Effect of inappropriate initial empiric antibiotic therapy on outcome of patients with community-acquired intra-abdominal infections requiring surgery

A Change in Nosocomial Infections among Surgical ICU Patients in the COVID-19 Era and MALDI-TOF Mass Spectrometry-A Cross-Sectional Study

During the COVID-19 pandemic, changes occurred within the surgical patient population. An increase in the frequency of resistant Gram-negative bacteria has since been recorded worldwide. After the start of the COVID-19 pandemic, microbiological diagnostics in our institution was performed using MALDI-TOF mass spectrometry. With this study, we wanted to confirm whether it contributed to a greater number of pathogenic bacteria detected in surgical ICU patients. A total of 15,033 samples taken from 1781 surgical patients were compared during the period from 2016 to February 2020 and during the COVID-19 pandemic from March 2020 to February 2023. On patients' admission, pathogenic bacteria were mostly isolated from the respiratory system (43.1% and 44.9%), followed by urine cultures (18.4 vs. 15.4%) before and during the pandemic. After the onset of the COVID-19 pandemic, there was a significant increase in the frequency of isolation of Enterobacter spp. (5.4 before vs. 9%, p = 0.014) and other enterobacteria (6.9 vs. 10.8%, p = 0.017) on patients' admission to the ICU, respectively. Despite this change, mortality in the ICU during the post-COVID-19 period was reduced from 23 to 9.6% (p < 0.001). The frequency of bacterial isolation did not change with the application of MALDI-TOF technology. By identifying the microorganism while simultaneously recognizing some resistance genes, we were able to start targeted therapy earlier. With the application of other infection control methods, MALDI-TOF may have contributed to the reduction in mortality in surgical ICU patients during the COVID-19 pandemic.

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.

Efficacy, safety, and tolerability of antimicrobial agents for complicated intra-abdominal infection: a systematic review and network meta-analysis

BACKGROUND

Which antimicrobial agents provide the optimal efficacy, safety, and tolerability for the empirical treatment of complicated intra-abdominal infection (cIAI) remains unclear but is paramount in the context of evolving antimicrobial resistance. Therefore, updated meta-analyses on this issue are warranted.

METHODS

We systematically searched four major electronic databases from their inception through October 2022. Randomized controlled trials examining antimicrobial agents for cIAI treatment were included. Two reviewers independently assessed the quality of included studies utilizing the Cochrane Collaboration's risk of bias tool as described in the updated version 1 of the Cochrane Collaboration Handbook and extracted data from all manuscripts according to a predetermined list of topics. All meta-analyses were conducted using R software. The primary outcome was clinical success rate in patients with cIAIs.

RESULTS

Forty-five active-controlled trials with low to medium methodological quality and involving 14,267 adults with cIAIs were included in the network meta-analyses. The vast majority of patients with an acute physiology and chronic health evaluation II score < 10 had low risk of treatment failure or death. Twenty-one regimens were investigated. In the network meta-analyses, cefepime plus metronidazole was more effective than tigecycline and ceftolozane/tazobactam plus metronidazole (odds ratio [OR] = 1.96, 95% credibility interval [CrI] 1.05 ~ 3.79; OR = 3.09, 95% CrI 1.02 ~ 9.79, respectively). No statistically significant differences were found among antimicrobial agents regarding microbiological success rates. Cefepime plus metronidazole had lower risk of all-cause mortality than tigecycline (OR = 0.22, 95% CrI 0.05 ~ 0.85). Statistically significant trends were observed favoring cefotaxime plus metronidazole, which exhibited fewer discontinuations because of adverse events (AEs) when compared with eravacycline, meropenem and ceftolozane/tazobactam plus metronidazole (OR = 0.0, 95% CrI 0.0 ~ 0.8; OR = 0.0, 95% CrI 0.0 ~ 0.7; OR = 0.0, 95% CrI 0.0 ~ 0.64, respectively). Compared with tigecycline, eravacycline was associated with fewer discontinuations because of AEs (OR = 0.17, 95% CrI 0.03 ~ 0.81). Compared with meropenem, ceftazidime/avibactam plus metronidazole had a higher rate of discontinuation due to AEs (OR = 2.09, 95% CrI 1.0 ~ 4.41). In pairwise meta-analyses, compared with ceftriaxone plus metronidazole, ertapenem and moxifloxacin (one trial, OR = 1.93, 95% CI 1.06 ~ 3.50; one trial, OR = 4.24, 95% CI 1.18 ~ 15.28, respectively) were associated with significantly increased risks of serious AEs. Compared with imipenem/cilastatin, tigecycline (four trials, OR = 1.57, 95%CI 1.07 ~ 2.32) was associated with a significantly increased risk of serious AEs. According to the surface under the cumulative ranking curve, Cefepime plus metronidazole was more likely to be optimal among all treatments in terms of efficacy and safety, tigecycline was more likely to be worst regimen in terms of tolerability, and eravacycline was more likely to be best tolerated.

CONCLUSION

This study suggests that cefepime plus metronidazole is optimal for empirical treatment of patients with cIAIs and that tigecycline should be prescribed cautiously considering the safety and tolerability concerns. However, it should be noted that data currently available on the effectiveness, safety, and tolerability of antimicrobial agents pertain mostly to lower-risk patients with cIAIs.

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.

Effectiveness of Five Antibiotic Regimens for the Treatment of Intra-Abdominal Infection in Bogotá

Background: Intra-abdominal infection (IAI) results in prolonged in-hospital length-of-stay, critical care unit requirements, and multiple surgical procedures. Several antimicrobial agents are available for treatment of IAI. In Colombia, there are no data on the comparative effectiveness of the different regimens used. Patients and Methods: A multicenter retrospective cohort study was completed in four third-level hospitals by comparing treatment effectiveness of five different antibiotic protocols (ampicillin-sulbactam, clindamycin-amikacin, piperacillin-tazobactam, amikacin-metronidazole, and cefuroxime-metronidazole) in patients with a diagnosis of IAI. Analysis was based on a composed outcome of therapeutic failure (change of antibiotic because of no clinical improvement, requirement of surgical re-intervention, post-operative infection, change of antibiotic because of antimicrobial resistance, and in-hospital mortality). Association of each antibiotic protocol to therapeutic failure was assessed through logistic regression analysis. Results: Five hundred ninety-three individuals were included. Two hundred twenty-nine were prescribed ampicillin-sulbactam; 170, clindamycin-amikacin; 77, amikacin-metronidazole; 83, piperacillin-tazobactam; and 34, cefuroxime-metronidazole. Therapeutic failure rate was 22%. Multivariable analysis showed none of the evaluated antibiotic protocols had an association with the primary outcome. Variables having an association for higher risk were age >70 years old (odds ratio [OR], 2.08; 95% confidence interval [CI], 1.04-4.18); complicated IAI (OR, 3.36; 95% CI, 1.4-8.07); and World Society of Emergency Surgery (WSES) Sepsis Severity Score (OR, 1.31; 95% CI, 1.18-1.45). Adequate source control (OR, 0.16; 95% CI, 0.05-0.45) and hospitalization at Health Center 2 (OR, 0.30; 95% CI, 0.14-0.63) were identified as protective factors. Conclusions: There are no differences between the rate of therapeutic failure among the different antibiotic protocols evaluated. This outcome depends heavily on risk factors related to disease severity when surgical intervention occurs.

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

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

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.

Time to source control and outcome in community-acquired intra-abdominal infections: The multicentre observational PERICOM study

BACKGROUND

Optimal management of community-acquired intra-abdominal infections (IAI) requires timely surgical source control and adequate anti-infective treatment.

OBJECTIVE

To describe the initial management of community-acquired IAI admitted to the emergency department and assess the association between the length of time to either diagnosis or therapeutic procedures and patient outcomes.

DESIGN

A prospective, multicentre, observational study.

SETTING

Thirteen teaching hospitals in France between April 2018 and February 2019.

PATIENTS

Two hundred and five patients aged at least 18 years diagnosed with community-acquired IAI.

MAIN OUTCOME MEASURES

The primary outcome was hospital length of stay. The secondary outcome was hospital mortality.

RESULTS

Patients had a mean age of 56 (± 21) years and a median [interquartile] SAPS II of 26 [17 to 34]. Among the study cohort, 18% were postoperatively transferred to intensive care unit and 7% had died by day 28. Median [IQR] time to imaging, antibiotic therapy and surgery were 4 [2 to 6], 7.5 [4 to 12.5] and 9 [5.5 to 17] hours, respectively. The length of time to surgical source control [0.99, 95% confidence interval (CI), 0.98 to 0.99], SOFA greater than 2 [0.36 (95% CI, 0.26 to 0.651)], age greater than 60 years [0.65 (95% CI, 0.45 to 0.94)], generalized peritonitis [0.7 (95% CI, 0.56 to 0.89)] and laparotomy surgery [0.657 (95% CI, 0.42 to 0.78)] were associated with longer hospital length of stay. The duration of time to surgical source control [1.02 (95% CI, 1.01 to 1.04)], generalized peritonitis [2.41 (95% CI, 1.27 to 4.61)], and SOFA score greater than 2 [6.14 (95% CI, 1.40 to 26.88)] were identified as independent risk factors for 28-day mortality.

CONCLUSION

This multicentre observational study revealed that the time to surgical source control, patient severity and generalized peritonitis were identified as independent risk factors for increased hospital LOS and mortality in community-acquired IAI. Organisational strategies to reduce the time to surgical management of intra-abdominal infections should be further evaluated.

STUDY REGISTRATION

ClinicalTrials.gov on 1 April 2018, NCT03544203.

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.

Updates on bacterial resistance and empirical antibiotics treatment of complicated acute appendicitis in children

OBJECTIVE

Through historical comparison with our previous study published 10 years ago, this paper aims to provide latest analysis of local bacteriology of acute complicated appendicitis and evaluate the effects of early escalation of potent antibiotics on course of postoperative recovery.

METHODS

A 5-year retrospective review of all children receiving emergency laparoscopic appendicectomies for acute appendicitis from December 2014 to November 2019 was conducted.

RESULTS

257 cases of acute appendicitis were included, 126 were complicated appendicitis (38 gangrenous, 88 ruptured). 96 had positive peritoneal swab culture, 53 (42.1%) grew resistant bacterial strains, including extended spectrum beta-lactamase producing E. coli (ESBL E. coli), Pseudomonas aeruginosa, against traditional empirical triple antibiotics. The prevalence had significantly increased over the past decade (p = 0.008). In our patients, piperacillin/tazobactam, ertapenem, gentamicin provided coverage of 69.8%, 45.3% and 45.3% respectively. For patients with early escalation of postoperative antibiotics, no statistical significance was identified in terms of postoperative complications (p = 0.883), or duration of antibiotics (p = 0.0615).

CONCLUSION

Growing prevalence of resistant strains were observed over the decade. Piperacillin/tazobactam provided the best coverage (69.8%) against resistant bacterial strains in our patients. Early escalation of antibiotics failed to reduce postoperative complications and antibiotics duration.

TYPE OF STUDY

Clinical Research, Retrospective Historical Comparative Study Level of Evidence: Level III.

Antibiotic-resistant microorganisms in patients with bloodstream infection of intraabdominal origin: risk factors and impact on mortality

BACKGROUND

Knowledge of resistance patterns is essential to choose empirical treatment. We aimed to determine the risk factors for antibiotic-resistant microorganisms (ARM) in intraabdominal infections (IAI) and their impact on mortality.

METHODS

Retrospective cohort study of patients with bacteremia from IAI origin in a single hospital between January 2006 and July 2017.

RESULTS

A total of 1485 episodes were recorded, including 381 (25.6%) due to ARM. Independent predictors of ARM were cirrhosis (OR 2; [95% CI 1.15-3.48]), immunosuppression (OR 1.49; 1.12-1.97), prior ceftazidime exposure (OR 3.7; 1.14-11.9), number of prior antibiotics (OR 2.33; 1.61-3.35 for 1 antibiotic), biliary manipulation (OR 1.53; 1.02-2.96), hospital-acquisition (OR 2.77; 1.89-4) and shock (OR 1.48; 1.07-2). Mortality rate of the whole cohort was 11.1%. Age (OR 1.03; 1.01-1.04), cirrhosis (OR 2.32; 1.07-4.38), urinary catheter (OR 1.99; 1.17-3.38), ultimately (OR 2.28; 1.47-3.51) or rapidly (OR 13.3; 7.12-24.9) fatal underlying disease, nosocomial infection (OR 2.76; 1.6-4.75), peritonitis (OR 1.95, 1.1-3.45), absence of fever (OR 2.17; 1.25-3.77), shock (OR 5.96; 3.89-9.13), and an ARM in non-biliary infections (OR 2.14; 1.19-3.83) were independent predictors of 30-day mortality. Source control (OR 0.24; 0.13-0.44) and 2015-2017 period (OR 0.29; 0.14-0.6) were protective.

CONCLUSION

Biliary manipulation and septic shock are predictors of ARM. The presence of an ARM from a non-biliary focus is a poor-prognosis indicator. Source control continues to be of paramount importance.

Outcome of community- versus hospital-acquired intra-abdominal infections in intensive care unit: a retrospective study

Background

To compare patients hospitalised in the intensive care unit (ICU) after surgery for community-acquired intra-abdominal infection (CA-IAI) and hospital-acquired intra-abdominal infection (HA-IAI) in terms of mortality, severity and complications.

Methods

Retrospective study including all patients admitted to 2 ICUs within 48 h of undergoing surgery for peritonitis.

Results

Two hundred twenty-six patients were enrolled during the study period. Patients with CA-IAI had an increased 28-day mortality rate compared to those with HA-IAI (30% vs 15%, respectively (p = 0.009)). At 90 days, the mortality rates were 36.7 and 37.5% in the CA-IAI group and HA-IAI group, respectively, with a similar APACHE II score on admission (median: 21 [15–25] vs. 21 [15–24] respectively, p = 0.63). The patients with HA-IAI had prolonged ICU and hospital stays (median: 17 [7–36] vs. 6[3–12] days, p < 0.001 and 41 [24–66] vs. 17 [7–32] days, p = 0.001), and experienced more complications (reoperation and reintubation) than those with CA-IAI.

Conclusion

CA-IAI group had higher 28-day mortality rate than HA-IAI group. Mortality was similar at 90 days but those with HA-IAI had a prolonged ICU and hospital stay. In addition, they developed more complications.

Epidemiology and Risk Factors for Superficial Surgical Site Infections after Appendectomy for Acute Appendicitis: A Secondary Data Analysis

Background: The identification of risk factors for superficial surgical site infections (SSSIs) associated with appendectomy is paramount in the management of patients with acute appendicitis (AA). Methods: This study was a secondary data analysis from a prospective multi-center observational study. It included all consecutive hospitalized patients with AA who underwent appendectomy and were monitored for complications at 30 days after the intervention. A case-control approach was used to evaluate risk factors associated with the occurrence of SSSI. Results: Among 2,667 patients, 156 (5.8%) developed an SSSI. The series included 1,449 males (54.3%) and 1,218 females with a median age of 29 years (interquartile range [IQR] 20-45 years). Antimicrobial therapy within the previous 30 days was reported by 170 patients (6.4%), and a C-reactive protein concentration (CRP) >50 mg/L was observed in 609 (22.8%). A total of 960 patients (36.0%) underwent open surgery, 1,699 (63.7%) laparoscopic surgery, and 8 (0.3%) another surgical intervention. In 2,575 patients (95.6%), a pathological appendix was detected during the operation. In 776 patients (29.1%), an intra-operative abdominal drain (IAD) was placed; 125 patients (4.7%) were admitted to the intensive care unit. The median hospital length of stay was 3 days (IQR 2-5 days). The overall mortality rate was 0.11%. Multinomial logistic regression analysis of risk factors demonstrated that statistically significant risk factors independently associated with the occurrence of SSSIs were antimicrobial therapy within the previous 30 days, CRP >50 mg/L, open surgical procedures, presence of IAD, and intra-operative findings of complex appendicitis. Conclusions: Knowledge of five easily recognizable variables, assessable at hospital admission or as soon as the surgical intervention is concluded, might identify patients with a greater risk of developing an SSSI.

Acute Respiratory Distress Syndrome From an Infectious Disease Perspective

Acute respiratory distress syndrome (ARDS) is an inflammatory form of lung injury in response to various clinical entities or inciting events, quite frequently due to an underlying infection. Morbidity and mortality associated with ARDS are significant. Hence, early recognition and targeted treatment are crucial to improve clinical outcomes. This article encompasses the most common infectious etiologies of ARDS and their clinical presentations and management, along with commonly encountered infectious complications in such patients.

Intra-abdominal infections: the role of different classifications on the selection of the best antibiotic treatment

Background

Intra-abdominal infections (IAIs) represent a most frequent gastrointestinal emergency and serious cause of morbimortality. A full classification, including all facets of IAIs, does not exist. Two classifications are used to subdivide IAIs: uncomplicated or complicated, considering infection extent; and community-acquired, healthcare-associated or hospital-acquired, regarding the place of acquisition. Adequacy of initial empirical antibiotic therapy prescribed is an essential need. Inadequate antibiotic therapy is associated with treatment failure and increased mortality. This study was designed to determine accuracy of different classifications of IAIs to identify infections by pathogens sensitive to current treatment guidelines helping the selection of the best antibiotic therapy.

Methods

A retrospective cohort study including all adult patients discharged from hospital with a diagnosis of IAI between 1st of January and 31st of October, 2016. All variables potentially associated with pre-defined outcomes: infection by a pathogen sensitive to non-pseudomonal cephalosporin or ciprofloxacin plus metronidazole (ATB 1, primary outcome), sensitive to piperacillin-tazobactam (ATB 2) and hospital mortality (secondary outcomes) were studied through logistic regression. Accuracy of the models was assessed by area under receiver operating characteristics (AUROC) curve and calibration was tested using the Hosmer-Lemeshow goodness-of-fit test.

Results

Of 1804 patients screened 154 met inclusion criteria. Sensitivity to ATB 1 was independently associated with male gender (adjusted OR = 2.612) and previous invasive procedures in the last year (adjusted OR = 0.424) (AUROC curve = 0,65). Sensitivity to ATB 2 was independently associated with liver disease (adjusted OR = 3.580) and post-operative infections (adjusted OR = 2.944) (AUROC curve = 0.604). Hospital mortality was independently associated with age ≥ 70 (adjusted OR = 4.677), solid tumour (adjusted OR = 3.127) and sensitivity to non-pseudomonal cephalosporin or ciprofloxacin plus metronidazole (adjusted OR = 0.368).

The accuracy of pre-existing classifications to identify infection by a pathogen sensitive to ATB 1 was 0.59 considering place of acquisition, 0.61 infection extent and 0.57 local of infection, for ATB 2 it was 0.66, 0.50 and 0.57, respectively.

Conclusion

None of existing classifications had a good discriminating power to identify IAIs caused by pathogens sensitive to current antibiotic treatment recommendations. A new classification, including patients’ individual characteristics like those included in the current model, might have a higher potential to distinguish IAIs by resistant pathogens allowing a better choice of empiric antibiotic therapy.

Bacterial colonization of the stomach and duodenum in a Swedish population with and without proton pump inhibitor treatment

Background and Aim

Microbial contamination of the abdominal cavity is a serious concern during transgastric endoscopic interventions and perforations, particularly in patients who have inhibited gastric acid secretion due to treatment with proton pump inhibitors (PPIs).

The aim of this study was to investigate the gastric and duodenal bacterial flora in patients with and without PPI treatment.

Methods

Patients referred for gastroscopy, without recent antibiotic treatment, were eligible for inclusion. Use of PPIs was recorded. Samples for bacterial culturing were obtained from the antrum of the stomach and from the duodenal bulb through a gastroscope. Positive cultures were examined for bacterial types and subtypes. Biopsies were taken in the antrum for urease test to detect Helicobacter pylori.

Results

Bacterial cultures from the stomach were obtained from 103 patients, and duodenal samples were also cultured from 49 of them, for a total of 53 patients with PPI use and 50 patients without. Positive gastric cultures were found in 42 of 53 patients with PPI use and in 13 of 50 without (P < 0.0001). Duodenal cultures were positive in 20 of 24 with PPI and 8 of 25 without (P < 0.0001). The most commonly identified bacterial species were oral strains of Streptococcus, followed by Neisseria and Haemophilus influenzae. Of 103 patients, 10 had a positive urease test, indicating H. pylori infection, 1 with PPI and 9 without.

Conclusions

Bacterial growth in the stomach and duodenum is more common in patients with PPI treatment. The dominating bacterial species found in the stomach and duodenum originates from the oropharynx.

Clinical trials registry: Trial registration number 98041 in Researchweb (FoU in Sweden).

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

Introduction

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

Material and methods

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

Results

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

Conclusion

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

Electronic supplementary material

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

Antibiotic Resistance in Community-Acquired Intra-Abdominal Infections: Diabetes Mellitus as a Risk Factor

Background: Antimicrobial drug resistance in community-acquired (CA) infections is a growing problem. Knowing the local epidemiology is essential to design empirical antibiotic therapy. Therefore, we conducted this study to evaluate the resistance patterns of microorganisms isolated from surgical samples of community-acquired intra-abdominal infections (IAIs) and to determine the factors associated with resistance. Methods: We analyzed retrospectively the records of patients treated from January 2015 to June 2017 who had IAIs with positives aerobic cultures performed in the first 72 hours after admission. Surgical site infections, abdominal wall procedures, peritoneal dialysis catheters, and patients with admissions in the prior month were excluded. To identify the factors associated with resistance, we considered the resistance to the regimen recommended at our institution, ampicillin/sulbactam (AMS) plus ciprofloxacin (CIP). Results: There were 119 patients with 133 isolates, 59% women, and mean age 54 years. The main sources of infection were appendicitis (38%) and cholecystitis (20%), with 64 patients presenting a complicated IAI (cIAI), defined by the presence of peritonitis (55%). Resistance in Enterobacteriaceae was AMS 32% (6.4% intermediate resistance), CIP 31%, cefotaxime 9%, piperacillin/tazobactam (PTZ) 3%, trimethoprim/sulfamethoxazole 32%, gentamicin 9.5%, and amikacin 2%. Considering all patients, resistance to AMS + CIP was 16.8%. Factors associated with resistant to this regimen was, by univariable and multivariable analysis, the presence of diabetes mellitus (odds ratio [OR] 3.6; 95% confidence interval [CI] 1.1-11.6; p = 0.03). Female gender (OR 2.7; CI 0.9-8.4; p = 0.08) and complicated IAI (OR 2.0; CI 0.7-5.4; p = 0.17) were associated with resistance but did not reach statistical significance. Conclusion: High resistance to CIP and AMS was observed. Although the combination of AMS + CIP offers coverage for 84% of patients, PTZ should be considered as an option for patients with severe infections or diabetes mellitus. Finding factors associated with antibiotic resistance could help to select empirical therapy for CA IAIs better.

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.

Influence of age on the clinical efficacy of tigecycline in severely ill patients

OBJECTIVES

The aim of this study was to define the relationship between age and response to tigecycline among patients treated for complicated skin and soft-tissue infections (cSSTIs) and complicated intra-abdominal infections (cIAIs).

METHODS

Pooled data derived from five European observational studies on the use of tigecycline (July 2006-October 2011), either as monotherapy or in combination with other antibiotics, for the treatment of cSSTI or cIAI were used in the analysis.

RESULTS

The total population (N=1782 patients) was divided into three age categories: <65 years (804 patients); 65-80 years (836 patients) and >80 years (139 patients) (data unknown/missing for 3 patients). The overall mean Acute Physiology and Chronic Health Evaluation (APACHE) II score for patients with cSSTI and cIAI was 15.0±7.9 and 16.9±7.6, respectively, and the overall mean Sequential Organ Failure Assessment (SOFA) score was 5.8±3.9 and 7.0±4.2, respectively. Overall, patients with cSSTI and cIAI in the three age groups showed a good response to tigecycline treatment (76.2-80.0% and 69.2-81.1%, respectively) with patients aged ≤80 years showing higher response rates. Patients with cIAI appeared to be at greater risk for all types of adverse events compared with those with cSSTI, particularly in the older age groups.

CONCLUSION

In these real-life studies, tigecycline, either alone or in combination, achieved favourable clinical response rates in all age categories of patients with cSSTIs and cIAIs with a high severity of illness.

Risk factors for mortality and cost implications of complicated intra-abdominal infections in critically ill patients

PURPOSE

To assess risk factors for 28-day mortality and cost implications in intensive care unit (ICU) patients with complicated intra-abdominal infections (cIAIs).

METHODS

Single-center retrospective cohort study of prospectively collected data analysing ICU patients with a microbiologically confirmed complicated intra-abdominal infections.

RESULTS

137 complicated intra-abdominal infections were included and stratified according to the adequacy of antimicrobial therapy (initial inadequate antimicrobial therapy [IIAT], n = 44; initial adequate antimicrobial therapy [IAAT], n = 93). The empirical use of enterococci/methicillin-resistant Staphylococcus aureus active agents and of carbapenems was associated with a higher rate of therapeutic adequacy (p = 0.016 and p = 0.01, respectively) while empirical double gram-negative and antifungal therapy did not. IAAT showed significantly lower mortality at 28 and 90 days and increased clinical cure and microbiological eradication (p < 0.01). In the logistic and Cox-regression models, IIAT and inadequate source control were the unique predictors of 28-day mortality. No costs differences were related to the adequacy of empirical therapy and source control. The empirical double gram-negative and antifungal therapy (p = 0.03, p = 0.04) as well as the isolation of multidrug-resistant (MDR) bacteria and the microbiological failure after targeted therapy were drivers of increased costs (p = 0.004, p = 0.04).

CONCLUSIONS

IIAT and inadequate source control are confirmed predictors of mortality in ICU patients with complicated intra-abdominal infections. Empirical antimicrobial strategies and MDR may drive hospital costs.

Compliance with an empirical antimicrobial protocol improves the outcome of complicated intra-abdominal infections: a prospective observational study

BACKGROUND

Despite improvements in medical and surgical care, mortality attributed to complicated intra-abdominal infections (cIAI) remains high. Appropriate initial antimicrobial therapy (ABT) is key to successful management. The main causes of non-compliance with empirical protocols have not been clearly described.

METHODS

An empirical ABT protocol was designed according to guidelines, validated in the institution and widely disseminated. All patients with cIAI (2009-2011) were then prospectively studied to evaluate compliance with this protocol and its impact on outcome. Patients were classified into two groups according to whether or not they received ABT in compliance with the protocol.

RESULTS

310 patients were included: 223 (71.9%) with community-acquired and 87 (28.1%) with healthcare-associated cIAI [mean age 60(17-97) yr, mean SAPS II score 24(16)]. Empirical ABT complied with the protocol in 52.3% of patients. The appropriateness of empirical ABT to target the bacteria isolated was 80%. Independent factors associated with non-compliance with the protocol were the anaesthetist's age ≥36 yr [OR 2.1; 95%CI (1.3-3.4)] and the presence of risk factors for multidrug-resistant bacteria (MDRB) [OR 5.4; 95%CI (3.0-9.5)]. Non-compliance with the protocol was associated with higher mortality (14.9 vs 5.6%, P=0.011) and morbidity: relaparotomy (P=0.047), haemodynamic failure (P=0.001), postoperative pneumonia (P=0.025), longer duration of mechanical ventilation (P<0.001), longer ICU stay (P<0.001) and longer hospital stay (P=0.002). On multivariate logistic regression analysis, non-compliance with the ABT protocol was independently associated with mortality [OR 2.4; 95% CI (1.1-5.7), P=0.04].

CONCLUSIONS

Non-compliance with empirical ABT guidelines in cIAI is associated with increased morbidity and mortality. Information campaigns should target older anaesthetists and risk factors for MDRB.

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.

Antibiotic use among older adults on an acute care general surgery service

BACKGROUND

Antibiotics play an important role in the treatment of many surgical diseases that affect older adults, and the potential for inappropriate use of these drugs is high. Our objective was to describe antibiotic use among older adults admitted to an acute care surgery service at a tertiary care teaching hospital.

METHODS

Detailed data regarding diagnosis, comorbidities, surgery and antibiotic use were retrospectively collected for patients 70 years and older admitted to an acute care surgery service. We evaluated antibiotic use (perioperative prophylaxis and treatment) for appropriateness based on published guidelines.

RESULTS

During the study period 453 patients were admitted to the acute care surgery service, and 229 underwent surgery. The most common diagnoses were small bowel obstruction (27.2%) and acute cholecystitis (11.0%). In total 251 nonelective abdominal operations were performed, and perioperative antibiotic prophylaxis was appropriate in 49.5% of cases. The most common prophylaxis errors were incorrect timing (15.5%) and incorrect dose (12.4%). Overall 206 patients received treatment with antibiotics for their underlying disease process, and 44.2% received appropriate first-line drug therapy. The most common therapeutic errors were administration of second- or third-line antibiotics without indication (37.9%) and use of antibiotics when not indicated (12.1%). There was considerable variation in the duration of treatment for patients with the same diagnoses.

CONCLUSION

Inappropriate antibiotic use was common among older patients admitted to an acute care surgery service. Quality improvement initiatives are needed to ensure patients receive optimal care in this complex hospital environment.

Cost-effectiveness of ceftolozane/tazobactam plus metronidazole versus piperacillin/tazobactam as initial empiric therapy for the treatment of complicated intra-abdominal infections based on pathogen distributions drawn from national surveillance data in the United States

BACKGROUND

The prevalence of antimicrobial resistance among gram-negative pathogens in complicated intra-abdominal infections (cIAIs) has increased. In the absence of timely information on the infecting pathogens and their susceptibilities, local or regional epidemiology may guide initial empirical therapy and reduce treatment failure, length of stay and mortality. The objective of this study was to assess the cost-effectiveness of ceftolozane/tazobactam + metronidazole compared with piperacillin/tazobactam in the treatment of hospitalized US patients with cIAI at risk of infection with resistant pathogens.

METHODS

We used a decision-analytic Monte Carlo simulation model to compare the costs and quality-adjusted life years (QALYs) of persons infected with nosocomial gram-negative cIAI treated empirically with either ceftolozane/tazobactam + metronidazole or piperacillin/tazobactam. Pathogen isolates were randomly drawn from the Program to Assess Ceftolozane/Tazobactam Susceptibility (PACTS) database, a surveillance database of non-duplicate bacterial isolates collected from patients with cIAIs in medical centers in the USA from 2011 to 2013. Susceptibility to initial therapy was based on the measured susceptibilities reported in the PACTS database determined using standard broth micro-dilution methods as described by the Clinical and Laboratory Standards Institute (CLSI).

RESULTS

Our model results, with baseline resistance levels from the PACTS database, indicated that ceftolozane/tazobactam + metronidazole dominated piperacillin/tazobactam, with lower costs ($44,226/patient vs. $44,811/patient respectively) and higher QALYs (12.85/patient vs. 12.70/patient, respectively). Ceftolozane/tazobactam + metronidazole remained the dominant choice in one-way and probabilistic sensitivity analyses.

CONCLUSIONS

Based on surveillance data, ceftolozane/tazobactam is more likely to be an appropriate empiric therapy for cIAI in the US. Results from a decision-analytic simulation model indicate that use of ceftolozane/tazobactam + metronidazole would result in cost savings and improves QALYs, compared with piperacillin/tazobactam.

Unmet needs in the management of intra-abdominal infections

INTRODUCTION

Intra-abdominal infections remain a leading cause of death, morbidity and resource use in surgical wards and intensive care units. The growing complexity of their management has led to new paradigms and unresolved issues in anti-infective therapy described in the current review. Areas covered: We analyzed the literature, recent guidelines, and expert opinions published over the last decade. Expert commentary: Prospective randomized trials are difficult to perform and observational studies or database analyses should be encouraged. Epidemiologic and microbiologic reports should be promoted, especially in developing/resource-limited countries and in specific subpopulations such as children, older people and patients with underlying diseases. The diagnostic process, including imaging procedures, could be improved. The value of biomarkers for diagnosis, monitoring and discontinuation of therapy should be clarified and improved. New microbiologic techniques are needed to speed up the diagnostic process and to improve the adequacy of anti-infective therapy. Very little progress has been made in the detection of clinical failures. Many aspects of anti-infective management, both for bacteria and fungi, remain unresolved, such as the high inoculum, the type of microorganisms to be treated, the timing of therapy, the value of de-escalation, drug monitoring and duration of therapy. New antibiotics are expected.

Cost-effectiveness of ceftolozane/tazobactam plus metronidazole compared with piperacillin/tazobactam as empiric therapy for the treatment of complicated intra-abdominal infections based on the in-vitro surveillance of bacterial isolates in the UK

AIMS

An increase in the prevalence of antimicrobial resistance among gram-negative pathogens has been noted recently. A challenge in empiric treatment of complicated intra-abdominal infection (cIAI) is identifying initial appropriate antibiotic therapy, which is associated with reduced length of stay and mortality compared with inappropriate therapy. The objective of this study was to assess the cost-effectiveness of ceftolozane/tazobactam + metronidazole compared with piperacillin/tazobactam (commonly used in this indication) in the treatment of patients with cIAI in UK hospitals.

METHODS

A decision-analytic Monte Carlo simulation model was used to compare costs (antibiotic and hospitalization costs) and quality-adjusted life years (QALYs) of patients infected with gram-negative cIAI and treated empirically with either ceftolozane/tazobactam + metronidazole or piperacillin/tazobactam. Bacterial isolates were randomly drawn from the Program to Assess Ceftolozane/Tazobactam Susceptibility (PACTS) database, a surveillance database of non-duplicate bacterial isolates collected from patients in the UK infected with gram-negative pathogens. Susceptibility to initial empiric therapy was based on the measured susceptibilities reported in the PACTS database.

RESULTS

Ceftolozane/tazobactam + metronidazole was cost-effective when compared with piperacillin/tazobactam, with an incremental cost-effectiveness ratio (ICER) of £4,350/QALY and 0.36 hospitalization days/patient saved. Costs in the ceftolozane/tazobactam + metronidazole arm were £2,576/patient, compared with £2,168/patient in the piperacillin/tazobactam arm. The ceftolozane/tazobactam + metronidazole arm experienced a greater number of QALYs than the piperacillin/tazobactam arm (14.31/patient vs 14.21/patient, respectively). Ceftolozane/tazobactam + metronidazole remained cost-effective in one-way sensitivity and probabilistic sensitivity analyses.

CONCLUSIONS

Economic models can help to identify the appropriate choice of empiric therapy for the treatment of cIAI. Results indicated that empiric use of ceftolozane/tazobactam + metronidazole is cost-effective vs piperacillin/tazobactam in UK patients with cIAI at risk of resistant infection. This will be valuable to commissioners and clinicians to aid decision-making on the targeting of resources for appropriate antibiotic therapy under the premise of antimicrobial stewardship.

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.

Ceftazidime-avibactam for the treatment of complicated intra-abdominal infections

INTRODUCTION

The treatment of complicated intra-abdominal infections (cIAI) is increasingly challenging due to increased resistance of Gram-negative organisms. These multidrug resistant organisms lead to an increase in morbidity and mortality. This has led to renewed interest in use of older β-lactam antibiotics in combination with newer β-lactamase inhibitors. Ceftazidime-avibactam is one of the newest such combination antibiotics, which has been released for treatment of complicated intra-abdominal infections in combination with metronidazole. Areas covered: In this drug evaluation manuscript cIAI along with the chemistry, pharmacodynamics, pharmacokinetics, metabolism and clinical study results of ceftazidime-avibactam are reviewed. Expert opinion: The role of ceftazidime-avibactam in combination with metronidazole in the treatment of cIAI is still to be defined. Patients with cIAI known to be infected with Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae would be clear candidates for treatment with this agent, as would patients infected with more common types of extended-spectrum β-lactamase producing Gram-negative pathogens if a carbapenem alternative were desired. At present, it is difficult to establish a clear group of patients with cIAI for whom initial empiric therapy with this agent would be warranted.

Clinical characteristics and antimicrobial patterns in complicated intra-abdominal infections: a 6-year epidemiological study in southern China

Complicated intra-abdominal infection (cIAIs) are a common and important cause of morbidity worldwide. In this study, the clinical features, microbiological profiles, antimicrobial patterns and treatments of 3233 cIAI patients (mean age, 47.6 years; 54.7% male) with 3531 hospitalisations from 2008-2013 were retrospectively investigated. The most commonly isolated bacteria were Escherichia coli (47.6%), Klebsiella pneumoniae (16.9%), Enterococcus faecalis (10.4%) and Pseudomonas aeruginosa (8.8%). Ciprofloxacin, aminoglycoside (gentamicin), piperacillin/tazobactam and carbapenems exhibited activity against 53%, 76%, 88% and 100% of extended-spectrum β-lactamase (ESBL)-positive Enterobacteriaceae isolates, respectively. Pseudomonas aeruginosa isolates exhibited 100%, 95%, 88%, 71% and 76% susceptibility to aminoglycoside (gentamicin), ciprofloxacin, meropenem, imipenem and ceftazidime, respectively, and Enterococcus remained 100% susceptible to vancomycin and linezolid. β-Lactam antibacterials other than penicillin (specifically third-generation cephalosporins) and imidazole derivatives (ornidazole and metronidazole) were the most common first-line treatments. Patients subjected to regimen change after initial antibiotic treatment had predisposing conditions (e.g. older age, more severe co-morbidities) and a higher incidence of P. aeruginosa infection; in addition, these patients encountered a higher average cost of care and worse clinical outcomes compared with those without medication modification. Taken together, these findings indicate the importance of appropriate initial empirical therapy and suggest the use of combination therapy comprising cephalosporins and metronidazole.

Effect of initial empiric antibiotic therapy combined with control of the infection focus on the prognosis of patients with secondary peritonitis

BACKGROUND

In patients with intra-abdominal infection, inappropriate initial empiric antibiotic therapy is associated with greater morbidity. We evaluated the impact of adequate empiric antibiotic treatment together with control of the infection focus on the morbidity and mortality rates of patients with secondary peritonitis.

METHODS

This was a prospective, observational study with the participation of 24 Spanish hospitals and 362 patients with secondary peritonitis (262 community-acquired, 100 post-operative). Therapeutic failure (infectious complications or death) was classified into four categories according to whether empiric antibiotic treatment was appropriate and the infection focus was controlled.

RESULTS

The rates of therapeutic failure, re-operation, and mortality were 48%, 13%, and 8%, respectively. Empiric antibiotic treatment was inappropriate in 39% of cases, which was associated with a higher rate of surgical site infection (53% vs. 40%; p=0.031) and death (12% vs. 5%; p=0.021) than was observed in patients receiving appropriate initial empiric therapy. Eight percent of patients in whom control of the infection focus was not obtained suffered from more infectious complications (76% vs. 52%; p=0.01) and surgical site infections (69% vs. 44%; p=0.01); and in this group, both therapeutic failure and mortality rates were similar, independent of whether the empiric antibiotic therapy was appropriate.

CONCLUSION

Inappropriate initial empiric antibiotic therapy was associated with higher rates of therapeutic failure, surgical site infection, re-operation, and death. Classification of therapeutic failure into four categories according to the appropriateness of empiric antibiotic therapy and the success of infection control provided excellent discrimination of morbidity and death.

Does it Matter if we get it right? Impact of appropriateness of empiric antimicrobial therapy among surgical patients

Previous studies have shown conflicting evidence regarding the impact of inappropriate, initial antibiotic therapy. The purpose of this study was to evaluate the impact of inappropriate empiric antimicrobial therapy for the treatment of infection among surgical patients. We hypothesized that inappropriate empiric antimicrobial therapy would predict increased mortality risk compared with appropriate therapy. This was a retrospective analysis of a prospectively maintained database of all surgical patients admitted to a tertiary care center from 1996 to 2007 and treated for sepsis. "Appropriate" empiric antibiotic treatment was determined by sensitivity testing. Demographics and comorbidities, infection sites, infection organisms, and outcomes were compared between inappropriately and appropriately treated groups. Multivariable log-binomial regression was performed. There were 2,855 patients (7,158 infectious episodes) identified by culture analysis as either appropriately or inappropriately treated. Three hundred seventeen (15%) inappropriately treated infectious episodes resulted in death compared with 718 (14%) of the appropriately treated infectious episodes. After adjusting for statistically significant variables, inappropriately treated episodes of infection were not found to be associated with an increased risk for mortality compared with appropriately treated episodes of infection (relative risk, 1.0; 95% confidence interval, 0.99 - 1.02; P = 0.36). Our study observed no difference in mortality between appropriately and inappropriately treated infections within a surgical population.

Inadequate Source Control and Inappropriate Antibiotics are Key Determinants of Mortality in Patients with Intra-Abdominal Sepsis and Associated Bacteremia

BACKGROUND

Patients with intra-abdominal sepsis and associated bacteremia have a high mortality rate. However, outcomes studies in this population are limited, in part because of the small numbers of such patients. The objective of this study was to describe characteristics of critically ill patients with secondary blood stream infection (BSI) of intra-abdominal origin and identify predictors of mortality.

METHODS

This retrospective, single-center study evaluated patients admitted between January 2005 and January 2011 with bacteremia because of an intra-abdominal source. Patients were included if they met criteria for severe sepsis based on International Classification of Diseases, 9th Revision (ICD 9) codes for acute organ dysfunction, had a positive blood culture, had at least one ICD 9 code indicative of an intra-abdominal process, and had a confirmed or clinically suspected intra-abdominal infection (IAI) within 72 h of the blood culture. Chart review was performed to confirm the presence of these criteria and also the absence of any other potential source of bacteremia. Data were collected on patient demographics, BSI source, source control procedure details, microorganisms isolated, and antibiotics administered. Multivariable logistic regression analysis was performed to identify independent predictors of mortality.

RESULTS

Three hundred six patients with BSI were identified, of which 108 episodes were deemed to be of intra-abdominal origin. Gram-negative organisms comprised 43% of blood isolates, followed by gram-positives (33%), anaerobes (14%), and yeast (9%). Appropriate antimicrobial therapy was administered in 71% of patients. The overall mortality rate was 27.8%. As compared with survivors, non-survivors were older, more likely to have underlying COPD or asthma, and have renal or metabolic failure (p<0.05 for all). Among non-survivors, adequate source control was obtained less frequently (64% vs. 91%, p=0.002) and median time to appropriate antibiotics was longer (23 h vs. 4 h, p=0.004). Logistic regression analysis revealed inadequate source control (p=0.002) and inappropriate antibiotics (p=0.016) to be independently associated with mortality.

CONCLUSIONS

Critically ill patients with a BSI of abdominal origin are at high risk for mortality. Failure to achieve adequate source control and administration of inappropriate antibiotics were independent predictors of mortality. Thus, these represent potential opportunities to impact outcomes in patients with complicated IAI.

Impact of a Dynamic Microbiological Environment on the Clinical Efficacy of Ertapenem and Piperacillin/Tazobactam in the Treatment of Complicated Community-Acquired Intra-Abdominal Infection in Spain: A Cost-Consequence Analysis

BACKGROUND AND OBJECTIVE

The microbial susceptibility of many antibiotics has been affected by prescribing patterns and their extensive use. The purpose of this evaluation was to assess how these changes could affect the initial efficacy of ertapenem and piperacillin/tazobactam in the treatment of complicated intra-abdominal infections (IAIs) acquired in the community and the potential consequences this may have in healthcare costs in Spain.

METHODS

The Initial efficacy of ertapenem and piperacillin/tazobactam for patients with APACHE (Acute Physiology and Chronic Health Evaluation) II scores <10 was extracted from a multicenter randomized study and were combined with the current microbial susceptibilities obtained from the SMART study, a multinational surveillance program. Country-specific pathogens distribution was extracted from a national study in patients with community-acquired IAI. The estimated effectiveness was used in a decision-analytic model to compare total costs between ertapenem and piperacillin/tazobactam in the treatment of complicated IAI. The model performs extensive one-way and probabilistic sensitivity analyses.

RESULTS

The model suggested a savings of €209 (year 2012 values) per patient when complicated IAIs acquired in the community (APACHE II <10) were treated with ertapenem instead of piperacillin/tazobactam. One-way sensitivity analyses showed length of stay as the key driver parameter. Further analysis of this parameter and probabilistic sensitivity analysis confirmed the robustness of our evaluation, with a 58% likelihood of ertapenem being dominant.

CONCLUSIONS

Ertapenem appears to be a cost-saving strategy over piperacillin/tazobactam for the treatment of patients with complicated IAIs acquired in the community in Spain.

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.

Clinical and economic consequences of failure of initial antibiotic therapy for patients with community-onset complicated intra-abdominal infections

Objectives

Complicated intra-abdominal infection (cIAI) is infection that extends beyond the hollow viscus of origin into the peritoneal space, and is associated with either abscess formation or peritonitis. There are few studies that have assessed the actual costs and outcomes associated with failure of initial antibiotic therapy for cIAI. The aims of this study were to evaluate risk factors and impact on costs and outcomes of failure of initial antibiotic therapy for community-onset cIAI.

Methods

A retrospective study was performed at eleven tertiary-care hospitals. Hospitalized adults with community-onset cIAI who underwent an appropriate source control procedure between August 2008 and September 2011 were included. Failure of initial antibiotic therapy was defined as a change of antibiotics due to a lack of improvement of the clinical symptoms and signs associated with cIAI in the first week.

Results

A total of 514 patients hospitalized for community-onset cIAI were included in the analysis. The mean age of the patients was 53.3 ± 17.6 years, 72 patients (14%) had health care-associated infection, and 48 (9%) experienced failure of initial antibiotic therapy. Failure of initial antibiotic therapy was associated with increased costs and morbidity. After adjustment for covariates, patients with unsuccessful initial therapy received an additional 2.9 days of parenteral antibiotic therapy, were hospitalized for an additional 5.3 days, and incurred $3,287 in additional inpatient charges. Independent risk factors for failure of initial antibiotic therapy were health care-associated infection, solid cancer, and APACHE II ≥13.

Conclusions

To improve outcomes and costs in patients with community-onset cIAI, rapid assessment of health care-associated risk factors and severity of disease, selection of an appropriate antibiotic regimen accordingly, and early infection source control should be performed.

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.

Characteristics of surgical patients receiving inappropriate empiric antimicrobial therapy

BACKGROUND

Inappropriate antibiotics have been observed to result in an increased duration of antibiotic treatment and hospital length of stay, development of multidrug-resistant organisms, and mortality rate compared with appropriate antibiotic treatment. Few studies have evaluated independent risk factors associated with inappropriateness. The purpose of this study was to identify independent predictors of inappropriate, empiric antimicrobial therapy for the treatment of severe sepsis.

METHODS

This was a retrospective analysis of a prospectively maintained database of all surgical/trauma patients admitted to a tertiary care center from 1996 to 2007 and treated for sepsis. "Appropriate" empiric antibiotic treatment was determined by sensitivity testing. Demographics and comorbidities, infection sites, infection organisms, and outcomes between strata were compared. Differences in outcome were estimated using relative risk and 95% confidence intervals for correlated data.

RESULTS

A total of 2,855 patients (7,158 infections) were identified. Independent predictors of inappropriate, empiric antimicrobial therapy for the treatment of severe sepsis included site of infection and organism type. Severity of illness, age, medical conditions, and community versus health care-associated infections were not associated with inappropriate therapy. Although inappropriate empiric therapy was associated with a longer length of stay and duration of antimicrobial use, it did not result in higher mortality.

CONCLUSION

Our study observed that inappropriate empiric antibiotic selection is related to site of infection and pathogen. Other clinical variables do not appear to predict inappropriateness of antibiotic treatment. Efforts should be focused on early broad-spectrum therapy and more rapid microbiologic methods.

LEVEL OF EVIDENCE

Therapeutic/care management study, level II.

Clinical and Economic Consequences of Failure of Initial Antibiotic Therapy for Hospitalized Patients With Complicated Skin and Skin-Structure Infections

Objective.

To estimate the consequences of failure of initial antibiotic therapy for patients with complicated skin and skin-structure infections.

Design.

Retrospective cohort study.

Setting.

Large US multihospital database.

Patients.

We identified a total of 47,219 patients (age 18 years or older) who were admitted to the hospital for complicated skin and skin-structure infections from April 1, 2003, through March 31, 2004, and who received intravenous antibiotics during the first 2 hospital-days (ie, initial antibiotic therapy). Failure of therapy was defined as drainage, debridement, or receipt of other intravenous antibiotics at any subsequent time (except for changes to narrower-spectrum agents or any therapy change immediately before discharge). Predictors of failure of antibiotic therapy and mortality were examined using multivariate logistic regression. Analysis of covariance was used to estimate the impact of treatment failure on duration of intravenous antibiotic therapy, length of stay, and total inpatient charges.

Results.

For 10,782 admitted patients (22.8%), there was evidence of failure of initial antibiotic therapy. In multivariate analyses, treatment failure was associated with receipt of vasoactive medications during the first 2 hospital-days (odds ratio [OR], 1.66 [95% confidence interval {CI}, 1.19-2.31]), initiation of antibiotic therapy in the intensive care unit (OR, 1.53 [95% CI, 1.28-1.84]), and the patient's Charlson comorbidity index (OR per 1-point increase, 1.06 [95% CI, 1.04-1.08]); treatment failure was also was associated with a 3-fold increase in mortality (OR, 2.91 [95% CI, 2.34-3.62]). Compared with patients for whom initial treatment was successful, patients who experienced treatment failure received intravenous antibiotic therapy for a mean of 5.7 additional days, were hospitalized for a mean of 5.4 additional days, and incurred a mean of $5,285 (in 2003 dollars) in additional inpatient charges (all P <.01).

Conclusion.

Failure of initial antibiotic therapy in the treatment of complicated skin and skin-structure infections is associated with significantly worse clinical and economic outcomes.

Cost of care and antibiotic prescribing attitudes for community-acquired complicated intra-abdominal infections in Italy: a retrospective study

INTRODUCTION

Complicated intra-abdominal infections (cIAIs) are a common cause of morbidity worldwide, and in spite of improvements in patient care, therapeutic failure still occurs, impacting in-hospital resource consumption. This study aimed to assess the costs associated with the treatment of community-acquired cIAIs, from the Italian National Health Service perspective.

METHODS

This retrospective study analyzed the charts of patients who were discharged from four Italian university hospitals between January 1 and December 31, 2009 with a primary diagnosis of community-acquired cIAIs. Patient characteristics, diagnosis, surgical procedure, antibiotic therapy, and length of hospital stay were all recorded and the cost of total hospital care was estimated. Costs were calculated in Euros at 2009 values.

RESULTS

The records of 260 patients (mean age 48.9 years; 57% males) were analyzed. The average cost of care for a patient hospitalized due to cIAI was €4385 (95% CI 3650-5120), with an average daily cost of €419 (95% CI 378-440). Antibiotic therapy represented just under half (44.3%) of hospitalization costs. The strongest predictor of the increase in hospital costs was clinical failure: patients who clinically failed received an average of 8.2 additional days of antibiotic therapy and spent 11 more days in hospital compared with patients who responded to first-line therapy (both p < 0.05 vs. patients who were successfully treated). Furthermore, they incurred €5592 in additional hospitalization costs (2.88 times the cost associated with clinical success) with 53% (€2973) of the additional costs attributable to antibiotic therapy. Overall, antibiotic appropriateness rate was 78.8% (n = 205), and was significantly higher in patients receiving combination therapy compared with those treated with monotherapy (97.3% vs. 64.6%).

CONCLUSION

The results of this study suggest that hospitals need to be aware of the clinical and economic consequences of antibiotic therapy of cIAIs and to reduce overall resource use and costs by improving the rate of success with appropriate initial empiric therapy.

Early versus later response to treatment in patients with community-acquired pneumonia: analysis of the REACH study

Background

Key goals in the treatment of CAP include early response to treatment and achievement of clinical stability. The US FDA recommends early response endpoints (72 hours after initiation of treatment) in clinical trials for the treatment of community-acquired bacterial pneumonia. REACH (REtrospective Study to Assess the Clinical Management of Patients With Moderate-to-Severe Complicated Skin and Soft Tissue Infections [cSSTI] or CAP in the Hospital Setting) was a retrospective observational study, providing current data on the clinical management and resource burden of CAP in real-life settings in European hospitals. This analysis reviews the characteristics and outcomes of patients showing early positive response to treatment (time to clinical stability [TCS] ≤4 days, as assessed by Halm’s criteria) compared with patients with later positive response (TCS >4 days).

Methods

Patients were adults, hospitalized with CAP (2010–2011) and requiring in-hospital treatment with intravenous antibiotics.

Results

Of the 2039 patients included in REACH, 585 (28.7%) had TCS assessed by Halm’s criteria: 332 (56.8%) showed early response (median 3.0 days), and 253 (43.2%) showed later response to treatment (median 7.0 days). Use of Halm’s criteria varied across participating countries, ranging from 0% (Belgium) to 49.1% (UK). Patient characteristics and relevant medical history were similar between the two groups. There were no notable differences in initial antibiotic therapy between groups, except that more early responders had been treated with amoxicillin–clavulanate and amoxicillin monotherapy (22.6%; 7.5%, respectively) than later responders (5.9%; 1.2%, respectively). Initial treatment modification and re-infection or recurrences were less frequent in early responders compared with later responders (14.2% and 3.3% vs. 34.8% and 5.9%, respectively). Early responders had a shorter duration of hospitalization (mean 9.4 ± SD 7.0; median 8.0 days vs. mean 15.6 ± SD 10.5; median 12.0 days, respectively), lower rate of ICU admission (3.3% vs. 21.3%) and shorter duration of ICU stay (mean 6.2 ± SD 5.7; median 4.0 days vs. mean 10.4 ± SD 10.1; median 8.0 days, respectively) compared with later responders. Mortality was low in both groups.

Conclusions

Achieving early clinical stabilization in CAP (≤4 days) is associated with improved outcomes, lower requirement for initial treatment modification or readmission and lower resource use, compared with a later response.

Trial registration

NCT01293435

The microbiology of bacterial peritonitis due to appendicitis in children

AIM

The aim of this study was to investigate the microbiology of secondary bacterial peritonitis due to appendicitis and the appropriateness of current antimicrobial practice in one institution.

METHODS

A 14-year retrospective single-centre study of 69 consecutive paediatric patients (age 1-14 years) with appendicitis-related peritonitis and positive peritoneal specimen cultures was conducted. Post-operative outcomes, microbiology and antibiotic susceptibility of peritoneal isolates were analysed in all patients.

RESULTS

Escherichia coli was identified in 56/69 (81 %) peritoneal specimens; four isolates were resistant to amoxicillin-clavulanate, and one other isolate was resistant to gentamicin. Anaerobes were identified in 37/69 (54 %) peritoneal specimens; two anaerobic isolates were resistant to amoxicillin-clavulanate and one isolate was resistant to metronidazole. Pseudomonas aeruginosa was identified in 4/69 (6 %) peritoneal specimens, and all were susceptible to gentamicin. Streptococcal species (two Group F streptococci and three β-haemolytic streptococci) were identified in 5/69 (7 %) specimens, and all were susceptible to amoxicillin-clavulanate. Combination therapy involving amoxicillin-clavulanate and aminoglycoside is appropriate empirical treatment in 68/69 (99 %) patients. Addition of metronidazole to this regime would provide 100 % initial empirical coverage. Inadequate initial empiric antibiotic treatment and the presence of amoxicillin-clavulanate resistant E. coli were independent predictors of the post-operative infectious complications observed in 14/69 (20 %) patients.

CONCLUSION

E. coli and mixed anaerobes are the predominant organisms identified in secondary peritonitis from appendicitis in children. Inadequate initial empirical antibiotic and amoxicillin-clavulanate resistant E. coli may contribute to increased post-operative infectious complications. This study provides evidence-based information on choice of combination therapy for paediatric appendicitis-related bacterial peritonitis.

Role of moxifloxacin for the treatment of community-acquired [corrected] complicated intra-abdominal infections in Taiwan

Complicated intra-abdominal infections (cIAIs) are common yet serious infections that can potentially lead to substantial morbidity and morbidity. As an essential adjunct to source control, the goals of antimicrobial therapy are to promote patient recovery, reduce recurrence risk, and prevent antimicrobial resistance. The current international guidelines on the empirical treatment of community-acquired complicated IAIs were published by the Infectious Diseases Society of America (IDSA) and Surgical Infections Society (SIS) in 2010. These guidelines all recommend the use of a fluoroquinolone (ciprofloxacin or levofloxacin) plus metronidazole for mild-to-moderate- and high-severity cases. Moxifloxacin monotherapy is recommended by the current IDSA/SIS guidelines for the treatment of mild-to-moderate complicated IAIs. Moxifloxacin has demonstrated a broad spectrum coverage of both aerobic and anaerobic pathogens, good tissue penetration into the gastrointestinal tract, and a good tolerability profile. Clinical data have demonstrated that moxifloxacin is at least as effective as other standard therapeutic regimens recommended by current clinical guidelines. Due to the high rates of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae and fluoroquinolone-resistant Enterobacteriaceae among isolates causing community-acquired IAIs in Asia, any fluoroquinolones (including moxifloxacin) are not recommended as drugs of choice for the empirical treatment of community-acquired IAIs, particularly in countries (China, India, Thailand, and Vietnam) with fluoroquinolone resistance rates among Escherichia coli isolates of >20%. Given the low rates of fluoroquinolone-resistant (<20%) and extended-spectrum β-lactamase (ESBL)-producing (<10%) Enterobacteriaceae isolates associated community-acquired IAIs in Taiwan, it appears that moxifloxacin is considered an appropriate first-line therapy for patients with community-acquired complicated IAIs in this country.

Empiric antibiotic selection strategies for healthcare-associated pneumonia, intra-abdominal infections, and catheter-associated bacteremia

Initial selection and early deployment of appropriate/adequate empiric antimicrobial therapy is critical to minimize the significant morbidity and mortality associated with hospital- or healthcare-associated infections (HAIs). Initial empiric therapy that inadequately covers the pathogen(s) causing a serious HAI has been associated with increased mortality, longer hospital stay, and elevated healthcare costs. Moreover, subsequent modification of initial inadequate therapy, later in the disease process when culture results become available, may not remedy the impact of the initial choice. Because of this, it is important that initial empiric therapy covers the most likely pathogens associated with infection in a particular patient, even if this initial regimen turns out to be unnecessarily broad, based on subsequent culture results. The current paradigm for management of serious HAIs is to initiate empiric therapy with a broad-spectrum regimen covering likely pathogens, based on local surveillance and susceptibility data, and presence of risk factors for involvement of a resistant microorganism. Subsequent modification (de-escalation) of the initial regimen becomes possible later, when culture results are available and clinical status can be better assessed, 2 to 4 days after initiation of empiric therapy. When possible, de-escalation and other steps to modify antimicrobial exposure are important for minimizing risk of antimicrobial resistance development. This article examines the general process for selection of initial empiric antibiotic therapy for patients with HAIs, illustrated through 3 case studies dealing with healthcare-associated pneumonia, complicated intra-abdominal infection, and catheter-associated bacteremia, respectively.

Initial microbial spectrum in severe secondary peritonitis and relevance for treatment

This study aims to determine whether abdominal microbial profiles in early severe secondary peritonitis are associated with ongoing infection or death. The study is performed within a randomized study comparing two surgical treatment strategies in patients with severe secondary peritonitis (n = 229). The microbial profiles of cultures retrieved from initial emergency laparotomy were tested with logistic regression analysis for association with ‘ongoing infection needing relaparotomy’ and in-hospital death. No microbial profile or the presence of yeast or Pseudomonas spp. was related to the risk of ongoing infection needing relaparotomy. Resistance to empiric therapy for gram positive cocci and coliforms was moderately associated with ongoing abdominal infection (OR 3.43 95%CI 0.95–12.38 and OR 7.61, 95%CI 0.75–76.94). Presence of only gram positive cocci, predominantly Enterococcus spp, was borderline independently associated with in-hospital death (OR 3.69, 95%CI 0.99–13.80). In secondary peritonitis microbial profiles do not predict ongoing abdominal infection after initial emergency laparotomy. However, the moderate association of ongoing infection with resistance to the empiric therapy compels to more attention for resistance when selecting empiric antibiotic coverage.