Prevalence and Outcomes of Infection Among Patients in Intensive Care Units in 2017

Active fractions from Jingfang Baidu Powder alleviate Klebsiella-induced Pneumonia by inhibiting TLR4/Myd88-ERK signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Jingfang Baidu Powder (JFBDP) is a classic traditional Chinese medicine prescription. Although Jingfang Baidu powder obtained a general consensus on clinical efficacy in treating pneumonia, there were many Chinese herbal drugs in formula, complex components, and large oral dosage, which brings certain obstacles to clinical application.

AIM OF THE STUDY

Therefore, screening of the active fraction that exerts anti-pneumonia helps improve the pharmaceutical preparation, improve the treatment compliance of patients, and further contribute to the clinical application, and the screening of the new active ingredients with anti-pneumonia. The histopathological observation, real-time quantitative PCR, western blotting, and immunofluorescence were applied to evaluate the anti-pneumonia efficacy of active fractions from JFBDP.

RESULTS

Three fractions from JFBDP inhibit the gene expression of IL-1β, IL-10, CCL3, CCL5, and CCL22 in lung tissue infected by Klebsiella at various degrees, and presented a good dose-response relationship. JF50 showed stronger anti-inflammatory effects among three fractions including JF30, JF50, and JF75. Besides, JF50 significantly reduced the protein expression of TLR4 and Myd88 in lung tissue infected with Klebsiella, and it also significantly inhibited p-ERK and p-NF-κB p65. JF50 significantly inhibits the protein expression of Caspase 3, Caspase 8, and Caspase 9 in lung tissue infected with Klebsiella at the dose of 25 mg/kg and 50 mg/kg.

CONCLUSION

JF50 improves lung pathological damage in Klebsiella pneumonia mice by inhibiting the TLR4/Myd88/NF-κB-ERK signaling pathway, and inhibiting apoptosis of lung tissue cells. These findings provide a reference for further exploring the active substance basis of Jingfang Baidu Powder in treating bacterial pneumonia.

Automated surveillance of antimicrobial consumption in intensive care, northern Sweden: an observational case study

BACKGROUND

The digitalization of information systems allows automatic measurement of antimicrobial consumption (AMC), helping address antibiotic resistance from inappropriate drug use without compromising patient safety.

OBJECTIVES

Describe and characterize a new automated AMC surveillance service for intensive care units (ICUs), with data stratified by referral clinic and linked with individual patient risk factors, disease severity, and mortality.

METHODS

An automated service collecting data from the electronic medical record was developed, implemented, and validated in a healthcare region in northern Sweden. We performed an observational study from January 1, 2018, to December 31, 2021, encompassing general ICU care for all ≥18-years-olds in a catchment population of 270000 in secondary care and 900000 in tertiary care. We used descriptive analyses to associate ICU population characteristics with AMC outcomes over time, including days of therapy (DOT), length of therapy, defined daily doses, and mortality.

RESULTS

There were 5608 admissions among 5190 patients with a median age of 65 (IQR 48-75) years, 41.2% females. The 30-day mortality was 18.3%. Total AMC was 1177 DOTs in secondary and 1261 DOTs per 1000 patient days and tertiary care. AMC varied significantly among referral clinics, with the highest total among 810 general surgery admissions in tertiary care at 1486 DOTs per 1000 patient days. Case-mix effects on the AMC were apparent during COVID-19 waves highlighting the need to account for case-mix. Patients exposed to more than three antimicrobial drug classes (N = 242) had a 30-day mortality rate of 40.6%, with significant variability in their expected rates based on admission scores.

CONCLUSION

We introduce a new service and instructions for automating local ICU-AMC data collection. The versatile long-term ICU-AMC metrics presented, covering patient factors, referral clinics and mortality outcomes, are expected to be beneficial in refining antimicrobial drug use.

Immunosuppression at ICU admission is not associated with a higher incidence of ICU-acquired bacterial bloodstream infections: the COCONUT study

BACKGROUND

Immunosuppression at intensive care unit (ICU) admission has been associated with a higher incidence of ICU-acquired infections, some of them related to opportunistic pathogens. However, the association of immunosuppression with the incidence, microbiology and outcomes of ICU-acquired bacterial bloodstream infections (BSI) has not been thoroughly investigated.

METHODS

Retrospective single-centered cohort study in France. All adult patients hospitalized in the ICU of Lille University-affiliated hospital for > 48 h between January 1st and December 31st, 2020, were included, regardless of their immune status. Immunosuppression was defined as active cancer or hematologic malignancy, neutropenia, hematopoietic stem cell and solid organ transplants, use of steroids or immunosuppressive drugs, human immunodeficiency virus infection and genetic immune deficiency. The primary objective was to compare the 28-day cumulative incidence of ICU-acquired bacterial BSI between immunocompromised and non-immunocompromised patients. Secondary objectives were to assess the microbiology and outcomes of ICU-acquired bacterial BSI in the two groups.

RESULTS

A total of 1313 patients (66.9% males, median age 62 years) were included. Among them, 271 (20.6%) were immunocompromised at ICU admission. Severity scores at admission, the use of invasive devices and antibiotic exposure during ICU stay were comparable between groups. Both prior to and after adjustment for pre-specified baseline confounders, the 28-day cumulative incidence of ICU-acquired bacterial BSI was not statistically different between immunocompromised and non-immunocompromised patients. The distribution of bacteria was comparable between groups, with a majority of Gram-negative bacilli (~ 64.1%). The proportion of multidrug-resistant bacteria was also similar between groups. Occurrence of ICU-acquired bacterial BSI was associated with a longer ICU length-of-stay and a longer duration of invasive mechanical ventilation, with no significant association with mortality. Immune status did not modify the association between occurrence of ICU-acquired bacterial BSI and these outcomes.

CONCLUSION

The 28-day cumulative incidence of ICU-acquired bacterial BSI was not statistically different between patients with and without immunosuppression at ICU admission.

Cancer and sepsis: future challenges for long-term outcome

PURPOSE OF REVIEW

The purpose of this review is to investigate the long-term outcomes of cancer patients who experience sepsis or septic shock.

RECENT FINDINGS

Sepsis is a frequent cause of ICU admission in cancer patients, accounting for approximately 15% of such cases. Short-term mortality rates among these patients vary widely across studies, but they are consistently found to be slightly higher than those of noncancer patients. However, there is a lack of evidence regarding the long-term outcomes of cancer patients who have experienced sepsis or septic shock. The few available studies have reported relatively high mortality rates, reaching around 80% in a few cohort studies. Although several observational studies have noted a decrease in 1-year mortality rates over time, observational data also suggest that sepsis may increase the risk of cancer in the long run.

SUMMARY

As cancer is becoming a chronic disease, there is an urgent need for studies on the quality of life of cancer patients who have experienced sepsis. The relationship between sepsis and cancer extends beyond its impact on the progression of cancer, as sepsis might also contribute to the development of cancer.

The role of centre and country factors on process and outcome indicators in critically ill patients with hospital-acquired bloodstream infections

PURPOSE

The primary objective of this study was to evaluate the associations between centre/country-based factors and two important process and outcome indicators in patients with hospital-acquired bloodstream infections (HABSI).

METHODS

We used data on HABSI from the prospective EUROBACT-2 study to evaluate the associations between centre/country factors on a process or an outcome indicator: adequacy of antimicrobial therapy within the first 24 h or 28-day mortality, respectively. Mixed logistical models with clustering by centre identified factors associated with both indicators.

RESULTS

Two thousand two hundred nine patients from two hundred one intensive care units (ICUs) were included in forty-seven countries. Overall, 51% (n = 1128) of patients received an adequate antimicrobial therapy and the 28-day mortality was 38% (n = 839). The availability of therapeutic drug monitoring (TDM) for aminoglycosides everyday [odds ratio (OR) 1.48, 95% confidence interval (CI) 1.03-2.14] or within a few hours (OR 1.79, 95% CI 1.34-2.38), surveillance cultures for multidrug-resistant organism carriage performed weekly (OR 1.45, 95% CI 1.09-1.93), and increasing Human Development Index (HDI) values were associated with adequate antimicrobial therapy. The presence of intermediate care beds (OR 0.63, 95% CI 0.47-0.84), TDM for aminoglycoside available everyday (OR 0.66, 95% CI 0.44-1.00) or within a few hours (OR 0.51, 95% CI 0.37-0.70), 24/7 consultation of clinical pharmacists (OR 0.67, 95% CI 0.47-0.95), percentage of vancomycin-resistant enterococci (VRE) between 10% and 25% in the ICU (OR 1.67, 95% CI 1.00-2.80), and decreasing HDI values were associated with 28-day mortality.

CONCLUSION

Centre/country factors should be targeted for future interventions to improve management strategies and outcome of HABSI in ICU patients.

Estimated glomerular filtration rate as a tool for early identification of patients with insufficient exposure to beta-lactam antibiotics in intensive care units

BACKGROUND

Only about 50% of intensive care unit (ICU) patients reach a free trough concentration above MIC (100% fT > MIC) of beta-lactam antibiotics. Although dose adjustments based on therapeutic drug monitoring (TDM) could be beneficial, TDM is not widely available. We investigated serum creatinine-based estimated GFR (eGFR) as a rapid screening tool to identify ICU patients at risk of insufficient exposure.

METHOD

Ninety-three adult patients admitted to four ICUs in southeast Sweden treated with piperacillin/tazobactam, meropenem, or cefotaxime were included. Beta-lactam trough concentrations were measured. The concentration target was set to 100% fT > MICECOFF (2, 4, and 16 mg/L based on calculated free levels for meropenem, cefotaxime, and piperacillin, respectively). eGFR was primarily determined via Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) and compared to three other eGFR equations. Data was analysed using logistic regression and receiver operative characteristic (ROC) curves.

RESULTS

With intermittent standard dosing, insufficient exposure was common in patients with a relative eGFR ≥48mL/min/1.73m2 [85%, (45/53)], particularly when treated with cefotaxime [96%, (24/25)]. This eGFR cut-off had a sensitivity of 92% and specificity of 82% (AUC 0.871, p < 0.001) in identifying insufficient exposure. In contrast, patients with eGFR <48mL/min/1.73m2 had high target attainment [90%, (36/40)] with a wide variability in drug exposure. There was no difference between the four eGFR equations (AUC 0.866-0.872, cut-offs 44-51 ml/min/1.73m2).

CONCLUSION

Serum creatinine-based eGFR is a simple and widely available surrogate marker with potential for early identification of ICU patients at risk of insufficient exposure to piperacillin, meropenem, and cefotaxime.

Antimicrobial stewardship and molecular diagnostics: a symbiotic approach to combating resistance in the ED and ICU

PURPOSE OF REVIEW

This review aims to evaluate the incorporation of rapid molecular diagnostics (RMD) in antimicrobial stewardship programs (ASPs) in the management of patients in the emergency department (ED) and intensive care unit (ICU), highlighting a shift from conventional microbiological diagnostic tests to RMD strategies to optimize antimicrobial use and improve patient outcomes.

RECENT FINDINGS

Recent advances in RMD have demonstrated the superior accuracy of RMD in identifying pathogens, combined with shorter turnaround times. RMD allows speeding up of antimicrobial decision making in the ED and facilitates faster escalation when empirical therapy was inappropriate, as well as more efficient de-escalation of empirical therapy later in the course of the treatment. Implementation of RMD however may be challenging.

SUMMARY

RMD hold great value in simplifying patient management and mitigating antimicrobial exposure, particularly in settings with high levels of antimicrobial resistance where the use of broad-spectrum antimicrobials is high. While the impact on the use of antimicrobials is significant, the impact on patient outcomes is not yet clear. Successful integration of RMD in clinical decision making in the ED and ICU requires a team approach and continued education, and its use should be adapted to the local epidemiology and infrastructure.

Population pharmacokinetics of daptomycin in critically ill patients receiving extracorporeal membrane oxygenation

BACKGROUND

Daptomycin is widely used in critically ill patients for Gram-positive bacterial infections. Extracorporeal membrane oxygenation (ECMO) is increasingly used in this population and can potentially alter the pharmacokinetic (PK) behaviour of antibiotics. However, the effect of ECMO has not been evaluated in daptomycin. Our study aims to explore the effect of ECMO on daptomycin in critically ill patients through population pharmacokinetic (PopPK) analysis and to determine optimal dosage regimens based on both efficacy and safety considerations.

METHODS

A prospective, open-label PK study was carried out in critically ill patients with or without ECMO. The total concentration of daptomycin was determined by UPLC-MS/MS. NONMEM was used for PopPK analysis and Monte Carlo simulations.

RESULTS

Two hundred and ninety-three plasma samples were collected from 36 critically ill patients, 24 of whom received ECMO support. A two-compartment model with first-order elimination can best describe the PK of daptomycin. Creatinine clearance (CLCR) significantly affects the clearance of daptomycin while ECMO has no significant effect on the PK parameters. Monte Carlo simulations showed that, when the MICs for bacteria are  ≥1 mg/L, the currently recommended dosage regimen is insufficient for critically ill patients with CLCR > 30 mL/min. Our simulations suggest 10 mg/kg for patients with CLCR between 30 and 90 mL/min, and 12 mg/kg for patients with CLCR higher than 90 mL/min.

CONCLUSIONS

This is the first PopPK model of daptomycin in ECMO patients. Optimal dosage regimens considering efficacy, safety, and pathogens were provided for critical patients based on pharmacokinetic-pharmacodynamic analysis.

A retrospective study of the predictors of mortality among patients in intensive care units at North West-Bank hospitals in Palestine

OBJECTIVES

The intensive care unit (ICU) mortality rate remains high, especially in developing countries, regardless of the advances in critical management. There is a lack of studies about mortality causes in hospitals and particularly ICUs in Palestine.This study evaluated the demographic and clinical characteristics of critically ill patients and determined the predictors of mortality among patients in the ICU.

METHODS

A retrospective study assessed all patients who stayed in the ICU for more than 24 h from January 2017 to January 2019. Data were collected from the patient's files. Patient characteristics (background, clinical variables, and comorbidities) were recorded.

RESULTS

The study included 227 eligible ICU patients. The cases' mean age was 55.5 (SD ± 18.2) years. The overall ICU mortality rate was 31.7%. The following factors were associated with high adjusted mortality odds: admission from inside the hospital (adjusted odds ratio (aOR), 2.1, 95% CI: 1.1-3.9, p < 0.05), creatinine level ≥2 mg/dl on admission (aOR, 2.7, 95% CI: 1.3-5.8, p < 0.01), hematology malignancy patients (aOR, 3.4, 95% CI: 1.6-6.7, p = 0.001), immune-compromised (aOR, 2.5, 95% CI: 1.3-4.7, p < 0.01), septic shock (aOR, 27.1, 95% CI: 7.9-88.3, p < 0.001), hospital-acquired infections (aOR: 13.4, 95% CI: 4.1-57.1, p < 0.001), and patients with multiple-source infection (aOR: 16.3, 95% CI: 6.4-57.1, p < 0.001). Also, high SOFA and APACHE scores predicted morality (p < 0.001).

CONCLUSION

The mortality rate among ICU patients was high. It was higher among those admitted from the hospital wards, septic shock, hospital-acquired infection, multiple infection sources, and multi-drug resistance infections. Thus, strategies should be developed to enhance the ICU environment and provide sufficient resources to minimize the effects of these predictors.

Antibiotic stewardship and nosocomial infection prevention in critically ill patients: a quality improvement program

OBJECTIVE

The objective of this study was to evaluate the impact of the implementation of a bundle of interventions through a "Program for Antibiotic Management and Nosocomial Infection Prevention" in the intensive care unit on antibiotic and devices use and healthcare-associated infections.

METHODS

This was a quasi-experimental study of consecutive series of cases in periods before and after the establishment of protocols and checklists for the use of antibiotics as well as other measures to prevent healthcare-associated infection as part of a quality improvement program. Antimicrobial consumption was assessed by the defined daily dose.

RESULTS

A total of 1,056 and 1,323 admissions in the pre-intervention and post-intervention phases, respectively, were evaluated. The defined daily dose per 100 patient-day decreased from 89±8 to 77±11 (p=0.100), with a decrease in carbapenems, glycopeptides, polymyxins, penicillins, and cephalosporins. The rates of ventilator and central venous catheter use decreased from 52.8 to 44.1% and from 76 to 70%, respectively. The rates of healthcare-associated infection decreased from 19.2 to 15.5%.

CONCLUSION

Quality improvement actions focused primarily on antimicrobial management and prevention of healthcare-associated infection are feasible and have the potential to decrease antibiotic use and healthcare-associated infection rates.

Pneumonia Characteristics in an Intensive Care Unit Setting during and after the COVID-19 Pandemic-A Single-Center Prospective Study

Background: During and after the COVID-19 pandemic, there was a suspicion of varying rates of respiratory tract infections (RTIs), particularly pneumonia (PN). Methods: This research evaluated epidemiological indicators of community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP) in the COVID-19 pandemic and post-pandemic period, including pathogens, ventilator-associated pneumonia (VAP), selected risk factors, and PN mortality. Results: At 1740 patients, throughout the 22,774 patient-days (Pt-D) and 18,039 ventilation days (Vt-D), there were 681 PN cases (39.14%): CAP 336 (19.31%) and HAP 345 (19.83%). CAP caused by SARS-CoV-2 was diagnosed in 257/336 (76.49%) patients. The clinical manifestations of PNs were CAP with 336/681 (49.34%), VAP with 232/681 (34.07%), and non-ventilator HAP (NV-HAP) with 113/681 cases (16.59%). The incidence rate of CAP/1000 Pt-D has been over 3 times higher in the pandemic period of 2020-2021 (20.25) than in the post-pandemic period of 2022 (5.86), p = 0.000. Similarly, higher incidence rates of VAP/1000 Pt-D were found in the pandemic period (p = 0.050). For NV-HAP, this difference was not statistically significant (p = 0.585). VAP occurred more frequently in the group of patients with PN in the course of COVID-19 compared to patients without COVID-19 (52/234 [22.2%] vs. 180/1506 [11.95%]); (p = 0.000). The most common CAP pathogen (during the pandemic) was SARS CoV-2 234/291 (80.4%), followed by MSSA/MRSA 8/291 (2.75%), whereas the most common VAP/NV-HAP pathogen was Acinetobacter baumannii XDR/MDR. The highest PN mortality was found in the patients with CAP caused by SARS-CoV-2 159/257 (61.87%). Conclusions: Pneumonias were diagnosed in nearly 40% of Intensive Care Unit (ICU) patients. Surveillance of pneumonias during the specific observation period was beneficial in the epidemiological and microbiological analysis of the ICU patients.

Identifying the risk factors of ICU-acquired fungal infections: clinical evidence from using machine learning

Background

Fungal infections are associated with high morbidity and mortality in the intensive care unit (ICU), but their diagnosis is difficult. In this study, machine learning was applied to design and define the predictive model of ICU-acquired fungi (ICU-AF) in the early stage of fungal infections using Random Forest.

Objectives

This study aimed to provide evidence for the early warning and management of fungal infections.

Methods

We analyzed the data of patients with culture-positive fungi during their admission to seven ICUs of the First Affiliated Hospital of Chongqing Medical University from January 1, 2015, to December 31, 2019. Patients whose first culture was positive for fungi longer than 48 h after ICU admission were included in the ICU-AF cohort. A predictive model of ICU-AF was obtained using the Least Absolute Shrinkage and Selection Operator and machine learning, and the relationship between the features within the model and the disease severity and mortality of patients was analyzed. Finally, the relationships between the ICU-AF model, antifungal therapy and empirical antifungal therapy were analyzed.

Results

A total of 1,434 cases were included finally. We used lasso dimensionality reduction for all features and selected six features with importance ≥0.05 in the optimal model, namely, times of arterial catheter, enteral nutrition, corticosteroids, broadspectrum antibiotics, urinary catheter, and invasive mechanical ventilation. The area under the curve of the model for predicting ICU-AF was 0.981 in the test set, with a sensitivity of 0.960 and specificity of 0.990. The times of arterial catheter (p = 0.011, OR = 1.057, 95% CI = 1.053-1.104) and invasive mechanical ventilation (p = 0.007, OR = 1.056, 95%CI = 1.015-1.098) were independent risk factors for antifungal therapy in ICU-AF. The times of arterial catheter (p = 0.004, OR = 1.098, 95%CI = 0.855-0.970) were an independent risk factor for empirical antifungal therapy.

Conclusion

The most important risk factors for ICU-AF are the six time-related features of clinical parameters (arterial catheter, enteral nutrition, corticosteroids, broadspectrum antibiotics, urinary catheter, and invasive mechanical ventilation), which provide early warning for the occurrence of fungal infection. Furthermore, this model can help ICU physicians to assess whether empiric antifungal therapy should be administered to ICU patients who are susceptible to fungal infections.

Can linezolid be validly measured in endotracheal aspiration in critically ill patients? A proof-of-concept trial

BACKGROUND

Therapeutic drug monitoring (TDM) of anti-infectives such as linezolid is routinely performed in blood of intensive care unit (ICU) patients to optimize target attainment. However, the concentration at the site of infection is considered more important for a successful therapy. Until now, bronchoalveolar lavage (BAL) is the gold standard to measure intrapulmonary concentrations of anti-infective agents. However, it is an invasive method and unsuitable for regular TDM. The aim of this proof-of-concept study was to investigate whether it is possible to reliably determine the intrapulmonary concentration of linezolid from endotracheal aspiration (ENTA).

METHODS

Intubated ICU patients receiving 600 mg intravenous linezolid twice daily were examined in steady state. First, preliminary experiments were performed in six patients to investigate which patients are suitable for linezolid measurement in ENTA. In a second step, trough and peak linezolid concentrations of plasma and ENTA were determined in nine suitable patients.

RESULTS

Linezolid can validly be detected in ENTA with viscous texture and > 0.5 mL volume. The mean (SD) linezolid trough concentration was 2.02 (1.27) mg/L in plasma and 1.60 (1.36) mg/L in ENTA, resulting in a median lung penetration rate of 104%. The mean (SD) peak concentration in plasma and ENTA was 10.77 (5.93) and 4.74 (2.66) mg/L.

CONCLUSIONS

Linezolid can validly be determined in ENTA with an adequate texture and volume. The penetration rate is comparable to already published BAL concentrations. This method might offer a simple and non-invasive method for TDM at the site of infection "lung". Due to promising results of the feasibility study, comparison of ENTA and BAL in the same patient should be investigated in a further trial.

Medical Device-Associated Biofilm Infections and Multidrug-Resistant Pathogens

Medical devices such as venous catheters (VCs) and urinary catheters (UCs) are widely used in the hospital setting. However, the implantation of these devices is often accompanied by complications. About 60 to 70% of nosocomial infections (NIs) are linked to biofilms. The main complication is the ability of microorganisms to adhere to surfaces and form biofilms which protect them and help them to persist in the host. Indeed, by crossing the skin barrier, the insertion of VC inevitably allows skin flora or accidental environmental contaminants to access the underlying tissues and cause fatal complications like bloodstream infections (BSIs). In fact, 80,000 central venous catheters-BSIs (CVC-BSIs)-mainly occur in intensive care units (ICUs) with a death rate of 12 to 25%. Similarly, catheter-associated urinary tract infections (CA-UTIs) are the most commonlyhospital-acquired infections (HAIs) worldwide.These infections represent up to 40% of NIs.In this review, we present a summary of biofilm formation steps. We provide an overview of two main and important infections in clinical settings linked to medical devices, namely the catheter-asociated bloodstream infections (CA-BSIs) and catheter-associated urinary tract infections (CA-UTIs), and highlight also the most multidrug resistant bacteria implicated in these infections. Furthermore, we draw attention toseveral useful prevention strategies, and advanced antimicrobial and antifouling approaches developed to reduce bacterial colonization on catheter surfaces and the incidence of the catheter-related infections.

Recent trends and challenges to overcome Pseudomonas aeruginosa infections

INTRODUCTION

Pseudomonas aeruginosa (PA) is a Gram-negative bacterium that can cause a wide range of severe infections in immunocompromised patients. The most difficult challenge is due to its ability to rapidly develop multi drug-resistance. New strategies are urgently required to improve the outcome of patients with PA infections. The present patent review highlights the new molecules acting on different targets involved in the antibiotic resistance.

AREA COVERED

This review offers an insight into new potential PA treatment disclosed in patent literature. From a broad search of documents claiming new PA inhibitors, we selected and summarized molecules that showed in vitro and in vivo activity against PA spp. in the period 2020 and 2023. We collected the search results basing on the targets explored.

EXPERT OPINION

This review examined the main patented compounds published in the last three years, with regard to the structural novelty and the identification of innovative targets. The main areas of antibiotic resistance have been explored. The compounds are structurally unrelated to earlier antibiotics, characterized by a medium-high molecular weight and the presence of heterocycle rings. Peptides and antibodies have also been reported as potential alternatives to chemical treatment, hereby expanding the therapeutic possibilities in this field.

Individualised, short-course antibiotic treatment versus usual long-course treatment for ventilator-associated pneumonia (REGARD-VAP): a multicentre, individually randomised, open-label, non-inferiority trial

BACKGROUND

Ventilator-associated pneumonia (VAP) is associated with increased mortality, prolonged hospitalisation, excessive antibiotic use and, consequently, increased antimicrobial resistance. In this phase 4, randomised trial, we aimed to establish whether a pragmatic, individualised, short-course antibiotic treatment strategy for VAP was non-inferior to usual care.

METHODS

We did an individually randomised, open-label, hierarchical non-inferiority-superiority trial in 39 intensive care units in six hospitals in Nepal, Singapore, and Thailand. We enrolled adults (age ≥18 years) who met the US Centers for Disease Control and Prevention National Healthcare Safety Network criteria for VAP, had been mechanically ventilated for 48 h or longer, and were administered culture-directed antibiotics. In culture-negative cases, empirical antibiotic choices were made depending on local hospital antibiograms reported by the respective microbiology laboratories or prevailing local guidelines. Participants were assessed until fever resolution for 48 h and haemodynamic stability, then randomly assigned (1:1) to individualised short-course treatment (≤7 days and as short as 3-5 days) or usual care (≥8 days, with precise durations determined by the primary clinicians) via permuted blocks of variable sizes (8, 10, and 12), stratified by study site. Independent assessors for recurrent pneumonia and participants were masked to treatment allocation, but clinicians were not. The primary outcome was a 60-day composite endpoint of death or pneumonia recurrence. The non-inferiority margin was prespecified at 12% and had to be met by analyses based on both intention-to-treat (all study participants who were randomised) and per-protocol populations (all randomised study participants who fulfilled the eligibility criteria, met fitness criteria for antibiotic discontinuation, and who received antibiotics for the duration specified by their allocation group). This study is registered with ClinicalTrials.gov, number NCT03382548.

FINDINGS

Between May 25, 2018, and Dec 16, 2022, 461 patients were enrolled and randomly assigned to the short-course treatment group (n=232) or the usual care group (n=229). Median age was 64 years (IQR 51-74) and 181 (39%) participants were female. 460 were included in the intention-to-treat analysis after excluding one withdrawal (231 in the short-course group and 229 in the usual care group); 435 participants received the allocated treatment and fulfilled eligibility criteria, and were included in the per-protocol population. Median antibiotic treatment duration for the index episodes of VAP was 6 days (IQR 5-7) in the short-course group and 14 days (10-21) in the usual care group. 95 (41%) of 231 participants in the short-course group met the primary outcome, compared with 100 (44%) of 229 in the usual care group (risk difference -3% [one-sided 95% CI -∞ to 5%]). Results were similar in the per-protocol population. Non-inferiority of short-course antibiotic treatment was met in the analyses, although superiority compared with usual care was not established. In the per-protocol population, antibiotic side-effects occurred in 86 (38%) of 224 in the usual care group and 17 (8%) of 211 in the short-course group (risk difference -31% [95% CI -37 to -25%; p<0·0001]).

INTERPRETATION

In this study of adults with VAP, individualised shortened antibiotic duration guided by clinical response was non-inferior to longer treatment durations in terms of 60-day mortality and pneumonia recurrence, and associated with substantially reduced antibiotic use and side-effects. Individualised, short-course antibiotic treatment for VAP could help to reduce the burden of side-effects and the risk of antibiotic resistance in high-resource and resource-limited settings.

FUNDING

UK Medical Research Council; Singapore National Medical Research Council.

TRANSLATIONS

For the Thai and Nepali translations of the abstract see Supplementary Materials section.

Substantial decline of organ preservation fluid contamination following adoption of ischemia-free liver transplantation: a post-hoc analysis

INTRODUCTION

Preservation fluid (PF) contaminations are common in conventional liver transplantation (CLT) and presumably originate from organ or PF exposures to the external environment in a non-strict sterile manner. Such exposures and PF contamination may be avoided in ischaemia-free liver transplantation (IFLT) because of the strict sterile surgical procedures. In this study, the authors evaluated the impact of IFLT on organ PF contamination.

METHODS

A post-hoc analysis using data from the first randomized controlled trial of IFLT was performed to compare the incidence, pathogenic spectrum of PF contamination, and incidence of early recipient infection between IFLT and CLT. Multivariable logistic regression was used to explore risk factors for PF contamination.

RESULTS

Of the 68 cases recruited in the trial, 64 were included in this post-hoc analysis. The incidence of culture-positive PF was 9.4% (3/32) in the IFLT group versus 78.1% (25/32) in the CLT group ( P <0.001). Three microorganisms were isolated from PF in the IFLT group, while 43 were isolated in the CLT group. The recipient infection rate within postoperative day 14 was 3.1% (1/32) in the IFLT group vs 15.6% (5/32) in the CLT group, although this difference did not reach statistical significance ( P =0.196). Multivariate analysis revealed that adopting IFLT is an independent protective factor for culture-positive PF.

CONCLUSION

PF contamination is substantially decreased in IFLT, and IFLT application is an independent protective factor for PF contamination. Using rigorous sterile measures and effective antibiotic therapy during IFLT may decrease PF contamination.

Blood microbial signatures associated with mortality in patients with sepsis: A pilot study

Sepsis is a life-threatening illness caused by the dysregulated host response to infection. Nevertheless, our current knowledge of the microbial landscape in the blood of septic patients is still limited. Next-generation sequencing (NGS) is a sensitive method to quantitatively characterize microbiomes at various sites of the human body. In this study, we analyzed the blood microbial DNA of 22 adult patients with sepsis and 3 healthy subjects. The presence of non-human DNA was identified in both healthy and septic subjects. Septic patients had a markedly altered microbial DNA profile compared to healthy subjects over α- and β-diversity. Unexpectedly, the patients could be further divided into two subgroups (C1 and C2) based on β-diversity analysis. C1 patients showed much higher bacteria, viruses, fungi, and archaea abundance, and a higher level of α-diversity (Chao1, Observed and Shannon index) than both C2 patients and healthy subjects. The most striking difference was seen in the case of Streptomyces violaceusniger, Phenylobacterium sp. HYN0004, Caulobacter flavus, Streptomyces sp. 11-1-2, and Phenylobacterium zucineum, the abundance of which was the highest in the C1 group. Notably, C1 patients had a significantly poorer outcome than C2 patients. Moreover, by analyzing the patterns of microbe-microbe interactions in healthy and septic subjects, we revealed that C1 and C2 patients exhibited distinct co-occurrence and co-exclusion relationships. Together, our study uncovered two distinct microbial signatures in the blood of septic patients. Compositional and ecological analysis of blood microbial DNA may thus be useful in predicting mortality of septic patients.

Unraveling the molecular dynamics of Pseudomonas aeruginosa biofilms at the air-liquid interface

Aim: The aim of this study was to probe the dynamics of Pseudomonas aeruginosa PA14 air-liquid interface (ALI) biofilms over time through global proteomic analysis. Materials & methods: P. aeruginosa PA14 ALI biofilm samples, collected over 48-144 h, underwent differential expression analysis to identify varying proteins at each time point. Results: A consistent set of 778 proteins was identified, with variable expression over time. Upregulated proteins were mainly linked to 'amino acid transport and metabolism'. Biofilm-related pathways, including cAMP/Vfr and QS, underwent significant changes. Flagella were more influential than pili, especially in early biofilm development. Proteins associated with virulence, transporters and iron showed differential expression throughout. Conclusion: The findings enhance our understanding of ALI biofilm development.

Impact of attaining aggressive vs. conservative PK/PD target on the clinical efficacy of beta-lactams for the treatment of Gram-negative infections in the critically ill patients: a systematic review and meta-analysis

BACKGROUND

To perform a systematic review with meta-analysis with the dual intent of assessing the impact of attaining aggressive vs. conservative beta-lactams PK/PD target on the clinical efficacy for treating Gram-negative infections in critical patients, and of identifying predictive factors of failure in attaining aggressive PK/PD targets.

METHODS

Two authors independently searched PubMed-MEDLINE and Scopus database from inception to 23rd December 2023, to retrieve studies comparing the impact of attaining aggressive vs. conservative PK/PD targets on clinical efficacy of beta-lactams. Independent predictive factors of failure in attaining aggressive PK/PD targets were also assessed. Aggressive PK/PD target was considered a100%fT>4xMIC, and clinical cure rate was selected as primary outcome. Meta-analysis was performed by pooling odds ratios (ORs) extrapolated from studies providing adjustment for confounders using a random-effects model with inverse variance method.

RESULTS

A total of 20,364 articles were screened, and 21 observational studies were included in the meta-analysis (N = 4833; 2193 aggressive vs. 2640 conservative PK/PD target). Attaining aggressive PK/PD target was significantly associated with higher clinical cure rate (OR 1.69; 95% CI 1.15-2.49) and lower risk of beta-lactam resistance development (OR 0.06; 95% CI 0.01-0.29). Male gender, body mass index > 30 kg/m2, augmented renal clearance and MIC above the clinical breakpoint emerged as significant independent predictors of failure in attaining aggressive PK/PD targets, whereas prolonged/continuous infusion administration of beta-lactams resulted as protective factor. The risk of bias was moderate in 19 studies and severe in the other 2.

CONCLUSIONS

Attaining aggressive beta-lactams PK/PD targets provided significant clinical benefits in critical patients. Our analysis could be useful to stratify patients at high-risk of failure in attaining aggressive PK/PD targets.

Deciphering the gastrointestinal carriage of Klebsiella pneumoniae

Bacterial infections pose a significant global health threat, accounting for an estimated 7.7 million deaths. Hospital outbreaks driven by multi-drug-resistant pathogens, notably Klebsiella pneumoniae (K. pneumoniae), are of grave concern. This opportunistic pathogen causes pneumonia, urinary tract infections, and bacteremia, particularly in immunocompromised individuals. The rise of hypervirulent K. pneumoniae adds complexity, as it increasingly infects healthy individuals. Recent epidemiological data suggest that asymptomatic gastrointestinal carriage serves as a reservoir for infections in the same individual and allows for host-to-host transmission via the fecal-oral route. This review focuses on K. pneumoniae's gastrointestinal colonization, delving into epidemiological evidence, current animal models, molecular colonization mechanisms, and the protective role of the resident gut microbiota. Moreover, the review sheds light on in vivo high-throughput approaches that have been crucial for identifying K. pneumoniae factors in gut colonization. This comprehensive exploration aims to enhance our understanding of K. pneumoniae gut pathogenesis, guiding future intervention and prevention strategies.

In vitro activity of antibiotics potentially effective against difficult-to-treat strains of Gram-negative rods: retrospective study

Bacterial resistance surveillance is one of the main outputs of microbiological laboratories and its results are important part of antimicrobial stewardship (AMS). In this study, the susceptibility of specific bacteria to selected antimicrobial agents was tested. The susceptibility of 90 unique isolates of pathogens of critical priority obtained from clinically valid samples of ICU patients in 2017-2021 was tested. 50% of these fulfilled difficult-to-treat resistance (DTR) criteria and 50% were susceptible to all antibiotics included in the definition. 10 Enterobacterales strains met DTR criteria, and 2 (20%) were resistant to colistin (COL), 2 (20%) to cefiderocol (FCR), 7 (70%) to imipenem/cilastatin/relebactam (I/R), 3 (30%) to ceftazidime/avibactam (CAT) and 5 (50%) to fosfomycin (FOS). For Enterobacterales we also tested aztreonam/avibactam (AZA) for which there are no breakpoints yet. The highest MIC of AZA observed was 1 mg/l, MIC range in the susceptible cohort was 0.032-0.064 mg/l and in the DTR cohort (incl. class B beta-lactamase producers) it was 0.064-1 mg/l. Two (13.3%) isolates of Pseudomonas aeruginosa (15 DTR strains) were resistant to COL, 1 (6.7%) to FCR, 13 (86.7%) to I/R, 5 (33.3%) to CAT, and 5 (33.3%) to ceftolozane/tazobactam. All isolates of Acinetobacter baumannii with DTR were susceptible to COL and FCR, and at the same time resistant to I/R and ampicillin/sulbactam. New antimicrobial agents are not 100% effective against DTR. Therefore, it is necessary to perform susceptibility testing of these antibiotics, use the data for surveillance (including local surveillance) and conform to AMS standards.

Antimicrobial resistance of Pseudomonas aeruginosa: navigating clinical impacts, current resistance trends, and innovations in breaking therapies

Pseudomonas aeruginosa, a Gram-negative bacterium, is recognized for its adaptability and opportunistic nature. It poses a substantial challenge in clinical settings due to its complicated antibiotic resistance mechanisms, biofilm formation, and capacity for persistent infections in both animal and human hosts. Recent studies revealed a potential zoonotic transmission of P. aeruginosa between animals, the environment, and human populations which highlights awareness of this microbe. Implementation of the One Health approach, which underscores the connection between human, animal, and environmental health, we aim to offer a comprehensive perspective on the current landscape of P. aeruginosa management. This review presents innovative strategies designed to counteract P. aeruginosa infections. Traditional antibiotics, while effective in many cases, are increasingly compromised by the development of multidrug-resistant strains. Non-antibiotic avenues, such as quorum sensing inhibition, phage therapy, and nanoparticle-based treatments, are emerging as promising alternatives. However, their clinical application encounters obstacles like cost, side effects, and safety concerns. Effectively addressing P. aeruginosa infections necessitates persistent research efforts, advancements in clinical development, and a comprehension of host-pathogen interactions to deal with this resilient pathogen.

Assessment of the practical impact of adjusting beta-lactam dosages based on therapeutic drug monitoring in critically ill adult patients: a systematic review and meta-analysis of randomized clinical trials and observational studies

An estimated 70% of critically ill patients receive antibiotics, most frequently beta-lactams. The pharmacokinetic properties of these substances in this patient population are poorly predictable. Therapeutic drug monitoring (TDM) is helpful in making personalized decisions in this field, but its overall impact as a clinical decision-supporting tool is debated. We aimed to evaluate the clinical implications of adjusting beta-lactam dosages based on TDM in the critically ill population by performing a systematic review and meta-analysis of available investigations. Randomized controlled trials and observational studies were retrieved by searching three major databases. The intervention group received TDM-guided beta-lactam treatment, that is, at least one dose reconsideration based on the result of the measurement of drug concentrations, while TDM-unadjusted dosing was employed in the comparison group. The outcomes were evaluated using forest plots with random-effects modeling and subgroup analysis. Eight eligible studies were identified, including 1044 patients in total. TDM-guided beta-lactam treatment was associated with improved clinical cure from infection [odds ratio (OR): 2.22 (95% confidence interval (CI): 1.78-2.76)] and microbiological eradication [OR: 1.72 (CI: 1.05-2.80)], as well as a lower probability of treatment failure [OR: 0.47 (CI: 0.36-0.62)], but the heterogeneity of studies was remarkably high, especially in terms of mortality (70%). The risk of bias was moderate. While the TDM-guided administration of beta-lactams to critically ill patients has a favorable impact, standardized study designs and larger sample sizes are required for developing evidence-based protocols in this field.

Beta-lactam antibiotic concentrations in critically ill patients with standard and adjusted dosages: A prospective observational study

INTRODUCTION

Antibiotic concentration target attainment is known to be poor in critically ill patients. Dose adjustment is recommended in patients with altered clearance, obesity and those with bacterial species with intermediate susceptibility. The aim of this study was to investigate the variation of antibiotic concentration in critically ill patients with standard or adjusted dosing regimens.

METHODS

The concentration of three beta-lactam antibiotics used in the intensive care unit (ICU) setting, cefotaxime, piperacillin/tazobactam, and meropenem, was measured in patients with confirmed or suspected infection. Mid-dose and trough values were collected during a single dosing interval. The pharmacokinetic endpoints were a free antibiotic concentration that, during the whole dosing interval, was above MIC (100% ƒT > MIC, primary endpoint) or above four times MIC (100% ƒT > 4MIC, secondary endpoint). Non-species related MIC breakpoints were used (1 mg/L for cefotaxime, 8 mg/L for piperacillin/tazobactam, and 2 mg/L for meropenem).

RESULTS

We included 102 patients (38 cefotaxime, 30 piperacillin/tazobactam, and 34 meropenem) at a single ICU, with a median age of 66 years. In total, 73% were males, 40% were obese (BMI ≥30) and the median SAPS 3 score was 63 points. Of all patients, 78 patients (76%) reached the primary endpoint (100%ƒT > MIC), with 74% for cefotaxime, 67% for piperacillin/tazobactam and 88% for meropenem. Target attainment for 100% ƒT > 4MIC was achieved in 40 (39%) patients, overall, with 34% for cefotaxime, 30% for piperacillin/tazobactam and 53% for meropenem. In patients with standard dose 71% attained 100%ƒT > MIC and 37% for 100%ƒT > 4MIC. All patients with reduced dose attained 100%ƒT > MIC and 27% attained 100% ƒT > 4MIC. In patients with increased dose 79% attained 100%ƒT > MIC and 48% 100%ƒT > 4MIC respectively.

CONCLUSIONS

Beta-lactam antibiotics concentration vary widely in critically ill patients. The current standard dosing regimens employed during the study were not sufficient to reach 100% ƒT > MIC in approximately a quarter of the patients. In patients where dose adjustment was performed, the group with increased dose also had low target attainment, as opposed to patients with dose reduction, who all reached target. This suggests the need for further individualization of dosing where therapeutic drug monitoring can be an alternative to further increase target attainment.

Desirability of Outcome Ranking and Response Adjusted for Antibiotic Risk (DOOR/RADAR) Post Hoc Analysis Supports Equipoise for Antibiotic Initiation Strategies in Intensive Care Unit-Acquired Pneumonia

Background: Pneumonia is the most common intensive care unit (ICU)-acquired infection and source of potential sepsis in ICU populations but can be difficult to diagnose in real-time. Despite limited data, rapid initiation of antibiotic agents is endorsed by society guidelines. We hypothesized that a post hoc analysis of a recent randomized pilot study would show no difference between two antibiotic initiation strategies. Patients and Methods: The recent Trial of Antibiotic Restraint in Presumed Pneumonia (TARPP) was a pragmatic cluster-randomized pilot of antibiotic initiation strategies for patients with suspected ICU-acquired pneumonia. Participating ICUs were cluster-randomized to either an immediate initiation protocol or a specimen-initiated protocol where a gram stain was required for initiation of antibiotics. Patients in the study were divided into one of seven mutually exclusive outcome rankings (desirability of outcome ranking; DOOR): (1) Survival, No Pneumonia, No adverse events; (2) Survival, Pneumonia, No adverse events; (3) Survival, No Pneumonia, ventilator-free-alive days ≤14; (4) Survival, Pneumonia, ventilator-free-alive days ≤14; (5) Survival, No Pneumonia, Subsequent episode of suspected pneumonia; (6) Survival, Pneumonia, Subsequent episode of suspected pneumonia; and (7) Death. These rankings were further refined using the duration of antibiotics prescribed for pneumonia (response adjusted for antibiotic risk; RADAR). Results: There were 186 patients enrolled in the study. After applying the DOOR analysis, a randomly selected patient was equally likely to have a better outcome in specimen-initiated arm as in the immediate initiation arm (DOOR probability: 50.8%; 95% confidence interval [CI], 42.7%-58.9%). Outcome probabilities were similar after applying the RADAR analysis (52.5%; 95% CI, 44.2%-60.6%; p = 0.31). Conclusions: We found that patients for whom antibiotic agents were withheld until there was objective evidence (specimen-initiated group) had similar outcome rankings to patients for whom antibiotic agents were started immediately. This supports the findings of the TARPP pilot trial and provides further evidence for equipoise between these two treatment strategies.

Prevalence and factors associated with methicillin-resistant Staphylococcus aureus colonization on admission to geriatric care units: impact on screening practices

OBJECTIVES

Universal screening for methicillin-resistant Staphylococcus aureus (MRSA) entails additional costs, and there is no consensus for targeted screening for high-risk units. The aims of this study were to determine the prevalence of MRSA in geriatric care units, and to identify the factors associated with MRSA colonization on admission.

METHODS

This retrospective case-control study (1:1) in the geriatric care unit of six Belgian hospitals covered the period from 1st January 2021 to 31st December 2022. Cases were patients with a positive MRSA screening result within 48 h of admission to the geriatric care unit, and controls were patients with a negative screening result.

RESULTS

In total, 556 patients were included in this study (278 in each group). Prevalence per 100 admissions for the total sample was 2.3 [95% confidence interval (CI) 2.2-2.6]. Significant multi-variate factors associated with MRSA carriage on admission were: history of MRSA, nursing home origin, and chronic skin lesions. Applying these three factors would give an area under the receiver operating characteristic (ROC) curve of 0.73 (95% CI 0.71-0.77), and would allow screening to be carried out in only 55.4% of cases (95% CI 51.2-59.6%).

CONCLUSIONS

Using these factors as screening criteria in geriatric care units could significantly reduce the number of patients screened for MRSA, while maintaining satisfactory sensitivity and specificity.

Risk Factors and Clinical Characteristics of Pandrug-Resistant Pseudomonas aeruginosa

The emergence of increasingly resistant strains of Pseudomonas aeruginosa is a great public health concern. Understanding the risk factors and clinical characteristics of patients with pandrug-resistant P. aeruginosa (PDR-PA) can help inform clinicians in creating guidelines for both prevention and management. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, this scoping review retrieved existing literature on PDR-PA by searching PubMed, SCOPUS, Embase, Web of Science, and CINAHL databases. From the 21 studies that satisfied the inclusion criteria,1,059 P. aeruginosa samples were identified, and 161, or 15.2% of the isolates were found to have pandrug resistance. Furthermore, our review suggests that PDR-PA was largely hospital-acquired, and patients suffering from burn injuries and chronic lung diseases had a higher risk of colonization than other hospitalized individuals. In five out of the 21 studies, administration of the antibiotic colistin emerged to be the preferred therapeutic strategy. With regards to concurrent infections, Acinetobacter and Klebsiella species were found to occur most frequently with PDR-PA, suggesting mutualistic interactions that enable further antimicrobial resistance. In conclusion, this review showed the prevalence of PDR-PA and outlined the demographic and clinical profile of affected patients. Further research is needed to investigate the transmission and outcomes of PDR-PA infections and to find potential therapeutic strategies.

Comparative Impact of an Optimized PK/PD Target Attainment of Piperacillin-Tazobactam vs. Meropenem on the Trend over Time of SOFA Score and Inflammatory Biomarkers in Critically Ill Patients Receiving Continuous Infusion Monotherapy for Treating Documented Gram-Negative BSIs and/or VAP

(1) Background: The advantage of using carbapenems over beta-lactam/beta-lactamase inhibitor combinations in critically ill septic patients still remains a debated issue. We aimed to assess the comparative impact of an optimized pharmacokinetic/pharmacodynamic (PK/PD) target attainment of piperacillin-tazobactam vs. meropenem on the trend over time of both Sequential Organ Failure Assessment (SOFA) score and inflammatory biomarkers in critically ill patients receiving continuous infusion (CI) monotherapy with piperacillin-tazobactam or meropenem for treating documented Gram-negative bloodstream infections (BSI) and/or ventilator-associated pneumonia (VAP). (2) Methods: We performed a retrospective observational study comparing critically ill patients receiving targeted treatment with CI meropenem monotherapy for documented Gram-negative BSIs or VAP with a historical cohort of critical patients receiving CI piperacillin-tazobactam monotherapy. Patients included in the two groups were admitted to the general and post-transplant intensive care unit in the period July 2021-September 2023 and fulfilled the same inclusion criteria. The delta values of the SOFA score between the baseline of meropenem or piperacillin-tazobactam treatment and those at 48-h (delta 48-h SOFA score) or at 7-days (delta 7-days SOFA) were selected as primary outcomes. Delta 48-h and 7-days C-reactive protein (CRP) and procalcitonin (PCT), microbiological eradication, resistance occurrence, clinical cure, multi-drug resistant colonization at 90-day, ICU, and 30-day mortality rate were selected as secondary outcomes. Univariate analysis comparing primary and secondary outcomes between critically ill patients receiving CI monotherapy with piperacillin-tazobactam vs. meropenem was carried out. (3) Results: Overall, 32 critically ill patients receiving CI meropenem monotherapy were compared with a historical cohort of 43 cases receiving CI piperacillin-tazobactam monotherapy. No significant differences in terms of demographics and clinical features emerged at baseline between the two groups. Optimal PK/PD target was attained in 83.7% and 100.0% of patients receiving piperacillin-tazobactam and meropenem, respectively. No significant differences were observed between groups in terms of median values of delta 48-h SOFA (0 points vs. 1 point; p = 0.89) and median delta 7-days SOFA (2 points vs. 1 point; p = 0.43). Similarly, no significant differences were found between patients receiving piperacillin-tazobactam vs. meropenem for any of the secondary outcomes. (4) Conclusion: Our findings may support the contention that in critically ill patients with documented Gram-negative BSIs and/or VAP, the decreases in the SOFA score and in the inflammatory biomarkers serum levels achievable with CI piperacillin-tazobactam monotherapy at 48-h and at 7-days may be of similar extent and as effective as to those achievable with CI meropenem monotherapy provided that optimization on real-time by means of a TDM-based expert clinical pharmacological advice program is granted.

Impact of a multidisciplinary management team on clinical outcome in ICU patients affected by Gram-negative bloodstream infections: a pre-post quasi-experimental study

BACKGROUND

Bloodstream infections (BSIs) by Gram-negative pathogens play a major role in intensive care patients, both in terms of prevalence and severity, especially if multi-drug resistant pathogens are involved. Early appropriate antibiotic therapy is therefore a cornerstone in the management of these patients, and growing evidence shows that implementation of a multidisciplinary team may improve patients' outcomes. Our aim was to evaluate the clinical and microbiological impact of the application of a multidisciplinary team on critically ill patients.

METHODS

Pre-post study enrolling critically ill patients with Gram negative bloodstream infection in intensive care unit. In the pre-intervention phase (from January until December 2018) patients were managed with infectious disease consultation on demand, in the post-intervention phase (from January until December 2022) patients were managed with a daily evaluation by a multidisciplinary team composed of intensivist, infectious disease physician, clinical pharmacologist and microbiologist.

RESULTS

Overall, 135 patients were enrolled during the study period, of them 67 (49.6%) in the pre-intervention phase and 68 (50.4%) in the post-intervention phase. Median age was 67 (58-75) years, sex male was 31.9%. Septic shock, the need for continuous renal replacement therapy and mechanical ventilation at BSI onset were similar in both groups, no difference of multidrug-resistant organisms (MDRO) prevalence was observed. In the post-phase, empirical administration of carbapenems decreased significantly (40.3% vs. 62.7%, p = 0.02) with an increase of appropriate empirical therapy (86.9% vs. 55.2%, p < 0.001) and a decrease of overall antibiotic treatment (12 vs. 16 days, p < 0.001). Despite no differences in delta SOFA and all-cause 30-day mortality, a significant decrease in microbiological failure (10.3% vs. 29.9%, p = 0.005) and a new-onset 30-day MDRO colonization (8.3% vs. 36.6%, p < 0.001) in the post-phase was reported. At multivariable analysis adjusted for main covariates, the institution of a multidisciplinary management team (MMT) was found to be protective both for new MDRO colonization [OR 0.17, 95%CI(0.05-0.67)] and microbiological failure [OR 0.37, 95%CI (0.14-0.98)].

CONCLUSIONS

The institution of a MMT allowed for an optimization of antimicrobial treatments, reflecting to a significant decrease in new MDRO colonization and microbiological failure among critically ill patients.

Bacterial Infections in Intensive Care Units: Epidemiological and Microbiological Aspects

Intensive care units constitute a critical setting for the management of infections. The patients' fragilities and spread of multidrug-resistant microorganisms lead to relevant difficulties in the patients' care. Recent epidemiological surveys documented the Gram-negative bacteria supremacy among intensive care unit (ICU) infection aetiologies, accounting for numerous multidrug-resistant isolates. Regarding this specific setting, clinical microbiology support holds a crucial role in the definition of diagnostic algorithms. Eventually, the complete patient evaluation requires integrating local epidemiological knowledge into the best practice and the standardization of antimicrobial stewardship programs. Clinical laboratories usually receive respiratory tract and blood samples from ICU patients, which express a significant predisposition to severe infections. Therefore, conventional or rapid diagnostic workflows should be modified depending on patients' urgency and preliminary colonization data. Additionally, it is essential to complete each microbiological report with rapid phenotypic minimum inhibitory concentration (MIC) values and information about resistance markers. Microbiologists also help in the eventual integration of ultimate genome analysis techniques into complicated diagnostic workflows. Herein, we want to emphasize the role of the microbiologist in the decisional process of critical patient management.

Provider Perceptions of Antibiotic Initiation Strategies for Hospital-Acquired Pneumonia

Background: The practice of rapidly initiating antibiotic therapy for patients with suspected infection has recently been criticized yet remains commonplace. Provider comfort level has been an understudied aspect of this practice. Hypothesis: We hypothesized that there would be no significant differences in provider comfort level between the two treatment groups. Methods: We prospectively surveyed critical care intensivists who provided care for patients enrolled in the Trial of Antibiotic Restraint in Presumed Pneumonia (TARPP), which was a multicenter cluster-randomized crossover trial that evaluated an immediate antibiotic initiation protocol compared with a protocol of specimen-initiated antibiotic initiation in ventilated patients with suspected new-onset pneumonia. At the end of each enrollment arm, physicians at each center were surveyed regarding their overall comfort level with the recently completed treatment arm, and perception of adherence. Both a paired and unpaired analysis was performed. Results: We collected 51 survey responses from 31 unique participants. Providers perceived a higher rate of adherence to the immediate initiation arm than the specimen-initiated arm (Always Adherent: 37.5% vs. 11.1%; p = 0.045). Providers were less comfortable waiting for objective evidence of infection in the specimen-initiated arm than with starting antibiotic agents immediately (Very Comfortable: 83.3% vs. 40.7%; p = 0.004). For the smaller paired analysis, there was no longer a difference in comfort level. Conclusions: There may be differences in provider comfort levels and perceptions of adherence when considering two different antibiotic initiation strategies for suspected pneumonia in ventilated patients. These findings should be considered when planning future studies.

Epidemiology and patterns of empiric antimicrobial therapy practice in patients with community-onset sepsis using data from a Japanese nationwide medical claims database-the Japan Sepsis Alliance (JaSA) study group

Objectives

We aimed to describe empiric antimicrobial options for patients with community-onset sepsis using nationwide real-world data from Japan.

Methods

This retrospective cohort study used nationwide Japanese data from a medical reimbursement system database. Patients aged ≥20 years with both presumed infections and acute organ dysfunction who were admitted to hospitals from the outpatient department or emergency department between 2010 and 2017 were enrolled. We described the initial choices of antimicrobials for patients with sepsis stratified by intensive care unit (ICU) or ward.

Results

There were 1,195,741 patients with community-onset sepsis; of these, 1,068,719 and 127,022 patients were admitted to the wards and ICU, respectively. Third-generation cephalosporins and carbapenem were most commonly used for patients with community-onset sepsis. We found that 1.7% and 6.0% of patients initially used antimicrobials for methicillin-resistant Staphylococcus aureus coverage in the wards and ICU, respectively. Although half of the patients initially used antipseudomonal agents, only a few patients used a combination of antipseudomonal agents. Moreover, few patients initially used a combination of antimicrobials to treat methicillin-resistant Staphylococcus aureus and Pseudomonas sp.

Conclusion

Third-generation cephalosporins and carbapenem were most frequently used for patients with sepsis. A combination therapy of antimicrobials for drug-resistant bacteria coverage was rarely provided to these patients.

Is Zero Ventilator-Associated Pneumonia Achievable? Updated Practical Approaches to Ventilator-Associated Pneumonia Prevention

Ventilator-associated pneumonia (VAP) remains a significant clinical entity with reported incidence rates of 7% to 15%. Given the considerable adverse consequences associated with this infection, VAP prevention became a core measure required in most US hospitals. Many institutions took pride in implementing effective VAP prevention bundles that combined at least head of bed elevation, hand hygiene, chlorhexidine oral care, and subglottic drainage. Spontaneous breathing and awakening trials have also consistently been shown to shorten the duration of mechanical ventilation and secondarily reduce the occurrence of VAP.

Therapeutic drug monitoring of imipenem/cilastatin and meropenem in critically ill adult patients

OBJECTIVES

To investigate the factors influencing imipenem/cilastatin (IMI) and meropenem (MEM) concentrations in critically ill adult patients and the role of these concentrations in the clinical outcome.

METHODS

Plasma trough concentrations of IMI and MEM were detected by high-performance liquid chromatography. A target value of 100%-time above MIC was used for the drugs.

RESULTS

A total of 186 patients were included, with 87 receiving IMI and 99 receiving MEM. The percentages of patients reaching the target IMI and MEM concentrations were 44.8% and 38.4%, respectively. The proportions of patients infected with drug-resistant bacteria were 57.5% and 69.7% in the IMI group and MEM group, respectively. In the multivariate analysis, the risk factors for an IMI concentration that did not reach the target were infection with drug-resistant bacteria, and those for MEM were infection with drug-resistant bacteria, estimated glomerular filtration rate, and diabetes mellitus. A total of 47.1% of patients had good outcomes in the IMI cohort, and 38.1% of patients had good outcomes in the MEM cohort. The duration of mechanical ventilation and IMI concentration were associated with ICU stay in patients in the IMI cohort, while MEM concentration and severe pneumonia affected the clinical outcome of patients in the MEM cohort.

CONCLUSION

Infection with drug-resistant bacteria is an important factor influencing whether IMI and MEM concentrations reach the target. Furthermore, IMI and MEM concentrations are associated with the clinical outcome, and elevated doses of IMI and MEM should be given to patients who are infected with drug-resistant bacteria.

Frequency of bloodstream infections caused by six key antibiotic-resistant pathogens for prioritization of research and discovery of new therapies in Europe: a systematic review

BACKGROUND

To prioritize healthcare investments, ranking of infections caused by antibiotic-resistant bacteria should be based on accurate incidence data.

OBJECTIVES

We performed a systematic review to estimate frequency measures of antimicrobial resistance for six key bacteria causing bloodstream infections (BSI) in European countries.

DATA SOURCES

We searched PubMed, Web of Science, Embase databases, and the ECRAID-Base Epidemiological-Network platform.

STUDY ELIGIBILITY CRITERIA

We included studies and surveillance systems assessing resistance-percentage, prevalence, or incidence-density of BSI because of carbapenem-resistant Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, and Escherichia coli, third-generation cephalosporins-resistant E. coli and K. pneumoniae, vancomycin-resistant Enterococcus faecium, and methicillin-resistant Staphylococcus aureus.

METHODS

Reviewers independently assessed published data and evaluated study quality with the modified Joanna Briggs Institute critical appraisal tool. Pooled estimates were determined using random effects meta-analysis. Consistency of data was assessed using random effects meta-regression (Wald test, p > 0.05).

RESULTS

We identified 271 studies and 52 surveillance systems from 32 European countries. Forty-five studies (16%) reported on BSI, including 180 frequency measures most commonly as resistance-percentage (88, 48.9%). Among 309 frequency measures extracted from 24 (46%) surveillance systems, 278 (89%) were resistance-percentages. Frequency measures of methicillin-resistant S. aureus and vancomycin-resistant E. faecium BSI were more frequently reported from Southern Europe and Western Europe (80%), whereas carbapenem-resistant P. aeruginosa BSI from Northern Europe and Western Europe (88%). Highest resistance-percentages were detected for carbapenem-resistant A. baumannii (66% in Central Eastern Europe) and carbapenem-resistant K. pneumoniae (62.8% in Southern Europe). Pooled estimates showed lower resistance-percentages in community versus healthcare-associated infections and in children versus adults. Estimates from studies and surveillance systems were mostly consistent among European regions. The included data was of medium quality.

DISCUSSION

Pathogen-specific frequency measures of antimicrobial resistance in BSI are insufficient to inform antibiotic stewardship and research and development strategies. Improving data collection and standardization of frequency measures is urgently needed.

ICU-acquired infections in immunocompromised patients

Immunocompromised patients account for an increasing proportion of the typical intensive care unit (ICU) case-mix. Because of the increased availability of new drugs for cancer and auto-immune diseases, and improvement in the care of the most severely immunocompromised ICU patients (including those with hematologic malignancies), critically ill immunocompromised patients form a highly heterogeneous patient population. Furthermore, a large number of ICU patients with no apparent immunosuppression also harbor underlying conditions altering their immune response, or develop ICU-acquired immune deficiencies as a result of sepsis, trauma or major surgery. While infections are associated with significant morbidity and mortality in immunocompromised critically ill patients, little specific data are available on the incidence, microbiology, management and outcomes of ICU-acquired infections in this population. As a result, immunocompromised patients are usually excluded from trials and guidelines on the management of ICU-acquired infections. The most common ICU-acquired infections in immunocompromised patients are ventilator-associated lower respiratory tract infections (which include ventilator-associated pneumonia and tracheobronchitis) and bloodstream infections. Recently, several large observational studies have shed light on some of the epidemiological specificities of these infections-as well as on the dynamics of colonization and infection with multidrug-resistant bacteria-in these patients, and these will be discussed in this review. Immunocompromised patients are also at higher risk than non-immunocompromised hosts of fungal and viral infections, and the diagnostic and therapeutic management of these infections will be covered. Finally, we will suggest some important areas of future investigation.

Can rifaximin for hepatic encephalopathy be discontinued during broad-spectrum antibiotic treatment?

Hepatic encephalopathy (HE) is a formidable complication in patients with decompensated cirrhosis, often necessitating the administration of rifaximin (RFX) for effective management. RFX, is a gut-restricted, poorly-absorbable oral rifamycin derived antibiotic that can be used in addition to lactulose for the secondary prophylaxis of HE. It has shown notable reductions in infection, hospital readmission, duration of hospital stay, and mortality. However, limited data exist about the concurrent use of RFX with broad-spectrum antibiotics, because the patients are typically excluded from studies assessing RFX efficacy in HE. A pharmacist-driven quasi-experimental pilot study was done to address this gap. They argue against the necessity of RFX in HE during broad-spectrum antibiotic treatment, particularly in critically ill patients in intensive care unit (ICU). The potential for safe RFX discontinuation without adverse effects is clearly illuminated and valuable insight into the optimization of therapeutic strategies is offered. The findings also indicate that RFX discontinuation during broad-spectrum antibiotic therapy was not associated with higher rates of delirium or coma, and this result remained robust after adjustment in multivariate analysis. Furthermore, rates of other secondary clinical and safety outcomes, including ICU mortality and 48-hour changes in vasopressor requirements, were comparable. However, since the activity of RFX is mainly confined to the modulation of gut microbiota, its potential utility in patients undergoing extensive systemic antibiotic therapy is debatable, given the overlapping antibiotic activity. Further, this suggests that the action of RFX on HE is class-specific (related to its activity on gut microbiota), rather than drug-specific. A recent double-blind randomized controlled (ARiE) trial provided further evidence-based support for RFX withdrawal in critically ill cirrhotic ICU patients receiving broad-spectrum antibiotics. Both studies prompt further discussion about optimal therapeutic strategy for patients facing the dual challenge of HE and systemic infections. Despite these compelling results, both studies have limitations. A prospective, multi-center evaluation of a larger sample, with placebo control, and comprehensive neurologic evaluation of HE is warranted. It should include an exploration of longer-term outcome and the impact of this protocol in non-critically ill liver disease patients.

Systemic inflammatory response syndrome triggered by blood-borne pathogens induces prolonged dendritic cell paralysis and immunosuppression

Blood-borne pathogens can cause systemic inflammatory response syndrome (SIRS) followed by protracted, potentially lethal immunosuppression. The mechanisms responsible for impaired immunity post-SIRS remain unclear. We show that SIRS triggered by pathogen mimics or malaria infection leads to functional paralysis of conventional dendritic cells (cDCs). Paralysis affects several generations of cDCs and impairs immunity for 3-4 weeks. Paralyzed cDCs display distinct transcriptomic and phenotypic signatures and show impaired capacity to capture and present antigens in vivo. They also display altered cytokine production patterns upon stimulation. The paralysis program is not initiated in the bone marrow but during final cDC differentiation in peripheral tissues under the influence of local secondary signals that persist after resolution of SIRS. Vaccination with monoclonal antibodies that target cDC receptors or blockade of transforming growth factor β partially overcomes paralysis and immunosuppression. This work provides insights into the mechanisms of paralysis and describes strategies to restore immunocompetence post-SIRS.

Treatment and Management of Acinetobacter Pneumonia: Lessons Learned from Recent World Event

Acinetobacter pneumonia is a significant healthcare-associated infection that poses a considerable challenge to clinicians due to its multidrug-resistant nature. Recent world events, such as the COVID-19 pandemic, have highlighted the need for effective treatment and management strategies for Acinetobacter pneumonia. In this review, we discuss lessons learned from recent world events, particularly the COVID-19 pandemic, in the context of the treatment and management of Acinetobacter pneumonia. We performed an extensive literature review to uncover studies and information pertinent to the topic. The COVID-19 pandemic underscored the importance of infection control measures in healthcare settings, including proper hand hygiene, isolation protocols, and personal protective equipment use, to prevent the spread of multidrug-resistant pathogens like Acinetobacter. Additionally, the pandemic highlighted the crucial role of antimicrobial stewardship programs in optimizing antibiotic use and curbing the emergence of resistance. Advances in diagnostic techniques, such as rapid molecular testing, have also proven valuable in identifying Acinetobacter infections promptly. Furthermore, due to the limited availability of antibiotics for treating infections caused A. baumannii, alternative strategies are needed like the use of antimicrobial peptides, bacteriophages and their enzymes, nanoparticles, photodynamic and chelate therapy. Recent world events, particularly the COVID-19 pandemic, have provided valuable insights into the treatment and management of Acinetobacter pneumonia. These lessons emphasize the significance of infection control, antimicrobial stewardship, and early diagnostics in combating this challenging infection.

Practical Lessons on Antimicrobial Therapy for Critically Ill Patients

Sepsis stands as a formidable global health challenge, with persistently elevated mortality rates in recent decades. Each year, sepsis not only contributes to heightened morbidity but also imposes substantial healthcare costs on survivors. This narrative review aims to highlight the targeted measures that can be instituted to alleviate the incidence and impact of sepsis in intensive care. Here we discuss measures to reduce nosocomial infections and the prevention of equipment and patient colonisation by resilient pathogens. The overarching global crisis of bacterial resistance to newly developed antimicrobial agents intensifies the imperative for antimicrobial stewardship and de-escalation. This urgency has been accentuated in recent years, notably during the COVID-19 pandemic, as high-dose steroids and opportunistic infections presented escalating challenges. Ongoing research into airway colonisation's role in influencing disease outcomes among critically ill patients underscores the importance of tailoring treatments to disease endotypes within heterogeneous populations, which are important lessons for intensivists in training. Looking ahead, the significance of novel antimicrobial delivery systems and drug monitoring is poised to increase. This narrative review delves into the multifaceted barriers and facilitators inherent in effectively treating critically ill patients vulnerable to nosocomial infections. The future trajectory of intensive care medicine hinges on the meticulous implementation of vigilant stewardship programs, robust infection control measures, and the continued exploration of innovative and efficient technological solutions within this demanding healthcare landscape.

Effects of intensive care unit quality assessment on changes in medical staff in medical institutions and in-hospital mortality

BACKGROUND

Quality assessments are being introduced in many countries to improve the quality of care and maintain acceptable quality levels. In South Korea, various quality assessments are being conducted to improve the quality of care, but there is insufficient evidence on intensive care units (ICUs). This study aims to evaluate the impact of ICU quality assessments on the structural indicators in medical institutions and the resulting in-hospital mortality of patients.

METHODS

This study used data collected in the 2nd and 3rd ICU quality assessments in 2017 and 2019. A total of 72,879 patients admitted to ICUs were included during this period, with 265 institutions that received both assessments. As for structural indicators, changes in medical personnel and equipment were assessed, and in-hospital deaths were evaluated as patient outcomes. To evaluate the association between medical staff and in-hospital mortality, a generalized estimating equation model was performed considering both hospital and patient variables.

RESULTS

Compared to the second quality evaluation, the number of intensivist physicians and experienced nurses increased in the third quality evaluation; however, there was still a gap in the workforce depending on the type of medical institution. Among all ICU patients admitted during the evaluation period, 12.0% of patients died in the hospital. In-hospital mortality decreased at the 3rd assessment, and hospitals employing intensivist physicians were associated with reduced in-hospital deaths. In addition, an increase in the number of experienced nurses was associated with a decrease in in-hospital mortality, while an increase in the nurse-to-bed ratio increased mortality.

CONCLUSIONS

ICU quality assessments improved overall structural indicators, but the gap between medical institutions has not improved and interventions are required to bridge this gap. In addition, it is important to maintain skilled medical personnel to bring about better results for patients, and various efforts should be considered. This requires continuous monitoring and further research on long-term effects.

Genomic and metabolic versatility of Pseudomonas aeruginosa contributes to its inter-kingdom transmission and survival

Pseudomonas aeruginosa is one of the most versatile bacteria with renowned pathogenicity and extensive drug resistance. The diverse habitats of this bacterium include fresh, saline and drainage waters, soil, moist surfaces, taps, showerheads, pipelines, medical implants, nematodes, insects, plants, animals, birds and humans. The arsenal of virulence factors produced by P. aeruginosa includes pyocyanin, rhamnolipids, siderophores, lytic enzymes, toxins and polysaccharides. All these virulent elements coupled with intrinsic, adaptive and acquired antibiotic resistance facilitate persistent colonization and lethal infections in different hosts. To date, treating pulmonary diseases remains complicated due to the chronic secondary infections triggered by hospital-acquired P. aeruginosa. On the contrary, this bacterium can improve plant growth by suppressing phytopathogens and insects. Notably, P. aeruginosa is one of the very few bacteria capable of trans-kingdom transmission and infection. Transfer of P. aeruginosa strains from plant materials to hospital wards, animals to humans, and humans to their pets occurs relatively often. Recently, we have identified that plant-associated P. aeruginosa strains could be pathologically similar to clinical isolates. In this review, we have highlighted the genomic and metabolic factors that facilitate the dominance of P. aeruginosa across different biological kingdoms and the varying roles of this bacterium in plant and human health.

An integrated method for targeted Oxford Nanopore sequencing and automated bioinformatics for the simultaneous detection of bacteria, fungi, and ARG

AIMS

The use of metagenomics for pathogen identification in clinical practice has been limited. Here we describe a workflow to encourage the clinical utility and potential of NGS for the screening of bacteria, fungi, and antimicrobial resistance genes (ARGs).

METHODS AND RESULTS

The method includes target enrichment, long-read sequencing, and automated bioinformatics. Evaluation of several tools and databases was undertaken across standard organisms (n = 12), clinical isolates (n = 114), and blood samples from patients with suspected bloodstream infections (n = 33). The strategy used could offset the presence of host background DNA, error rates of long-read sequencing, and provide accurate and reproducible detection of pathogens. Eleven targets could be successfully tested in a single assay. Organisms could be confidently identified considering ≥60% of best hits of a BLAST-based threshold of e-value 0.001 and a percent identity of >80%. For ARGs, reads with percent identity of >90% and >60% overlap of the complete gene could be confidently annotated. A kappa of 0.83 was observed compared to standard diagnostic methods. Thus, a workflow for the direct-from-sample, on-site sequencing combined with automated genomics was demonstrated to be reproducible.

CONCLUSION

NGS-based technologies overcome several limitations of current day diagnostics. Highly sensitive and comprehensive methods of pathogen screening are the need of the hour. We developed a framework for reliable, on-site, screening of pathogens.

Bacterial pneumonia-induced shedding of epithelial heparan sulfate inhibits the bactericidal activity of cathelicidin in a murine model

Bacterial pneumonia is a common clinical syndrome leading to significant morbidity and mortality worldwide. In the current study, we investigate a novel, multidirectional relationship between the pulmonary epithelial glycocalyx and antimicrobial peptides in the setting of methicillin-resistant Staphylococcus aureus (MRSA) pneumonia. Using an in vivo pneumonia model, we demonstrate that highly sulfated heparan sulfate (HS) oligosaccharides are shed into the airspaces in response to MRSA pneumonia. In vitro, these HS oligosaccharides do not directly alter MRSA growth or gene transcription. However, in the presence of an antimicrobial peptide (cathelicidin), increasing concentrations of HS inhibit the bactericidal activity of cathelicidin against MRSA as well as other nosocomial pneumonia pathogens (Klebsiella pneumoniae and Pseudomonas aeruginosa) in a dose-dependent manner. Surface plasmon resonance shows avid binding between HS and cathelicidin with a dissociation constant of 0.13 μM. These findings highlight a complex relationship in which shedding of airspace HS may hamper host defenses against nosocomial infection via neutralization of antimicrobial peptides. These findings may inform future investigation into novel therapeutic targets designed to restore local innate immune function in patients suffering from primary bacterial pneumonia.NEW & NOTEWORTHY Primary Staphylococcus aureus pneumonia causes pulmonary epithelial heparan sulfate (HS) shedding into the airspace. These highly sulfated HS fragments do not alter bacterial growth or transcription, but directly bind with host antimicrobial peptides and inhibit the bactericidal activity of these cationic polypeptides. These findings highlight a complex local interaction between the pulmonary epithelial glycocalyx and antimicrobial peptides in the setting of bacterial pneumonia.

Population pharmacokinetics and individualized dosing of tigecycline for critically ill patients: a prospective study with intensive sampling

Background: Due to the heterogeneity of critically ill patients, the pharmacokinetics of tigecycline are unclear, and the optimal dosing strategy is controversial. Methods: A single-center prospective clinical study that included critically ill patients who received tigecycline was performed. Blood samples were intensively sampled (eight samples each), and plasma drug concentrations were determined. A population pharmacokinetic (PPK) model was developed and evaluated by goodness-of-fit plots, bootstrap analysis and visual predictive checks. Monte Carlo simulation was conducted to optimize the dosage regimen. Results: Overall, 751 observations from 98 patients were included. The final PPK model was a two-compartment model incorporating covariates of creatinine clearance on clearance (CL), body weight on both central and peripheral volumes of distribution (V1 and V2), γ-glutamyl transferase and total bilirubin on intercompartment clearance (Q), and albumin on V2. The typical values of CL, Q, V1 and V2 were 3.09 L/h, 39.7 L/h, 32.1 L and 113 L, respectively. A dosage regimen of 50 mg/12 h was suitable for complicated intra-abdominal infections, but 100 mg/12 h was needed for community-acquired pneumonia, skin and skin structure infections and infections caused by less-susceptive bacteria. Conclusion: The Tigecycline PPK model was successfully developed and validated. Individualized dosing of tigecycline could be beneficial for critically ill patients.