTS

There were 337 eligible patients with 83% women. The most common uropathogens among 357 bacterial isolates were Escherichia coli (71%) and Klebsiella spp. (9%). Overall levofloxacin resistance rate was 17%. Resistance rates for HA-UTIs were significantly greater than those for community-associated-UTI: levofloxacin, 38% vs 10%; trimethoprim-sulfamethoxazole, 26% vs 17%; amoxicillin, 53% vs 45%; and amoxicillin-clavulanate, 16% vs 6%. Nitrofurantoin resistance rates were similar (9%). Independent risk factors for levofloxacin resistance were long-term medical conditions (adjusted odds ratio [aOR], 4.23; P = .001), HA-UTI (aOR, 2.56; P = .006), and prior quinolone use within 1 week (aOR, 14.90; P = .02) and within 1 to 4 weeks (aOR, 4.62; P = .04).

CONCLUSIONS

We report high rates of quinolone resistance in ED patients with UTIs at our institution. For patients with risk factors for quinolone resistance, empiric therapy with cephalosporins or nitrofurantoin may be preferred. Urine culture and susceptibility testing should be performed to guide definitive therapy for HA-UTIs.

A multicentre study of antifungal strategies and outcome of Candida spp. peritonitis in intensive-care units

Information on the species causing Candida peritonitis, their in vitro susceptibility, antifungal strategies in this setting and patient outcome is still scarce. AmarCand was a prospective, non-interventional study in 271 adult intensive-care unit (ICU) patients with proven invasive Candida infection who received systemic antifungal therapy (France, 2005-2006). Of these ICU patients, 93 (median age 65 years, simplified acute physiology score II 52) had Candida peritonitis, including 73 nosocomial peritonitis, 53 concomitant bacterial peritoneal infections and 26 candidaemias. Candida species were C. albicans (n = 63/108 isolates, 58%), C. glabrata (n = 22, 20%), C. krusei (n = 9), C. kefyr (n = 5), C. parapsilosis (n = 3), C. tropicalis (n = 3), C. ciferii (n = 2) and C. lusitaniae (n = 1). Of tested isolates, 28% were fluconazole-resistant or susceptible dose-dependent (C. albicans 3/32, C. glabrata 9/14, C. krusei 4/4). Empiric antifungal treatment was started 1 day (median) after peritonitis diagnosis, with fluconazole (n = 2 patients), caspofungin (n = 12), voriconazole (n = 3), amphotericin B (n = 2), or a combination (n = 4). Following susceptibility testing, empiric antifungal treatment was judged inadequate in 9/45 (20%) patients and modified in 30 patients (fluconazole was replaced by caspofungin (n = 14) or voriconazole (n = 4)). Mortality in ICU was 38% (35/93) and was not influenced by type of Candida species, fluconazole susceptibility, time to treatment, candidaemia, nosocomial acquisition, or concomitant bacterial infection. No specific factors for death were identified. In summary, a high proportion of fluconazole-resistant or susceptible dose-dependent strains was cultured. These results confirm the high mortality rates of Candida peritonitis and plead for additional investigation in this population. Antifungal treatment for severe cases of Candida peritonitis in ICU patients remains the standard care.