Clinical outcomes of prolonged infusion (extended infusion or continuous infusion) versus intermittent bolus of meropenem in severe infection: A meta-analysis

Evaluation of the Efficacy of Piperacillin/Tazobactam in Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae Urinary Tract Infections: A Systematic Review of the Literature

OBJECTIVE

To evaluate the efficacy of piperacillin/tazobactam (PTZ) for the treatment of extended-spectrum beta-lactamase-producing enterobacteriaceae (ESBL-PE) urinary tract infections (UTIs).

DATA SOURCES

A systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards on PubMed, MEDLINE, Embase, Web of Science Core Collection, and Cochrane Central through July 2024.

STUDY SELECTION AND DATA EXTRACTION

Studies providing efficacy data associated with PTZ in patients ≥18 years old experiencing an ESBL-PE UTI that documented clinical and microbiological cure data were included.

DATA SYNTHESIS

A total of 577 articles were obtained for screening. After applying the inclusion and exclusion criteria, 7 studies comparing PTZ with carbapenems comprised of 1156 patient cases were analyzed. Piperacillin/tazobactam was found to be noninferior to carbapenems in the treatment of both uncomplicated and complicated UTI's caused by ESBL-PE. The observed noninferiority encompassed clinical response, clinical cure, and microbiological cure outcome metrics. Although not specifically evaluated in this systematic review, adverse effects associated with PTZ were found to be minimal and lesser in incidence than with the carbapenem comparators in aggregate.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

While a definitive dosing strategy remains elusive, a PTZ total daily dose of 13.5 g infused over 3 to 4 hours may be appropriate for this indication.

CONCLUSION

Piperacillin/tazobactam may be an effective carbapenem-sparing agent for the treatment of ESBL-PE UTIs that show in-vitro susceptibility to PTZ. However, additional robust randomized clinical trials are still needed to validate the findings of this review and determine the best dosage regimen of PTZ for ESBL-PE UTIs.

Optimizing meropenem therapy in critical infections: a review of pharmacokinetics/pharmacodynamics research and clinical practice

INTRODUCTION

Meropenem is a first-line antibiotic used in the treatment of severe infections. However, patients with critical infections often exhibit a notably low pharmacokinetic/pharmacodynamic (PK/PD) compliance rate, especially in cases involving multidrug-resistant gram-negative bacteria and in specific patient populations.

AREAS COVERED

This article reviews the relevant literature on the use of meropenem in treating severe infections, with data primarily sourced from PubMed, Web of Science, Embase, and Cochrane databases before July 2024. The primary analysis focuses on determining the optimal clinical efficacy target value for meropenem in treating multidrug-resistant Gram-negative bacteria infection, exploring PK/PD research, individualizing drug regiments for special populations, and evaluating safety.

EXPERT OPINION

Based on the PK/PD properties of meropenem across different special populations such as children and elderly patients, as well as its efficacy against severe infections and multidrug-resistant Gram-negative infections, prolonged and continuous infusion regimens of meropenem have already shown some clinical benefit. Personalized dosing of meropenem for critical infections should be guided by real-time therapeutic drug monitoring (TDM). However, there is a notable lack of sufficient data, highlighting the necessity for large-scale, multi-center clinical trials to validate the safety and effectiveness of meropenem in treating severe infections.

Impact of prolonged versus intermittent infusion of meropenem on mortality and clinical outcomes in patients with severe infection: A systematic review and meta-analysis

OBJECTIVES

To compare the clinical outcomes of patients with severe infection treated with prolonged or intermittent infusion of meropenem.

METHODS

PubMed, Embase, and Cochrane Central databases were searched until July 2023. Randomized controlled trials (RCTs) or observational studies comparing prolonged versus intermittent infusion of meropenem were considered eligible. The primary outcomes included all-cause mortality and clinical improvement, while secondary outcomes encompassed hospital and intensive care unit (ICU) stay duration, microbial eradication rate, and adverse events. A meta-analysis was conducted using a random-effects model. The risk of bias of included studies was assessed using the modified JADAD scale for RCTs and the Newcastle-Ottawa Scale for observational studies.

RESULTS

Fourteen studies were included, with a total of 1698 patients. Prolonged infusion of meropenem was associated with a significantly lower mortality rate compared to intermittent infusion (RR = 0.81, 95 % CI: 0.68-0.98). It also significantly improved clinical improvement rates (RR = 1.35, 95 % CI: 1.11-1.64) and microbial eradication rates (RR = 1.19, 95 % CI: 1.08-1.32). There were no statistically significant differences in ICU length of stay or hospital length of stay. Subgroup analyses showed that prolonged infusion was significantly associated with lower mortality and better clinical improvement rates in patients with an APACHE II score <20.

CONCLUSIONS

Prolonged infusion of meropenem is more effective than intermittent infusion in reducing mortality, improving clinical outcomes, and enhancing microbial eradication, without increasing adverse events. These benefits are particularly evident in patients with lower disease severity (APACHE II < 20), emphasizing the importance of patient stratification in optimizing treatment strategies.

REGISTRATION

This systematic review and meta-analysis is registered with PROSPERO (number: CRD42023445360).

A Real-Life Study of Prolonged Meropenem Infusion in Neonates and Children Admitted to Intensive Care Units: Are Three Hours Long Enough?

Background/Objectives: Meropenem is a broad-spectrum antibiotic essential for treating resistant Gram-negative infections in pediatric patients. Current dosing recommendations may not consistently achieve optimal pharmacokinetic (PK) targets, especially in critically ill children. Methods: We conducted a retrospective cohort study at IRCCS Istituto Giannina Gaslini, analyzing 97 plasma levels from 86 pediatric patients (<18 years) hospitalized between January 2020 and December 2023 in the neonatal and pediatric intensive care unit. Patients receiving meropenem for proven or suspected infections were included. Demographic, clinical, and PK parameters were assessed, with a focus on trough concentrations (Ctrough). Results: The median age was 25 months, with neonates representing 15.5% of cases. The median Ctrough was 2.8 mg/L and was significantly higher in neonates (8.9 mg/L) compared to older patients (2.2 mg/L, p < 0.001). Only 27.8% of patients achieved the target Ctrough of >8 mg/L, with estimated glomerular filtration rate (eGFR) being the primary factor influencing these levels. Patients with Ctrough > 8 mg/L had a significantly lower eGFR (61 mL/min/1.73 m2) compared to those below this threshold (131 mL/min/1.73 m2, p = 0.001). Conclusions: The current meropenem dosing regimen may not reliably meet PK targets in critically ill pediatric patients, particularly those with augmented renal clearance or when treating pathogens with increased meropenem MIC. Our findings suggest that increased dosages and prolonged infusion times may be necessary to optimize therapeutic efficacy against resistant Gram-negative bacteria in this vulnerable population. Further studies are needed to refine dosing strategies and improve patient outcomes.

Reprint of: Does two-step infusion improve the pharmacokinetics/pharmacodynamics target attainment of meropenem in critically Ill patients?

The optimal method for administering meropenem remains controversial. This study was conducted to explore the optimal two-step infusion strategy (TIT), and to investigate whether TIT is superior to intermittent infusion therapy (IIT) and prolonged infusion therapy (PIT). A physiologically based pharmacokinetics model for critically ill patients was established and evaluated. The validated model was utilized to evaluate the pharmacokinetics/pharmacodynamics (PK/PD) target attainment of meropenem. The PK/PD target attainment of different TITs varied greatly, and the total infusion duration and the first-step dose greatly affected these values. The optimal TIT was 0.25 g (30 min) + 0.75 g (150 min) at MICs of ≤2 mg/L, and 0.25 g (45 min) + 0.75 g (255 min) at MICs of 4-8 mg/L. The PK/PD target attainment of optimal TIT, PIT, and IIT were 100 % at MICs of ≤1 mg/L. When MIC increased to 2-8 mg/L, the PK/PD target attainment of optimal TIT was similar to that of PIT and higher than IIT. In conclusion, TIT did not significantly improve the PK/PD target attainment of meropenem compared with PIT. IIT is adequate at MICs of ≤1 mg/L, and PIT may be the optimal meropenem infusion method in critically ill patients with MICs of 2-8 mg/L.

Is the high dose extended infusion of meropenem useful in the treatment of highly resistant gram-negative bacteria in children?

OBJECTIVES

Multidrug resistant infections present a treatment challenge for clinicians. These infections have been associated with increased morbidity and mortality. Recently, there has been increasing discussion in the literature that high dose extended infusion of meropenem may be helpful. We aimed to evaluate the clinical efficacy of high dose extended infusion of meropenem in the treatment of highly resistant Gram-negative infections.

METHODS

This retrospective observational study was conducted between December 2014 and December 2020 at Hacettepe University Ihsan Dogramaci Children's Hospital. Clinical and microbiological data of children diagnosed with invasive multidrug and extremely drug resistant Gram-negative infections were studied. The findings of patients given high dose extended infusion of meropenem were compared with patients who received colistin or tigecycline.

RESULTS

Overall, 158 pediatric patients infected with multidrug and extremely drug resistant gram-negatives were enrolled; 76 treated with high-dose prolonged infusion of meropenem; 60 treated with colistin and 22 with tigecycline. The overall clinical response at the end of the treatment was 81.6 % in meropenem group, 83.3 % in colistin group and 77.3 % in tigecycline group (P = 0.821). Microbiological response at the end of the treatment was 81.1 % in meropenem group, 76.4 % in colistin group and 72.2 % in tigecycline group (P = 0.694).

CONCLUSION

Meropenem, with an adjusted dose (high-dose and extended), seems a crucial and robust fighting agent in the treatment of pediatric patients infected with highly-resistant Gram-negative bacteria. It may also be useful in preventing the use of the latest fighting tools such as colistin and tigecycline during the antibacterial stewardship process.

Optimization of meropenem continuous infusion based on Monte Carlo simulation integrating with degradation study

OBJECTIVE

Meropenem degradation poses a challenge to continuous infusion (CI) implementation. However, data about the impact of degradation on the probability of target attainment (PTA) of meropenem has been limited. This study evaluated the stability of meropenem brands and the consequence of in-bottle degradation on PTA in different environmental scenarios.

METHOD

Seven meropenem generic brands prepared at concentrations of 1 g/48mL and 2 g/48mL in saline were examined at 25, 30, and 37°C over 8 h. A linear mixed-effects model was used to estimate degradation rate constant and potential covariates. In-bottle stability data was subsequently integrated as input for a deterministic and stochastic simulation using a published population pharmacokinetic model of critical illness. The impact of the degradation on target attainment at 98%fT>MIC was assessed.

RESULTS

Time, temperature, and infusion concentration were factors affecting the stability of the meropenem solution for all products. The differences in the degradation of seven generics were subtle, so their simulated plasma concentrations were equal. Meropenem CI with 8 h renewal infusion achieved a higher PTA than the extended 3 h infusion, even at the highest degradation condition. The impact of meropenem degradation on PTA was minimal vis-à-vis the meropenem dose, patient's renal function, and microbial susceptibility. Meropenem degradation reduced PTA by an observable magnitude in patients with augmented renal clearance and difficult-to-treat pathogens. Dose escalation up to 1.5-2g every 8 h could restore this reduction to the target 90% PTA.

CONCLUSION

Meropenem CI with 8 h of renewal infusion, considering stability even in tropical areas, was feasible to maximize the efficacy to difficult-to-treat pathogens.

Impact of Continuous Infusion Meropenem PK/PD Target Attainment on C-Reactive Protein Dynamics in Critically Ill Patients With Documented Gram-Negative Hospital-Acquired or Ventilator-Associated Pneumonia

BACKGROUND AND OBJECTIVE

Population pharmacokinetic/pharmacodynamic (PK/PD) modelling of antibiotics including C-reactive protein (C-RP) dynamics could be helpful in predicting the efficacy of antimicrobials. We developed a PK/PD model for assessing the impact of continuous infusion (CI) meropenem PK/PD target attainment on C-RP dynamics in critically ill patients with documented Gram-negative hospital- (HAP) or ventilator-acquired pneumonia (VAP).

METHODS

Patients were grouped according to the type of antibiotic treatment received [meropenem monotherapy; meropenem plus empirical anti-MRSA (methicillin-resistant Staphylococcus aureus) therapy; meropenem in combination with another anti-Gram-negative active agent; meropenem plus a targeted anti-MRSA therapy]. A one-compartment population PK model of CI meropenem was developed by including all patients. A full C-RP production inhibition model was developed for fitting the PD data by including only patients receiving meropenem monotherapy or meropenem plus empirical anti-MRSA therapy. Monte Carlo simulations explored the relationship between the type of PK/PD target attainment of CI meropenem, defined as optimal (steady-state plasma concentration [Css] to minimum inhibitory concentration [MIC] ratio = 4-8), quasi-optimal (Css/MIC = 1-4) and sub-optimal (Css/MIC < 1) and the magnitude of C-RP production inhibition over time.

RESULTS

A total of 64 patients providing 211 meropenem concentrations were included in the PK analysis, whereas 47 patients providing 328 C-RP data were included in the PD model. Simulations showed that optimal PK/PD target attainment was associated with the highest and most rapid C-RP production inhibition (44% and 56% at days 2 and 4, respectively). Conversely, sub-optimal PK/PD target attainment was shown to be almost ineffective (< 5% at day 4 and < 10% at day 10).

CONCLUSION

Our PK/PD model predicted that attaining optimal PK/PD target with CI meropenem may grant prompt and intense C-RP decrease among critically ill patients receiving targeted monotherapy for Gram-negative HAP/VAP, thus anticipating efficacy.

A Retrospective Analysis of Intravenous Push versus Extended Infusion Meropenem in Critically Ill Patients

Meropenem is a broad-spectrum antibiotic used for the treatment of multi-drug-resistant infections. Due to its pharmacokinetic profile, meropenem's activity is optimized by maintaining a specific time the serum concentration remains above the minimum inhibitory concentration (MIC) via extended infusion (EI), continuous infusion, or intermittent infusion dosing strategies. The available literature varies regarding the superiority of these dosing strategies. This study's primary objective was to determine the difference in time to clinical stabilization between intravenous push (IVP) and EI administration. We performed a retrospective pilot cohort study of 100 critically ill patients who received meropenem by IVP (n = 50) or EI (n = 50) during their intensive care unit (ICU) admission. There was no statistically significant difference in the overall achievement of clinical stabilization between IVP and EI (48% vs. 44%, p = 0.17). However, the median time to clinical stability was shorter for the EI group (20.4 vs. 66.2 h, p = 0.01). EI administration was associated with shorter hospital (13 vs. 17 days; p = 0.05) and ICU (6 vs. 9 days; p = 0.02) lengths of stay. Although we did not find a statistically significant difference in the overall time to clinical stabilization, the results of this pilot study suggest that EI administration may produce quicker clinical resolutions than IVP.

Does Two-Step Infusion Improve the Pharmacokinetics/Pharmacodynamics Target Attainment of Meropenem in Critically Ill Patients?

The optimal method for administering meropenem remains controversial. This study was conducted to explore the optimal two-step infusion strategy (TIT), and to investigate whether TIT is superior to intermittent infusion therapy (IIT) and prolonged infusion therapy (PIT). A physiologically based pharmacokinetics model for critically ill patients was established and evaluated. The validated model was utilized to evaluate the pharmacokinetics/pharmacodynamics (PK/PD) target attainment of meropenem. The PK/PD target attainment of different TITs varied greatly, and the total infusion duration and the first-step dose greatly affected these values. The optimal TIT was 0.25 g (30 min) + 0.75 g (150 min) at MICs of ≤2 mg/L, and 0.25 g (45 min) + 0.75 g (255 min) at MICs of 4-8 mg/L. The PK/PD target attainment of optimal TIT, PIT, and IIT were 100 % at MICs of ≤1 mg/L. When MIC increased to 2-8 mg/L, the PK/PD target attainment of optimal TIT was similar to that of PIT and higher than IIT. In conclusion, TIT did not significantly improve the PK/PD target attainment of meropenem compared with PIT. IIT is adequate at MICs of ≤1 mg/L, and PIT may be the optimal meropenem infusion method in critically ill patients with MICs of 2-8 mg/L.

Guidelines for Antibacterial Treatment of Carbapenem-Resistant Enterobacterales Infections

This guideline aims to promote the prudent use of antibacterial agents for managing carbapenem-resistant Enterobacterales (CRE) infections in clinical practice in Korea. The general section encompasses recommendations for the management of common CRE infections and diagnostics, whereas each specific section is structured with key questions that are focused on antibacterial agents and disease-specific approaches. This guideline covers both currently available and upcoming antibacterial agents in Korea.

Clinical outcomes and risk factors of Acinetobacter baumannii meningitis in pediatric patients at a tertiary hospital in China

Objectives

To summarize the clinical characteristics, outcomes and identify risk factors of Acinetobacter baumannii (AB) meningitis in children.

Methods

This was a single-center, retrospective study. Children hospitalized between January 2016 and December 2021 who were diagnosed with AB meningitis were included. The clinical characteristics and outcomes were reviewed. Risk factors were determined using univariate analyses (chi-square and Mann-Whitney U tests).

Results

Seventeen patients were included; 15 cases were secondary to neurosurgery, and two were neonates with primary bacterial meningitis. Common symptoms included fever, convulsions and nervous system abnormalities. Cerebrospinal fluid (CSF) tests typically showed increased white blood cell counts dominated by neutrophils, reduced glucose levels and elevated protein levels. Ten patients were successfully treated (successful treatment [ST] group); seven had failed treatment (failed treatment [FT] group). Univariate analyses revealed that mechanical ventilation, routine white cell counts in the peripheral blood, procalcitonin, protein in the CSF, septic shock and carbapenem-resistant AB (CRAB) differed significantly between the groups.

Conclusion

AB meningitis in children has a high mortality rate. FT was associated with mechanical ventilation, septic shock, CRAB, lower peripheral leukocyte counts, higher protein levels in the CSF and procalcitonin. Larger studies are needed to identify independent risk factors for adverse outcomes.

Antibiotics, Analgesic Sedatives, and Antiseizure Medications Frequently Used in Critically Ill Neonates: A Narrative Review

Antibiotic, analgesic sedative, and antiseizure medications are among the most commonly used medications in preterm/sick neonates, who are at high risk of nosocomial infections, central nervous system complications, and are exposed to numerous painful/stressful procedures. These severe and potentially life-threatening complications may have serious short- and long-term consequences and should be prevented and/or promptly treated. The reported variability in the medications used in neonates indicates the lack of adequate neonatal studies regarding their effectiveness and safety. Important obstacles contributing to inadequate studies in preterm/sick infants include difficulties in obtaining parental consent, physicians' unwillingness to recruit preterm infants, the off-label use of many medications in neonates, and other scientific and ethical concerns. This review is an update on the use of antimicrobials (antifungals), analgesics (sedatives), and antiseizure medications in neonates, focusing on current evidence or knowledge gaps regarding their pharmacokinetics, indications, safety, dosage, and evidence-based guidelines for their optimal use in neonates. We also address the effects of early antibiotic use on the intestinal microbiome and its association with long-term immune-related diseases, obesity, and neurodevelopment (ND). Recommendations for empirical treatment and the emergence of pathogen resistance to antimicrobials and antifungals are also presented. Finally, future perspectives on the prevention, modification, or reversal of antibiotic resistance are discussed.

Comparing prolonged infusion to intermittent infusion strategies for beta-lactam antibiotics in patients with gram-negative bacterial infections: a systematic review and meta-analysis

INTRODUCTION

Our objective is to determine whether prolonged infusion (PI) of beta-lactam antibiotics yields superior outcomes compared to intermittent infusion (II) in patients with Gram-Negative Bacterial (GNB) infections.

METHODS

We systematically searched papers from PubMed, the Cochrane Library, Embase, and Clinicaltrials.gov, targeting mortality as the primary outcome and looking at the clinical cure rate, hospital and intensive care unit (ICU) stay lengths, antibiotic treatment duration, and mechanical ventilation (MV) duration as secondary outcomes.

RESULTS

Our meta-analysis of 18 studies, including 5 randomized control trials and 13 observational studies, with a total of 3,035 patients-1,510 in the PI group and 1,525 in the II group, revealed significant findings. PI was associated with reduced mortality (RR, 0.67; 95% CI, 0.55-0.81; p = 0.001; I2 = 4.52%) and a shorter MV duration (SMD, -0.76; 95% CI, -1.37 to -0.16; p = 0.01; I2 = 87.81%) compared to II. However, no differences were found in clinical cure rates, antibiotic treatment duration, length of hospital stay, or length of ICU stay.

CONCLUSIONS

The PI approach for administering beta-lactam antibiotics in patients with suspected or confirmed GNB infections may be advantageous in reducing mortality rates and the duration of MV when compared to the II strategy.

Intra-abdominal infections survival guide: a position statement by the Global Alliance For Infections In Surgery

Intra-abdominal infections (IAIs) are an important cause of morbidity and mortality in hospital settings worldwide. The cornerstones of IAI management include rapid, accurate diagnostics; timely, adequate source control; appropriate, short-duration antimicrobial therapy administered according to the principles of pharmacokinetics/pharmacodynamics and antimicrobial stewardship; and hemodynamic and organ functional support with intravenous fluid and adjunctive vasopressor agents for critical illness (sepsis/organ dysfunction or septic shock after correction of hypovolemia). In patients with IAIs, a personalized approach is crucial to optimize outcomes and should be based on multiple aspects that require careful clinical assessment. The anatomic extent of infection, the presumed pathogens involved and risk factors for antimicrobial resistance, the origin and extent of the infection, the patient's clinical condition, and the host's immune status should be assessed continuously to optimize the management of patients with complicated IAIs.

How to use meropenem in pediatric patients undergoing CKRT? Integrated meropenem pharmacokinetic model for critically ill children

Standard dosing could fail to achieve adequate systemic concentrations in ICU children or may lead to toxicity in children with acute kidney injury. The population pharmacokinetic analysis was used to simultaneously analyze all available data (plasma, prefilter, postfilter, effluent, and urine concentrations) and provide the pharmacokinetic characteristics of meropenem. The probability of target fT > MIC attainment, avoiding toxic levels, during the entire dosing interval was estimated by simulation of different intermittent and continuous infusions in the studied population. A total of 16 critically ill children treated with meropenem were included, with 7 of them undergoing continuous kidney replacement therapy (CKRT). Only 33% of children without CKRT achieved 90% of the time when the free drug concentration exceeded the minimum inhibitory concentration (%fT > MIC) for an MIC of 2 mg/L. In dose simulations, only continuous infusions (60-120 mg/kg in a 24-h infusion) reached the objective in patients <30 kg. In patients undergoing CKRT, the currently used schedule (40 mg/kg/12 h from day 2 in a short infusion of 30 min) was clearly insufficient in patients <30 kg. Keeping the dose to 40 mg/kg q8h without applying renal adjustment and extended infusions (40 mg/kg in 3- or 4-h infusion every 12 h) was sufficient to reach 90% fT > MIC (>2 mg/L) in patients >10 kg. In patients <10 kg, only continuous infusions reached the objective. In patients >30 kg, 60 mg/kg in a 24-h infusion is sufficient and avoids toxicity. This population model could help with an individualized dosing approach that needs to be adopted in critically ill pediatric patients. Critically ill patients subjected to or not to CKRT may benefit from the administration of meropenem in an extended or continuous infusion.

Continuous versus intermittent infusion of beta-lactam antibiotics: where do we stand today? A narrative review

Introduction

Antimicrobial resistance (AMR) is among the greatest threats to global healthcare. The World Health Organization (WHO) estimates that by 2050 ten million deaths will be attributed to AMR annually. In response, the WHO has implemented antibiotic stewardship programs which focus on optimizing antibiotic use and raise, amongst others, the issue of the preferred method of intravenous antibiotic administration. Various studies have attempted to answer this question with conflicting results.

Review

This review examined several studies assessing extended/continuous infusion compared to intermittent infusion of three beta-lactams: piperacillin-tazobactam, cefepime, and meropenem. The findings and conclusions of each study were summarized and compared to one another to provide a general overview of the current evidence.

Conclusions

We conclude that continuous/extended infusion showed a greater clinical benefit in highly critical cases, namely sepsis and febrile neutropenia, compared to intermittent infusion. Additionally, in cases where a pathogen was identified, continuous/extended infusion showed superiority. Nonetheless, high-quality studies with larger samples are needed to demonstrate the difference between these two modes of infusion in a way that would better inform guidelines and policies, aiding in the fight against AMR.

Problematic meta-analyses: Bayesian and frequentist perspectives on combining randomized controlled trials and non-randomized studies

PURPOSE

In the literature, the propriety of the meta-analytic treatment-effect produced by combining randomized controlled trials (RCT) and non-randomized studies (NRS) is questioned, given the inherent confounding in NRS that may bias the meta-analysis. The current study compared an implicitly principled pooled Bayesian meta-analytic treatment-effect with that of frequentist pooling of RCT and NRS to determine how well each approach handled the NRS bias.

MATERIALS & METHODS

Binary outcome Critical-Care meta-analyses, reflecting the importance of such outcomes in Critical-Care practice, combining RCT and NRS were identified electronically. Bayesian pooled treatment-effect and 95% credible-intervals (BCrI), posterior model probabilities indicating model plausibility and Bayes-factors (BF) were estimated using an informative heavy-tailed heterogeneity prior (half-Cauchy). Preference for pooling of RCT and NRS was indicated for Bayes-factors > 3 or < 0.333 for the converse. All pooled frequentist treatment-effects and 95% confidence intervals (FCI) were re-estimated using the popular DerSimonian-Laird (DSL) random effects model.

RESULTS

Fifty meta-analyses were identified (2009-2021), reporting pooled estimates in 44; 29 were pharmaceutical-therapeutic and 21 were non-pharmaceutical therapeutic. Re-computed pooled DSL FCI excluded the null (OR or RR = 1) in 86% (43/50). In 18 meta-analyses there was an agreement between FCI and BCrI in excluding the null. In 23 meta-analyses where FCI excluded the null, BCrI embraced the null. BF supported a pooled model in 27 meta-analyses and separate models in 4. The highest density of the posterior model probabilities for 0.333 < Bayes factor < 1 was 0.8.

CONCLUSIONS

In the current meta-analytic cohort, an integrated and multifaceted Bayesian approach gave support to including NRS in a pooled-estimate model. Conversely, caution should attend the reporting of naïve frequentist pooled, RCT and NRS, meta-analytic treatment effects.

Meropenem population pharmacokinetics and model-based dosing optimisation in patients with serious bacterial infection

OBJECTIVES

The objective of this study was to develop a population pharmacokinetic model of meropenem in a heterogeneous population of patients with a serious bacterial infection in order to propose dosing optimisation leading to improved achievement of the pharmacokinetic/pharmacodynamic (PK/PD) target.

METHODS

A total of 174 meropenem serum levels obtained from 144 patients during therapeutic drug monitoring were analysed using a non-linear mixed-effects modelling approach and Monte Carlo simulation was then used to compare various dosing regimens in order to optimise PK/PD target attainment.

RESULTS

The meropenem volume of distribution of the patient population was 54.95 L, while clearance started at 3.27 L/hour and increased by 0.91 L/hour with each 1 mL/s/1.73 m2 of estimated glomerular filtration rate. Meropenem clearance was also 0.31 L/hour higher in postoperative patients with central nervous system infection. Meropenem administration by continuous infusion showed a significantly higher probability of attaining the PK/PD target than a standard 30 min infusion (95.3% vs 49.5%).

CONCLUSIONS

A daily meropenem dose of 3 g, 6 g and 10.5 g administered by continuous infusion was shown to be accurate for patients with moderate to severe renal impairment, normal renal function to mild renal impairment and augmented renal clearance, respectively.

Machine Learning-Led Optimization of Combination Therapy: Confronting the Public Health Threat of Extensively Drug Resistant Gram-Negative Bacteria

Developing optimized regimens for combination antibiotic therapy is challenging and often performed empirically over many clinical studies. Novel implementation of a hybrid machine-learning pharmacokinetic/pharmacodynamic/toxicodynamic (ML-PK/PD/TD) approach optimizes combination therapy using human PK/TD data along with in vitro PD data. This study utilized human population PK (PopPK) of aztreonam, ceftazidime/avibactam, and polymyxin B along with in vitro PDs from the Hollow Fiber Infection Model (HFIM) to derive optimal multi-drug regimens de novo through implementation of a genetic algorithm (GA). The mechanism-based PD model was constructed based on 7-day HFIM experiments across 4 clinical, extensively drug resistant Klebsiella pneumoniae isolates. GA-led optimization was performed using 13 different fitness functions to compare the effects of different efficacy (60%, 70%, 80%, or 90% of simulated subjects achieving bacterial counts of 102  CFU/mL) and toxicity (66% of simulated subjects having a target polymyxin B area under the concentration-time curve [AUC] of 100 mg·h/L and aztreonam AUC of 1,332 mg·h/L) on the optimized regimen. All regimens, except those most heavily weighted for toxicity prevention, were able to achieve the target efficacy threshold (102  CFU/mL). Overall, GA-based regimen optimization using preclinical data from animal-sparing in vitro studies and human PopPK produced clinically relevant dosage regimens similar to those developed empirically over many years for all three antibiotics. Taken together, these data provide significant insight into new therapeutic approaches incorporating ML to regimen design and treatment of resistant bacterial infections.

[Clinical practice guidelines for meropenem therapy in neonatal sepsis (2024)]

Meropenem is one of the most widely used special-grade antimicrobial agents in the treatment of neonatal sepsis. However, its irrational use has led to an increasingly severe problem of bacterial multidrug resistance. The guideline was developed following standardized methods and procedures, and provides 12 recommendations specifically addressing 9 clinical issues. The recommendations cover various aspects of meropenem use in neonates, including timing of administration, recommended dosage, extended infusion, monitoring and assessment, antimicrobial adjustment strategies, treatment duration, and treatment strategies for carbapenem-resistant Enterobacteriaceae infections. The aim of the guideline is to provide evidence-based recommendations and guidance for the rational use of meropenem in neonates with sepsis.

A Randomized Clinical Trial of Bayesian-Guided Beta-Lactam Infusion Strategy and Associated Bacterial Resistance and Clinical Outcomes in Patients With Severe Pneumonia

BACKGROUND

Antimicrobial resistance is a growing health concern worldwide. The objective of this study was to evaluate the effect of beta-lactam infusion on the emergence of bacterial resistance in patients with severe pneumonia in the intensive care unit.

METHODS

Adult intensive care patients receiving cefepime, meropenem, or piperacillin-tazobactam for severe pneumonia caused by Gram-negative bacteria were randomized to receive beta-lactams as an intermittent (30 minutes) or continuous (24 hours) infusion. Respiratory samples for culture and susceptibility testing, with minimum inhibitory concentrations (MIC), were collected once a week for up to 4 weeks. Beta-lactam plasma concentrations were measured and therapeutic drug monitoring was performed using Bayesian software as the standard of care.

RESULTS

The study was terminated early owing to slow enrollment. Thirty-five patients were enrolled in this study. Cefepime (n = 22) was the most commonly prescribed drug at randomization, followed by piperacillin (n = 8) and meropenem (n = 5). Nineteen patients were randomized into the continuous infusion arm and 16 into the intermittent infusion arm. Pseudomonas aeruginosa was the most common respiratory isolate (n = 19). Eighteen patients were included in the final analyses. No differences in bacterial resistance were observed between arms ( P = 0.67). No significant differences in superinfection ( P = 1), microbiological cure ( P = 0.85), clinical cure at day 7 ( P = 0.1), clinical cure at end of therapy ( P = 0.56), mortality ( P = 1), intensive care unit length of stay ( P = 0.37), or hospital length of stay ( P = 0.83) were observed. Achieving 100% ƒT > MIC ( P = 0.04) and ƒT > 4 × MIC ( P = 0.02) increased likelihood of clinical cure at day 7 of therapy.

CONCLUSIONS

No differences in the emergence of bacterial resistance or clinical outcomes were observed between intermittent and continuous infusions. Pharmacokinetic/pharmacodynamic target attainment may be associated with a clinical cure on day 7.

Interprofessional Therapeutic Drug Monitoring of Carbapenems Improves ICU Care and Guideline Adherence in Acute-on-Chronic Liver Failure

(1) Background: Acute-on-chronic liver failure (ACLF) is a severe, rapidly progressing disease in patients with liver cirrhosis. Meropenem is crucial for treating severe infections. Therapeutic drug monitoring (TDM) offers an effective means to control drug dosages, especially vital for bactericidal antibiotics like meropenem. We aimed to assess the outcomes of implementing TDM for meropenem using an innovative interprofessional approach in ACLF patients on a medical intensive care unit (ICU). (2) Methods: The retrospective study was conducted on a medical ICU. The outcomes of an interprofessional approach comprising physicians, hospital pharmacists, and staff nurses to TDM for meropenem in critically ill patients with ACLF were examined in 25 patients. Meropenem was administered continuously via an infusion pump after the application of an initial loading dose. TDM was performed weekly using high-performance liquid chromatography (HPLC). Meropenem serum levels, implementation of the recommendations of the interprofessional team, and meropenem consumption were analyzed. (3) Results: Initial TDM for meropenem showed a mean meropenem serum concentration of 20.9 ± 9.6 mg/L in the 25 analyzed patients. Of note, in the initial TDM, only 16.0% of the patients had meropenem serum concentrations within the respective target range, while 84.0% exceeded this range. Follow-up TDM showed serum concentrations of 15.2 ± 5.7 mg/L (9.0-24.6) in Week 2 and 11.9 ± 2.3 mg/L (10.2-13.5) in Week 3. In Week 2, 41.7% of the patients had meropenem serum concentrations that were within the respective target range, while 58.3% of the patients were above this range. In Week 3, 50% of the analyzed serum concentrations of meropenem were within the targeted range, and 50% were above the range. In total, 100% of the advice given by the interprofessional team regarding meropenem dosing or a change in antibiotic therapy was implemented. During the intervention period, the meropenem application density was 37.9 recommended daily doses (RDD)/100 patient days (PD), compared to 42.1 RDD/100 PD in the control period, representing a 10.0% decrease. (4) Conclusions: Our interprofessional approach to TDM significantly reduced meropenem dosing, with all the team's recommendations being implemented. This method not only improved patient safety but also considerably decreased the application density of meropenem.

Pharmacokinetics and Therapeutic Target Attainment of Meropenem in Pediatric Post-Liver Transplant Patients: Extended vs Intermittent Infusion

PURPOSE

The aim of this study is to characterize the concentration-time profile, pharmacokinetics parameters, and therapeutic target attainment of meropenem in pediatric post-liver transplant patients according to the duration of infusion.

METHODS

This is a prospective cohort of pediatric transplant recipients with preserved renal function receiving meropenem 40 mg/kg every 8 hours. The patients were stratified into 2 groups based on infusion duration: G1 (15 minutes of intermittent infusion) and G1 (3 hours of extended infusion). Two blood samples per child were collected during the same interval within 48 hours of starting the antimicrobial. Meropenem concentrations were determined by high-performance liquid chromatography with tandem mass spectrometry. Pharmacokinetic parameters were assessed using a noncompartmental analysis. The therapeutic target was defined as 100% of the time above the minimum inhibitory concentration.

FINDINGS

Fourteen patients with 28 measured meropenem concentrations were included. Lower values of volume of distribution and meropenem clearance compared with other critically ill pediatric populations were found. All patients achieved the therapeutic target against gram-negative pathogens with a minimum inhibitory concentration of ≤8 mg/L. Patients receiving a 15-minute infusion had higher values of peak and trough concentrations, resulting in unnecessary increased total drug exposure when compared to patients receiving a 3-hour infusion (P < .05).

CONCLUSIONS

Meropenem at 120 mg/kg/d attained the therapeutic target against sensitive microorganisms in pediatric liver transplant recipients. The extended infusion should be preferred for patient safety. Because of the pharmacokinetic changes resulting from liver transplantation, individualized meropenem dosing regimens may be necessary.

Chemical stability and physical compatibility of meropenem in admixtures for continuous and extended intravenous infusions

INTRODUCTION

Prolonged intravenous infusion of beta-lactams increase the clinical cure rate compared to conventional administration in critical or septic patients. This study aimed to determine chemical stability and physical compatibility of meropenem at conditions used in clinical practice to evaluate the stability of the preparation during its administration and the possibility of anticipated preparation.

METHODS

Admixtures in study were: (i) meropenem 6g in 0.9% sodium chloride (NS) in infusor of 2mL/h 50mL or 10mL/h 240mL; (ii) meropenem 1 or 2g in NS in infusion bag of 250mL. Temperatures of study were: (i) infusor: 4.5°C, 32°C or 12h at 4.5°C followed by 32°C; (ii) Infusion bag: 4.5°C, 24.5°C or 6h at 4.5°C followed by 24.5°C. Time of study was 5-6 days in infusor and 1 day in infusion bag. Chemical stability was evaluated by high performance liquid chromatography and physical compatibility by measuring pH and visual inspection.

RESULTS

Chemical stability and physical compatibility of meropenem in admixtures in infusors were reduced at high meropenem concentration and high temperature. Admixtures in infusion bag show chemical stability and physical compatibility for at least 1 day.

CONCLUSION

Administration of meropenem 6g in infusion of 24h in 240mL of 0.9% NaCl in infusor of 10mL/h could be possible if the admixture is infused at 4.5°C. Extended infusion of meropenem 1 or 2g in 0.9% NaCl in infusion bag (250mL) in 3-4h is also feasible. Anticipated preparation of the admixtures in infusion bag is possible with a stability of 24h.

Extended infusion of β-lactams significantly reduces mortality and enhances microbiological eradication in paediatric patients: a systematic review and meta-analysis

Background

Paediatric patients are often exposed to subtherapeutic levels or treatment failure of β-lactams, and prolonged infusion may be beneficial. We aimed to investigate the efficacy and safety of extended infusion (EI; defined as ≥3 h) or continuous infusion vs. short, intermittent infusion (SI; defined as ≤60 min) of β-lactams in patients <21 years of age.

Methods

A systematic review and meta-analysis was conducted to compare EI and continuous infusion with SI of β-lactams in children. A systematic search was performed in MEDLINE (via PubMed), Embase, CENTRAL, and Scopus databases for randomised controlled trials (RCTs) and observational studies published from database inception up to August 22, 2023. Any comparative study concerned with mortality, clinical efficacy, adverse events, or plasma concentrations of β-lactams for any infection was eligible. Case reports, case series, and patients aged >21 years were excluded. Odds ratios (OR) and median differences with 95% confidence intervals (CI) were calculated using a random-effects model. Risk of bias (ROB) was assessed using ROB2 and ROBINS-I tools. The protocol was registered with PROSPERO, CRD42022375397.

Findings

In total, 19,980 articles were screened, out of which 19 studies (4195 patients) were included in the meta-analysis. EI administration was associated with a significantly lower all-cause mortality in both RCTs and non-RCTs [OR 0.74; CI 0.55-0.99; I2 = 0%; CI 0-58%]. Early microbiological eradication was higher with EI [OR 3.18; CI 2.24-4.51; I2 = 0%; CI 0-90%], but the clinical cure did not differ significantly between the two groups [OR 1.20; CI 0.17-8.71; I2 = 79%; CI 32-93%]. Achieving the optimal plasma level (50-100% fT > MIC) appeared favourable in the EI group compared to the SI. No significant differences were observed in the adverse events. The overall ROB was high because of the small sample sizes and clinically heterogeneous populations.

Interpretation

Our findings suggest that extended infusion of β-lactams was associated with lower mortality and increased microbiological eradication and was considered safe compared to short-term infusion.

Funding

None.

Extended Versus Intermittent Meropenem Infusion in the Treatment of Nosocomial Pneumonia: A Retrospective Single-Center Study

The efficacy of extended meropenem infusions in patients with nosocomial pneumonia is not well defined. Therefore, we compared the clinical outcomes of extended versus intermittent meropenem infusions in the treatment of nosocomial pneumonia. We performed a retrospective analysis of extended versus intermittent meropenem infusions in adult patients who had been treated for nosocomial pneumonia at a medical ICU between 1 May 2018 and 30 April 2020. The primary outcome was mortality at 14 days. Overall, 64 patients who underwent an extended infusion and 97 with an intermittent infusion were included in this study. At 14 days, 10 (15.6%) patients in the extended group and 22 (22.7%) in the intermittent group had died (adjusted hazard ratio (HR), 0.55; 95% confidence interval (CI): 0.23-1.31; p = 0.174). In the subgroup analysis, significant differences in mortality at day 14 were observed in patients following empirical treatment with meropenem (adjusted HR, 0.17; 95% CI: 0.03-0.96; p = 0.045) and in Gram-negative pathogens identified by blood or sputum cultures (adjusted HR, 0.01; 95% CI: 0.01-0.83; p = 0.033). Extended infusion of meropenem compared with intermittent infusion as a treatment option for nosocomial pneumonia may have a potential advantage in specific populations.

Carbapenems versus β-lactam and β-lactamase inhibitors for treatment of nosocomial pneumonia: A systematic review and meta-analysis

Background

Carbapenems and β-lactam and β-lactamase inhibitors (BLBLIs) have been used empirically in nosocomial pneumonia, but their efficacy and safety are controversial.

Objective

We carried out a systematic review with meta-analysis to evaluate the efficacy and safety of carbapenems versus BLBLIs against nosocomial pneumonia.

Methods

PubMed, Embase, Cochrane Central Register of Controlled Trials, CNKI, Wangfang, VIP and Sinomed were searched systematically through April 29, 2023 for clinical trials comparing carbapenems with BLBLIs for treatment of nosocomial pneumonia. Random-effects models were used to evaluate the impact of treatment on the risk ratio (RR) of all-cause mortality, clinical response, microbiologic response, resistance by Pseudomonas aeruginosa, adverse effects (AEs), and serious adverse effects. The quality of the evidence was assessed with the Cochrane risk of bias tool. The review was registerted in the INPLASY (INPLASY202340113).

Results

Seven randomized controlled trials containing 3306 patients met our inclusion criteria Our meta-analysis showed no significant difference in all-cause mortality (RR = 0.88, 95% confidence interval [CI] = 0.75-1.03, I2 = 0%) or clinical cure (1.02, 0.96-1.09, 30%) or clinical failure (1.19, 0.97-1.47, 0%) or microbiologic clinical cure (0.98, 0.89-1.06, 40%) or Pseudomonas aeruginosa resistance (RR 2.43, CI 0.86-6.81, 49%, P = 0.09) or adverse events (0.98, 0.93-1.02, 0%) between carbapenems groups versus BLBLIs groups, but a significant difference was found for severe adverse events (RR 0.83, CI 0.73-0.94, 0%).

Conclusion

Differences in the prevalence of mortality, clinical cure, or clinical failure were not observed between carbapenems groups versus BLBLIs groups in terms of nosocomial pneumonia. The use of carbapenems was linked to a tendency towards the emergence of P. aeruginosa resistance, however, no statistically significant difference was observed.

Prolonged vs short-term infusion of β-lactam antibiotics for the treatment of febrile neutropenia: A systematic review and meta-analysis

BACKGROUND

The optimisation of the use of β-lactam antibiotics (BLA) via prolonged infusions in life-threatening complications such as febrile neutropenia (FN) is still controversial. This systematic review and meta-analysis aim to evaluate the efficacy of this strategy in onco-haematological patients with FN.

METHODS

A systematic search was performed of PubMed, Web of Science, Cochrane, EMBASE, World Health Organization, and ClinicalTrials.gov, from database inception until December 2022. The search included randomised controlled trials (RCTs) and observational studies that compared prolonged vs short-term infusions of the same BLA. The primary outcome was all-cause mortality. Secondary outcomes were defervescence, requirement of vasoactive drugs, length of hospital stay and adverse events. Pooled risk ratios were calculated using random effects models.

RESULTS

Five studies were included, comprising 691 episodes of FN, mainly in haematological patients. Prolonged infusion was not associated with a reduction in all-cause mortality (pRR 0.83; 95% confidence interval 0.47-1.48). Nor differences were found in secondary outcomes.

CONCLUSIONS

The limited data available did not show significant differences in terms of all-cause mortality or significant secondary outcomes in patients with FN receiving BLA in prolonged vs. short-term infusion. High-quality RCTs are needed to determine whether there are subgroups of FN patients who would benefit from prolonged BLA infusion.

Continuous vs Intermittent Meropenem Administration in Critically Ill Patients With Sepsis: The MERCY Randomized Clinical Trial

IMPORTANCE

Meropenem is a widely prescribed β-lactam antibiotic. Meropenem exhibits maximum pharmacodynamic efficacy when given by continuous infusion to deliver constant drug levels above the minimal inhibitory concentration. Compared with intermittent administration, continuous administration of meropenem may improve clinical outcomes.

OBJECTIVE

To determine whether continuous administration of meropenem reduces a composite of mortality and emergence of pandrug-resistant or extensively drug-resistant bacteria compared with intermittent administration in critically ill patients with sepsis.

DESIGN, SETTING, AND PARTICIPANTS

A double-blind, randomized clinical trial enrolling critically ill patients with sepsis or septic shock who had been prescribed meropenem by their treating clinicians at 31 intensive care units of 26 hospitals in 4 countries (Croatia, Italy, Kazakhstan, and Russia). Patients were enrolled between June 5, 2018, and August 9, 2022, and the final 90-day follow-up was completed in November 2022.

INTERVENTIONS

Patients were randomized to receive an equal dose of the antibiotic meropenem by either continuous administration (n = 303) or intermittent administration (n = 304).

MAIN OUTCOMES AND MEASURES

The primary outcome was a composite of all-cause mortality and emergence of pandrug-resistant or extensively drug-resistant bacteria at day 28. There were 4 secondary outcomes, including days alive and free from antibiotics at day 28, days alive and free from the intensive care unit at day 28, and all-cause mortality at day 90. Seizures, allergic reactions, and mortality were recorded as adverse events.

RESULTS

All 607 patients (mean age, 64 [SD, 15] years; 203 were women [33%]) were included in the measurement of the 28-day primary outcome and completed the 90-day mortality follow-up. The majority (369 patients, 61%) had septic shock. The median time from hospital admission to randomization was 9 days (IQR, 3-17 days) and the median duration of meropenem therapy was 11 days (IQR, 6-17 days). Only 1 crossover event was recorded. The primary outcome occurred in 142 patients (47%) in the continuous administration group and in 149 patients (49%) in the intermittent administration group (relative risk, 0.96 [95% CI, 0.81-1.13], P = .60). Of the 4 secondary outcomes, none was statistically significant. No adverse events of seizures or allergic reactions related to the study drug were reported. At 90 days, mortality was 42% both in the continuous administration group (127 of 303 patients) and in the intermittent administration group (127 of 304 patients).

CONCLUSIONS AND RELEVANCE

In critically ill patients with sepsis, compared with intermittent administration, the continuous administration of meropenem did not improve the composite outcome of mortality and emergence of pandrug-resistant or extensively drug-resistant bacteria at day 28.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03452839.

Characteristics, Outcomes, and Clinical Indicators of Bloodstream Infections in Neutropenic Patients with Hematological Malignancies: A 7-Year Retrospective Study

Purpose

The aim of this study was to investigate the current epidemiology, its changes during the study years, and inflammatory biomarkers of bacterial bloodstream infections (BSIs) in neutropenic patients with hematological malignancies. We assessed mortality risk factors and multidrug-resistant (MDR) gram-negative BSI predictors.

Patients and Methods

We conducted a retrospective study from January 2015 to December 2021, which included adult neutropenic oncohematological patients with confirmed BSIs. We used univariable and multivariable analyses to analyze the risk factors. Each index's reliability for bacterial BSI diagnosis was assessed using the receiver-operating characteristic curve and area under the curve.

Results

A total of 514 isolates were obtained from the 452 patients. The average mortality was 17.71%. Gram-negative organisms were the predominant causes of BSI. Escherichia coli was the most common microorganism (49.90%). The overall variation trend of the isolation rate of MDR and carbapenem-resistant gram-negative bacteria increased. Multivariate analysis indicated that: 1) neutropenia that lasted for more than 7 days, patients ≥ 60 years of age, septic shock, hospitalization for >20 days, BSI with a carbapenem-resistant strain, and treatment with linezolid or vancomycin in infections lasting less than 30 days were independent mortality risk factors; 2) severe neutropenia exceeding 7 days, unreasonable empirical therapy, and receipt of aminoglycosides or 3rd or 4th generation cephalosporins in infections lasting less than 30 days were independent risk factors of MDR gram-negative bacteria. Procalcitonin, absolute neutrophil count, and white blood cell indicate higher diagnostic accuracy for BSIs. Moreover, bacteria time to detection was better at differentiating Gram-negative and Gram-positive bacterial infections.

Conclusion

We analyzed the risk factors for BSI neutropenic patients with hematological malignancies, the distribution of bacteria, antibiotic resistance, and the changes in clinical parameters. This single-center retrospective study may provide clinicians with novel insights into the diagnosis and treatment of BSI to improve future clinical outcomes.

The Efficacy and Influencing Factors of Polymyxin B in High-Level Carbapenem-Resistant Klebsiella pneumoniae Infections

Background

Polymyxin B (PMB) is a remedial treatment for carbapenem-resistant Klebsiella pneumoniae (CRKP) infection; however, there is a paucity of reports on the treatment of high-level CRKP infections with polymyxin B. Studies are needed to explore its treatment efficacy and associated influencing factors.

Methods

Patients with high-level CRKP infections treated with PMB during hospitalization from June 2019 to June 2021 in a hospital were retrospectively studied, and risk factors affecting the efficacy were explored by subgroup analysis.

Results

A total of 92 patients were enrolled, and the results showed that the PMB-based regimen had a bacterial clearance rate of 45.7%, an all-cause discharge mortality rate of 22.8%, and an incidence of acute kidney injury (AKI) of 27.2% for high-level CRKP treatment. The combination of β-lactams other than carbapenems facilitated bacterial clearance, and the combination of electrolyte disturbances and higher APACHE II scores was detrimental to microbial clearance. Risk factors for all-cause discharge mortality were advanced age, concomitant antifungal drugs, concomitant tigecycline and incidence of AKI.

Conclusion

PMB-based regimens are an effective option for the treatment of high-level CRKP infections. However, the optimal dose of treatment and the choice of combination regimens need to be explored in further studies.

Outpatient parenteral antimicrobial therapy with continuous infusion of meropenem: A retrospective analysis of three years of clinical experience

INTRODUCTION

Data regarding outpatient parenteral antimicrobial therapy (OPAT) with continuous infusion of meropenem (CIM) remain scarce and controversial. We aimed to analyze its outcomes.

METHODS

We conducted a retrospective analysis of a cohort of patients who received OPAT with CIM during a three-year period at a single center in northwest Spain. Demographics, clinical data and OPAT outcomes were recorded.

RESULTS

Since January 2017-December 2019, 34 patients received 35 OPAT episodes with CIM. The median age was 75 years, and 18 (51.4%) had a Charlson comorbidity index>2. Twelve (34.3%) had respiratory infection, 11 (31.4%) urinary tract infection, and 12 (34.3%) other infections. Twenty-one (60%) received a dose of 6g/day, and 27 (77.1%) received combined antibiotic therapy. The duration of OPAT with CIM was 10 median days. Pseudomonas aeruginosa was the most frequently (34.3%) isolated microorganism and 10 (28.6%) infections were polymicrobial. During OPAT and hospital at home unit admission, 4 (11.4%) patients had any adverse reaction that required CIM withdrawal, 2 (5.7%) were readmitted, and 3 (8.8%) died (2 infection-related deaths). After 30 days from discharge 6 (18.8%) of 32 not-censored patients had unplanned readmissions (2 infection-related), 6 (18.8%) developed recurrence (3 relapses, 3 reinfections) and 1 (3.1%) died (none-infection-related death). Twenty-three (71.9%) of these 32 patients did not experience unplanned readmission, recurrence or death.

CONCLUSION

CIM can be an option to be administrated in OPAT programs in selected patients. Further studies are warranted to increase evidence regarding its use, and to externally validate our findings.

Continuous infusion of beta-lactam antibiotics: narrative review of systematic reviews, and implications for outpatient parenteral antibiotic therapy

INTRODUCTION

Continuous infusion (CI) of beta-lactam antibiotics may be of benefit in some patients, particularly those with severe infections. However, most studies have been small and conflicting results have been reported. The best available evidence on clinical outcomes of beta-lactam CI comes from systematic reviews/meta-analyses that integrate the available data.

AREAS COVERED

A search of PubMed from inception to the end of February 2022 for systematic reviews of clinical outcomes with beta-lactam CI for any indication identified 12 reviews, all of which focused on hospitalized patients, most of whom were critically ill. A narrative overview of these systematic reviews/meta-analyses is provided. No systematic reviews evaluating the use of beta-lactam CI for outpatient parenteral antibiotic therapy (OPAT) were identified, as few studies have focused on this area. Relevant data are summarized, and consideration is given to issues that need to be addressed when using beta-lactam CI in the setting of OPAT.

EXPERT OPINION

Evidence from systematic reviews supports a role for beta-lactam CI in the treatment of hospitalized patients with severe/life-threatening infections. Beta-lactam CI can play a role in patients receiving OPAT for severe chronic/difficult-to-treat infections, but additional data are needed to clarify its optimal use.

Does Cytokine-Release Syndrome Induced by CAR T-Cell Treatment Have an Impact on the Pharmacokinetics of Meropenem and Piperacillin/Tazobactam in Patients with Hematological Malignancies? Findings from an Observational Case-Control Study

Chimeric antigen receptor (CAR) T-cell therapy is a promising approach for some relapse/refractory hematological B-cell malignancies; however, in most patients, cytokine release syndrome (CRS) may occur. CRS is associated with acute kidney injury (AKI) that may affect the pharmacokinetics of some beta-lactams. The aim of this study was to assess whether the pharmacokinetics of meropenem and piperacillin may be affected by CAR T-cell treatment. The study included CAR T-cell treated patients (cases) and oncohematological patients (controls), who were administered 24-h continuous infusion (CI) meropenem or piperacillin/tazobactam, optimized by therapeutic drug monitoring, over a 2-year period. Patient data were retrospectively retrieved and matched on a 1:2 ratio. Beta-lactam clearance (CL) was calculated as CL = daily dose/infusion rate. A total of 38 cases (of whom 14 and 24 were treated with meropenem and piperacillin/tazobactam, respectively) was matched with 76 controls. CRS occurred in 85.7% (12/14) and 95.8% (23/24) of patients treated with meropenem and piperacillin/tazobactam, respectively. CRS-induced AKI was observed in only 1 patient. CL did not differ between cases and controls for both meropenem (11.1 vs. 11.7 L/h, p = 0.835) and piperacillin (14.0 vs. 10.4 L/h, p = 0.074). Our findings suggest that 24-h CI meropenem and piperacillin dosages should not be reduced a priori in CAR T-cell patients experiencing CRS.

The clinical and paraclinical effectiveness of four-hour infusion vs. half-hour infusion of high-dose ampicillin-sulbactam in treatment of critically ill patients with sepsis or septic shock: An assessor-blinded randomized clinical trial

PURPOSE

This study was conducted to determine whether critically ill patients admitted to the intensive care unit (ICU) with sepsis and septic shock may benefit from extended infusion of ampicillin/sulbactam compared with those receiving intermittent infusion.

MATERIAL AND METHODS

This randomized assessor-blinded clinical trial was conducted in the ICUs of Nemazee and Shahid Rajaee hospital, Shiraz, Iran, from August 2019 to August 2021. The participants randomly received 9 g Ampicillin/Sulbactam every 8 h by either extended (infused over 4 h) or intermittent (infused over 30 min) intravenous infusion if their estimated glomerular filtration rate based on Cockrorft-Gault formula was higher than 60 ml/min.

RESULTS

Totally, 136 patients were enrolled and allocated to the intervention and control groups, each with 68 patients. Clinical cure was significantly higher in the extended group (P = 0.039), but ICU and hospital length of stay did not differ between the groups (P = 0.87 and 0.83, respectively). The ICU (P = 0.031) and hospital (P = 0.037) mortality rates in the extended infusion group were significantly lower than those in the intermittent infusion group.

CONCLUSION

These data should be replicated in larger clinical trials before providing any recommendation in favor of this method of administration in clinical practice.

Case report: Successful experience using continuous infusion of meropenem in a geriatric patient with hip fracture complicated by sepsis

This article highlights a clinical case of successful treatment of a 79-year-old multimorbid patient with a hip fracture resulting from a household injury. On the first day, the patient's injury was complicated by infection and pneumonia. As a result, arterial hypotension, tachysystole, and respiratory failure progressed. With manifestations of sepsis, the patient was transferred to the intensive care unit. Surgical treatment in such a situation was contraindicated due to the high operational and anesthesiological risks, the unstable severe condition of the patient, as well as the presence of concomitant pathology in the form of coronary heart disease, obesity, and schizophrenia. According to the new sepsis management guideline, it was decided to use a continuous 24-h infusion of meropenem in addition to the complex treatment of sepsis. The use of continuous infusion of meropenem in this clinical situation may have caused the patient's clinical improvement, which increased her quality of life and decreased the length of ICU stay and total hospital stay, despite an unfavorable cumulative prognosis and a high risk of in-hospital mortality.

Optimizing Meropenem in Highly Resistant Klebsiella pneumoniae Environments: Population Pharmacokinetics and Dosing Simulations in Critically Ill Patients

Critically ill patients are characterized by substantial pathophysiological changes that alter the pharmacokinetics (PK) of hydrophilic antibiotics, including carbapenems. Meropenem is a key antibiotic for multidrug-resistant Gram-negative bacilli, and such pathophysiological alterations can worsen treatment outcomes. This study aimed to determine the population PK of meropenem and to propose optimized dosing regimens for the treatment of multidrug-resistant Klebsiella pneumoniae in critically ill patients. Two plasma samples were collected from eligible patients over a dosing interval. Nonparametric population PK modeling was performed using Pmetrics. Monte Carlo simulations were applied to different dosing regimens to determine the probability of target attainment and the cumulative fraction of response, taking into account the local MIC distribution for K. pneumoniae. The targets of 40% and 100% for the fraction of time that free drug concentrations remained above the MIC (ƒT>MIC) were tested, as suggested for critically ill patients. A one-compartment PK model using data from 27 patients showed high interindividual variability. Significant PK covariates were the 8-h creatinine clearance for meropenem and the presence of an indwelling catheter for pleural, abdominal, or cerebrospinal fluid drainage for the meropenem volume of distribution. The target 100% ƒT>MIC for K. pneumoniae, with a MIC of ≤2 mg/liter, could be attained by the use of a continuous infusion of 2.0 g/day. Meropenem therapy in critically ill patients could be optimized for K. pneumoniae isolates with an MIC of ≤2 mg/liter by using a continuous infusion in settings with more than 50% isolates have a MIC of ≥32mg/L.

Therapeutic drug monitoring of meropenem and pharmacokinetic-pharmacodynamic target assessment in critically ill pediatric patients from a prospective observational study

OBJECTIVES

To compare the unbound plasma meropenem concentrations at mid-dosing intervals (C_mid, 50%fT), end-dosing intervals (C_trough, 100%fT), and proportions of patients achieving 50%fT and 100%fT above MIC (50%fT_>MIC and 100%fT_>MIC) between extended infusion (EI) and intermittent bolus (IB) administration in a therapeutic drug monitoring (TDM) program in children.

METHODS

A prospective observational study was conducted in children aged 1 month to 18 years receiving meropenem every 8 h by either EI or IB. Meropenem C_mid, C_trough, and proportions of patients achieving 50%fT_>MIC and 100%fT_>MIC were compared.

RESULTS

TDM data from 72 patients with a median age (IQR) of 12 months (3-37) were used. Meropenem dose was 120 and 60 mg/kg/day in EI and IB groups, respectively. Geometric mean (95% CI) C_mid of EI versus IB was 17.3 mg/L (13.7-21.8) versus 3.4 mg/L (1.7-6.7) (P<0.001). Geometric mean (95% CI) C_trough of EI versus IB was 2.3 mg/L (1.6-3.4) versus 0.8 mg/L (0.4-1.5) (P=0.005). Greater proportions of patients achieving 50%fT_>MIC and 100%fT_>MIC were observed in the EI group.

CONCLUSIONS

A meropenem dose of 20 mg/kg/dose given by IB should not be used in critically ill children, even if they are not suspected of having a CNS infection. A dose of 40 mg/kg/dose given by EI resulted in higher C_mid, C_trough, and proportions of patients achieving 50%fT_>MIC and 100%fT_>MIC.

Treatment of ventilator-associated pneumonia due to carbapenem-resistant Gram-negative bacteria with novel agents: a contemporary, multidisciplinary ESGCIP perspective

INTRODUCTION

: In the past 15 years, treatment of VAP caused by carbapenem-resistant Gram-negative bacteria (CR-GNB) has represented an intricate challenge for clinicians.

AREAS COVERED

In this perspective article, we discuss the available clinical data about novel agents for the treatment of CR-GNB VAP, together with general PK/PD principles for the treatment of VAP, in the attempt to provide some suggestions for optimizing antimicrobial therapy of CR-GNB VAP in the daily clinical practice.

EXPERT OPINION

Recently, novel BL and BL/BLI combinations have become available that have shown potent in vitro activity against CR-GNB and have attracted much interest as novel, less toxic, and possibly more efficacious options for the treatment of CR-GNB VAP compared with previous standard of care. Besides randomized controlled trials, a good solution to enrich our knowledge on how to use these novel agents at best in the near future, while at the same time remaining adherent to current evidence-based guidelines, is to improve our collaboration to conduct larger multinational observational studies to collect sufficiently large populations treated in real life with those novel agents for which guidelines currently do not provide a recommendation (in favor or against) for certain causative organisms.

An Outer Membrane Protein YiaD Contributes to Adaptive Resistance of Meropenem in Acinetobacter baumannii

Acinetobacter baumannii is an important nosocomial pathogen that can develop various resistance mechanisms to many antibiotics. However, little is known about how it evolves from an antibiotic sensitive to a resistant phenotype. In this study, we investigated the transition of outer membrane proteins (OMPs) under antibiotic stress and identified YiaD as an OMP marker involved in the development of adaptive resistance to meropenem (MEM) in A. baumannii. Following stimulation of a carbapenem-sensitive strain AB5116 with sub-MIC of MEM, yiaD showed significantly decreased expression, and this decrease continued with prolonged stimulation for 8 h. The downregulation of yiaD was not only observed in clinically sensitive strains but also in 45 carbapenem-resistant isolates that produced the β-lactamases TEM and OXA-23. However, the extent of the reduction of yiaD expression in resistant strains was less than that in sensitive strains. Lack of yiaD resulted in a 4-fold increase in the MIC of AB5116 to MEM. The same level of depressed susceptibility induced by yiaD deletion was observed in both a growth curve test and a survival rate assay. Moreover, the colony shape became enlarged and irregular after loss of yiaD, and the biofilm formation ability of A. baumannii was influenced by YiaD. These results suggest that YiaD could respond to the stimulus of MEM in A. baumannii with a downregulation trend that kept pace with the prolonged stimulation time, indicating that it participates in various routes to benefit MEM resistance evolution in both carbapenem-sensitive and -resistant A. baumannii strains.

IMPORTANCEAcinetobacter baumannii can develop various resistance mechanisms to carbapenems. However, the factors involved in the evolutionary process that leads from transition to the sensitive to resistant phenotype are not clear. The outer membrane protein YiaD of A. baumannii was downregulated under the stress of meropenem (MEM), and its expression level was continuously reduced with prolonged stimulation time. The downregulation of yiaD was not only observed in sensitive strains but also in carbapenem-resistant isolates producing the β-lactamases TEM and OXA-23. However, the extent of yiaD reduction was less in resistant strains than in sensitive strains. Lack of yiaD resulted in an increased MEM MIC, enlarged and irregular colonies, and decreased biofilm formation ability. These results suggest that YiaD responds to MEM stimulus in A. baumannii and participates in the adaptive resistance of MEM in both carbapenem-sensitive and -resistant strains.

Klebsiella pneumoniae invasion syndrome: a case of liver abscess combined with lung abscess, endophthalmitis, and brain abscess

Klebsiella pneumoniae invasion syndrome (KPIS) is a critical multi-site infection that is usually caused by highly virulent Klebsiella pneumonia. It is relatively common in Asian patients with diabetes and leads to sepsis, which has a high mortality rate. We report the case of a man in his early 40s who presented to the hospital with blurred vision in his left eye of 7 days’ duration and fever of 1 day’s duration. After a complete examination, he was diagnosed with KPIS on the basis of his liver abscessation, lung abscessation, endophthalmitis of the left eye and brain abscessation. After needle puncture and drainage of the left eye and liver abscess and anti-bacterial treatment with meropenem, the patient recovered well. When KPIS is suspected, attention should be paid to the sites of infection and the selection of the most appropriate antibiotics, but the most important aim should be to drain the lesions in a timely manner to improve the patient’s prognosis.

Extended Infusion of Meropenem in Neonatal Sepsis: A Historical Cohort Study

This single-center historical cohort study investigated the effectiveness and safety of extended infusion (EI) compared with short-term infusion (STI) of meropenem in neonatal sepsis. Patient electronic health records from Peking University Third Hospital (1 December 2011−1 April 2021) were screened. Neonates diagnosed with sepsis and treated with meropenem in the neonatal intensive care unit were included (256 patients) as STI (0.5 h, 129 patients) and EI (2−3 h, 127 patients) groups. Three-day clinical effectiveness and three-day microbial clearance were considered the main outcomes. Univariate and multivariate analyses were performed. Baseline characteristics were similar in both groups. EI of meropenem was associated with a significantly higher 3-day clinical effectiveness rate (0.335 (0.180, 0.623), p = 0.001) and 3-day microbial clearance (4.127 (1.235, 13.784), p = 0.021) than STI, with comparable safety. Subgroup analyses showed that neonates with very low birth weight benefited from EI in terms of 3-day clinical effectiveness rate (75.6% versus 56.6%, p = 0.007), with no significant difference in the 3-day clinical effectiveness (85.1% versus 78.3%, p = 0.325) and microbial clearance (6% versus 5%, p > 0.999) rates between 3 h and 2 h infusions. Thus, EI of meropenem may be associated with better effectiveness and comparable safety in treating neonatal sepsis than STI. Nonetheless, historically analyzed safety evaluation might be biased, and these findings need confirmation in randomized controlled trials of larger sample sizes.

Investigation of pharmacokinetic and clinical outcomes of various meropenem regimens in patients with ventilator-associated pneumonia and augmented renal clearance

INTRODUCTION

Augmented renal clearance (ARC) defined as creatinine clearance (Clcr) above 130 mL/min/1.73m² may lead to suboptimal antibacterial treatment. The aim of this study was to determine a strategy for meropenem administration to achieve both pharmacodynamic-pharmacokinetic (PK-PD) target (50%fT > MIC) and better clinical outcomes in patients with VAP and ARC.

MATERIALS AND METHODS

In this randomized clinical trial, patients with VAP and high risk for ARC were recruited. An 8-h urine collection was performed on the 1st, 3rd, and 5th days of study to measure Clcr. Included patients were divided into three groups: (1) 1 g meropenem, 3-h infusion, (2) 2 g meropenem, 3-h infusion, (3) 1 g meropenem, 6-h infusion. On the 2nd, 3rd, and 5th days of treatment, peak and trough blood samples were collected to undergo HPLC assay. MICs were assessed using microdilution method. Patients were also clinically monitored for 14 days.

RESULTS

Forty-five patients were included. Group 3 showed significanty higher rate of patients achieving fT > MIC > 50% (100% for group 3 versus 40% for group 2 and 13% for group 1; p = 0.0001). Mean fT > MIC% was significantly higher in group 3 (78.77 ± 5.87 for group 3 versus 49.6 ± 7.38 for group 2 and 43.2 ± 7.98 for group 1; p = 0.0001). Statistical analysis showed no significant differences among groups regarding clinical improvement.

CONCLUSION

According to the findings of this trial, prolonged meropenem infusion is an appropriate strategy compared to dose elevation among ARC patients.

Impact of Maximizing Css/MIC Ratio on Efficacy of Continuous Infusion Meropenem Against Documented Gram-Negative Infections in Critically Ill Patients and Population Pharmacokinetic/Pharmacodynamic Analysis to Support Treatment Optimization

Introduction: optimal treatment of Gram-negative infections in critically ill patients is challenged by changing pathophysiological conditions, reduced antimicrobial susceptibility and limited therapeutic options. The aim of this study was to assess the impact of maximizing Css/MIC ratio on efficacy of continuous infusion (CI) meropenem in treating documented Gram-negative infections in critically ill patients and to perform a population pharmacokinetic/pharmacodynamic analysis to support treatment optimization.

Materials and Methods: Classification and regression tree (CART) analysis was used to identify whether a cutoff of steady-state meropenem concentration (Css)-to-minimum inhibitory concentration (MIC) (Css/MIC) ratio correlated with favorable clinical outcome. A non-parametric approach with Pmetrics was used for pharmacokinetic analysis and covariate evaluation. The probability of target attainment (PTA) of the identified Css/MIC ratio was calculated by means of Monte Carlo simulations. Cumulative fraction of response (CFRs) were calculated against common Enterobacterales, P. aeruginosa and A. baumannii as well.

Results: a total of 74 patients with 183 meropenem Css were included. CART analysis identified a Css/MIC ratio ≥4.63 as cutoff value significantly associated with favorable clinical outcomes. Multivariate regression analysis confirmed the association [OR (95%CI): 20.440 (2.063–202.522); p < 0.01]. Creatinine clearance (CL_CR) was the only covariate associated with meropenem clearance. Monte Carlo simulations showed that, across different classes of renal function, dosages of meropenem ranging between 0.5 and 2 g q6h over 6 h (namely by CI) may grant PTAs of Css/MIC ratios ≥4.63 against susceptible pathogens with an MIC up to the EUCAST clinical breakpoint of 2 mg/L. The CFRs achievable with these dosages were very high (>90%) against Enterobacterales across all the classes of renal function and against P. aeruginosa among patients with CL_CR < 30 ml/min/1.73 m², and quite lower against A. baumannii.

Discussion: our findings suggest that Css/MIC ratio ≥4.63 may be considered the pharmacodynamic target useful at maximizing the efficacy of CI meropenem in the treatment of Gram-negative infections in critically ill patients. Dosages ranging between 0.5 g q6h and 2 g q6h by CI may maximize the probability of favorable clinical outcome against meropenem-susceptible Gram-negative pathogens among critically ill patients having different degrees of renal function.

β-lactam Resistance in Pseudomonas aeruginosa: Current Status, Future Prospects

Pseudomonas aeruginosa is a major opportunistic pathogen, causing a wide range of acute and chronic infections. β-lactam antibiotics including penicillins, carbapenems, monobactams, and cephalosporins play a key role in the treatment of P. aeruginosa infections. However, a significant number of isolates of these bacteria are resistant to β-lactams, complicating treatment of infections and leading to worse outcomes for patients. In this review, we summarize studies demonstrating the health and economic impacts associated with β-lactam-resistant P. aeruginosa. We then describe how β-lactams bind to and inhibit P. aeruginosa penicillin-binding proteins that are required for synthesis and remodelling of peptidoglycan. Resistance to β-lactams is multifactorial and can involve changes to a key target protein, penicillin-binding protein 3, that is essential for cell division; reduced uptake or increased efflux of β-lactams; degradation of β-lactam antibiotics by increased expression or altered substrate specificity of an AmpC β-lactamase, or by the acquisition of β-lactamases through horizontal gene transfer; and changes to biofilm formation and metabolism. The current understanding of these mechanisms is discussed. Lastly, important knowledge gaps are identified, and possible strategies for enhancing the effectiveness of β-lactam antibiotics in treating P. aeruginosa infections are considered.

Evaluation of Empirical Meropenem Bolus Protocol in Pseudomonas aeruginosa: A Three-Year Analysis in Tertiary Intensive Care Unit

Purpose

To describe meropenem empirical use, susceptibility trend, and associated factors for acquired nonsusceptibility in P. aeruginosa in the intensive care unit.

Patients and Methods

This study was conducted in the intensive and high care unit of a tertiary care hospital in Indonesia to evaluate empirical meropenem bolus administration protocol. All patients admitted during the 3 year study period from January 2018 through January 2021 with culture-confirmed P. aeruginosa infection were included in the study. Primary data were collected from hospital database electronic medical record and series of local biannual report of microorganism susceptibility pattern.

Results

The data suggested that there was increasing trend in meropenem nonsusceptibility and multidrug-resistance rates. A total of 135 patients with various primary diagnoses and comorbidities were studied. P. aeruginosa isolates were mostly (73.4%) obtained from sputum specimen. Empirical meropenem therapy was administrated in 24.4% of patients with standard- and high-dose as indicated. Nonsusceptibility was acquired in 37% patients who mostly received empirical therapy. Multivariable analysis revealed protocol being evaluated as a statistically significant risk factor for nonsusceptibility in P. aeruginosa (PR = 30.65; p <0.001).

Conclusion

Empirical meropenem administration protocol in this study was an independent determinant of nonsusceptibility acquisition in P. aeruginosa. These findings proved that empirical therapeutic strategy modification is indispensable and routine evaluation practice should be promulgated.

Extended or Continuous Infusion of Carbapenems in Children with Severe Infections: A Systematic Review and Narrative Synthesis

We systematically reviewed the efficacy and safety of an extended or continuous infusion (EI/CI) versus short-term infusion (STI) of carbapenems in children with severe infections. Databases, including PubMed, Embase, the Cochrane Library, Clinicaltrials.gov, China National Knowledge Infrastructure, WanFang Data, and SinoMed, were systematically searched from their inceptions to 10 August 2020, for all types of studies (such as randomized controlled trials (RCTs), retrospective studies, and pharmacokinetic or population pharmacokinetic (PK/PPK) studies) comparing EI/CI versus STI in children with severe infection. There was no limitation on language, and a manual search was also conducted. The data were screened, evaluated, extracted, and reviewed by two researchers independently. Quantitative (meta-analysis) or qualitative analyses of the included studies were performed. Twenty studies (including two RCTs, one case series, six case reports, and 11 PK/PPK studies) were included in this review (CRD42020162845). The RCTs’ quality evaluation results revealed a risk of selection and concealment bias. Qualitative analysis of RCTs demonstrated that, compared with STI, an EI (3 to 4 h) of meropenem in late-onset neonatal sepsis could improve the clinical effectiveness and microbial clearance rates, and reduce the rates of mortality; however, the differences in the incidence of other adverse events were not statistically significant. Retrospective studies showed that children undergoing an EI of meropenem experienced satisfactory clinical improvement. In addition, the results of the PK/PPK study showed that an EI (3 or 4 h)/CI of carbapenems in severely infected children was associated with a more satisfactory goal achievement rate (probability of target attainment) and a cumulative fraction of response than STI therapy. In summary, the EI/CI of carbapenems in children with severe infection has a relatively sufficient PK or pharmacodynamic (PD) basis and satisfactory efficacy and safety. However, due to the limited quantity and quality of studies, the EI/CI therapy should not be used routinely in severely infected children. This conclusion should be further verified by more high-quality controlled clinical trials or observational studies based on PK/PD theories.