Effect of therapeutic drug monitoring-based dose optimization of piperacillin/tazobactam on sepsis-related organ dysfunction in patients with sepsis: a randomized controlled trial

Antibiotic dose optimisation in the critically ill: targets, evidence and future strategies

PURPOSE OF REVIEW

To highlight the recent evidence for antibiotic pharmacokinetics and pharmacodynamics (PK/PD) in enhancing patient outcomes in sepsis and septic shock. We also summarise the limitations of available data and describe future directions for research to support translation of antibiotic dose optimisation to the clinical setting.

RECENT FINDINGS

Sepsis and septic shock are associated with poor outcomes and require antibiotic dose optimisation, mostly due to significantly altered pharmacokinetics. Many studies, including some randomised controlled trials have been conducted to measure the clinical outcome effects of antibiotic dose optimisation interventions including use of therapeutic drug monitoring. Current data support antibiotic dose optimisation for the critically ill. Further investigation is required to evolve more timely and robust precision antibiotic dose optimisation approaches, and to clearly quantify whether any clinical and health-economic benefits support expanded use of this treatment intervention.

SUMMARY

Antibiotic dose optimisation appears to improve outcomes in critically ill patients with sepsis and septic shock, however further research is required to quantify the level of benefit and develop a stronger knowledge of the role of new technologies to facilitate optimised dosing.

Determinants of beta-lactam PK/PD target attainment in critically ill patients: A single center retrospective study

PURPOSE

We aimed to identify factors associated with achieving target BL plasma concentrations and describe real world data for therapeutic drug monitoring (TDM).

METHODS

A retrospective single center study was conducted. We collected data from patients admitted to ICU with at least one BL TDM. We assessed the proportion of patients attaining the recommended plasma concentrations (i.e 100%fT > 4 to 8 MIC). Univariate and multivariate analyses was performed to identify the determinants of BL target attainment.

RESULTS

156 patients were included. At the first dosing, 34% achieved target BL plasma concentrations, 50% were overdosed, and 16% were underdosed. Median time for 1st TDM were 4 (SD = 2.9) days. Multivariate analysis revealed that CKD-EPI estimated glomerular filtration rate (OR = 1.02; CI [1.01; 1.03]; p < 0.0001) and total body weight (OR = 1.03; CI [1.01; 1.04]; p = 0.0048) were the main determinant of BL target attainment. Conversely, Continuous Renal Replacement Therapy (OR = 0.28; CI [0.09; 0.89]; p = 0.0318) and meropenem use (OR = 0.31; CI [0.14; 0.69]; p = 0.0041) were identified as risk factors for overdosing. No factor was associated with underdosing.

CONCLUSION

Achieving target BL plasma concentrations remains challenging in ICUs. Identifying predictive factors of BL target attainment would favor implementing rapid dosing optimization strategies in both under and overdosing high risk patients.

Predictive performance of multi-model approaches for model-informed precision dosing of piperacillin in critically ill patients

OBJECTIVES

Piperacillin (PIP)/tazobactam is a frequently prescribed antibiotic; however, over- or underdosing may contribute to toxicity, therapeutic failure, and development of antimicrobial resistance. An external evaluation of 24 published PIP-models demonstrated that model-informed precision dosing (MIPD) can enhance target attainment. Employing various candidate models, this study aimed to assess the predictive performance of different MIPD-approaches comparing (i) a single-model approach, (ii) a model selection algorithm (MSA) and (iii) a model averaging algorithm (MAA).

METHODS

Precision, accuracy and expected target attainment, considering either initial (B1) or initial and secondary (B2) therapeutic drug monitoring (TDM)-samples per patient, were assessed in a multicentre dataset (561 patients, 11 German centres, 3654 TDM-samples).

RESULTS

The results demonstrated a slight superiority in predictive performance using MAA in B1, regardless of the candidate models, compared to MSA and the best single models (MAA, MSA, best single models: inaccuracy ±3%, ±10%, ±8%; imprecision: <25%, <31%, <28%; expected target attainment >77%, >71%, >73%). The inclusion of a second TDM-sample notably improved precision and target attainment for all MIPD-approaches, particularly within the context of MSA and most of the single models. The expected target attainment is maximized (up to >90%) when the TDM-sample is integrated within 24 h.

CONCLUSIONS

In conclusion, MAA streamlines MIPD by reducing the risk of selecting an inappropriate model for specific patients. Therefore, MIPD of PIP using MAA implicates further optimisation of antibiotic exposure in critically ill patients, by improving predictive performance with only one sample available for Bayesian forecasting, safety, and usability in clinical practice.

Target attainment of beta-lactam antibiotics and ciprofloxacin in critically ill patients and its association with 28-day mortality

OBJECTIVES

This study aims to assess pharmacodynamic target attainment in critically ill patients and identify factors influencing target attainment and mortality outcomes.

METHODS

We analysed data from the DOLPHIN trial. Beta-lactam and ciprofloxacin peak and trough concentration were measured within the first 36 h (T1) after initiation of treatment. The study outcome included the rate of pharmacodynamic target attainment of 100 % ƒT>1xEpidemiological cut-off value (ECOFF) for beta-lactams, and of fAUC0-24h/ECOFF>125 for ciprofloxacin at T1.

RESULTS

The target attainment rates were 78.1 % (n = 228/292) for beta-lactams, and 41.5 % (n = 39/94) for ciprofloxacin, respectively. Lower estimated glomerular filtration rate and higher SOFA score were associated with target attainment. In patients receiving beta-lactams, 28-day mortality was significantly higher in patients who attained 100 % ƒT>1xECOFF (28.9 % vs. 12.5 %; p = 0.01). In the multivariate analysis, attainment of 100 % ƒT>4xECOFF, but not 100 % ƒT>1xECOFF, was associated with a higher 28-day mortality (OR 2.70, 95 % CI 1.36-5.48 vs. OR 1.28, 95 % CI 0.53-3.34).

CONCLUSIONS

A high rate of target attainment (100 % ƒT>1xECOFF) for beta-lactams and a lower rate for ciprofloxacin was observed. Achieving exposures of 100 % ƒT>4xECOFF was associated with 28-day mortality. The impact of antibiotic target attainment on clinical outcome needs to be a focus of future research.

The OPAT opportunity for beta-lactam individualization

Beta-lactam therapeutic drug monitoring has been growing in prevalence in the acute care hospital setting. Expansion of its use to outpatient parenteral antimicrobial therapy requires careful consideration of potential logistical and therapeutic barriers.

Unraveling the impact of therapeutic drug monitoring via machine learning for patients with sepsis

Clinical studies investigating the benefits of beta-lactam therapeutic drug monitoring (TDM) among critically ill patients are hindered by small patient groups, variability between studies, patient heterogeneity, and inadequate use of TDM. Accordingly, definitive conclusions regarding the efficacy of TDM remain elusive. To address these challenges, we propose an innovative approach that leverages data-driven methods to unveil the concealed connections between therapy effectiveness and patient data, collected through a randomized controlled trial (DRKS00011159; 10th October 2016). Our findings reveal that machine learning algorithms can successfully identify informative features that distinguish between healthy and sick states. These hold promise as potential markers for disease classification and severity stratification, as well as offering a continuous and data-driven "multidimensional" Sequential Organ Failure Assessment (SOFA) score. The positive impact of TDM on patient recovery rates is demonstrated by unraveling the intricate connections between therapy effectiveness and clinically relevant data via machine learning.

Model-informed precision dosing: State of the art and future perspectives

Model-informed precision dosing (MIPD) stands as a significant development in personalized medicine to tailor drug dosing to individual patient characteristics. MIPD moves beyond traditional therapeutic drug monitoring (TDM) by integrating mathematical predictions of dosing, and considering patient-specific factors (patient characteristics, drug measurements) as well as different sources of variability. For this purpose, rigorous model qualification is required for the application of MIPD in patients. This review delves into new methods in model selection and validation, also highlighting the role of machine learning in improving MIPD, the utilization of biosensors for real-time monitoring, as well as the potential of models integrating biomarkers for efficacy or toxicity for precision dosing. The clinical evidence of TDM and MIPD is discussed for various medical fields including infection medicine, oncology, transplant medicine, and inflammatory bowel diseases, thereby underscoring the role of pharmacokinetics/pharmacodynamics and specific biomarkers. Further research, particularly randomized clinical trials, is warranted to corroborate the value of MIPD in enhancing patient outcomes and advancing personalized medicine.

Antimicrobial therapeutic drug monitoring in critically ill adult patients - An international perspective on access, utilisation, and barriers

BACKGROUND

Therapeutic drug monitoring (TDM) is an effective method for individualising antimicrobial therapy in critically ill patients. The 2021 ADMIN-intensive care unit survey studied a wide range of intensive care unit clinicians worldwide to gain their perspectives on antimicrobial TDM. This article reports the responses from this survey relating to TDM access, utilisation, and barriers.

METHODS

An online survey consisted of multiple-choice questions and 5-point Likert scales. The survey examined respondent's access to minimum inhibitory concentration (MIC) results, drug assays, and dosing software, as well as barriers to TDM.

RESULTS

The survey included 538 clinicians from 409 hospitals in 45 countries, with 71% physicians and 29% pharmacists. Despite most respondents having access to assays, 21% and 26% of respondents lacked access to vancomycin and aminoglycosides, respectively. In lower-income countries, almost 40% reported no access. Delayed drug assay turnaround time was the most significant barrier to TDM, particularly in lower-income countries. Routine access to MIC results was unavailable for 41% of respondents, with 25% of lower-income country respondents having no access to MIC or susceptibility reports.

CONCLUSIONS

This global survey indicated that consistent TDM usage is hindered by assay access in some sites and the timeliness of assay results in others. Addressing barriers to TDM, particularly in low-income countries, should be a priority to ensure equitable access to affordable TDM.

Development of an eco-friendly capillary electrophoresis method for the simultaneous determination of piperacillin, tazobactam and ibuprofen in plasma samples: application to a pharmacokinetic study in rats

Piperacillin (PIP) and tazobactam (TAZ) are broad-spectrum beta-lactam antimicrobial agents, which are frequently co-prescribed in intensive care units (ICUs) worldwide. Ibuprofen (IBU) is a potent pain killer which is commonly co-prescribed with PIP and TAZ postoperatively. The combination therapy of PIP, TAZ, and IBU has been administered commonly after surgical procedures to combat aerobic and anaerobic microbes and exert anti-inflammatory and analgesic effects. This study describes, for the first time, the development of a new capillary electrophoresis (CE) method with a photodiode array detector for the simultaneous determination of PIP, TAZ, and IBU in plasma samples. The experimental factors affecting the elution of analytes were carefully optimized. The final analysis was achieved using a fused silica capillary (58 cm effective length and 75 μm ID) and a background electrolyte solution containing a methanol/borax buffer solution (15 mM and pH 9.3) in a ratio of (10 : 90 v/v) with a driving voltage of 30 kV and detection at 210 nm. The relationship between the peak area and concentration was linear from 1 to 200 μg mL-1 for both PIP and TAZ and from 3 to 200 μg mL-1 for TAZ. The method used was thoroughly validated in accordance with the validation requirements set out by the Food and Drug Administration (FDA) for bio-analytical processes. The proposed CE method was employed to conduct pharmacokinetic and bioavailability studies of the drugs in rat models. The pharmacokinetic results revealed that there is a significant impact upon prescribing this combination concurrently when compared to their single administration. To illustrate, the time required to reach their maximum concentrations (T max) was increased by 0.25 h for both PIP and TAZ, whereas it was increased by 0.5 for IBU. When it comes to their maximum concentration (C max), it was increased by 13.7%, 55.5%, and 44% for PIP, TAZ, and IBU, respectively. Furthermore, the bioavailabilities of PIP, TAZ, and IBU were significantly increased by 55.4%, 19.7%, and 35.6%, respectively. These findings require caution when these drugs are co-prescribed as there is a noticeable augmentation in their therapeutic impacts. Additionally, the greenness of the proposed method was assessed by three metric tools. In conclusion, the method is a valuable tool for further studies on drug-drug interaction in humans.

Use of the DMAIC Lean Six Sigma quality improvement framework to improve beta-lactam antibiotic adequacy in the critically ill

Beta-lactam antibiotics are widely used in the intensive care unit due to their favorable effectiveness and safety profiles. Beta-lactams given to patients with sepsis must be delivered as soon as possible after infection recognition (early), treat the suspected organism (appropriate), and be administered at a dose that eradicates the infection (adequate). Early and appropriate antibiotic delivery occurs in >90% of patients, but less than half of patients with sepsis achieve adequate antibiotic exposure. This project aimed to address this quality gap and improve beta-lactam adequacy using the Define, Measure, Analyze, Improve, and Control Lean Six Sigma quality improvement framework. A multidisciplinary steering committee was formed, which completed a stakeholder analysis to define the gap in practice. An Ishikawa cause and effect (Fishbone) diagram was used to identify the root causes and an impact/effort grid facilitated prioritization of interventions. An intervention that included bundled education with the use of therapeutic drug monitoring (TDM; i.e. drug-level testing) was projected to have the highest impact relative to the amount of effort and selected to address beta-lactam inadequacy in the critically ill. The education and TDM intervention were deployed through a Plan, Do, Study, Act cycle. In the 3 months after "go-live," 54 episodes of beta-lactam TDM occurred in 41 unique intensive care unit patients. The primary quality metric of beta-lactam adequacy was achieved in 94% of individuals after the intervention. Ninety-four percent of clinicians gauged the education provided as sufficient. The primary counterbalance of antimicrobial days of therapy, a core antimicrobial stewardship metric, was unchanged over time (favorable result; P = .73). Application of the Define, Measure, Analyze, Improve, and Control Lean Six Sigma quality improvement framework effectively improved beta-lactam adequacy in critically ill patients. The approach taken in this quality improvement project is widely generalizable to other drugs, drug classes, or settings to increase the adequacy of drug exposure.

Understanding antimicrobial pharmacokinetics in critically ill patients to optimize antimicrobial therapy: A narrative review

Effective treatment of sepsis not only demands prompt administration of appropriate antimicrobials but also requires precise dosing to enhance the likelihood of patient survival. Adequate dosing refers to the administration of doses that yield therapeutic drug concentrations at the infection site. This ensures a favorable clinical and microbiological response while avoiding antibiotic-related toxicity. Therapeutic drug monitoring (TDM) is the recommended approach for attaining these goals. However, TDM is not universally available in all intensive care units (ICUs) and for all antimicrobial agents. In the absence of TDM, healthcare practitioners need to rely on several factors to make informed dosing decisions. These include the patient's clinical condition, causative pathogen, impact of organ dysfunction (requiring extracorporeal therapies), and physicochemical properties of the antimicrobials. In this context, the pharmacokinetics of antimicrobials vary considerably between different critically ill patients and within the same patient over the course of ICU stay. This variability underscores the need for individualized dosing. This review aimed to describe the main pathophysiological changes observed in critically ill patients and their impact on antimicrobial drug dosing decisions. It also aimed to provide essential practical recommendations that may aid clinicians in optimizing antimicrobial therapy among critically ill patients.

Study protocol for ADAPT-TDM: A beta-lactam antibiotic Dose AdaPtation feasibility randomised controlled Trial using Therapeutic Drug Monitoring

INTRODUCTION

Critically ill patients are at risk of suboptimal beta-lactam antibiotic (beta-lactam) exposure due to the impact of altered physiology on pharmacokinetics. Suboptimal concentrations can lead to treatment failure or toxicity. Therapeutic drug monitoring (TDM) involves adjusting doses based on measured plasma concentrations and individualising dosing to improve the likelihood of improving exposure. Despite its potential benefits, its adoption has been slow, and data on implementation, dose adaptation and safety are sparse. The aim of this trial is to assess the feasibility and fidelity of implementing beta-lactam TDM-guided dosing in the intensive care unit setting.

METHODS AND ANALYSIS

A beta-lactam antibiotic Dose AdaPtation feasibility randomised controlled Trial using Therapeutic Drug Monitoring (ADAPT-TDM) is a single-centre, unblinded, feasibility randomised controlled trial aiming to enroll up to 60 critically ill adult participants (≥18 years). TDM and dose adjustment will be performed daily in the intervention group; the standard of care group will undergo plasma sampling, but no dose adjustment. The main outcomes include: (1) feasibility of recruitment, defined as the number of participants who are recruited from a pool of eligible participants, and (2) fidelity of TDM, defined as the degree to which TDM as a test is delivered as intended, from accurate sample collection, sample processing to result availability. Secondary outcomes include target attainment, uptake of TDM-guided dosing and incidence of neurotoxicity, hepatotoxicity and nephrotoxicity.

ETHICS AND DISSEMINATION

This study has been approved by the Alfred Hospital human research ethics committee, Office of Ethics and Research Governance (reference: Project No. 565/22; date of approval: 22/11/2022). Prospective consent will be obtained and the study will be conducted in accordance with the Declaration of Helsinki. The finalised manuscript, including aggregate data, will be submitted for publication in a peer reviewed journal. ADAPT-TDM will determine whether beta-lactam TDM-guided dose adaptation is reproducible and feasible and provide important information required to implement this intervention in a phase III trial.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry, ACTRN12623000032651.

Revealing the role of Peg13: A promising therapeutic target for mitigating inflammation in sepsis

To investigate the role of Peg13 in modulating the inflammatory response in sepsis, we established Lipopolysaccharide (LPS)-induced 293T cells and mouse models. Peg13 expression was assessed at various time points after infection using RT-qPCR. The levels of high mobility group box 1 (HMGB1) and interleukin-6 (IL-6) were quantified through ELISA. A total of 44 septic patients and 36 healthy participants were recruited to measure Peg13 and HMGB1 levels in the blood. Peg13 demonstrated significant down-regulation in the supernatant of LPS-induced 293T cells and in the blood of LPS-induced mice. Moreover, the levels of proinflammatory cytokines HMGB1 and IL-6 were elevated in both the supernatant of LPS-induced cell models and blood specimens from LPS-induced murine models, and this elevation could be notably reduced by Peg13 suppression. In a clinical context, Peg13 and HMGB1 levels were higher in septic patients compared to healthy subjects. Peg13 exhibited a negative correlation with HMGB1, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) among septic patients. Peg13 mitigates the inflammatory response by reducing the release of proinflammatory cytokines HMGB1 and IL-6 in sepsis, presenting a potential therapeutic target for alleviating inflammation in sepsis treatment.

Balancing the scales: achieving the optimal beta-lactam to beta-lactamase inhibitor ratio with continuous infusion piperacillin/tazobactam against extended spectrum beta-lactamase producing Enterobacterales

Piperacillin/tazobactam (TZP) is administered intravenously in a fixed ratio (8:1) with the potential for inadequate tazobactam exposure to ensure piperacillin activity against Enterobacterales. Adult patients receiving continuous infusion (CI) of TZP and therapeutic drug monitoring (TDM) of both agents were evaluated. Demographic variables and other pertinent laboratory data were collected retrospectively. A population pharmacokinetic approach was used to select the best kidney function model predictive of TZP clearance (CL). The probability of target attainment (PTA), cumulative fraction of response (CFR) and the ratio between piperacillin and tazobactam were computed to identify optimal dosage regimens by continuous infusion across kidney function. This study included 257 critically ill patients (79.3% male) with intra-abdominal, bloodstream, and hospital-acquired pneumonia infections in 89.5% as the primary indication. The median (min-max range) age, body weight, and estimated glomerular filtration rate (eGFR) were 66 (23-93) years, 75 (39-310) kg, and 79.2 (6.4-234) mL/min, respectively. Doses of up to 22.5 g/day were used to optimize TZP based on TDM. The 2021 chronic kidney disease epidemiology equation in mL/min best modeled TZP CL. The ratio of piperacillin:tazobactam increased from 6:1 to 10:1 between an eGFR of <20 mL/min and >120 mL/min. At conventional doses, the PTA is below 90% when eGFR is ≥100 mL/min. Daily doses of 18 g/day and 22.5 g/day by CI are expected to achieve a >80% CFR when eGFR is 100-120 mL/min and >120-160 mL/min, respectively. Inadequate piperacillin and tazobactam exposure is likely in patients with eGFR ≥ 100 mL/min. Dose regimen adjustments informed by TDM should be evaluated in this specific population.

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.

Achievement of therapeutic antibiotic exposures using Bayesian dosing software in critically unwell children and adults with sepsis

PURPOSE

Early recognition and effective treatment of sepsis improves outcomes in critically ill patients. However, antibiotic exposures are frequently suboptimal in the intensive care unit (ICU) setting. We describe the feasibility of the Bayesian dosing software Individually Designed Optimum Dosing Strategies (ID-ODS™), to reduce time to effective antibiotic exposure in children and adults with sepsis in ICU.

METHODS

A multi-centre prospective, non-randomised interventional trial in three adult ICUs and one paediatric ICU. In a pre-intervention Phase 1, we measured the time to target antibiotic exposure in participants. In Phase 2, antibiotic dosing recommendations were made using ID-ODS™, and time to target antibiotic concentrations were compared to patients in Phase 1 (a pre-post-design).

RESULTS

175 antibiotic courses (Phase 1 = 123, Phase 2 = 52) were analysed from 156 participants. Across all patients, there was no difference in the time to achieve target exposures (8.7 h vs 14.3 h in Phase 1 and Phase 2, respectively, p = 0.45). Sixty-one courses in 54 participants failed to achieve target exposures within 24 h of antibiotic commencement (n = 36 in Phase 1, n = 18 in Phase 2). In these participants, ID-ODS™ was associated with a reduction in time to target antibiotic exposure (96 vs 36.4 h in Phase 1 and Phase 2, respectively, p < 0.01). These patients were less likely to exhibit subtherapeutic antibiotic exposures at 96 h (hazard ratio (HR) 0.02, 95% confidence interval (CI) 0.01-0.05, p < 0.01). There was no difference observed in in-hospital mortality.

CONCLUSIONS

Dosing software may reduce the time to achieve target antibiotic exposures. It should be evaluated further in trials to establish its impact on clinical outcomes.

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.

Exploring the Impact of Model-Informed Precision Dosing on Procalcitonin Concentrations in Critically Ill Patients: A Secondary Analysis of the DOLPHIN Trial

Model-informed precision dosing (MIPD) might be used to optimize antibiotic treatment. Procalcitonin (PCT) is a biomarker for severity of infection and response to antibiotic treatment. The aim of this study was to assess the impact of MIPD on the course of PCT and to investigate the association of PCT with pharmacodynamic target (PDT) attainment in critically ill patients. This is a secondary analysis of the DOLPHIN trial, a multicentre, open-label, randomised controlled trial. Patients with a PCT value available at day 1 (T1), day 3 (T3), or day 5 (T5) after randomisation were included. The primary outcome was the absolute difference in PCT concentration at T1, T3, and T5 between the MIPD and the standard dosing group. In total, 662 PCT concentrations from 351 critically ill patients were analysed. There was no statistically significant difference in PCT concentration between the trial arms at T1, T3, or T5. The median PCT concentration was highest in patients who exceeded 10× PDT at T1 [13.15 ng/mL (IQR 5.43-22.75)]. In 28-day non-survivors and in patients that exceeded PDT at T1, PCT decreased significantly between T1 and T3, but plateaued between T3 and T5. PCT concentrations were not significantly different between patients receiving antibiotic treatment with or without MIPD guidance. The potential of PCT to guide antibiotic dosing merits further investigation.

Extended Infusion of Beta-Lactams and Glycopeptides: A New Era in Pediatric Care? A Systematic Review and Meta-Analysis

Optimizing antibiotic therapy is imperative with rising bacterial resistance and high infection mortality. Extended infusion defined as a continuous infusion (COI) or prolonged infusion (PI) of beta-lactams and glycopeptides might improve efficacy and safety compared to their intermittent administration (IA). This study aimed to evaluate the efficacy and safety of extended infusion in pediatric patients. Adhering to Cochrane standards, we conducted a systematic review with meta-analysis investigating the efficacy and safety of COI (24 h/d) and PI (>1 h/dose) compared to IA (≤1 h/dose) of beta-lactams and glycopeptides in pediatrics. Primary outcomes included mortality, clinical success, and microbiological eradication. Five studies could be included for the outcome mortality, investigating meropenem, piperacillin/tazobactam, cefepime, or combinations of these. The pooled relative risk estimate was 0.48 (95% CI 0.26-0.89, p = 0.02). No significant differences between the administration modes were found for the outcomes of clinical success, microbiological eradication (beta-lactams; glycopeptides), and mortality (glycopeptides). No study reported additional safety issues, e.g., adverse drug reactions when using COI/PI vs. IA. Our findings suggest that the administration of beta-lactams by extended infusion leads to a reduction in mortality for pediatric patients.

Covariates in population pharmacokinetic studies of critically ill adults receiving β-lactam antimicrobials: a systematic review and narrative synthesis

Introduction

Population pharmacokinetic studies of β-lactam antimicrobials in critically ill patients derive models that inform their dosing. In non-linear mixed-effects modelling, covariates are often used to improve model fit and explain variability. We aimed to investigate which covariates are most commonly assessed and which are found to be significant, along with global patterns of publication.

Methods

We conducted a systematic review, searching MEDLINE, Embase, CENTRAL and Web of Science on 01 March 2023, including studies of critically ill adults receiving β-lactam antimicrobials who underwent blood sampling for population pharmacokinetic studies. We extracted and categorized all reported covariates and assessed reporting quality using the ClinPK checklist.

Results

Our search identified 151 studies with 6018 participants. Most studies reported observational cohorts (120 studies, 80%), with the majority conducted in high-income settings (136 studies, 90%). Of the 1083 identified covariate instances, 237 were unique; the most common categories were patient characteristics (n = 404), biomarkers (n = 206) and physiological parameters (n = 163). Only seven distinct commonly reported covariates (CLCR, weight, glomerular filtration rate, diuresis, need for renal replacement, serum albumin and C-reactive protein) were significant more than 20% of the time.

Conclusions

Covariates are most commonly chosen based on biological plausibility, with patient characteristics and biomarkers the most frequently investigated. We developed an openly accessible database of reported covariates to aid investigators with covariate selection when designing population pharmacokinetic studies. Novel covariates, such as sepsis subphenotypes, have not been explored yet, leaving a research gap for future work.

[Guideline-conform treatment of sepsis]

The time to administration of broad-spectrum antibiotics and (secondarily) to the initiation of hemodynamic stabilization are the most important factors influencing survival of patients with sepsis and septic shock; however, the basic prerequisite for the initiation of an adequate treatment is that a suspected diagnosis of sepsis is made first. Therefore, the treatment of sepsis, even before it has begun, is an interdisciplinary and interprofessional task. This article provides an overview of the current state of the art in sepsis treatment and points towards new evidence that has the potential to change guideline recommendations in the coming years. In summary, the following points are critical: (1) sepsis must be diagnosed as soon as possible and the implementation of a source control intervention (in case of a controllable source) has to be implemented as soon as (logistically) possible. (2) In general, intravenous broad-spectrum antibiotics should be given within the first hour after diagnosis if sepsis or septic shock is suspected. In organ dysfunction without shock, where sepsis is a possible but unlikely cause, the results of focused advanced diagnostics should be awaited before a decision to give broad-spectrum antibiotics is made. If it is not clear within 3 h whether sepsis is the cause, broad-spectrum antibiotics should be given when in doubt. Administer beta-lactam antibiotics as a prolonged (or if therapeutic drug monitoring is available, continuous) infusion after an initial loading dose. (3) Combination treatment with two agents for one pathogen group should remain the exception (e.g. multidrug-resistant gram-negative pathogens). (4) In the case of doubt, the duration of anti-infective treatment should rather be shorter than longer. Procalcitonin can support the clinical decision to stop (not to start!) antibiotic treatment! (5) For fluid treatment, if hypoperfusion is present, the first (approximately) 2L (30 ml/kg BW) of crystalloid solution is usually safe and indicated. After that, the rule is: less is more! Any further fluid administration should be carefully weighed up with the help of dynamic parameters, the patient's clinical condition and echo(cardio)graphy.

Could an Optimized Joint Pharmacokinetic/Pharmacodynamic Target Attainment of Continuous Infusion Piperacillin-Tazobactam Be a Valuable Innovative Approach for Maximizing the Effectiveness of Monotherapy Even in the Treatment of Critically Ill Patients with Documented Extended-Spectrum Beta-Lactamase-Producing Enterobacterales Bloodstream Infections and/or Ventilator-Associated Pneumonia?

(1) Background: Piperacillin-tazobactam represents the first-line option for treating infections caused by full- or multi-susceptible Enterobacterales and/or Pseudomonas aeruginosa in critically ill patients. Several studies reported that attaining aggressive pharmacokinetic/pharmacodynamic (PK/PD) targets with beta-lactams is associated with an improved microbiological/clinical outcome. We aimed to assess the relationship between the joint PK/PD target attainment of continuous infusion (CI) piperacillin-tazobactam and the microbiological/clinical outcome of documented Gram-negative bloodstream infections (BSI) and/or ventilator-associated pneumonia (VAP) of critically ill patients treated with CI piperacillin-tazobactam monotherapy. (2) Methods: Critically ill patients admitted to the general and post-transplant intensive care unit in the period July 2021-September 2023 treated with CI piperacillin-tazobactam monotherapy optimized by means of a real-time therapeutic drug monitoring (TDM)-guided expert clinical pharmacological advice (ECPA) program for documented Gram-negative BSIs and/or VAP were retrospectively retrieved. Steady-state plasma concentrations (Css) of piperacillin and of tazobactam were measured, and the free fractions (f) were calculated according to respective plasma protein binding. The joint PK/PD target was defined as optimal whenever both the piperacillin fCss/MIC ratio was >4 and the tazobactam fCss/target concentration (CT) ratio was > 1 (quasi-optimal or suboptimal whenever only one or none of the two weas achieved, respectively). Multivariate logistic regression analysis was performed for testing variables potentially associated with microbiological outcome. (3) Results: Overall, 43 critically ill patients (median age 69 years; male 58.1%; median SOFA score at baseline 8) treated with CI piperacillin-tazobactam monotherapy were included. Optimal joint PK/PD target was attained in 36 cases (83.7%). At multivariate analysis, optimal attaining of joint PK/PD target was protective against microbiological failure (OR 0.03; 95%CI 0.003-0.27; p = 0.002), whereas quasi-optimal/suboptimal emerged as the only independent predictor of microbiological failure (OR 37.2; 95%CI 3.66-377.86; p = 0.002). (4) Conclusion: Optimized joint PK/PD target attainment of CI piperacillin-tazobactam could represent a valuable strategy for maximizing microbiological outcome in critically ill patients with documented Gram-negative BSI and/or VAP, even when sustained by extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales. In this scenario, implementing a real-time TDM-guided ECPA program may be helpful in preventing failure in attaining optimal joint PK/PD targets among critically ill patients. Larger prospective studies are warranted to confirm our findings.

Efficiency of dosing software using Bayesian forecasting in achieving target antibiotic exposures in critically ill patients, a prospective cohort study

INTRODUCTION

Broad-spectrum antibiotics such as beta-lactams and vancomycin are frequently used to treat critically ill patients, however, a significant number do not achieve target exposures. Therapeutic drug monitoring (TDM) combined with Bayesian forecasting dosing software may improve target attainment in these patients. This study aims to describe the efficiency of dosing software for achieving target exposures of selected beta-lactam antibiotics and vancomycin in critically ill patients.

METHODS

A prospective cohort study was undertaken in an adult intensive care unit (ICU). Patients prescribed vancomycin, piperacillin-tazobactam and meropenem were included if they exhibited a subtherapeutic or supratherapeutic exposure informed by TDM. The dosing software, ID-ODS™, was used to generate dosing recommendations which could be either accepted or rejected by the treating team. Repeat antibiotic TDM were requested to determine if target exposures were achieved.

RESULTS

Between March 2020 and December 2021, 70 were included in the analysis. Software recommendations were accepted for 56 patients (80%) with 50 having repeated antibiotic measurements. Forty-three of the 50 patients (86%) achieved target exposures after one software recommendation, with 3 of the remaining 7 patients achieving target exposures after 2. Forty-seven patients out of the 50 patients (94%) achieved the secondary outcome of clinical cure. There were no antibiotic exposure-related adverse events reported.

CONCLUSION

The use of TDM combined with Bayesian forecasting dosing software increases the efficiency for achieving target antibiotic exposures in the ICU. Clinical trials comparing this approach with other dosing strategies are required to further validate these findings.

Early treatment response to piperacillin/tazobactam in patients with bloodstream infections caused by non-ESBL ampicillin/sulbactam-resistant Escherichia coli: a binational cohort study

PURPOSE

This study aimed to compare treatment outcomes for bloodstream infections (BSI) caused by a piperacillin/tazobactam (PIP/TAZ)-susceptible E. coli among three patient groups: BSI caused by ampicillin/sulbactam (AMP/SLB)-resistant isolates treated with PIP/TAZ, BSI caused by AMP/SLB-sensitive isolates treated with PIP/TAZ, and BSI caused by AMP/SLB-resistant isolates treated with another monotherapy.

METHODS

This retrospective study was conducted in two academic centres in Europe. Adult patients with E. coli BSI were screened from 2014 to 2020. Inclusion criteria were non-ESBL BSI and initial monotherapy for ≥ 72 h. To reduce the expected bias between the patient groups, propensity score matching was performed. The primary outcome was early treatment response after 72 h and required absence of SOFA score increase in ICU/IMC patients, as well as resolution of fever, leukocytosis, and bacteraemia.

RESULTS

Of the 1707 patients screened, 315 (18.5%) were included in the final analysis. Urinary tract infection was the most common source of BSI (54.9%). Monotherapies other than PIP/TAZ were cephalosporins (48.6%), carbapenems (34.3%), and quinolones (17.1%). Enhanced early treatment response rate was detected (p = 0.04) in patients with BSI caused by AMP/SLB-resistant isolates treated with another monotherapy (74.3%) compared to those treated with PIP/TAZ (57.1%), and was mainly driven by the use of cephalosporins and quinolones (p ≤ 0.03). Clinical success, 28-day mortality, and rate of relapsing BSI did not significantly differ between the groups.

CONCLUSIONS

Our study suggests that initial use of PIP/TAZ may be associated with reduced early treatment response in E. coli BSI caused by AMP/SLB-resistant isolates compared to alternative monotherapies.

Efficacy of therapeutic drug monitoring-based antibiotic regimen in critically ill patients: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The efficacy of therapeutic drug monitoring (TDM)-based antimicrobial dosing optimization strategies on pharmacokinetics/pharmacodynamics and specific drug properties for critically ill patients is unclear. Here, we conducted a systematic review and meta-analysis of randomized controlled trials to evaluate the effectiveness of TDM-based regimen in these patients.

METHODS

Articles from three databases were systematically retrieved to identify relevant randomized control studies. Version two of the Cochrane tool for assessing risk of bias in randomized trials was used to assess the risk of bias in studies included in the analysis, and quality assessment of evidence was graded using the Grading of Recommendations Assessment, Development, and Evaluation approach. Primary outcome was the 28-day mortality and secondary outcome were in-hospital mortality, clinical cure, length of stay in the intensive care unit (ICU) and target attainment at day 1 and 3.

RESULTS

In total, 5 studies involving 1011 patients were included for meta-analysis of the primary outcome, of which no significant difference was observed between TDM-based regimen and control groups (risk ratio [RR] 0.94, 95% confidence interval [CI]: 0.77-1.14; I2 = 0%). In-hospital mortality (RR 0.96, 95% CI: 0.76-1.20), clinical cure (RR 1.23, 95% CI: 0.91-1.67), length of stay in the ICU (mean difference 0, 95% CI: - 2.18-2.19), and target attainment at day 1 (RR 1.14, 95% CI: 0.88-1.48) and day 3 (RR 1.35, 95% CI: 0.90-2.03) were not significantly different between the two groups, and all evidence for the secondary outcomes had a low or very low level of certainty because the included studies had serious risk of bias, variation of definition for outcomes, and small sample sizes.

CONCLUSION

TDM-based regimens had no significant efficacy for clinical or pharmacological outcomes. Further studies with other achievable targets and well-defined outcomes are required.

TRIAL REGISTRATION

Clinical trial registration; PROSPERO ( https://www.crd.york.ac.uk/prospero/ ), registry number: CRD 42022371959. Registered 24 November 2022.

Practical considerations for individualizing drug dosing in critically ill adults receiving renal replacement therapy

Critically ill patients with sepsis admitted to the intensive care unit (ICU) often present with or develop renal dysfunction requiring renal replacement therapy (RRT) in addition to antimicrobial therapy. While early and appropriate antimicrobials for sepsis have been associated with an increased probability of survival, adequate dosing is also required in these patients. Adequate dosing of antimicrobials refers to dosing strategies that achieve serum drug levels at the site of infection that are able to provide a microbiological and/or clinical response while avoiding toxicity from excessive antibiotic exposure. Therapeutic drug monitoring (TDM) is the recommended strategy to achieve this goal, however, TDM is not routinely available in all ICUs and for all antimicrobials. In the absence of TDM, clinicians are therefore required to make dosing decisions based on the clinical condition of the patient, the causative organism, the characteristics of RRT, and an understanding of the physicochemical properties of the antimicrobial. Pharmacokinetics (PK) of antimicrobials can be highly variable between critically ill patients and also within the same patient over the course of their ICU stay. The initiation of RRT, which can be in the form of intermittent hemodialysis, continuous, or prolonged intermittent therapy, further complicates the predictability of drug disposition. This variability highlights the need for individualized dosing. This review highlights the practical considerations for the clinician for antimicrobial dosing in critically ill patients receiving RRT.

Adequacy of cefepime concentrations in the early phase of critical illness: A case for precision pharmacotherapy

STUDY OBJECTIVE

In critically ill patients, adequacy of early antibiotic exposure has been incompletely evaluated. This study characterized factors associated with inadequate cefepime exposure in the first 24 h of critical illness.

DESIGN

Prospective cohort study.

SETTING

Academic Medical Center.

PATIENTS

Critically ill adults treated with cefepime. Patients with acute kidney injury or treated with kidney replacement therapy or extracorporeal membrane oxygenation were excluded.

INTERVENTION

None.

MEASUREMENTS

A nonlinear mixed-effects pharmacokinetic (PK) model was developed to estimate cefepime concentrations for each patient over time. The percentage of time the free drug concentration exceeded 8 mg/L during the first 24 h of therapy was calculated (%ƒT>8; appropriate for the susceptible breakpoint for Pseudomonas aeruginosa). Factors predictive of low %ƒT>8 were explored with multivariable regression.

MAIN RESULTS

In the 100 included patients, a one-compartment PK model was developed with first-order elimination with covariates for weight and estimated glomerular filtration rate based on creatinine and cystatin C (eGFRSCr-CysC). The median (interquartile range) %ƒT>8 for cefepime in the first 24 h of therapy based on this model was 85% (66%, 100%). Less than 100% ƒT>8 during first 24 h of therapy occurred in 70 (70%) individuals. Lower Sequential Organ Failure Assessment score (p = 0.032) and higher eGFRSCr-CysC (p < 0.001) predicted a lower %ƒT>8. Central nervous system infection source was protective (i.e., associated with a higher %ƒT>8; p = 0.008).

CONCLUSIONS

During early critical illness, cefepime concentrations were inadequate in a significant proportion of patients. Antimicrobial optimization is needed to improve the precision of pharmacotherapy in the critically ill patients.

Cefepime Daily Exposure and the Associated Impact on the Change in Sequential Organ Failure Assessment Scores and Vasopressors Requirement in Critically Ill Patients Using Repeated-Measures Mixed-Effect Modeling

IMPORTANCE

Sepsis and septic shock are major healthcare problems that need early and appropriate management.

OBJECTIVES

To evaluate the association of daily cefepime pharmacokinetic/pharmacodynamic (PK/PD) parameters with change in Sequential Organ Failure Assessment (SOFA) score and vasopressors requirement.

DESIGN SETTING AND PARTICIPANTS

This is a retrospective study. Adult ICU patients who received cefepime for Gram-negative pneumonia or bloodstream infection (BSI) and had cefepime concentrations measured were included. Daily cefepime exposure was generated and PK/PD parameters calculated for patients. Repeated-measures mixed-effect modeling was used to evaluate the impact of PK/PD on the outcomes.

MAIN OUTCOMES AND MEASURES

Change in daily SOFA score and vasopressors requirement.

RESULTS

A total of 394 and 207 patients were included in the SOFA and vasopressors analyses, respectively. The mean (±sd) age was 55 years (19) and weight 81 kg (29). For the change in SOFA score, daily SOFA score, mechanical ventilation, renal replacement therapy, and number of vasopressors were included. In the vasopressors analysis, daily SOFA score, day of therapy, and hydrocortisone dose were significant covariates in the final model. Achieving cefepime concentrations above the minimum inhibitory concentration (MIC) (T>MIC) for 100% of the dosing interval was associated with 0.006 µg/kg/min decrease in norepinephrine-equivalent dose. Cefepime PK/PD did not have an impact on the daily change in SOFA score.

CONCLUSIONS AND RELEVANCE

Achieving 100% T>MIC was associated with negligible decrease in vasopressors requirement in ICU patients with Gram-negative pneumonia and BSI. There was no impact on the change in SOFA score.

Dimethyl Fumarate Protects against Lipopolysaccharide- (LPS-) Induced Sepsis through Inhibition of NF-κB Pathway in Mice

Sepsis is one of the most severe complications and causes of mortality in the clinic. It remains a great challenge with no effective treatment for clinicians worldwide. Inhibiting the release of proinflammatory cytokines during sepsis is considered as an important strategy for treating sepsis and improving survival. In the present study, we have observed the effect of dimethyl fumarate (DMF) on lipopolysaccharide- (LPS-) induced sepsis and investigated the possible mechanism. By screening a subset of the Johns Hopkins Drug Library, we identified DMF as a novel inhibitor of nitric oxide synthesis in LPS-stimulated RAW264.7 cells, suggesting that DMF could be a potential drug to treat sepsis. To further characterize the effect of DMF on LPS signaling, TNF-α, MCP-1, G-CMF, and IL-6 expression levels were determined by using cytokine array panels. In addition, an endotoxemia model with C57BL/6 mice was used to assess the in vivo efficacy of DMF on sepsis. The survival rate was assessed, and HE staining was performed to investigate histopathological damage to the organs. DMF was found to increase the survival of septic mice by 50% and attenuate organ damage, consistent with the reduction in IL-10, IL-6, and TNF-α (inflammatory cytokines) in serum. In vitro experiments revealed DMF's inhibitory effect on the phosphorylation of p65, IκB, and IKK, suggesting that the primary inhibitory effects of DMF can be attributed, at least in part, to the inhibition of phosphorylation of IκBα, IKK as well as nuclear factor-κB (NF-κB) upon LPS stimulation. The findings demonstrate that DMF dramatically inhibits NO and proinflammatory cytokine production in response to LPS and improves survival in septic mice, raising the possibility that DMF has the potential to be repurposed as a new treatment of sepsis.

The clinical application of beta-lactam antibiotic therapeutic drug monitoring in the critical care setting

Critically ill patients have increased variability in beta-lactam antibiotic (beta-lactam) exposure due to alterations in their volume of distribution and elimination. Therapeutic drug monitoring (TDM) of beta-lactams, as a dose optimization and individualization tool, has been recommended to overcome this variability in exposure. Despite its potential benefit, only a few centres worldwide perform beta-lactam TDM. An important reason for the low uptake is that the evidence for clinical benefits of beta-lactam TDM is not well established. TDM also requires the availability of specific infrastructure, knowledge and expertise. Observational studies and systematic reviews have demonstrated that TDM leads to an improvement in achieving target concentrations, a reduction in potentially toxic concentrations and improvement of clinical and microbiological outcomes. However, a small number of randomized controlled trials have not shown a mortality benefit. Opportunities for improved study design are apparent, as existing studies are limited by their inclusion of heterogeneous patient populations, including patients that may not even have infection, small sample size, variability in the types of beta-lactams included, infections caused by highly susceptible bacteria, and varied sampling, analytical and dosing algorithm methods. Here we review the fundamentals of beta-lactam TDM in critically ill patients, the existing clinical evidence and the practical aspects involved in beta-lactam TDM implementation.

Developing a Method for Quantifying Meropenem in Children-Volumetric Adsorptive Microsampling Versus Plasma Sampling

BACKGROUND

Meropenem is a carbapenem antibiotic often used in pediatric intensive care units due to its broad spectrum of activity. Therapeutic drug monitoring (TDM) is a useful tool to increase the effectiveness of meropenem by adjusting the dose based on plasma levels; however, the relatively large sample volume required for TDM can limit its use in children. Therefore, this study aimed to determine meropenem concentrations and consequently perform TDM effectively using the smallest possible sample volume. Volumetric absorptive microsampling (VAMS) is a sampling technology developed to collect a small, precise volume of blood. For the applicability of VAMS in TDM, plasma concentrations must be reliably calculated from whole blood (WB) collected by VAMS.

METHODS

VAMS technology using 10 µL of WB was evaluated and compared with EDTA-plasma sampling. High-performance liquid chromatography with UV detection was applied to quantify meropenem in VAMS and plasma samples after the removal of proteins by precipitation. Ertapenem was used as the internal standard. Samples were collected simultaneously from critically ill children receiving meropenem using VAMS and traditional sampling.

RESULTS

It was found that no consistent factor could be determined to calculate meropenem plasma concentrations from the WB, indicating that VAMS was not reliable in the TDM of meropenem. Therefore, to reduce the required sample amount in pediatric patients, a method for quantifying meropenem from 50 µL of plasma with a lower limit of quantification of 1 mg/L was developed and successfully validated.

CONCLUSIONS

A simple, reliable, and low-cost method was established using high-performance liquid chromatography-UV to determine the concentration of meropenem in 50 µL of plasma. VAMS using WB does not seem to be suitable for TDM of meropenem.

Which patients benefit from model-informed precision dosing of beta-lactam antibiotics and ciprofloxacin at the ICU?

OBJECTIVES

Antibiotic dosing is not optimal in the ICU. Our recent trial investigated the effect of model-informed precision dosing (MIPD) of beta-lactam antibiotics and ciprofloxacin and showed no significant differences in clinical outcomes in all patients. This study aimed to identify subgroups of patients in which the MIPD of these antibiotics could be beneficial for clinical outcomes.

METHODS

We analysed data from the DOLPHIN randomized controlled trial, which compared MIPD to standard dosing of beta-lactam antibiotics and ciprofloxacin in 388 ICU patients. We divided patients into subgroups based on baseline characteristics and assessed the effect of MIPD on 28-day mortality, 6-month mortality, change in sequential organ failure assessment (delta-SOFA), and ICU length of stay (LOS).

RESULTS

We found a lower 28-day mortality in patients with a SOFA below 8 randomized to MIPD (OR 0.40; 95% CI 0.17-0.88). However, patients with a higher SOFA show an increased 28-day mortality (OR 1.94; 95% CI 1.07-3.59) in the MIPD group. ICU LOS was increased in patients receiving MIPD with a SOFA below 8 (IRR 1.36; 95% CI 1.01-1.83) and those receiving MIPD for ceftriaxone (IRR 1.76; 95% CI 1.24-2.51). Patients receiving a dose recommendation within 24 hours show a trend towards decreased ICU LOS (IRR 0.77; 95% CI 0.52-1.16) and higher delta-SOFA (estimate -1.19; 95% CI -2.98-0.60).

CONCLUSIONS

ICU patients with a SOFA below 8 using MIPD had an increased ICU LOS but a lower 28-day mortality. Fast dose recommendations using MIPD of beta-lactam antibiotics and ciprofloxacin needs to be investigated in ICU patients.

[The current sepsis guidelines-What do you need to know?]

The current international sepsis guidelines from 2021 are based on the work of a panel of 60 international experts from various fields. They include a total of 93 recommendations, some of which include new aspects compared to the 2016 version of the guidelines. This article provides a subjective compilation by two internal medicine intensivists who highlight some aspects, especially of changes within the guidelines compared to the previous version. The focus is on the fields of screening, sepsis bundles, fluid and vasopressor treatment and adjuvant treatment. In addition, for the first time these guidelines address the important issue of long-term sequelae for sepsis survivors and their environment.

High dose esomeprazole as an anti-inflammatory agent in sepsis: Protocol for a randomized controlled trial

BACKGROUND

Sepsis is caused by dysregulated immune responses due to infection and still presents high mortality rate and limited efficacious therapies, apart from antibiotics. Recent evidence suggests that very high dose proton pump inhibitors might regulate major sepsis mediators' secretion by monocytes, which might attenuate excessive host reactions and improve clinical outcomes. This effect is obtained with doses which are approximately 50 times higher than prophylactic esomeprazole single daily administration and 17 times higher than the cumulative dose of a three day prophylaxis. We aim to perform a randomized trial to investigate if high dose esomeprazole reduces organ dysfunction in patients with sepsis or septic shock.

METHODS

This study, called PPI-SEPSIS, is a multicenter, randomized, double blind, placebo-controlled clinical trial on critically ill septic patients admitted to the emergency department or intensive care unit. A total of 300 patients will be randomized to receive high dose esomeprazole (80 mg bolus followed by 12 mg/h for 72 h and a second 80 mg bolus 12 h after the first one) or equivolume placebo (sodium chloride 0.9%), with 1:1 allocation. The primary endpoint of the study will be mean daily Sequential Organ Failure Assessment (SOFA) score over 10 days. Secondary outcomes will include antibiotic-free days, single organ failure severity, intensive care unit-free days at day 28, and mortality.

DISCUSSION

This trial aims to test the efficacy of high dose esomeprazole to reduce acute organ dysfunction in patients with septic shock.

TRIAL REGISTRATION

This trial was registered on ClinicalTrials.gov with the trial identification NCT03452865 in March 2018.

The efficacy of dexmedetomidine for septic shock: A meta-analysis of randomized controlled trials

INTRODUCTION

The efficacy of dexmedetomidine was elusive for septic shock. This meta-analysis aimed to explore the efficacy of dexmedetomidine for septic shock.

METHODS

PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases have been searched through October 2022 and we included randomized controlled trials reporting the effect of dexmedetomidine in patients with septic shock.

RESULTS

Five randomized controlled trials were included in the meta-analysis. Compared with control group for septic shock, dexmedetomidine treatment was able to substantially decrease Sequential Organ Failure Assessment score (mean difference [MD] = -0.99; 95% confidence interval [CI] = -1.14 to -0.84; P < .00001) and duration of mechanical ventilation (MD = -0.90; 95% CI = -1.27 to -0.54; P < .00001), but showed no obvious influence on morality at 28 days (odds ratio = 0.79; 95% CI = 0.38 to 1.66; P = 054), hospital mortality (odds ratio = 0.66; 95% CI = 0.35 to 1.24; P = .20) or intensive care unit length of stay (MD = -1.47; 95% CI = -4.60 to 1.66; P = .36).

CONCLUSIONS

Dexmedetomidine administration may help treat patients with septic shock.

Pharmacokinetic/Pharmacodynamic Target Attainment of Continuous Infusion Piperacillin-Tazobactam or Meropenem and Microbiological Outcome among Urologic Patients with Documented Gram-Negative Infections

(1) Objectives: To describe the relationship between pharmacokinetic/pharmacodynamic (PK/PD) target attainment of continuous infusion (CI) piperacillin-tazobactam or meropenem monotherapy and microbiological outcome in a case series of urological patients with documented Gram-negative infections. (2) Methods: Patients admitted to the urology ward who were treated with CI piperacillin-tazobactam or meropenem monotherapy for documented Gram-negative infections and underwent real-time therapeutic drug monitoring (TDM)-guided expert clinical pharmacological advice (ECPA) program from June 2021 to May 2023 were retrospectively retrieved. Average steady-state (Css) piperacillin-tazobactam and meropenem concentrations were determined, and the free fractions (fCss) were calculated. Optimal PK/PD target attainments were defined as an fCss/MIC ratio >4 for CI meropenem and an fCss/MIC ratio of piperacillin >4 coupled with an fCss/CT ratio for tazobactam >1 for piperacillin-tazobactam (joint PK/PD target). The relationship between beta-lactam PK/PD targets and microbiological outcome was explored. (3) Results: Sixteen urologic patients with documented Gram-negative infections (62.5% complicated urinary tract infections (cUTI)) had 30 TDM-guided ECPAs. At first TDM assessment, beta-lactam dosing adjustments were recommended in 11 out of 16 cases (68.75%, of which 62.5% decreases and 6.25% increases). Overall, beta-lactam dosing adjustments were recommended in 14 out of 30 ECPAs (46.6%). Beta-lactam PK/PD target attainments were optimal in 100.0% of cases. Microbiological failure occurred in two patients, both developing beta-lactam resistance. (4) Conclusion: A TDM-guided ECPA program may allow for optimizing beta-lactam treatment in urologic patients with documented Gram-negative infections, ensuring microbiological eradication in most cases.

'How to' Guide for Pharmacist-led Implementation of Beta-Lactam Therapeutic Drug Monitoring in the Critically Ill

Beta-lactam therapeutic drug monitoring (TDM) can improve precision dosing and clinical outcomes in critically ill patients, but has not been implemented widely in the United States. Mayo Clinic recently implemented a beta-lactam TDM program. This single-center experience forms the basis of the manuscript which outlines practical considerations involved with implementation, including the pharmacist's role as a leader. Our implementation effort focused on three primary domains. First, we aimed to ensure a supportive organizational infrastructure. Early leadership engagement by the pharmacist-led core team facilitated advocacy for the clinical need, allocation of resources, and assay development. Second, core clinical workflows were developed that addressed the preferred patient population for use, desirable pharmacokinetic and pharmacodynamic targets, and the preferred sampling strategy. Clinical tools to guide pharmacists in interpreting the results (e.g., pharmacokinetics calculator) and documenting decisions were developed. Third, stakeholders were offered repeated exposure to evidence and expertise to facilitate understanding and application of the new practice. This act of 'individual internalization' seems to be uniquely important to beta-lactam TDM implementation compared with implementation of other antimicrobial TDM programs. Educational strategies and supportive materials that were developed were focused on providing substantive and varied information tailored to the stakeholders' role in the process. For pharmacists, this included both clinical and operational considerations. A continuous improvement plan to support management of the process was instituted to address necessary updates and changes that inevitably emerged. In summary, the described approach to implementation of a pharmacist led beta-lactam TDM program could be used as a roadmap to aid other institutions that aim to develop such a program.

Why is the Implementation of Beta-Lactam Therapeutic Drug Monitoring for the Critically Ill Falling Short? A Multicenter Mixed-Methods Study

BACKGROUND

Beta-lactam therapeutic drug monitoring (BL TDM; drug level testing) can facilitate improved outcomes in critically ill patients. However, only 10%-20% of hospitals have implemented BL TDM. This study aimed to characterize provider perceptions and key considerations for successfully implementing BL TDM.

METHODS

This was a sequential mixed-methods study from 2020 to 2021 of diverse stakeholders at 3 academic medical centers with varying degrees of BL TDM implementation (not implemented, partially implemented, and fully implemented). Stakeholders were surveyed, and a proportion of participants completed semistructured interviews. Themes were identified, and findings were contextualized with implementation science frameworks.

RESULTS

Most of the 138 survey respondents perceived that BL TDM was relevant to their practice and improved medication effectiveness and safety. Integrated with interview data from 30 individuals, 2 implementation themes were identified: individual internalization and organizational features. Individuals needed to internalize, make sense of, and agree to BL TDM implementation, which was positively influenced by repeated exposure to evidence and expertise. The process of internalization appeared more complex with BL TDM than with other antibiotics (ie, vancomycin). Organizational considerations relevant to BL TDM implementation (eg, infrastructure, personnel) were similar to those identified in other TDM settings.

CONCLUSIONS

Broad enthusiasm for BL TDM among participants was found. Prior literature suggested that assay availability was the primary barrier to implementation; however, the data revealed many more individual and organizational attributes, which impacted the BL TDM implementation. Internalization should particularly be focused on to improve the adoption of this evidence-based practice.

Towards model-informed precision dosing of piperacillin: multicenter systematic external evaluation of pharmacokinetic models in critically ill adults with a focus on Bayesian forecasting

PURPOSE

Inadequate piperacillin (PIP) exposure in intensive care unit (ICU) patients threatens therapeutic success. Model-informed precision dosing (MIPD) might be promising to individualize dosing; however, the transferability of published models to external populations is uncertain. This study aimed to externally evaluate the available PIP population pharmacokinetic (PopPK) models.

METHODS

A multicenter dataset of 561 ICU patients (11 centers/3654 concentrations) was used for the evaluation of 24 identified models. Model performance was investigated for a priori (A) predictions, i.e., considering dosing records and patient characteristics only, and for Bayesian forecasting, i.e., additionally including the first (B1) or first and second (B2) therapeutic drug monitoring (TDM) samples per patient. Median relative prediction error (MPE) [%] and median absolute relative prediction error (MAPE) [%] were calculated to quantify accuracy and precision.

RESULTS

The evaluation revealed a large inter-model variability (A: MPE - 135.6-78.3% and MAPE 35.7-135.6%). Integration of TDM data improved all model predictions (B1/B2 relative improvement vs. A: |MPE|median_all_models 45.1/67.5%; MAPEmedian_all_models 29/39%). The model by Kim et al. was identified to be most appropriate for the total dataset (A/B1/B2: MPE - 9.8/- 5.9/- 0.9%; MAPE 37/27.3/23.7%), Udy et al. performed best in patients receiving intermittent infusion, and Klastrup et al. best predicted patients receiving continuous infusion. Additional evaluations stratified by sex and renal replacement therapy revealed further promising models.

CONCLUSION

The predictive performance of published PIP models in ICU patients varied considerably, highlighting the relevance of appropriate model selection for MIPD. Our differentiated external evaluation identified specific models suitable for clinical use, especially in combination with TDM.

Rationale and evidence for the use of new beta-lactam/beta-lactamase inhibitor combinations and cefiderocol in critically ill patients

BACKGROUND

Healthcare-associated infections involving Gram-negative bacteria (GNB) with difficult-to-treat resistance (DTR) phenotype are associated with impaired patient-centered outcomes and poses daily therapeutic challenges in most of intensive care units worldwide. Over the recent years, four innovative β-lactam/β-lactamase inhibitor (BL/BLI) combinations (ceftolozane-tazobactam, ceftazidime-avibactam, imipenem-relebactam and meropenem-vaborbactam) and a new siderophore cephalosporin (cefiderocol) have been approved for the treatment of certain DTR-GNB infections. The literature addressing their microbiological spectrum, pharmacokinetics, clinical efficacy and safety was exhaustively audited by our group to support the recent guidelines of the French Intensive Care Society on their utilization in critically ill patients. This narrative review summarizes the available evidence and unanswered questions on these issues.

METHODS

A systematic search for English-language publications in PUBMED and the Cochrane Library database from inception to November 15, 2022.

RESULTS

These drugs have demonstrated relevant clinical success rates and a reduced renal risk in most of severe infections for whom polymyxin- and/or aminoglycoside-based regimen were historically used as last-resort strategies-namely, ceftazidime-avibactam for infections due to Klebsiella pneumoniae carbapenemase (KPC)- or OXA-48-like-producing Enterobacterales, meropenem-vaborbactam for KPC-producing Enterobacterales, ceftazidime-avibactam/aztreonam combination or cefiderocol for metallo-β-lactamase (MBL)-producing Enterobacterales, and ceftolozane-tazobactam, ceftazidime-avibactam and imipenem-relebactam for non-MBL-producing DTR Pseudomonas aeruginosa. However, limited clinical evidence exists in critically ill patients. Extended-infusion scheme (except for imipenem-relebactam) may be indicated for DTR-GNB with high minimal inhibitory concentrations and/or in case of augmented renal clearance. The potential benefit of combining these agents with other antimicrobials remains under-investigated, notably for the most severe presentations. Other important knowledge gaps include pharmacokinetic information in particular situations (e.g., pneumonia, other deep-seated infections, and renal replacement therapy), the hazard of treatment-emergent resistance and possible preventive measures, the safety of high-dose regimen, the potential usefulness of rapid molecular diagnostic tools to rationalize their empirical utilization, and optimal treatment durations. Comparative clinical, ecological, and medico-economic data are needed for infections in whom two or more of these agents exhibit in vitro activity against the causative pathogen.

CONCLUSIONS

New BL/BLI combinations and cefiderocol represent long-awaited options for improving the management of DTR-GNB infections. Several research axes must be explored to better define the positioning and appropriate administration scheme of these drugs in critically ill patients.

Beta-Lactam Dose Optimisation in the Intensive Care Unit: Targets, Therapeutic Drug Monitoring and Toxicity

Beta-lactams are an important family of antibiotics used to treat infections and are commonly used in critically ill patients. Optimal use of these drugs in the intensive care unit (ICU) is important because of the serious complications from sepsis. Target beta-lactam antibiotic exposures may be chosen using fundamental principles of beta-lactam activity derived from pre-clinical and clinical studies, although the debate regarding optimal beta-lactam exposure targets is ongoing. Attainment of target exposures in the ICU requires overcoming significant pharmacokinetic (PK) and pharmacodynamic (PD) challenges. For beta-lactam drugs, the use of therapeutic drug monitoring (TDM) to confirm if the desired exposure targets are achieved has shown promise, but further data are required to determine if improvement in infection-related outcomes can be achieved. Additionally, beta-lactam TDM may be useful where a relationship exists between supratherapeutic antibiotic exposure and drug adverse effects. An ideal beta-lactam TDM service should endeavor to efficiently sample and report results in identified at-risk patients in a timely manner. Consensus beta-lactam PK/PD targets associated with optimal patient outcomes are lacking and should be a focus for future research.

Antibiotic stewardship in the ICU: time to shift into overdrive

Antibiotic resistance is a major health problem and will be probably one of the leading causes of deaths in the coming years. One of the most effective ways to fight against resistance is to decrease antibiotic consumption. Intensive care units (ICUs) are places where antibiotics are widely prescribed, and where multidrug-resistant pathogens are frequently encountered. However, ICU physicians may have opportunities to decrease antibiotics consumption and to apply antimicrobial stewardship programs. The main measures that may be implemented include refraining from immediate prescription of antibiotics when infection is suspected (except in patients with shock, where immediate administration of antibiotics is essential); limiting empiric broad-spectrum antibiotics (including anti-MRSA antibiotics) in patients without risk factors for multidrug-resistant pathogens; switching to monotherapy instead of combination therapy and narrowing spectrum when culture and susceptibility tests results are available; limiting the use of carbapenems to extended-spectrum beta-lactamase-producing Enterobacteriaceae, and new beta-lactams to difficult-to-treat pathogen (when these news beta-lactams are the only available option); and shortening the duration of antimicrobial treatment, the use of procalcitonin being one tool to attain this goal. Antimicrobial stewardship programs should combine these measures rather than applying a single one. ICUs and ICU physicians should be at the frontline for developing antimicrobial stewardship programs.

Pathogen-based target attainment of optimized continuous infusion dosing regimens of piperacillin-tazobactam and meropenem in surgical ICU patients: a prospective single center observational study

BACKGROUND

Several studies have indicated that commonly used piperacillin-tazobactam (TZP) and meropenem (MEM) dosing regimens lead to suboptimal plasma concentrations for a range of pharmacokinetic/pharmacodynamic (PK/PD) targets in intensive care unit (ICU) patients. These targets are often based on a hypothetical worst-case scenario, possibly overestimating the percentage of suboptimal concentrations. We aimed to evaluate the pathogen-based clinically relevant target attainment (CRTA) and therapeutic range attainment (TRA) of optimized continuous infusion dosing regimens of TZP and MEM in surgical ICU patients.

METHODS

A single center prospective observational study was conducted between March 2016 and April 2019. Free plasma concentrations were calculated by correcting total plasma concentrations, determined on remnants of blood gas samples by ultra-performance liquid chromatography with tandem mass spectrometry, for their protein binding. Break points (BP) of identified pathogens were derived from epidemiological cut-off values. CRTA was defined as a corrected measured total serum concentration above the BP and calculated for increasing BP multiplications up to 6 × BP. The upper limit of the therapeutic range was set at 157.2 mg/L for TZP and 45 mg/L for MEM. As a worst-case scenario, a BP of 16 mg/L for TZP and 2 mg/L for MEM was used.

RESULTS

781 unique patients were included with 1036 distinctive beta-lactam antimicrobial prescriptions (731 TZP, 305 MEM) for 1003 unique infections/prophylactic regimens (750 TZP, 323 MEM). 2810 samples were available (1892 TZP, 918 MEM). The median corrected plasma concentration for TZP was 86.4 mg/L [IQR 56.2-148] and 16.2 mg/L [10.2-25.5] for MEM. CRTA and TRA was consistently higher for the pathogen-based scenario than for the worst-case scenario, but nonetheless, a substantial proportion of samples did not attain commonly used PK/PD targets.

CONCLUSION

Despite these pathogen-based data demonstrating that CRTA and TRA is higher than in the often-used theoretical worst-case scenario, a substantial proportion of samples did not attain commonly used PK/PD targets when using optimised continuous infusion dosing regimens. Therefore, more dosing optimization research seems warranted. At the same time, a 'pathogen-based analysis' approach might prove to be more sensible than a worst-case scenario approach when evaluating target attainment and linked clinical outcomes.