Timing of antimicrobial therapy after identification of ventilator-associated condition is not associated with mortality in patients with ventilator-associated pneumonia: a cohort study

Cefiderocol for treating severe aerobic Gram-negative bacterial infections: technology evaluation to inform a novel subscription-style payment model

Background

To limit the use of antimicrobials without disincentivising the development of novel antimicrobials, there is interest in establishing innovative models that fund antimicrobials based on an evaluation of their value as opposed to the volumes used. The aim of this project was to evaluate the population-level health benefit of cefiderocol in the NHS in England, for the treatment of severe aerobic Gram-negative bacterial infections when used within its licensed indications. The results were used to inform the National Institute for Health and Care Excellence guidance in support of commercial discussions regarding contract value between the manufacturer and NHS England.

Methods

The health benefit of cefiderocol was first derived for a series of high-value clinical scenarios. These represented uses that were expected to have a significant impact on patients' mortality risks and health-related quality of life. The clinical effectiveness of cefiderocol relative to its comparators was estimated by synthesising evidence on susceptibility of the pathogens of interest to the antimicrobials in a network meta-analysis. Patient-level costs and health outcomes of cefiderocol under various usage scenarios compared with alternative management strategies were quantified using decision modelling. Results were reported as incremental net health effects expressed in quality-adjusted life-years, which were scaled to 20-year population values using infection number forecasts based on data from Public Health England. The outcomes estimated for the high-value clinical scenarios were extrapolated to other expected uses for cefiderocol.

Results

Among Enterobacterales isolates with the metallo-beta-lactamase resistance mechanism, the base-case network meta-analysis found that cefiderocol was associated with a lower susceptibility relative to colistin (odds ratio 0.32, 95% credible intervals 0.04 to 2.47), but the result was not statistically significant. The other treatments were also associated with lower susceptibility than colistin, but the results were not statistically significant. In the metallo-beta-lactamase Pseudomonas aeruginosa base-case network meta-analysis, cefiderocol was associated with a lower susceptibility relative to colistin (odds ratio 0.44, 95% credible intervals 0.03 to 3.94), but the result was not statistically significant. The other treatments were associated with no susceptibility. In the base case, patient-level benefit of cefiderocol was between 0.02 and 0.15 quality-adjusted life-years, depending on the site of infection, the pathogen and the usage scenario. There was a high degree of uncertainty surrounding the benefits of cefiderocol across all subgroups. There was substantial uncertainty in the number of infections that are suitable for treatment with cefiderocol, so population-level results are presented for a range of scenarios for the current infection numbers, the expected increases in infections over time and rates of emergence of resistance. The population-level benefits varied substantially across the base-case scenarios, from 896 to 3559 quality-adjusted life-years over 20 years.

Conclusion

This work has provided quantitative estimates of the value of cefiderocol within its areas of expected usage within the NHS.

Limitations

Given existing evidence, the estimates of the value of cefiderocol are highly uncertain.

Future work

Future evaluations of antimicrobials would benefit from improvements to NHS data linkages; research to support appropriate synthesis of susceptibility studies; and application of routine data and decision modelling to assess enablement value.

Study registration

No registration of this study was undertaken.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment Policy Research Programme (NIHR award ref: NIHR135591), conducted through the Policy Research Unit in Economic Methods of Evaluation in Health and Social Care Interventions, PR-PRU-1217-20401, and is published in full in Health Technology Assessment; Vol. 28, No. 28. See the NIHR Funding and Awards website for further award information.

Antibiotic Initiation Timing and Mortality in Trauma Patients With Ventilator-Associated Pneumonia

BACKGROUND

Early antibiotic initiation is considered a cornerstone in the management of ventilator-associated pneumonia (VAP). However, recent data suggests that early antibiotic initiation may not be necessary in all cases. Additionally, the benefits of early antibiotic administration for infection have not been studied in a dedicated trauma population. This study's aim was to evaluate the impact of antibiotic administration timing on in-hospital mortality in trauma patients with VAP.

METHODS

This retrospective case-control study identified all trauma patients at a single level 1 academic trauma center from 2016 to 2020. Patients with a TQIP-defined VAP were included and stratified into 2 subgroups by in-hospital mortality. Time interval between airway culture and antibiotic initiation was gathered. Baseline measures of injury and illness severity were collected. Univariate analysis of the data was performed.

RESULTS

Forty-five patients met inclusion criteria. Overall, 80% of patients survived admission (n = 36) and 20% of patients did not survive admission (n = 9). There were no significant differences in baseline characteristics or cultured organism between survivors and non-survivors. The median time interval between airway culture and antibiotic initiation was 2 hours (IQR 0-4.5) for survivors, and 0 hours (IQR 0-0) for non-survivors (P = .07). Antibiotics were administered within 1 hour of airway culture for 33.3% of survivors, and 77.8% of non-survivors (P = .02).

CONCLUSIONS

In a population of trauma patients with VAP, survivors had antibiotics initiated in more delayed fashion than non-survivors. These findings question the primacy of early antibiotic administration for suspected infection.

Clinical Features and Outcomes of Monobacterial and Polybacterial Episodes of Ventilator-Associated Pneumonia Due to Multidrug-Resistant Acinetobacter baumannii

Multidrug-resistant A. baumannii (MDRAB) VAP has high morbidity and mortality, and the rates are constantly increasing globally. Mono- and polybacterial MDRAB VAP might differ, including outcomes. We conducted a single-center, retrospective (January 2014−December 2016) study in the four ICUs (12−18−24 beds each) of a reference Lithuanian university hospital, aiming to compare the clinical features and the 30-day mortality of monobacterial and polybacterial MDRAB VAP episodes. A total of 156 MDRAB VAP episodes were analyzed: 105 (67.5%) were monomicrobial. The 30-day mortality was higher (p < 0.05) in monobacterial episodes: overall (57.1 vs. 37.3%), subgroup with appropriate antibiotic therapy (50.7 vs. 23.5%), and subgroup of XDR A. baumannii (57.3 vs. 36.4%). Monobacterial MDRAB VAP was associated (p < 0.05) with Charlson comorbidity index ≥3 (67.6 vs. 47.1%), respiratory comorbidities (19.0 vs. 5.9%), obesity (27.6 vs. 9.8%), prior hospitalization (58.1 vs. 31.4%), prior antibiotic therapy (99.0 vs. 92.2%), sepsis (88.6 vs. 76.5%), septic shock (51.9 vs. 34.6%), severe hypoxemia (23.8 vs. 7.8%), higher leukocyte count on VAP onset (median [IQR] 11.6 [8.4−16.6] vs. 10.9 [7.3−13.4]), and RRT need during ICU stay (37.1 vs. 17.6%). Patients with polybacterial VAP had a higher frequency of decreased level of consciousness (p < 0.05) on ICU admission (29.4 vs. 14.3%) and on VAP onset (29.4 vs. 11.4%). We concluded that monobacterial MDRAB VAP had different demographic/clinical characteristics compared to polybacterial and carried worse outcomes. These important findings need to be validated in a larger, prospective study, and the management implications to be further investigated.

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

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

Antibiotics in the first hour: is there new evidence?

INTRODUCTION

International guidelines have recommended for many years to start antimicrobials as early as possible in sepsis and shock. This concept has been challenged by the controversial results of experimental studies and clinical cohorts and resulted in intense debate in the literature. This review aims to summarize the available knowledge on early antimicrobial therapy and to consider perspectives.

AREAS COVERED

First, after a research using MEDLINE, we reviewed the studies that advocated the implementation of early antimicrobial therapy. We then discussed the drawbacks of these studies. Finally, we suggested possible explanations of the benefit and then absence of the prognostic impact of early antimicrobial therapy i.e. confounding factors, irreversibility of the inflammatory process, non-control of the source of the infection, pharmacodynamic considerations and the harmful effect of antimicrobial drugs.

EXPERT OPINION

Sepsis is very heterogeneous. The first antimicrobial therapy should be personalized. The sickest patients should be given early antimicrobial therapy, whereas a 'watch and wait process' should be preferred for less severe patients, to allow confirmation of sepsis, identification of pathogens and administration of adequate antimicrobial therapy. We propose steps to personalize the first antimicrobial therapy. New early diagnostic tools will assist the physicians in the future.

A Systematic Review of the Effect of Delayed Appropriate Antibiotic Treatment on the Outcomes of Patients With Severe Bacterial Infections

BACKGROUND

Patients with severe bacterial infections often experience delay in receiving appropriate treatment. Consolidated evidence of the impact of delayed appropriate treatment is needed to guide treatment and improve outcomes.

RESEARCH QUESTION

What is the impact of delayed appropriate antibacterial therapy on clinical outcomes in patients with severe bacterial infections?

STUDY DESIGN AND METHODS

Literature searches of MEDLINE and Embase, conducted on July 24, 2018, identified studies published after 2007 reporting the impact of delayed appropriate therapy on clinical outcomes for hospitalized adult patients with bacterial infections. Where appropriate, results were pooled and analyzed with delayed therapy modeled three ways: delay vs no delay in receiving appropriate therapy; duration of delay; and inappropriate vs appropriate initial therapy. This article reports meta-analyses on the effect of delay and duration of delay.

RESULTS

The eligibility criteria were met by 145 studies, of which 37 contributed data to analyses of effect of delay. Mortality was significantly lower in patients receiving appropriate therapy without delay compared with those experiencing delay (OR, 0.57; 95% CI, 0.45-0.72). Mortality was also lower in the no-delay group compared with the delay group in subgroups of studies reporting mortality at 20 to 30 days, during ICU stay, or in patients with bacteremia (OR, 0.57 [95% CI, 0.43-0.76]; OR, 0.47 [95% CI, 0.27-0.80]; and OR, 0.54 [95% CI, 0.40-0.75], respectively). No difference was found in time to appropriate therapy between those who died and those who survived (P = .09), but heterogeneity between studies was high.

INTERPRETATION

Avoiding delayed appropriate therapy is essential to reduce mortality in patients with severe bacterial infections.

CLINICAL TRIAL REGISTRATION

PROSPERO; No.: CRD42018104669; URL: www.crd.york.ac.uk/prospero/.

When not to start antibiotics: avoiding antibiotic overuse in the intensive care unit

BACKGROUND

Most intensive care unit (ICU) patients receive broad-spectrum antibiotics. While lifesaving in some, in others these treatments may be unnecessary and place patients at risk of antibiotic-associated harms.

OBJECTIVES

To review the literature exploring how we diagnose infection in patients in the ICU and address the safety and utility of a 'watchful waiting' approach to antibiotic initiation with selected patients in the ICU.

SOURCES

A semi-structured search of PubMed and Cochrane Library databases for articles published in English during the past 15 years was conducted.

CONTENT

Distinguishing infection from non-infectious mimics in ICU patients is uniquely challenging. At present, we do not have access to a rapid point-of-care test that reliably differentiates between individuals who need antibiotics and those who do not. A small number of studies have attempted to compare early aggressive versus conservative antimicrobial strategies in the ICU. However, this body of literature is small and not robust enough to guide practice.

IMPLICATIONS

This issue will not likely be resolved until there are diagnostic tests that rapidly and reliably identify the presence or absence of infection in the ICU population. In the meantime, prospective trials that identify clinical situations wherein it is safe to delay or withhold antibiotic initiation in the ICU until the presence of an infection is proven are warranted.

Choosing wisely: what is the actual role of antimicrobial stewardship in Intensive Care Units?

More than two-thirds of critically ill patients receive an antimicrobial therapy with a percentage between 30% and 50% of all prescribed antibiotics reported to be unnecessary, inappropriate or misused. Since inappropriate prescription of antibiotic drugs concurs to dissemination of the multidrug resistant organisms, a reasoned antibiotics use is crucial especially in Intensive Care Unit (ICU), where up to 60% of the admitted patients develops an infection during their ICU stay. Even if the concept of antimicrobial stewardship (AS) has been clearly described as a series of coordinated interventions designed to improve antimicrobial agents use, few studies are reporting about its effectiveness to improve outcomes, reduce adverse events and costs and decrease resistance rate spread. Moreover, although it is recognized that AS programs are particularly indicated in the critical setting due to the huge number of antimicrobial drugs used, the optimal characteristics of these interventions and the best system to evaluate their effectiveness are still unclear. Specific interventions, designed tacking into account the peculiarities of the ICU setting, are hence necessary to set-up an "in-ICU-stewardship," including prompt identification of infected patients, selection of appropriate empiric treatments, optimization of dosing and route of administration, improvement of diagnostic techniques, early de-escalation to achieve shorter duration and avoid unnecessary therapies. The present narrative review summarizes the "state of art" about AS programmes and discusses the effects of the interventions possibly applied in ICU setting to optimize the patient's treatment, reduce the micro-organisms resistance and contain the hospital resources utilization.

Does ventilator-associated event surveillance detect ventilator-associated pneumonia in intensive care units? A systematic review and meta-analysis

Background

Ventilator-associated event (VAE) is a new surveillance paradigm for monitoring complications in mechanically ventilated patients in intensive care units (ICUs). The National Healthcare Safety Network replaced traditional ventilator-associated pneumonia (VAP) surveillance with VAE surveillance in 2013. The objective of this study was to assess the consistency between VAE surveillance and traditional VAP surveillance.

Methods

We systematically searched electronic reference databases for articles describing VAE and VAP in ICUs. Pooled VAE prevalence, pooled estimates (sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV)) of VAE for the detection of VAP, and pooled estimates (weighted mean difference (WMD) and odds ratio ([OR)) of risk factors for VAE compared to VAP were calculated.

Results

From 2191 screened titles, 18 articles met our inclusion criteria, representing 61,489 patients receiving mechanical ventilation at ICUs in eight countries. The pooled prevalence rates of ventilator-associated conditions (VAC), infection-related VAC (IVAC), possible VAP, probable VAP, and traditional VAP were 13.8 %, 6.4 %, 1.1 %, 0.9 %, and 11.9 %, respectively. Pooled sensitivity and PPV of each VAE type for VAP detection did not exceed 50 %, while pooled specificity and NPV exceeded 80 %. Compared with VAP, pooled ORs of in-hospital death were 1.49 for VAC and 1.76 for IVAC; pooled WMDs of hospital length of stay were −4.27 days for VAC and −5.86 days for IVAC; and pooled WMDs of ventilation duration were −2.79 days for VAC and −2.89 days for IVAC.

Conclusions

VAE surveillance missed many cases of VAP, and the population characteristics identified by the two surveillance paradigms differed. VAE surveillance does not accurately detect cases of traditional VAP in ICUs.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1506-z) contains supplementary material, which is available to authorized users.

Antibiotic stewardship in the intensive care unit

The rapid emergence and dissemination of antimicrobial-resistant microorganisms in ICUs worldwide constitute a problem of crisis dimensions. The root causes of this problem are multifactorial, but the core issues are clear. The emergence of antibiotic resistance is highly correlated with selective pressure resulting from inappropriate use of these drugs. Appropriate antibiotic stewardship in ICUs includes not only rapid identification and optimal treatment of bacterial infections in these critically ill patients, based on pharmacokinetic-pharmacodynamic characteristics, but also improving our ability to avoid administering unnecessary broad-spectrum antibiotics, shortening the duration of their administration, and reducing the numbers of patients receiving undue antibiotic therapy. Either we will be able to implement such a policy or we and our patients will face an uncontrollable surge of very difficult-to-treat pathogens.