Critically ill patients with community-onset intraabdominal infections: Influence of healthcare exposure on resistance rates and mortality

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.

Critical appraisal beyond clinical guidelines for intraabdominal candidiasis

BACKGROUND

Regardless of the available antifungals, intraabdominal candidiasis (IAC) mortality continues to be high and represents a challenge for clinicians.

MAIN BODY

This opinion paper discusses alternative antifungal options for treating IAC. This clinical entity should be addressed separately from candidemia due to the peculiarity of the required penetration of antifungals into the peritoneal cavity. Intraabdominal concentrations may be further restricted in critically ill patients where pathophysiological facts alter normal drug distribution. Echinocandins are recommended as first-line treatment in guidelines for invasive candidiasis. However, considering published data, our pharmacodynamic analysis suggests the required increase of doses, postulated by some authors, to attain adequate pharmacokinetic (PK) levels in peritoneal fluid. Given the limited evidence in the literature on PK/PD-based treatments of IAC, an algorithm is proposed to guide antifungal treatment. Liposomal amphotericin B is advocated as first-line therapy in patients with sepsis/septic shock presenting candidemia or endophthalmitis, or with prior exposure to echinocandins and/or fluconazole, or with infections by Candida glabrata. Other situations and alternatives, such as new compounds or combination therapy, are also analysed.

CONCLUSION

There is a critical need for more robust clinical trials, studies examining patient heterogeneity and surveillance of antifungal resistance to enhance patient care and optimise treatment outcomes. Such evidence will help refine the existing guidelines and contribute to a more personalised and effective approach to treating this serious medical condition. Meanwhile, it is suggested to broaden the consideration of other options, such as liposomal amphotericin B, as first-line treatment until the results of the fungogram are available and antifungal stewardship could be implemented to prevent the development of resistance.

Epidemiology and Age-Related Mortality in Critically Ill Patients With Intra-Abdominal Infection or Sepsis: An International Cohort Study

BACKGROUND

The objective of this study is to describe the epidemiology and age-related mortality in older critically ill adults with intra-abdominal infections.

METHODS

This is a secondary analysis of a prospective, multinational, observational study (AbSeS, ClinicalTrials.gov #NCT03270345) including patients with intra-abdominal infection from 309 ICUs in 42 countries (January-December, 2016). Mortality was considered as ICU mortality with a minimum of 28 days of observation when patients were discharged earlier. Relationships with mortality were assessed by logistic regression analysis.

RESULTS

The cohort included 2337 patients. Four age groups were defined: middle-aged patients as reference category (40-59 years; n=659 [28.2%]), young-old (60-69 years; n=622 [26.6%]), middle-old (70-79 years; n=667 [28.5%]) and very-old patients (≥80 years; n=389 [16.6%]). Secondary peritonitis was the predominant infection (68.7%) and equally prevalent across age groups. Mortality increased with age: 20.9% in middle-aged patients, 30.5% in young-old, 31.2% in middle-old, and 44.7% in very-old patients (p<0.001). Compared to middle-aged patients, young-old age (OR 1.62, 95% CI 1.21-2.17), middle-old age (OR 1.80, 95% CI 1.35-2.41), and very-old age (OR 3.69, 95% CI 2.66-5.12) were independently associated with mortality. Other independent risk factors for mortality included late-onset hospital-acquired intra-abdominal infection, diffuse peritonitis, sepsis/septic shock, source control failure, liver disease, congestive heart failure, diabetes, and malnutrition.

CONCLUSIONS

For ICU patients with intra-abdominal infections, age above 60 years was associated with mortality while patients above 80 years had the worst prognosis. Comorbidities and overall disease severity further compromised survival. As all these factors are non-modifiable it remains unclear how to improve outcomes.

Secondary infections in mechanically ventilated patients with COVID-19: An overlooked matter?

Introduction

The susceptibility to infection probably increases in COVID-19 patients due to a combination of virus and drug-induced immunosuppression. The reported rate of secondary infections was quite low in previous studies. The objectives of our study were to investigate the rate of secondary infections, risk factors for secondary infections and risk factors for mortality in COVID-19 critically ill patients.

Material and methods

We performed a single-center retrospective study in mechanically ventilated critically ill COVID-19 patients admitted to our Critical Care Unit (CCU). We recorded the patients’ demographic data; clinical data; microbiology data and incidence of secondary infection during CCU stay, including ventilator-associated pneumonia (VAP) and nosocomial bacteremia (primary and secondary).

Results

A total of 107 patients with a mean age 62.2 ± 10.6 years were included. Incidence of secondary infection during CCU stay was 43.0% (46 patients), including nosocomial bacteremia (34 patients) and VAP (35 patients). Age was related to development of secondary infection (65.2 ± 7.3 vs. 59.9 ± 12.2 years, p=0.007). Age ≥ 65 years and secondary infection were independent predictors of mortality (OR=2.692, 95% CI 1.068-6.782, p<0.036; and OR=3.658, 95% CI 1.385-9.660, p=0.009, respectively). The hazard ratio for death within 90 days in the ≥ 65 years group and in patients infected by antimicrobial resistant pathogens was 1.901 (95% CI 1.198-3.018; p= 0.005 by log-rank test) and 1.787 (95% CI 1.023-3.122; p= 0.036 by log-rank test), respectively.

Conclusions

Our data suggest that the incidence of secondary infection and infection by antimicrobial resistant pathogens is very high in critically ill patients with COVID-19 with a significant impact on prognosis.

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.

Open abdomen management for severe peritonitis in elderly. Results from the prospective International Register of Open Abdomen (IROA): Cohort study

BACKGROUND

Analyzing the data of the International Register of Open Abdomen (IROA), the feasibility of open abdomen treatment has been demonstrated at every age. This new analysis on the IROA database investigates the risk factors for mortality in elderly patients treated with open abdomen for intra-abdominal infection.

METHODS

Data were derived from the IROA, a prospective observational international cohort study that enrolled patients treated with open abdomen worldwide. A univariate analysis of potential risk factors was performed. Inclusion criteria were patients older than 65 years and treated with open abdomen for intra-abdominal infection. End point was overall mortality, calculated within 30 days after open abdomen management, after 1-month and 1-year follow-up.

RESULTS

A total of 116 patients was analyzed with mean age of 76 ± 7 years. Definitive closure was achieved in 93 patients (93/116, 80.2%) for a mean open abdomen duration of 5.0 ± 5.0 days. Complicated patients were 101 (101/116, 87.1%) for a total of 201 complications. Overall, 62 out of 116 patients (53.4%) died: 23 patients (23/62, 37.1%) during open abdomen management, 29 patients (46.8%) within 30 days after abdominal closure, 9 patients (14.5%) after 1-month follow-up, and 1 patient (1.6%) after 1-year follow-up. Age did not affect mortality (75 ± 6 years in alive patients versus 77 ± 7 years in dead patients, p = 0.773). Definitive abdominal closure was the most important factor to prevent mortality.

CONCLUSIONS

This study confirmed that age alone cannot be considered a determinant for death, even in elderly patients managed with open abdomen for severe intra-abdominal infection.

Intra-Abdominal Infections by Carbapenemase-Producing Enterobacteriaceae in a Surgical Unit: Counting Mortality, Stay, and Costs

Background: Carbapenemase-producing Enterobacteriaceae (CPE)-related infections are a problem in public health at present, including intra-abdominal infections (IAI) and surgical populations. The aim of this study was to determine mortality and related risk factors, length of stay (LOS,) and costs for CPE-IAI in surgical patients. Patients and Methods: Review of CPE-related IAI acquired during admission in a general surgery department from January 2013 to December 2018. A mortality analysis was performed specifically in patients with CPE-IAI, and a global analysis of IAI including patients with CPE-IAI (cases) and matched patients with IAI by non-resistant bacteria (controls). Results: Forty patients with CPE-IAI were included, OXA-48-producing Klebsiella pneumoniae was present in 85%. Global mortality rate at 30 days for CPE-IAI was 17.5%; mortality-related factors were: solid tumor (p = 0.009), metastatic disease (p = 0.005), immunodeficiency (p = 0.039), blood transfusion (p = 0.009), and septic shock (p = 0.011). Predictors related to mortality for IAI in the global analysis included age (p = 0.046), Charlson index (p = 0.036), CPE isolation (p = 0.003), and septic shock (p < 0.001). Median global LOS was 43 days (IQR 27-64) in patients with CPE-IAI, and 27 days (IQR 18-35) in controls (p < 0.001). Median global cost of admission was $31,671 (IQR 14,006-55,745) for patients with CPE-IAI and $20,306 (IQR 11,974-27,947) for controls (p = 0.064). The most relevant locations of underlying disease for CPE-IAI were: colorectal (32.5%) with 57-day LOS (IQR 34-65) and cost of $42,877 (IQR 18,780-92,607), and pancreas (25%) with 60-day LOS (IQR 32-99) and cost of $56,371 (IQR 32,590-113,979). Conclusion: Carbapenemase-producing Enterobacteriaceae-related IAI is associated with substantial mortality, LOS, and costs. Factors related to CPE-IAI mortality are solid tumor, metastatic disease, immunodeficiency, blood transfusion, and septic shock. Carbapenemase-producing Enterobacteriaceae isolation in IAI implies higher risk of mortality.