A survival benefit of combination antibiotic therapy for serious infections associated with sepsis and septic shock is contingent only on the risk of death: a meta-analytic/meta-regression study

Evaluation of Adjunctive Aminoglycoside Therapy Compared to β-Lactam Monotherapy in Critically Ill Patients with Gram-Negative Bloodstream Infections

Background/Objectives: Gram-negative bloodstream infections (GN-BSIs) in the critically ill carry significant mortality, which is exacerbated by delays in appropriate therapy. To improve the time to effective therapy, aminoglycosides are often recommended as empiric adjunctive antimicrobials. However, there is a paucity of clinical data supporting this practice. This study's objective was to evaluate the safety and efficacy of adjunctive aminoglycosides compared to β-lactam monotherapy in patients admitted to the intensive care unit (ICU) with GN-BSI. Methods: This was a retrospective, propensity-matched cohort study of critically ill patients with GN-BSI. The primary outcome was 15-day all-cause mortality. The secondary endpoints evaluated included 30-day mortality, ICU-free survival days, 60-day relapse, 30-day readmission, development of acute kidney injury (AKI), and new resistance. Results: A total of 209 propensity-matched patients were included for analysis: 136 received β-lactam monotherapy and 73 received adjunctive aminoglycoside. The primary outcome of 15-day all-cause mortality was not significantly different between groups (17% vs. 21%; p = 0.644). Additional secondary endpoints of 30-day mortality (22% vs. 25%), ICU-free survival (12.1 vs. 12.2 days), 60-day relapse (3.3% vs. 7.4%), and 30-day readmission (23% vs. 18%) did not yield significant differences. The proportion of AKI was higher in the adjunctive aminoglycoside group but was not found to be significantly different (26.5% vs. 37%). Conclusions: The use of adjunctive aminoglycosides for GN-BSI did not affect clinical outcomes in the critically ill.

Antipseudomonal cephalosporins versus piperacillin/tazobactam or carbapenems for the definitive antibiotic treatment of Pseudomonas aeruginosa bacteraemia: new kids on the ICU block?

BACKGROUND

Pseudomonas aeruginosa bloodstream infections (Pa-BSIs) are still a major cause of mortality in ICUs, posing many treatment uncertainties.

METHODS

This multicentre, retrospective study analysed data from 14 Italian hospitals, including all consecutive adults developing Pa-BSI in ICU during 2021-22 and treated with antibiotics for at least 48 h. The primary aim was to identify predictors of 30 day mortality using Cox regression. Results were adjusted with inverse probability of treatment weighting (IPTW) and for immortal time bias.

RESULTS

Overall, 170 patients were included. High-risk BSI (source: lung, intra-abdominal, CNS) occurred in 118 (69%) patients, and 54 (32%) had septic shock. In 37 (22%), 73 (43%), 12 (7%) and 48 (28%) the definitive backbone therapy was piperacillin/tazobactam, carbapenems, colistin or new antipseudomonal cephalosporins (ceftolozane/tazobactam, n = 20; ceftazidime/avibactam, n = 22; cefiderocol, n = 6), respectively. Moreover, 58 (34%) received a second drug as combination therapy. The incidence of 30 day all-cause mortality was 27.6% (47 patients). By Cox regression, Charlson comorbidity index, neutropenia, septic shock and high-risk BSI were independent predictors of 30 day mortality, while previous colonization by P. aeruginosa, use of antipseudomonal cephalosporins as definitive treatment, and combination therapy were shown to be protective. However, after IPTW adjustment, only the protective effect of antipseudomonal cephalosporins was confirmed (adjusted HR = 0.27, 95% CI = 0.10-0.69), but not for combination therapy. Hence, the treatment effect was calculated: antipseudomonal cephalosporins significantly reduced mortality risk [-17% (95% CI = -4% to -30%)], while combination therapy was beneficial only in the case of septic shock [-66% (95% CI = -44% to -88%].

CONCLUSIONS

In ICU, antipseudomonal cephalosporins may be the preferred target therapy for the treatment of Pa-BSI; in addition, initial combination therapy may be protective in the case of septic shock.

Impact of aminoglycosides on survival rate and renal outcomes in patients with urosepsis: a multicenter retrospective study

BACKGROUND

Combination therapy with a beta-lactam and an aminoglycoside is currently recommended for the empirical treatment of urosepsis. Nephrotoxicity is the most common adverse effect of aminoglycosides and acute kidney injury (AKI) has a significant prognostic impact in septic shock. This study aimed to evaluate the impact of empirical antibiotic therapy with or without an aminoglycoside on survival and renal outcomes in patients admitted to the intensive care unit (ICU) with urosepsis.

METHODS

This multicenter, retrospective, comparative study included all adults admitted to the ICU for urinary sepsis or septic shock between January 2015 and May 2022 in four ICUs of three university hospitals within the Assistance Publique-Hôpitaux de Paris (APHP). The primary outcome was mortality on day 30 after ICU admission. Secondary endpoints included the lack of renal recovery, the need for new renal replacement therapy (RRT), the Major Adverse Kidney Events at day 30 (MAKE 30) and ICU length of stay. Confounding by indication was taken into account using propensity score weighting.

RESULTS

A total of 580 patients were included, median age was 69 years (interquartile: 58-77) and 53.6% were male. Overall, 335 patients (57.8%) were in septic shock and 448 (79.2%) had AKI on admission. A total of 579 patients (99.8%) received a beta-lactam as empirical therapy (with (n = 444) or without (n = 136) aminoglycosides). The overall 30-day mortality rate was 10.5% (61/580). After propensity score weighting, the mortality rate in patients receiving aminoglycosides was 7.7% (7/91) compared to 12.1% (11/91) in those not receiving aminoglycosides (adjusted hazard ratio (aHR) = 0.65 [0.35; 1.23], p = 0.19). No significant differences were found in the lack of renal recovery at day 30 (aHR = 0.88 [0.49; 1.58], p = 0.67), the need for new RRT within 30 days (aHR = 1.01 [0.54; 1.88], p = 0.97), MAKE 30 (aHR = 0.94 [0.60; 1.50], p = 0.81), and ICU length of stay among survivors (aHR = 1.07 [0.87; 1.31], p = 0.53).

CONCLUSIONS

Including aminoglycosides in the empirical antibiotic therapy did not significantly improve 30-day survival in patients admitted to the ICU for urosepsis. However, the use of aminoglycosides was not associated with worse renal outcomes.

Association between empirical antibiotic regimens in emergency department and prognosis of septic patients: A single-Centre real-world study

OBJECTIVES

In this study, we aimed to explore the association between the choice of empirical antibiotic therapy and outcomes in ED patients with sepsis.

METHODS

Patients admitted to ED with sepsis were identified from a single center in the United States, and the data is stored in the MIMIC-IV-ED database. Propensity score matched model was used to match patients receiving empirical mono or combination antibiotic therapy. Logistic regression model was used to assess the associations between empirical antibiotic therapy and in-hospital mortality.

RESULTS

A total of 11,380 ED patients with sepsis were included in the data analysis. After PSM, 3920 pairs of patients were matched between the empirical mono-antibiotic therapy group and combination antibiotic therapy group. No significant benefit was observed among the empirical combination antibiotic therapy patients compared with the mono-antibiotic therapy in in-hospital mortality (OR, 0.96; 95 % CI, 0.81-1.15; P: 0.684). Empirical quinolones mono-therapy was associated with significantly lower mortality compared to cephalosporins (OR, 2.12; 95 % CI, 1.35-3.50; P:0.002), penicillins (OR, 1.87; 95 % CI, 1.08-3.34; P:0.029) and vancomycin mono-therapy (OR, 2.15; 95 % CI, 1.19-3.97; P:0.012).

CONCLUSIONS

Empirical combination antibiotic therapy was not associated with reduced mortality in ED patients with sepsis. Compared with cephalosporins, penicillins and vancomycin, quinolone mono-antibiotic therapy was significantly associated with a decreased risk of in-hospital mortality, especially in patients with respiratory tract infections.

[Epidemiology, diagnosis and treatment of adult patients with nosocomial pneumonia]

BACKGROUND

 Nosocomial pneumonia, encompassing hospital-acquired (HAP) and ventilator-associated pneumonia (VAP), remains a major cause of morbidity and mortality in hospitalized adults. In response to evolving pathogen profiles and emerging resistance patterns, this updated S3 guideline (AWMF Register No. 020-013) provides an evidence-based framework to enhance the diagnosis, risk stratification, and treatment of nosocomial pneumonia.

METHODS

 The guideline update was developed by a multidisciplinary panel representing key German professional societies. A systematic literature review was conducted with subsequent critical appraisal using the GRADE methodology. Structured consensus conferences and external reviews ensured that the recommendations were clinically relevant, methodologically sound, and aligned with current antimicrobial stewardship principles.

RESULTS

 For the management of nosocomial pneumonia patients should be divided in those with and without risk factors for multidrug-resistant pathogens and/or Pseudomonas aeruginosa. Bacterial multiplex-polymerase chain reaction (PCR) should not be used routinely. Bronchoscopic diagnosis is not considered superior to non-bronchoscopic sampling in terms of main outcomes. Combination antibiotic therapy is now reserved for patients in septic shock and high risk for multidrug-resistant pathogens, while select patients may be managed with monotherapy (e. g., meropenem). In clinically stabilized patients, antibiotic therapy should be de-escalated and focused, as well as duration shortened to 7-8 days. In critically ill patients, prolonged application of suitable beta-lactam antibiotics should be preferred. Patients on the intensive care unit (ICU) are at risk for invasive pulmonary aspergillosis (IPA). Diagnostics for Aspergillus should be performed with an antigen test from bronchial lavage fluid.

CONCLUSION

 This updated S3 guideline offers a comprehensive, multidisciplinary approach to the management of nosocomial pneumonia in adults. By integrating novel diagnostic modalities and refined therapeutic strategies, it aims to standardize care, improve patient outcomes, and enhance antimicrobial stewardship to curb the emergence of resistant pathogens.

Impact of Empirical Treatment Recommendations From 2017 European Guidelines for Nosocomial Pneumonia

BACKGROUND

The management of nosocomial pneumonia represents a major challenge in the ICU. European guidelines from 2017 proposed an algorithm for the prescription of empirical antimicrobial treatment based on medical history, local ecology, and severity (ie, presence or absence of septic shock). We assessed this algorithm's usefulness by comparing outcomes with and without guideline adherence in a population at high risk of multiresistance and mortality.

RESEARCH QUESTION

Are the recommendations of the latest European guidelines effective in reducing the incidence of adverse outcomes in patients with nosocomial pneumonia admitted to the ICU?

STUDY DESIGN AND METHODS

We retrospectively analyzed data from a prospective cohort of 507 patients from 6 ICUs in our center. To minimize bias, we only included patients with microbiologically confirmed pneumonia. The primary outcome was 28-day mortality. Secondary outcomes were 90-day mortality, ICU mortality, inadequate treatment, treatment failure, and overtreatment.

RESULTS

In total, 315 patients met the inclusion criteria. Outcomes were comparable in the groups with and without guideline adherence, except for overtreatment, which was higher when guidelines were followed (42.5% vs 66.3%; P < .001). In the subgroup without septic shock treated according to guidelines, reductions were noted in both ICU mortality (28.8% vs 14.5%; P = .031) and adjusted 28-day mortality (hazard ratio, 3.07; 95% CI, 1.13-7.85; P = .027). By contrast, no benefit was observed when patients presented with septic shock at diagnosis.

INTERPRETATION

Our findings indicate that the European guideline treatment algorithm is effective in reducing mortality in patients without septic shock but not in those with septic shock at the time of diagnosis. Future studies should clarify whether adjustments need to be made to improve outcomes in patients with septic shock.

Optimization of Antimicrobial Use for Sepsis in Calves: Bayesian Evaluation of Existing and Novel Sepsis Scores

Early recognition and rapid appropriate antimicrobial treatment is essential for survival of sepsis. To date, it is unclear which sepsis score should be used for an early diagnosis in calves. The objective of this study was to evaluate two existing scores (Trefz and Fecteau), three novel calf sepsis screening models (CSS, CSSA, CSSB), and blood culture as diagnostic test for sepsis, using Bayesian latent class evaluation. A total of 131 sick calves were included in this study. Sepsis prevalence was 45%, 27%, 56%, 47%, and 55%, when using the Trefz score, Fecteau score, CSS, CSSA, and CSSB, respectively, and 22% had a relevant positive blood culture. The newly established models CSS (including ≥2 SIRS-criteria and abnormal mental state) and CSSB (alternative model CSS for practice, substituting abnormal leukocyte count with mucosae) had the highest sensitivity, with 86% and 84%, respectively, and could be interesting screening tests for sepsis. Sensitivity of the existing Trefz and Fecteau score was 70% and 35-39%, respectively. The presented new sepsis scoring systems have potential as screening tests to identify calves at risk, after which a calf-side diagnostic test is advised to confirm the diagnosis. Its use might aid in the rationalization of antimicrobial use in critically ill calves.

The Outcome of Hospital-Acquired Bloodstream Infection and Its Associated Factors in Critical Care Unit

Background

Hospital-acquired bloodstream infections (BSI) are associated with high morbidity and mortality rates. This study was conducted to describe the outcomes and the prognosis of hospital-acquired BSI in the Critical Care Unit, Hospital Pakar Universiti Sains Malaysia (HPUSM), as well as to identify associated factors of treatment failure and mortality at 28 days.

Methods

This prospective cohort study was conducted in the Critical Care Unit of HPUSM from September 2019 to March 2021. Eligible participants included patients with a positive blood culture recorded after 48 hours of admission to hospital.

Results

There was a total of 250 patients, whose positive blood cultures were isolated. The main isolated organisms were Klebsiella pneumonia (23.6%), Pseudomonas spp. (19.2%), Escherichia coli (12.8%) and Acinetobacter sp. (9.2%). The mortality of hospital-acquired BSI was 27.6%. Multiple logistic regression analysis revealed that age [adjusted odds ratio (OR) = 1.06; 95% confidence interval (CI): 1.03, 1.09; p < 0.001], cases with extended-spectrum beta-lactamases (ESBL) (adjusted OR = 5.57; 95% CI: 2.04, 15.21; p = 0.001), with multidrug-resistant (MDR) organisms (adjusted OR = 14.70; 95% CI: 3.97, 54.48; p < 0.001) and those with a sequential organ failure assessment (SOFA) score > 11 (adjusted OR = 4.16; 95% CI: 1.31, 13.19; p = 0.015) had statistically significant associations with treatment failure. Factors significantly associated with 28-day mortality included age (adjusted OR: 1.06: 95% CI; 1.03, 1.09; p < 0.001), MDR organisms (adjusted OR = 14.70; 95% CI: 3.97, 54.48; p < 0.001) and SOFA score > 11 (adjusted OR = 4.16; 95% CI: 1.31, 13.19; p = 0.015).

Conclusion

The elderly, ESBL, MDR organisms and high SOFA scores were associated with treatment failure and 28-day mortality in hospital-acquired BSI.

Key summary of German national guideline for adult patients with nosocomial pneumonia- Update 2024 Funding number at the Federal Joint Committee (G-BA): 01VSF22007

PURPOSE

This executive summary of a German national guideline aims to provide the most relevant evidence-based recommendations on the diagnosis and treatment of nosocomial pneumonia.

METHODS

The guideline made use of a systematic assessment and decision process using evidence to decision framework (GRADE). Recommendations were consented by an interdisciplinary panel. Evidence analysis and interpretation was supported by the German innovation fund providing extensive literature searches and (meta-) analyses by an independent methodologist. For this executive summary, selected key recommendations are presented including the quality of evidence and rationale for the level of recommendation.

RESULTS

The original guideline contains 26 recommendations for the diagnosis and treatment of adults with nosocomial pneumonia, thirteen of which are based on systematic review and/or meta-analysis, while the other 13 represent consensus expert opinion. For this key summary, we present 11 most relevant for everyday clinical practice key recommendations with evidence overview and rationale, of which two are expert consensus and 9 evidence-based (4 strong, 5 weak and 2 open recommendations). For the management of nosocomial pneumonia patients should be divided in those with and without risk factors for multidrug-resistant pathogens and/or Pseudomonas aeruginosa. Bacterial multiplex-polymerase chain reaction (PCR) should not be used routinely. Bronchoscopic diagnosis is not considered superior to´non-bronchoscopic sampling in terms of main outcomes. Only patients with septic shock and the presence of an additional risk factor for multidrug-resistant pathogens (MDRP) should receive empiric combination therapy. In clinically stabilized patients, antibiotic therapy should be de-escalated and focused. In critically ill patients, prolonged application of suitable beta-lactam antibiotics should be preferred. Therapy duration is suggested for 7-8 days. Procalcitonin (PCT) based algorithm might be used to shorten the duration of antibiotic treatment. Patients on the intensive care unit (ICU) are at risk for invasive pulmonary aspergillosis (IPA). Diagnostics for Aspergillus should be performed with an antigen test from bronchial lavage fluid.

CONCLUSION

The current guideline focuses on German epidemiology and standards of care. It should be a guide for the current treatment and management of nosocomial pneumonia in Germany.

Impact of adequate empirical combination therapy on mortality in septic shock due to Pseudomonas aeruginosa bloodstream infections: a multicentre retrospective cohort study

OBJECTIVES

To determine the association of adequate empirical combination therapy (AECT) with 30-day all-cause mortality in patients with septic shock due to Pseudomonas aeruginosa bloodstream infections (BSI).

METHODS

This multicentre, retrospective cohort study analysed data from 14 public hospitals in Italy, including all consecutive adult patients admitted during 2021-2022 with septic shock due to P. aeruginosa BSI. We compared the outcomes of patients receiving AECT to those on adequate empirical monotherapy (AEMT) using Cox regression analyses.

RESULTS

Of the 98 patients who received adequate empirical antibiotic treatment for septic shock due to P. aeruginosa BSI, 24 underwent AECT and 74 were given AEMT. AECT was associated with a lower 30-day all-cause mortality (25%, six out of 24) compared to AEMT (56.8%, 42 out of 74; P = 0.007). Multivariate Cox regression analysis indicated AECT as the only factor significantly associated with improved survival (aHR 0.30; 95% CI 0.12-0.71; P = 0.006). By contrast, the use of monotherapy or combination therapy in the definitive regimen did not influence mortality (aHR 0.73; 95% CI 0.25-2.14; P = 0.568).

CONCLUSIONS

AECT may be associated with reduced mortality compared to monotherapy in septic shock patients due to P. aeruginosa BSI. However, the administration of definitive adequate monotherapy or combination therapy yields similar outcomes, suggesting that once susceptibility is documented, switching to a single active in vitro drug is safe and feasible. Further studies are recommended to validate these findings.

Study of Empiric Antibiotic Prescription Patterns and Microbiological Isolates in Hemodynamically Stable and Unstable ICU Patients With Community-Acquired Sepsis

Background: The efficacy of combination empiric antibiotic therapy for all intensive care unit (ICU) patients with community-acquired sepsis is a subject of ongoing debate in the era of increasing antibiotic resistance. This study was conducted to evaluate the patterns of antibiotic usage and microbial resistance in sepsis patients admitted to the ICU with both hemodynamically stable (HS) and unstable states and to analyze their clinical outcomes. Methods: In this observational study, patients aged 18 years and above who received antibiotics upon admission and had a culture report were included. These patients were categorized into the following groups: HS and hemodynamically unstable (HU), single or combined antibiotics group (more than one antibiotic used empirically to cover one or more groups of organisms), culture-positive and culture-negative group. The microbiological isolates were grouped according to their identified resistance patterns. The outcome parameters involved assessing the differences in empiric antibiotics use upon admission and microbial resistance with hemodynamic stability and investigating any associations with ICU and hospital outcomes. Results: The study included a total of 2675 patients, of which 70.3% were in the HS group, and 29.7% in the HU group. The use of combination antibiotics was significantly higher (p < 0 .0001) across all groups. Carbapenems were used more frequently in the single antibiotic group (p < 0 .001). The culture was positive in 27.8% (n  =  747) of patients. A significantly higher number of patients in the HU group (p < 0 .001) were found to have carbapenem-resistant and multidrug-resistant organisms. The ICU and hospital mortality rates were significantly higher in the HU group (p < 0 .001), the culture-positive group with resistance (p < 0 .001), and the HS patients who received combination antibiotics. Conclusion: The usage of combination antibiotics, coupled with the presence of resistant organisms, emerged as an important variable in predicting ICU and hospital mortality rates in cases of community-acquired sepsis.

Guidelines for Antibiotics Prescription in Critically Ill Patients

How to cite this article: Khilnani GC, Tiwari P, Mittal S, Kulkarni AP, Chaudhry D, Zirpe KG, et al. Guidelines for Antibiotics Prescription in Critically Ill Patients. Indian J Crit Care Med 2024;28(S2):S104-S216.

Theoretical investigation of thermoelectric properties of methyl blue-based molecular junctions

Thermoelectric properties of a family of methyl blue-based molecular junctions were theoretically studied using a combination of density functional theory (DFT) methods, and quantum transport theory (QTT). Employing different numbers of amino groups not only proves itself as a powerful strategy for controlling the transport behaviour and lifting the transmission coefficient T(E) from 1.91 × 10-5 to 7.45 × 10-5 with increasing the amino groups from zero to four, but also it enhances the thermoelectric properties of these molecules, since it increases the Seebeck coefficient (S) from 106.8 to 202.4 μV K-1 and the electronic figure of merit (Z el T) has been raised from 0.15 to 0.35, making these molecules promising candidates for thermoelectric applications.

Clinical characteristics and antimicrobial therapy of healthcare-associated carbapenem-non-susceptible gram-negative bacterial meningitis: a 16-year retrospective cohort study

OBJECTIVE

Healthcare-associated Gram-negative bacterial meningitis is a substantial clinical issue with poor outcomes, especially for neurosurgical patients. Here, we aimed to study the characteristics and treatment options of patients with healthcare-associated carbapenem-non-susceptible (Carba-NS) Gram-negative bacterial meningitis.

METHODS

This observational cohort study was conducted at a teaching hospital from 2004 to 2019. The clinical characteristics of patients with meningitis with Carba-NS and carbapenem-susceptible (Carba-S) bacilli were compared, and the antimicrobial chemotherapy regimens and outcomes for Carba-NS Gram-negative bacterial meningitis were analyzed.

RESULTS

A total of 505 patients were included, of whom 83.8% were post-neurosurgical patients. The most common isolates were Acinetobacter spp. and Klebsiella spp., which had meropenem-resistance rates of 50.6% and 42.5%, respectively, and showed a markedly growing carbapenem-resistance trend. Kaplan-Meier curve analysis revealed that Carba-NS Gram-negative bacilli were associated with a significantly higher in-hospital mortality rate (18.8%, 35/186) compared to the Carba-S group (7.4%, 9/122; P = 0.001). For Carba-NS Enterobacterales meningitis, aminoglycoside-based and trimethoprim-sulfamethoxazole-based regimens yielded significantly higher clinical efficacy rates than non-aminoglycoside-based and non-trimethoprim-sulfamethoxazole-based regimens (69.0% vs. 38.7%, P = 0.019 and 81.8% vs. 46.9%, P = 0.036, respectively). For Carba-NS A. baumannii complex meningitis, tetracycline-based (including doxycycline, minocycline, or tigecycline) therapy achieved a significantly higher clinical efficacy rate (62.9%, 22/35) than the non-tetracycline-based therapy group (40.4%, 19/47; P = 0.044).

CONCLUSIONS

Our findings revealed that Carba-NS Gram-negative bacilli are associated with higher in-hospital mortality in patients with healthcare-associated meningitis. The combination therapies involving particular old antibiotics may improve patients' outcome.

TRIAL REGISTRATION

This study was registered on the Chinese Clinical Trial Register under ChiCTR2000036572 (08/2020).

Clinical outcomes in combination versus mono antibiotic therapy in ICU admitted patients with a suspected infection - A substudy of the DIANA study

PURPOSE

In a retrospective cohort study of intensive care unit (ICU) admitted adult patients with suspected or confirmed infection, associations between combination versus mono empirical antibiotic therapy and clinical cure at day 7 as well as mortality at day 7 and 28, were investigated.

MATERIALS AND METHODS

Patients from the DIANA study were grouped and analysed by combination versus mono antibiotic therapy. Clinical cure was defined as survival and resolution of all signs and symptoms related to the infection. Odds ratios (ORs) were calculated by logistic regression analyses.

RESULTS

Of the 1398 included patients, 568 patients (41%) received combination therapy. In total, 641(46%) patients achieved clinical cure and 135 (10%) patients had died as of day 7. There were no significant associations between combination and mono therapy relating to clinical cure and mortality.

CONCLUSIONS

This study found no differences in clinical cure and mortality between empirical combination versus mono therapy in a large cohort of ICU patients with a suspected infection.

Within-species variability of antibiotic interactions in Gram-negative bacteria

Treatments with antibiotic combinations are becoming increasingly important even though the supposed clinical benefits of combinations are, in many cases, unclear. Here, we systematically examined how several clinically used antibiotics interact and affect the antimicrobial efficacy against five especially problematic Gram-negative pathogens. A total of 232 bacterial isolates were tested against different pairwise antibiotic combinations spanning five classes, and the ability of all combinations in inhibiting growth was quantified. Descriptive statistics, principal component analysis (PCA), and Spearman's rank correlation matrix were used to determine the correlations between the different combinations on interaction outcome. Several important conclusions can be drawn from the 696 examined interactions. Firstly, within a species, the interactions are in general conserved but can be isolate-specific for a given antibiotic combination and can range from antagonistic to synergistic. Secondly, additive and antagonistic interactions are the most common observed across species and antibiotics, with 87.1% of isolate-antibiotic combinations being additive, 11.6% antagonistic, and only 0.3% showing synergy. These findings suggest that to achieve the highest precision and efficacy of combination therapy, not only isolate-specific interaction profiling ought to be routinely performed, in particular to avoid using drug combinations that show antagonistic interaction and an expected associated reduction in efficacy, but also discovering rare and potentially valuable synergistic interactions.IMPORTANCEAntibiotic combinations are often used to treat bacterial infections, which aim to increase treatment efficacy and reduce resistance evolution. Typically, it is assumed that one specific antibiotic combination has the same effect on different isolates of the same species, i.e., the interaction is conserved. Here, we tested this idea by examining how several clinically used antibiotics interact and affect the antimicrobial efficacy against several bacterial pathogens. Our results show that, even though within a species the interactions are often conserved, there are also isolate-specific differences for a given antibiotic combination that can range from antagonistic to synergistic. These findings suggest that isolate-specific interaction profiling ought to be performed in clinical microbiology routine to avoid using antagonistic drug combinations that might reduce treatment efficacy.

Multidrug-Resistant Sepsis: A Critical Healthcare Challenge

Sepsis globally accounts for an alarming annual toll of 48.9 million cases, resulting in 11 million deaths, and inflicts an economic burden of approximately USD 38 billion on the United States healthcare system. The rise of multidrug-resistant organisms (MDROs) has elevated the urgency surrounding the management of multidrug-resistant (MDR) sepsis, evolving into a critical global health concern. This review aims to provide a comprehensive overview of the current epidemiology of (MDR) sepsis and its associated healthcare challenges, particularly in critically ill hospitalized patients. Highlighted findings demonstrated the complex nature of (MDR) sepsis pathophysiology and the resulting immune responses, which significantly hinder sepsis treatment. Studies also revealed that aging, antibiotic overuse or abuse, inadequate empiric antibiotic therapy, and underlying comorbidities contribute significantly to recurrent sepsis, thereby leading to septic shock, multi-organ failure, and ultimately immune paralysis, which all contribute to high mortality rates among sepsis patients. Moreover, studies confirmed a correlation between elevated readmission rates and an increased risk of cognitive and organ dysfunction among sepsis patients, amplifying hospital-associated costs. To mitigate the impact of sepsis burden, researchers have directed their efforts towards innovative diagnostic methods like point-of-care testing (POCT) devices for rapid, accurate, and particularly bedside detection of sepsis; however, these methods are currently limited to detecting only a few resistance biomarkers, thus warranting further exploration. Numerous interventions have also been introduced to treat MDR sepsis, including combination therapy with antibiotics from two different classes and precision therapy, which involves personalized treatment strategies tailored to individual needs. Finally, addressing MDR-associated healthcare challenges at regional levels based on local pathogen resistance patterns emerges as a critical strategy for effective sepsis treatment and minimizing adverse effects.

Single-drug versus combination antimicrobial therapy in critically ill patients with hospital-acquired pneumonia and ventilator-associated pneumonia due to Gram-negative pathogens: a multicenter retrospective cohort study

KEY MESSAGES

In this study including 391 critically ill patients with nosocomial pneumonia due to Gram-negative pathogens, combination therapy was not associated with a reduced hazard of death at Day 28 or a greater likelihood of clinical cure at Day 14. No over-risk of AKI was observed in patients receiving combination therapy.

BACKGROUND

The benefits and harms of combination antimicrobial therapy remain controversial in critically ill patients with hospital-acquired pneumonia (HAP), ventilated HAP (vHAP) or ventilator-associated pneumonia (VAP) involving Gram-negative bacteria.

METHODS

We included all patients in the prospective multicenter OutcomeRea database with a first HAP, vHAP or VAP due to a single Gram-negative bacterium and treated with initial adequate single-drug or combination therapy. The primary endpoint was Day-28 all-cause mortality. Secondary endpoints were clinical cure rate at Day 14 and a composite outcome of death or treatment-emergent acute kidney injury (AKI) at Day 7. The average effects of combination therapy on the study endpoints were investigated through inverse probability of treatment-weighted regression and multivariable regression models. Subgroups analyses were performed according to the resistance phenotype of the causative pathogens (multidrug-resistant or not), the pivotal (carbapenems or others) and companion (aminoglycosides/polymyxins or others) drug classes, the duration of combination therapy (< 3 or ≥ 3 days), the SOFA score value at pneumonia onset (< 7 or ≥ 7 points), and in patients with pneumonia due to non-fermenting Gram-negative bacteria, pneumonia-related bloodstream infection, or septic shock.

RESULTS

Among the 391 included patients, 151 (38.6%) received single-drug therapy and 240 (61.4%) received combination therapy. VAP (overall, 67.3%), vHAP (16.4%) and HAP (16.4%) were equally distributed in the two groups. All-cause mortality rates at Day 28 (overall, 31.2%), clinical cure rate at Day 14 (43.7%) and the rate of death or AKI at Day 7 (41.2%) did not significantly differ between the groups. In inverse probability of treatment-weighted analyses, combination therapy was not independently associated with the likelihood of all-cause death at Day 28 (adjusted odd ratio [aOR], 1.14; 95% confidence interval [CI] 0.73-1.77; P = 0.56), clinical cure at Day 14 (aOR, 0.79; 95% CI 0.53-1.20; P = 0.27) or death or AKI at Day 7 (aOR, 1.07; 95% CI 0.71-1.63; P = 0.73). Multivariable regression models and subgroup analyses provided similar results.

CONCLUSIONS

Initial combination therapy exerts no independent impact on Day-28 mortality, clinical cure rate at Day 14, and the hazard of death or AKI at Day 7 in critically ill patients with mono-bacterial HAP, vHAP or VAP due to Gram-negative bacteria.

Addition of aminoglycosides reduces recurrence of infections with multidrug-resistant Gram-negative bacilli in patients with sepsis and septic shock

OBJECTIVES

Aminoglycosides and β-lactams have been recommended for treatment of sepsis/septic shock despite a lack of mortality benefit. Previous studies have examined resistance emergence for the same bacterial isolate using old dosing regimens and during a narrow follow-up window. We hypothesised that combination regimens employing aminoglycosides will decrease the cumulative incidence of infections due to multidrug-resistant (MDR) Gram-negative bacilli (GNB) compared with β-lactams alone.

METHODS

All adult patients admitted to Barnes Jewish Hospital between 2010 and 2017 with a diagnosis of sepsis/septic shock were included in this retrospective cohort study. Patients were divided into two treatment groups, with and without aminoglycosides. Patient demographics, severity of presentation, administered antibiotics, follow-up cultures with susceptibility results for a period of 4-60 days, and mortality were extracted. After propensity score matching, a Fine-Gray subdistribution proportional hazards model summarised the estimated incidence of subsequent infections with MDR-GNB in the presence of all-cause death as a competing risk.

RESULTS

A total of 10 212 septic patients were included, with 1996 (19.5%) treated with at least two antimicrobials including one aminoglycoside. After propensity score matching, the cumulative incidence of MDR-GNB infections between 4-60 days was lower in the combination group (incidence at 60 days 0.073, 95% CI 0.062-0.085) versus patients not receiving aminoglycosides (0.116, 95% CI 0.102-0.130). Patients aged ≤65 years and with haematological malignancies had a larger treatment effect in subgroup analyses.

CONCLUSION

Addition of aminoglycosides to β-lactams may protect against subsequent infections due to MDR-GNB in patients with sepsis/septic shock.

Amikacin-induced acute kidney injury in mechanically ventilated critically ill patients with sepsis

In this retrospective cohort study, we aimed to evaluate the incidence, risk factors and outcomes of amikacin-induced acute kidney injury (AKI) in critically ill patients with sepsis. A total of 311 patients were included in the study. Of them, 83 (26.7%) had amikacin-induced AKI. In model 1, the multivariable analysis demonstrated concurrent use of colistin (OR 25.51, 95%CI 6.99-93.05, p< 0.001), presence of septic shock during amikacin treatment (OR 4.22, 95%CI 1.76-10.11, p=0.001), and Charlson Comorbidity Index (OR 1.14, 95%CI 1.02-1.28, p=0.025) as factors independently associated with an increased risk of amikacin-induced AKI. In model 2, the multivariable analysis demonstrated concurrent use of at least one nephrotoxic agent (OR 1.95, 95%CI 1.10-3.45; p=0.022), presence of septic shock during amikacin treatment (OR 3.48, 95%CI 1.61-7.53; p=0.002), and Charlson Comorbidity Index (OR 1.12, 95%CI 1.01-1.26; p=0.037) as factors independently associated with an increased risk of amikacin-induced AKI. In conclusion, before amikacin administration, the risk of AKI should be considered, especially in patients with multiple complicated comorbid diseases, septic shock, and those receiving colistin therapy.

Effect of appropriate empirical antimicrobial therapy on mortality of patients with Gram-negative bloodstream infections: a retrospective cohort study

BACKGROUND

Little evidence exists regarding the prevalence of pathogens in bloodstream infections (BSIs), the mortality risk, and the benefit of combination therapy over monotherapy. This study aims to describe patterns of empiric antimicrobial therapy, and the epidemiology of Gram-negative pathogens, and to investigate the effect of appropriate therapy and appropriate combination therapy on the mortality of patients with BSIs.

METHODS

This was a retrospective cohort study including all patients with BSIs of Gram-negative pathogens from January 2017 to December 2022 in a Chinese general hospital. The in-hospital mortality was compared between appropriate and inappropriate therapy, and between monotherapy and combination therapy for patients receiving appropriate therapy. We used Cox regression analysis to identify factors independently associated with in-hospital mortality.

RESULTS

We included 205 patients in the study, of whom 147 (71.71%) patients received appropriate therapy compared with 58 (28.29%) who received inappropriate therapy. The most common Gram-negative pathogen was Escherichia coli (37.56%). 131 (63.90%) patients received monotherapy and 74 (36.10%) patients received combination therapy. The in-hospital mortality was significantly lower in patients administered appropriate therapy than inappropriate therapy (16.33% vs. 48.28%, p = 0.004); adjusted hazard ratio [HR] 0.55 [95% CI 0.35-0.84], p = 0.006). In-hospital mortality was also not different in combination therapy and monotherapy in the multivariate Cox regression analyses (adjusted HR 0.42 [95% CI 0.15-1.17], p = 0.096). However, combination therapy was associated with lower mortality than monotherapy in patients with sepsis or septic shock (adjusted HR 0.94 [95% CI 0.86-1.02], p = 0.047).

CONCLUSIONS

Appropriate therapy was associated with a protective effect on mortality among patients with BSIs due to Gram-negative pathogens. Combination therapy was associated with improved survival in patients with sepsis or septic shock. Clinicians need to choose optical empirical antimicrobials to improve survival outcomes in patients with BSIs.

Aminoglycosides for the Treatment of Severe Infection Due to Resistant Gram-Negative Pathogens

Aminoglycosides are a family of rapidly bactericidal antibiotics that often remain active against resistant Gram-negative bacterial infections. Over the past decade, their use in critically ill patients has been refined; however, due to their renal and cochleovestibular toxicity, their indications in the treatment of sepsis and septic shock have been gradually reduced. This article reviews the spectrum of activity, mode of action, and methods for optimizing the efficacy of aminoglycosides. We discuss the current indications for aminoglycosides, with an emphasis on multidrug-resistant Gram-negative bacteria, such as extended-spectrum β-lactamase-producing Enterobacterales, carbapenemase-producing Enterobacterales, multidrug-resistant Pseudomonas aeruginosa, and carbapenem-resistant Acinetobacter baumannii. Additionally, we review the evidence for the use of nebulized aminoglycosides.

Evaluation of synergistic activity of antibiotic combinations in extensive drug-resistant Acinetobacter species using checkerboard assay

Introduction. Acinetobacter is one of the challenging drug-resistant organisms that can endanger patients' lives if not treated properly.Aim. This study was designed to investigate the activity of three synergistic antimicrobial combinations against extensive drug-resistant Acinetobacter isolates; ampicillin/sulbactam plus amikacin, ampicillin/sulbactam plus ciprofloxacin, and meropenem plus amikacin.Methodology. Minimum inhibitory concentrations of 100 XDR-Acinetobacter isolates were determined using the Vitek2 system. The broth micro-dilution method was performed to determine tigecycline MIC. Checkerboard assay was used to evaluate in vitro activity of the three antibiotic combinations.Results. MIC results by the Vitek 2C system revealed that all Acinetobacter isolates were resistant to all tested antibiotics except for colistin against which no resistance was reported. As for tigecycline, all isolates were susceptible. Regarding MIC results of each antibiotic, all isolates were resistant to meropenem and ciprofloxacin. While 95 % of isolates were resistant to both ampicillin/sulbactam and amikacin. The activities of antibiotic combinations by checkerboard assay were as follows: ampicillin/sulbactam plus amikacin was synergic in 52 %, additive 40 % and indifferent in 8 % of isolates, ampicillin/sulbactam plus ciprofloxacin was synergic in 40 %, additive 46 % and indifferent in 14 % of isolates, meropenem/amikacin combination was synergic in 22 %, additive in 49 % of isolates and indifferent in 29 % of isolates. No antagonistic activity was detected against any of the tested antibiotic combinations.Conclusion. Ampicillin/sulbactam plus amikacin showed the highest synergistic activity followed by ampicillin/sulbactam plus ciprofloxacin. This reflects the value of adding aminoglycosides to either of a β-lactam or quinolone. The tested antibiotic combinations are promising treatment options for XDR-Acinetobacter.

Development of a Predictive Dosing Nomogram to Achieve PK/PD Targets of Amikacin Initial Dose in Critically Ill Patients: A Non-Parametric Approach

French guidelines recommend reaching an amikacin concentration of ≥8 × MIC 1 h after beginning infusion (C_1h), with MIC = 8 mg/L for probabilistic therapy. We aimed to elaborate a nomogram guiding clinicians in choosing the right first amikacin dose for ICU patients in septic shock. A total of 138 patients with 407 observations were prospectively recruited. A population pharmacokinetic model was built using a non-parametric, non-linear mixed-effects approach. The total body weight (TBW) influenced the central compartment volume, and the glomerular filtration rate (according to the CKD-EPI formula) influenced its clearance. A dosing nomogram was produced using Monte Carlo simulations of the amikacin amount needed to achieve a C_1h ≥ 8 × MIC. The dosing nomogram recommended amikacin doses from 1700 mg to 4200 mg and from 28 mg/kg to 49 mg/kg depending on the patient's TBW and renal clearance. However, a C_through ≤ 2.5 mg/L 24 h and 48 h after an optimal dose of amikacin was obtained with probabilities of 0.20 and 0.81, respectively. Doses ≥ 30 mg/kg are required to achieve a C_1h ≥ 8 × MIC with MIC = 8 mg/L. Targeting a MIC = 8 mg/L should depend on local ecology.

New advances in management and treatment of multidrug-resistant Klebsiella pneumoniae

INTRODUCTION

The management of multidrug-resistant (MDR) Klebsiella pneumoniae (KP) represents a major challenge in the field of infectious diseases. It is associated with a high rate of nosocomial infections with a mortality rate that reaches approximately 50%, even when using an effective antimicrobial therapy. Therefore, combined actions addressing infection control and antibiotic stewardship are required to delay the emergence of resistance. Since new antimicrobial agents targeting MDR-GNB bacteria have been produced during the last years and are now available for physicians to treat MDR, it is fundamental to choose appropriate antimicrobial therapy for K. pneumoniae infection.

AREAS COVERED

The PubMed database was searched to review the most significant recent literature on the topic, including data from articles coming from endemic areas and from the current European and American Guidelines.

EXPERT OPINION

We explore the most effective strategies for prevention of MDR-KP spread and the currently available treatment options, focusing on comparing old strategies and new compounds. We reviewed data concerning newly developed drugs that could play an important role in the future; we also propose a treatment algorithm that could be useful for physicians in daily clinical practice.

The combination effect of meropenem/sulbactam/polymyxin-B on the pharmacodynamic parameters for mutant selection windows against carbapenem-resistant Acinetobacter baumannii

The objective of this study was to evaluate whether combinations of sulbactam, meropenem, and polymyxin-B could reduce or close the gap of mutant selection window (MSW) of individual antibiotics against Acinetobacter baumannii harboring OXA-23. MICs of three antimicrobials used alone and in combination (meropenem/polymyxin-B or meropenem/polymyxin-B/sulbactam) were obtained in 11 clinical isolates and mutant prevention concentrations were determined in 4 of the 11 isolates. All isolates were resistant to meropenem or polymyxin-B. Combining meropenem and polymyxin-B with or without sulbactam resulted in synergistic bactericidal activities. Pharmacokinetic (PK) simulations of drug concentrations in the blood and epithelial lining fluid coupled with pharmacodynamic (PD) evaluations revealed that the fractions of time over the 24-h in terms of free drug concentration within the MSW (fT_MSW) and above the MPC (fT_>MPC) were optimized by combination therapy. The resultant clinical regimens of meropenem, polymyxin-B, and sulbactam evaluated in the PK-PD analysis were 2 g q8h, 2.5 mg/kg loading dose followed by 1.5 mg/kg q12h, and 3 g q8h, respectively, in patients with normal renal function. Subsequent corresponding equivalent exposure regimens would depend on the extent of renal failure. The overall results indicate that combination antibiotics consisting of sulbactam/meropenem/polymyxin-B can confer potential efficacy against A. baumannii harboring OXA-23, and reduce the opportunity for bacteria to develop further resistance. This study provides a framework for pharmacodynamic evaluation of drug-resistant mutant suppression in an antimicrobial co-administration setting. The results thereby lay the groundwork for additional studies and future clinical confirmation is warranted.

Compatibility of prolonged infusion antibiotics during Y-site administration

BACKGROUND

Antimicrobial resistance is a threat to global public health. The use of prolonged infusions in the hospital setting for certain antimicrobials is widely increasing in order to improve their efficacy and safety, including resistance development. Due to limited vascular access, it is important to clarify whether they can be infused through the same line with other drugs during Y-site administration.

AIM

The aim of this review is to update and summarize the evidence on Y-site compatibility of antibacterial agents administered as prolonged infusions in intensive care units (ICUs).

STUDY DESIGN

A literature review of PubMed, EMBASE and Trissel's Handbook on Injectable Drugs databases was conducted on the compatibility of selected antimicrobials administered simultaneously at a Y-site connection with parenteral nutrition and other widely used drugs in ICUs. All articles published up to October 30, 2021, in English or Spanish were included, regardless of the type of publication (original articles, case reports, letters, etc.). Eligible antimicrobials were those that can be administered as prolonged infusions: ceftazidime, cefepime, piperacillin/tazobactam, meropenem, ceftolozane/tazobactam, ceftaroline, cloxacillin, ceftobiprole, vancomycin and fosfomycin.

RESULTS

A total of 1302 drug-to-drug potential combinations were explored, 196 (15.05%) were found to be incompatible, and in 541 (41.55%), data were not available. The results were presented in a simple 2-dimensional consultation chart as a quick reference for health care professionals.

CONCLUSIONS

This review provides useful and reliable information on the compatibility of antimicrobials administered as Y-site infusion with other drugs commonly used in the critical setting. This review contributes to patient safety in nursing practice.

RELEVANCE TO CLINICAL PRACTICE

To our knowledge, this is the first review on Y-site compatibility of antimicrobials used as prolonged infusions with other commonly used drugs, including anti-emetics, analgesics and anti-epileptic and parenteral nutrition. The results of the current review need to be addressed to promote the knowledge sharing between health professionals and improve the quality and safety of patients. We believe that this review may serve as a simple and effective 2-dimensional updated drug-to-drug compatibility reference chart for critical care nurses.

Aminoglycoside Pharmacokinetics in Critically Ill Patients Undergoing Continuous Renal Replacement Therapy

BACKGROUND

There are few studies describing aminoglycoside pharmacokinetics during continuous renal replacement therapy (CRRT).

OBJECTIVE

To characterize the effect of CRRT on aminoglycoside clearance and volume of distribution (V_d).

METHODS

Retrospective observational pharmacokinetic study of adult critically ill oncologic patients who received a first dose of amikacin or tobramycin during CRRT between February 2012 and May 2017. Study outcomes included aminoglycoside clearance, V_d, and attainment of the target peak: MIC (minimum inhibitory concentration) ratio as a surrogate for dosing appropriateness.

RESULTS

In total, 80 patients were included, sustained low-efficiency dialysis (SLED), n = 49; continuous venovenous hemodialysis (CVVHD), n = 19; continuous venovenous hemofiltration (CVVH), n = 12. Fifty-one patients received amikacin at a median dose of 14.5 mg/kg per actual body weight and achieved a median peak level of 26.7 mg/L. Twenty-nine patients received tobramycin at a median dose of 6.5 mg/kg actual body weight and achieved a median peak level of 10.3 mg/L. The median aminoglycoside clearance was 63.1 mL/min and was similar between CRRT modality groups (P = 0.97). The median V_d was 0.47 L/kg and was different between the SLED and CVVH groups (P = 0.007). Attainment of target peak: MIC occurred in 29% in the total study population and 44% in the subgroup of 23 patients with isolates tested for aminoglycoside susceptibility.

CONCLUSION AND RELEVANCE

Critically ill oncology patients undergoing CRRT exhibited reduced clearance and expanded V_d that was not significantly different between CRRT modalities. Current dosing regimens led to low peak concentrations and poor attainment of pharmacokinetic targets.

Clinical Pharmacokinetics of Gentamicin in Various Patient Populations and Consequences for Optimal Dosing for Gram-Negative Infections: An Updated Review

Gentamicin is an aminoglycoside antibiotic with a small therapeutic window that is currently used primarily as part of short-term empirical combination therapy. Gentamicin dosing schemes still need refinement, especially for subpopulations where pharmacokinetics can differ from pharmacokinetics in the general adult population: obese patients, critically ill patients, paediatric patients, neonates, elderly patients and patients on dialysis. This review summarizes the clinical pharmacokinetics of gentamicin in these patient populations and the consequences for optimal dosing of gentamicin for infections caused by Gram-negative bacteria, highlighting new insights from the last 10 years. In this period, several new population pharmacokinetic studies have focused on these subpopulations, providing insights into the typical values of the most relevant pharmacokinetic parameters, the variability of these parameters and possible explanations for this variability, although unexplained variability often remains high. Both dosing schemes and pharmacokinetic/pharmacodynamic (PK/PD) targets varied widely between these studies. A gentamicin starting dose of 7 mg/kg based on total body weight (or on adjusted body weight in obese patients) appears to be the optimal strategy for increasing the probability of target attainment (PTA) after the first administration for the most commonly used PK/PD targets in adults and children older than 1 month, including critically ill patients. However, evidence that increasing the PTA results in higher efficacy is lacking; no studies were identified that show a correlation between estimated or predicted PK/PD target attainment and clinical success. Although it is unclear if performing therapeutic drug monitoring (TDM) for optimization of the PTA is of clinical value, it is recommended in patients with highly variable pharmacokinetics, including patients from all subpopulations that are critically ill (such as elderly, children and neonates) and patients on intermittent haemodialysis. In addition, TDM for optimization of the dosing interval, targeting a trough concentration of at least < 2 mg/L but preferably < 0.5–1 mg/L, has proven to reduce nephrotoxicity and is therefore recommended in all patients receiving more than one dose of gentamicin. The usefulness of the daily area under the plasma concentration–time curve for predicting nephrotoxicity should be further investigated. Additionally, more research is needed on the optimal PK/PD targets for efficacy in the clinical situations in which gentamicin is currently used, that is, as monotherapy for urinary tract infections or as part of short-term combination therapy.

Nosocomial Pneumonia in the Mechanically Ventilated Patient

Ventilator-associated pneumonia (VAP) is a common complication occurring in critically ill patients who are mechanically ventilated and is the leading cause of nosocomial infection-related death. Etiologic agents for VAP widely differ based on the population of intensive care unit patients, duration of hospital stay, and prior antimicrobial therapy. VAP due to multidrug-resistant pathogens is associated with the highest morbidity and mortality, likely due to delays in appropriate antimicrobial treatment. International guidelines are currently available to guide diagnostic and therapeutic strategies. VAP can be prevented through various pharmacological and non-pharmacological interventions, which are more effective when grouped as bundles. When VAP is clinically suspected, diagnostic strategies should include early collection of respiratory samples to guide antimicrobial therapy. Empirical treatment should be based on the most likely etiologic microorganisms and antibiotics likely to be active against these microorganisms. Response to therapy should be reassessed after 3 to 5 days and antimicrobials adjusted or de-escalated to reduce the burden of the disease. Finally, considering that drug resistance is increasing worldwide, several novel antibiotics are being tested to efficiently treat VAP in the coming decades.

Use of Photodynamic Therapy Associated with Antimicrobial Peptides for Bacterial Control: A Systematic Review and Meta-Analysis

Considering the challenges related to antimicrobial resistance, other strategies for controlling infections have been suggested, such as antimicrobial photodynamic therapy (aPDT) and antimicrobial peptides (AMP). This study aims to perform a systematic review and meta-analysis to obtain evidence on the antimicrobial effectiveness of aPDT associated with AMP and establish in vitro knowledge on this topic for further study designs. The PubMed, Scopus, Web of Science, Science Direct, Scielo, and Cochrane Library databases were searched. Two independent and calibrated researchers (Kappa = 0.88) performed all the systematic steps according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The odds ratio (OR) was used as the effect measure. The Peto method was used to perform the meta-analysis due to the sparse data. Twenty studies were included in the present review. The result was significant (OR = 0.14/p = 0.0235/I-squared = 0%), showing better outcomes of aPDT associated with peptides than those of aPDT alone for controlling the microbial load. Only 20% of the studies included evaluated this approach in a biofilm culture. Combined treatment with aPDT and AMP highly increased the ability of microbial reduction of Gram-positive and Gram-negative bacteria. However, additional blind studies are required to evaluate the efficacy of this therapy on microbial biofilms.

Potential Synergistic Antibiotic Combinations against Fluoroquinolone-Resistant Pseudomonas aeruginosa

The rise in multiple-drug-resistant (MDR) phenotypes in Gram-negative pathogens is a major public health crisis. Pseudomonas aeruginosa is one of the leading causes of nosocomial infections in clinics. Treatment options for P. aeruginosa have become increasingly difficult due tdo its remarkable capacity to resist multiple antibiotics. The presence of intrinsic resistance factors and the ability to quickly adapt to antibiotic monotherapy warrant us to look for alternative strategies like combinatorial antibiotic therapy. Here, we report the frequency of P. aeruginosa multidrug-resistant and extensively drug-resistance (XDR) phenotypes in a super-specialty tertiary care hospital in north India. Approximately 60 percent of all isolated P. aeruginosa strains displayed the MDR phenotype. We found highest antibiotic resistance frequency in the emergency department (EMR), as 20 percent of isolates were resistant to 15 antipseudomonal antibiotics. Presence of plasmids with quinolone-resistance determinants were major drivers for resistance against fluoroquinolone. Additionally, we explored the possible combinatorial therapeutic options with four antipseudomonal antibiotics—colistin, ciprofloxacin, tobramycin, and meropenem. We uncovered an association between different antibiotic interactions. Our data show that the combination of colistin and ciprofloxacin could be an effective combinatorial regimen to treat infections caused by MDR and XDR P. aeruginosa.

Pseudomonas aeruginosa Pneumonia: Evolution of Antimicrobial Resistance and Implications for Therapy

Pseudomonas aeruginosa (PA), a non-lactose-fermenting gram-negative bacillus, is a common cause of nosocomial infections in critically ill or debilitated patients, particularly ventilator-associated pneumonia (VAP), and infections of urinary tract, intra-abdominal, wounds, skin/soft tissue, and bloodstream. PA rarely affects healthy individuals, but may cause serious infections in patients with chronic structural lung disease, comorbidities, advanced age, impaired immune defenses, or with medical devices (e.g., urinary or intravascular catheters, foreign bodies). Treatment of pseudomonal infections is difficult, as PA is intrinsically resistant to multiple antimicrobials, and may acquire new resistance determinants even while on antimicrobial therapy. Mortality associated with pseudomonal VAP or bacteremias is high (> 35%) and optimal therapy is controversial. Over the past three decades, antimicrobial resistance (AMR) among PA has escalated globally, via dissemination of several international multidrug resistant "epidemic" clones. We discuss the importance of PA as a cause of pneumonia including health care-associated pneumonia, hospital-acquired pneumonia, VAP, the emergence of AMR to this pathogen, and approaches to therapy (both empirical and definitive).

Risk Factors and Algorithms for the Empirical Treatment of Hospital-Acquired Pneumonia and Ventilator-Associated Pneumonia

Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) continue to be major concerns for morbidity and mortality, especially in patients treated in the intensive care unit. With the rise in multidrug-resistant organisms, HAP and VAP treatment is challenged by the need for early appropriate treatment, with broad-spectrum agents, while still being aware of the principles of antibiotic stewardship. The two major society guidelines proposed a series of risk factors in their most recent guidelines to help identify patients who can most benefit from narrow- or broad-spectrum initial empiric antibiotic therapy. The guidelines reveal differences in the proposed risk factors and treatment approaches, as well as major similarities.

Empiric antimicrobial therapy for early-onset pneumonia in severe trauma patients

PURPOSE

The bacterial ecology involved in early pneumonia of severe trauma patients is mostly commensal and would allow wide use of narrow-spectrum antibiotics. We describe risk factors for treatment failure of severe trauma patients' pneumonia with the use of narrow-spectrum antimicrobial therapy in order to develop a score that could help clinicians to determine which patients might be treated with narrow-spectrum antibiotics.

METHODS

A retrospective, observational, monocentric cohort study was conducted of severe trauma patients requiring mechanical ventilation for > 48 h and developing a first episode of microbiologically confirmed pneumonia occurring within the first 10 days after admission.

RESULTS

Overall, 370 patients were included. The resistance rate against narrow-spectrum antibiotics (amoxicillin/clavulanic acid) was 22.7% (84 pneumonia). In a multivariate analysis, two independent risk factors were associated with this resistance: prior antimicrobial therapy ≥ 48 h (OR 4.00; 95 CI [2.39; 6.75]) and age ≥ 30y (OR 2.10; 95 CI [1.21; 3.78]). We created a prediction score that defined patient with one or two risk factors at high risk of resistance. This score presented a sensitivity of 0.92 [0.88; 0.94], a specificity of 0.33 [0.28; 0.38], a positive predictive value of 0.29 [0.24; 0.33] and a negative predictive value of 0.93 [0.90; 0.95].

CONCLUSION

Simple risk factors may help clinicians to identify severe trauma patients at high risk of pneumonia treatment failure with the use of narrow-spectrum antimicrobial therapy and, thus, use better tailored empiric therapy and limit the use of unnecessary broad-spectrum antimicrobial therapy.

Management of pneumonia in critically ill patients

Severe pneumonia is associated with high mortality (short and long term), as well as pulmonary and extrapulmonary complications. Appropriate diagnosis and early initiation of adequate antimicrobial treatment for severe pneumonia are crucial in improving survival among critically ill patients. Identifying the underlying causative pathogen is also critical for antimicrobial stewardship. However, establishing an etiological diagnosis is challenging in most patients, especially in those with chronic underlying disease; those who received previous antibiotic treatment; and those treated with mechanical ventilation. Furthermore, as antimicrobial therapy must be empiric, national and international guidelines recommend initial antimicrobial treatment according to the location's epidemiology; for patients admitted to the intensive care unit, specific recommendations on disease management are available. Adherence to pneumonia guidelines is associated with better outcomes in severe pneumonia. Yet, the continuing and necessary research on severe pneumonia is expansive, inviting different perspectives on host immunological responses, assessment of illness severity, microbial causes, risk factors for multidrug resistant pathogens, diagnostic tests, and therapeutic options.

Aminoglycoside dosing and monitoring for Pseudomonas aeruginosa during acute pulmonary exacerbations in cystic fibrosis

Aminoglycosides are commonly used for the treatment of Pseudomonas aeruginosa (PsA) in the setting of acute pulmonary exacerbations (PEx) in pediatric patients with cystic fibrosis (CF). There are controversies and practice differences between institutions related to aminoglycoside dosing and monitoring strategies. The purpose of this review article is to summarize the currently available literature and identify gaps in the literature related to pharmacokinetic parameter goals, aminoglycoside dosing strategies, and methods for monitoring serum aminoglycoside concentrations for treatment of PsA in CF PEx, and throughout will discuss anticipated changes with the increasing availability of highly effective CF transmembrane conductance regulator modulators. This review focuses on tobramycin, as it is the most commonly used aminoglycoside in CF PEx, and will briefly discuss special circumstances surrounding use of amikacin and gentamicin.

Current opinion in management of septic shock due to Gram-negative bacteria

PURPOSE OF REVIEW

The COVID-19 pandemic has caused multiple challenges to ICUs, including an increased rate of secondary infections, mostly caused by Gram-negative micro-organisms. Worrying trends of resistance acquisition complicate this picture. We provide a review of the latest evidence to guide management of patients with septic shock because of Gram-negative bacteria.

RECENT FINDINGS

New laboratory techniques to detect pathogens and specific resistance patterns from the initial culture are available. Those may assist decreasing the time to adequate antimicrobial therapy and avoid unnecessary broad-spectrum antibiotic overuse. New antimicrobials, including β-lactam/β-lactamase inhibitor combinations, such as ceftolozane-tazobactam, imipenem-relebactam or meropenem-vaborbactam and cephalosporins, such as cefiderocol targeted to specific pathogens and resistance patterns are available for use in the clinical setting. Optimization of antibiotic dosing and delivery should follow pharmacokinetic and pharmacodynamic principles and wherever available therapeutic drug monitoring. Management of sepsis has brought capillary refill time back to the spotlight along with more reasoned fluid resuscitation and a moderate approach to timing of dialysis initiation.

SUMMARY

Novel rapid diagnostic tests and antimicrobials specifically targeted to Gram-negative pathogens are available and should be used within the principles of antimicrobial stewardship including de-escalation and short duration of antimicrobial therapy.

Efficacy and safety of dual intravenous artesunate plus quinine compared to intravenous artesunate for cerebral malaria in a triple blinded parallel multisite randomized controlled trial in Nigerian children: DUAL PAQ TRIAL Protocol

Background

Evidence exists as to the criticality of the first 24 h in the management of cerebral malaria. The morbidity and the mortality rate (35%) with the current intravenous monotherapy for the initial treatment of cerebral malaria are unacceptably high. Combination therapy and a shorter course of effective medication have been shown to improve outcomes in human participants in the treatment of other diseases. This study outlines a protocol to conduct a triple blinded parallel randomized controlled trial on cerebral malaria using dual intravenous medications compared to the current standard of monotherapy.

Methods

This is a parallel multi-site randomized controlled superiority triple blinded trial consisting of intravenous artesunate plus quinine and a control arm of intravenous artesunate only. Eligible and assenting children aged 6 months to 17 years will be recruited from 4 tertiary hospitals by random selection from the list of tertiary hospitals in Nigeria. Participants will be randomized and assigned in parallel into two arms using random numbers generated from GraphPad Prism (version 9) by a clinical pharmacologist who has no link with the investigators, the patients, or the statistician. The primary measurable outcome is survival at 12, 24, and 48 h post-randomization. A composite secondary outcome consists of the number of children that regained consciousness, parasitaemia and defervescence at 12 and 24 h post-randomization and haematological and inflammatory markers at 24 and 48 h post-randomization. Adverse events both solicited and unsolicited are recorded all through the study post-randomization. The study is approved by the State Research Ethics Review Committee. Data analysis will be performed in GraphPad Prism version 9.

Discussion

The outcome of this analysis will give insight into the efficacy and safety of dual intravenous antimalaria in the treatment of cerebral malaria among Nigerian children compared with the standard of care. The safety profile of this intervention will also be highlighted. This may help inform physicians on the optimal treatment for cerebral malaria to improve outcomes and reduce recrudescence and treatment failure.

Trial registration

Pan Africa Clinical Trial Registry PACTR202102893629864. 23/02/2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05634-6.

Preexisting Clinical Frailty Is Associated With Worse Clinical Outcomes in Patients With Sepsis

OBJECTIVES

Frailty is a multidimensional syndrome or state of increased vulnerability to poor resolution of homoeostasis following a stressor event. Frailty is common in patients with sepsis. Sepsis and frailty are both associated with older age and chronic medical conditions. However, there is limited evidence about the direct association between frailty and sepsis. The aim of this study is to determine the association between preexisting clinical frailty and clinical outcomes in patients with sepsis.

DESIGN

A nationwide propensity score-matched cohort study analyzing data prospectively collected between September 2019 and February 2020.

SETTING

Nineteen tertiary or university-affiliated hospitals in South Korea.

PATIENTS

Adult patients who were diagnosed with sepsis.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Frailty status was assessed using the Clinical Frailty Scale. All patients were classified as "frail" (Clinical Frailty Scale score, 5-9) or "nonfrail" (Clinical Frailty Scale score, 1-4). Propensity score matching identified comparable nonfrail patients. The primary outcome was inhospital mortality. Multivariable logistic regression analysis was used to evaluate the association between frailty and inhospital mortality. The propensity score-matched cohort comprised 468 nonfrail patients and 468 frail patients; all covariate imbalances were alleviated. In the matched cohort (mean age, 69 ± 14 yr), 27.2% had septic shock at presentation. Inhospital mortality was 34.2% in the frail group and 26.9% in the nonfrail group (p = 0.019). The adjusted odds ratio for inhospital mortality in the frail group compared with the nonfrail group was 2.00 (95% CI, 1.39-2.89; p < 0.001). Among the patients who survived to discharge, the frail group was less likely to be discharged home compared with the nonfrail group, 64.0% versus 81.3%, respectively (p < 0.001).

CONCLUSIONS

In patients with sepsis, preexisting clinical frailty is associated with worse clinical outcomes than that in nonfrail patients, including inhospital mortality and discharge to home.

How Antibiotics Stewardship Can Be Safely Implemented in Patients with Septic Shock?

In critically ill patients with sepsis and septic shock, the need for prompt and adequate antibiotic therapy is balanced by the risk of excessive antibiotic exposure that leads to emergence of multidrug-resistant pathogens. As such, antibiotic stewardship programs propose a set of operating rules from antibiotic treatment initiation to de-escalation and finally cessation. In this review, we will describe the rationale for early antibiotic treatment in septic patients, how to optimize initial antibiotic treatment, rules for early treatment discontinuation in pathogen-negative sepsis, and optimal duration of antimicrobial therapy.

The effects of adding quinolones to beta-lactam antibiotics for sepsis

BACKGROUND

Sepsis is common, deadly, and a major challenge to treat. Quinolones added to beta-lactam antibiotics are currently recommended as a second-line empiric regimen in sepsis, but the evidence regarding their benefits and harms is unclear.

OBJECTIVE

To assess the benefits and harms of adding quinolones to standard care for sepsis.

DATA SOURCES

We conducted a systematic review of randomized clinical trials with meta-analysis and Trial Sequential Analysis. We searched CENTRAL, MEDLINE, Embase, LILACS, SCI-Expanded, and BIOSIS.

STUDY SELECTION

Randomized clinical trials assessing the effects of adding any quinolone to standard care for children and adults with sepsis.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers screened studies and extracted data. The certainty of the evidence was assessed by GRADE.

RESULTS

We included three trials randomizing 995 adults. All trials were at overall "high risk of bias." All trials compared a quinolone (moxifloxacin, levofloxacin, or ciprofloxacin) and a beta-lactam antibiotic versus the same beta-lactam antibiotic. We found no evidence of an effect of adding quinolones to beta-lactam antibiotics when assessing all-cause mortality (RR 1.07, 95% CI 0.86 to 1.33; 2 trials; 915 participants; very low certainty of evidence) and serious adverse events (RR 1.00, 95% CI 0.67 to 1.50; 977 participants; two trials; very low certainty of evidence). No trials reported on quality of life.

CONCLUSIONS

The effects of adding quinolones to beta-lactam antibiotics for the treatment of sepsis were unclear for all outcomes. Additional trial data are warranted to support the recommendation of empirical use of quinolones for sepsis.

Appropriateness of empirical antibiotic therapy and added value of adjunctive gentamicin in patients with septic shock: a prospective cohort study in the ICU

OBJECTIVES

To determine the appropriateness of empiric antibiotic therapy and the possible benefit of adding short-course gentamicin in septic shock patients with abdominal, urogenital, or an unknown focus. Secondary objectives were the effect of gentamicin addition on shock reversal and the incidence of a fungal infection.

METHODS

Microbiological cultures, antibiotic treatment, and antibiotic resistance patterns of the cultured microorganisms were recorded during the first 5 days of admission. Inappropriate antibiotic therapy was defined as a prescription within the first 24 h that did not cover cultured bacteria during the first 5 days of admission and was determined in the overall group and in patients receiving adjunctive gentamicin (combination therapy) versus patients receiving monotherapy. Binomial logistic regression analysis was used to investigate the association of gentamicin addition with shock reversal.

RESULTS

Of 203 septic shock patients, with abdominal (n = 143), urogenital (n = 27) or unknown (n = 33) focus, 115 patients received monotherapy, and 88 patients received combination therapy. Inappropriate therapy occurred in 29 patients (14%), more frequently in monotherapy (17%) versus combination therapy (10%). Combination therapy would have been effective in 55% of patients with inappropriate monotherapy. We found no association between gentamicin addition and shock reversal (p = .223). A fungal infection was present in 22 patients (11%).

CONCLUSION

Inappropriate empirical antibiotic therapy occurs in 17% of septic shock patients receiving monotherapy. In 55% of these patients, additional gentamicin would have resulted in appropriate therapy. When clinical course is unfavourable, lowering the threshold for administering adjunctive aminoglycoside and antifungal therapy should be considered.

A new molecular method for rapid etiological diagnosis of sepsis with improved performance

The value of blood cultures for confirming the clinical diagnosis of sepsis is suboptimal. There is growing interest in the potential of real-time PCR technology by detection of minute amounts of pathogen DNA in patient blood samples with results available within 4-6 h. Adopting a two-step approach, we evaluated the compliance of two versions of the MicrobScan assay on a total of 748 patients with suspected bloodstream infections. The results obtained with a second version of the MicrobScan assay are characterized by increased specificity (from 95.1 to 98.2%) and sensitivity (from 76.7 to 85.1), increased throughput and the possibility of simultaneously testing different kinds of samples collected from the potential sites of infection and utilizing different syndromic panels.

Mixed biofilms of pathogenic Candida-bacteria: regulation mechanisms and treatment strategies

Mixed-species biofilm is one of the most frequently recorded clinical problems. Mixed biofilms develop as a result of interactions between microorganisms of a single or multiple species (e.g. bacteria and fungi). Candida spp., particularly Candida albicans, are known to associate with various bacterial species to form a multi-species biofilm. Mixed biofilms of Candida spp. have been previously detected in vivo and on the surfaces of many biomedical instruments. Treating infectious diseases caused by mixed biofilms of Candida and bacterial species has been challenging due to their increased resistance to antimicrobial drugs. Here, we review and discuss the clinical significance of mixed Candida-bacteria biofilms as well as the signalling mechanisms involved in Candida-bacteria interactions. We also describe possible approaches for combating infections associated with mixed biofilms, such as the use of natural or synthetic drugs and combination therapy. The review presented here is expected to contribute to the advances in the biomedical field on the understanding of underlying interaction mechanisms of pathogens in mixed biofilm, and alternative approaches to treating the related infections.

A Multicenter Observational Study Evaluating Outcomes Associated With Antibiotic Combination Versus Monotherapy in Patients With Septic Shock

Supplemental Digital Content is available in the text.

Objectives:

To explore the association between antibiotic combination therapy and in-hospital mortality in patients with septic shock in two tertiary ICUs in different countries.

Design:

Retrospective observational study.

Setting:

ICUs of two tertiary hospitals, Royal Brisbane and Women’s Hospital, Brisbane, QLD, Australia, and Rigshospitalet, Copenhagen, Denmark.

Patients:

Adult patients with antibiotic treatment greater than or equal to 72 hours and vasopressor therapy greater than or equal to 24 hours.

Intervention:

Combination versus mono antibiotic therapy.

Measurements and Main Results:

Combination antibiotic therapy was defined as receiving two or more antibiotics from different classes, started within 12 hours of each other and with an overlapping duration of greater than or equal to 12 hours. Bivariate and multiple logistic regression analysis were performed comparing combination antibiotic therapy versus antibiotic monotherapy on in-hospital mortality. The analysis was adjusted for age, gender, centre, Acute Physiology and Chronic Health Evaluation II score, and chronic health evaluation. In total, 1,667 patients were included with 953 (57%) receiving combination therapy. Patients given combination therapy were older (60 ± 16 vs 56 ± 18), more likely admitted to Rigshospitalet (58% vs 16%), and had a higher Acute Physiology and Chronic Health Evaluation II score (26 ± 8 vs 23 ± 8). Combination therapy was associated with an increased mortality in univariate analysis (odds ratio = 1.33; 95% CI, 1.07–1.66); however, there was no significant association in the adjusted analysis (odds ratio = 0.88; 95% CI, 0.68–1.15).

Conclusions:

In this retrospective study, no association was found between use of combination therapy and in-hospital mortality. The large differences between centers probably reflect local traditions and lack of definitive evidence.

In vitro Antimicrobial Synergy Testing of Extensively Drug-Resistant Clinical Isolates at an Organ Transplant Center in Nepal

Purpose

Inappropriate use of broad-spectrum antibiotics contributes to the emergence of multidrug-resistant (MDR) bacteria. Finding novel antimicrobial agents and strategies based on synergistic combinations are essential to combat MDR infections. This study was designed to determine in vitro synergy of different antimicrobials against extensively drug-resistant (XDR) Gram-negative clinical isolates.

Methods

A descriptive, cross-sectional study was conducted at Human Organ Transplant Center, Nepal, for five months. Clinical isolates were checked for their drug-resistance properties including extended-spectrum beta-lactamase- (ESBL-) and metallo-beta-lactamase- (MBL-) production. The XDR isolates were further tested for antimicrobial synergy, and the results were interpreted as synergistic, additive, indifferent or antagonistic determining fractional inhibitory concentration of the antibiotics.

Results

Out of total 1155 clinical samples, 308 showed significant growth. Escherichia coli was the most common isolate (n=142) followed by Klebsiella pneumoniae, Acinetobacter calcoaceticus baumannii (Acb) complex, Pseudomonas aeruginosa and miscellaneous bacteria. Out of the culture positive isolates, 21.4% were MDR and 10.06% were XDR. The XDR population comprised K. pneumoniae (18.42%), E. coli (9.86%), Acb complex (7.41%) and P. aeruginosa (4.17%). Among the culture positive isolates, 4.5% and 5.8% were ESBL- and MBL-producers, respectively. Colistin, polymyxin B, and tigecycline were the antibiotics effective in majority of MDR isolates as compared to carbapenems. The combination of antibiotics - meropenem and colistin showed the highest proportion of "synergy" among all XDR E. coli whereas the combination of amikacin and colistin showed synergistic effect in XDR K. pneumoniae.

Conclusion

A significant proportion of isolates were MDR among which a large fraction was XDR. The combination of meropenem, amikacin and colistin with one another in pair showed beneficial activity in vitro. Such combinations can be utilized as effective therapy for XDR infections. Further studies are required to confirm these findings, and accordingly treatment protocols should be developed in the management of such infections.

Risk Factors for Intra-Abdominal Infections Caused by Carbapenemase-Producing Enterobacteriaceae in a Surgical Setting

Background: The aim of this study was to identify risk factors for acquisition of intra-abdominal infections (IAI) caused by carbapenemase-producing Enterobacteriaceae (CPE) in surgical patients. Methods: A matched case-control study was performed. We included all cases with CPE-related IAI acquired during admission to a general surgery department from January 2013 to December 2018, and they were matched with control subjects with IAI caused by non-resistant bacteria (ratio 1:3). Independent risk factors were obtained by logistic regression. Results: Forty patients with IAI-CPE were matched with 120 control subjects. Independent risk factors for acquisition of IAI-CPE were previous hospitalization (odds ratio [OR] 2.56; 95% confidence interval [CI] l 1.01-6.49; p = 0.047), digestive endoscopy (OR 4.11; 95% CI 1.40-12.07; p = 0.010), carbapenem therapy (OR 9.54; 95% CI 3.33-27.30; p < 0.001), and aminoglycoside use (OR 45.41; 95% CI 7.90-261.06; p < 0.001). Conclusions: Four clinical factors can identify patients at high-risk of IAI-CPE.