Rationale: Optimization of β-lactam antibiotic dosing for critically ill patients is an intervention that may improve outcomes in severe sepsis. Objectives: In this individual patient data meta-analysis of critically ill patients with severe sepsis, we aimed to compare clinical outcomes of those treated with continuous versus intermittent infusion of β-lactam antibiotics. Methods: We identified relevant randomized controlled trials comparing continuous versus intermittent infusion of β-lactam antibiotics in critically ill patients with severe sepsis. We assessed the quality of the studies according to four criteria. We combined individual patient data from studies and assessed data integrity for common baseline demographics and study endpoints, including hospital mortality censored at 30 days and clinical cure. We then determined the pooled estimates of effect and investigated factors associated with hospital mortality in multivariable analysis. Measurements and Main Results: We identified three randomized controlled trials in which researchers recruited a total of 632 patients with severe sepsis. The two groups were well balanced in terms of age, sex, and illness severity. The rates of hospital mortality and clinical cure for the continuous versus intermittent infusion groups were 19.6% versus 26.3% (relative risk, 0.74; 95% confidence interval, 0.56–1.00; P = 0.045) and 55.4% versus 46.3% (relative risk, 1.20; 95% confidence interval, 1.03–1.40; P = 0.021), respectively. In a multivariable model, intermittent β-lactam administration, higher Acute Physiology and Chronic Health Evaluation II score, use of renal replacement therapy, and infection by nonfermenting gram-negative bacilli were significantly associated with hospital mortality. Continuous β-lactam administration was not independently associated with clinical cure. Conclusions: Compared with intermittent dosing, administration of β-lactam antibiotics by continuous infusion in critically ill patients with severe sepsis is associated with decreased hospital mortality.

Antimicrobial de-escalation (ADE) is a strategy to reduce the spectrum of antimicrobials and aims to prevent the emergence of bacterial resistance. We present a systematic review describing the definitions, determinants and outcomes associated with ADE. We included 2 randomized controlled trials and 12 cohort studies. There was considerable variability in the definition of ADE. It was more frequently performed in patients with broad-spectrum and/or appropriate antimicrobial therapy (P = .05 to .002), when more agents were used (P = .002), and in the absence of multidrug-resistant pathogens (P < .05). Where investigated, lower or improving severity scores were consistently associated with ADE (P = .04 to <.001). The pooled effect of ADE on mortality is protective (relative risk, 0.68; 95% confidence interval, .52–.88). Because the determinants of ADE are markers of clinical improvement and/or of lower risk of treatment failure this effect on mortality cannot be retained as evidence. None of the studies were designed to investigate the effect of ADE on antimicrobial resistance.

There is little evidence and few guidelines to inform the most appropriate dosing and monitoring for antimicrobials in the ICU. We aimed to survey current practices around the world. An online structured questionnaire was developed and sent by e-mail to obtain information on local antimicrobial prescribing practices for glycopeptides, piperacillin/tazobactam, carbapenems, aminoglycosides and colistin. A total of 402 professionals from 328 hospitals in 53 countries responded, of whom 78% were specialists in intensive care medicine (41% intensive care, 30% anaesthesiology, 14% internal medicine) and 12% were pharmacists. Vancomycin was used as a continuous infusion in 31% of units at a median (IQR) daily dose of 25 (25–30) mg/kg. Piperacillin/tazobactam was used as an extended infusion by 22% and as a continuous infusion by 7%. An extended infusion of carbapenem (meropenem or imipenem) was used by 27% and a continuous infusion by 5%. Colistin was used at a daily dose of 7.5 (3.9–9) million IU (MIU)/day, predominantly as a short infusion. The most commonly used aminoglycosides were gentamicin (55%) followed by amikacin (40%), with administration as a single daily dose reported in 94% of the cases. Gentamicin was used at a daily dose of 5 (5–6) mg/day and amikacin at a daily dose of 15 (15–20) mg/day. Therapeutic drug monitoring of vancomycin, piperacillin/tazobactam and meropenem was used by 74%, 1% and 2% of the respondents, respectively. Peak aminoglycoside concentrations were sampled daily by 28% and trough concentrations in all patients by 61% of the respondents. We found wide variability in reported practices for antibiotic dosing and monitoring. Research is required to develop evidence-based guidelines to standardize practices.

Purpose The DIANA study aimed to evaluate how often antimicrobial de-escalation (ADE) of empirical treatment is performed in the intensive care unit (ICU) and to estimate the effect of ADE on clinical cure on day 7 following treatment initiation. Methods Adult ICU patients receiving empirical antimicrobial therapy for bacterial infection were studied in a prospective observational study from October 2016 until May 2018. ADE was defined as (1) discontinuation of an antimicrobial in case of empirical combination therapy or (2) replacement of an antimicrobial with the intention to narrow the antimicrobial spectrum, within the first 3 days of therapy. Inverse probability (IP) weighting was used to account for time-varying confounding when estimating the effect of ADE on clinical cure. Results Overall, 1495 patients from 152 ICUs in 28 countries were studied. Combination therapy was prescribed in 50%, and carbapenems were prescribed in 26% of patients. Empirical therapy underwent ADE, no change and change other than ADE within the first 3 days in 16%, 63% and 22%, respectively. Unadjusted mortality at day 28 was 15.8% in the ADE cohort and 19.4% in patients with no change [p = 0.27; RR 0.83 (95% CI 0.60–1.14)]. The IP-weighted relative risk estimate for clinical cure comparing ADE with no-ADE patients (no change or change other than ADE) was 1.37 (95% CI 1.14–1.64). Conclusion ADE was infrequently applied in critically ill-infected patients. The observational effect estimate on clinical cure suggested no deleterious impact of ADE compared to no-ADE. However, residual confounding is likely.

Objectives: Antimicrobial stewardship (AMS) programmes have been developed with the intention of reducing inappropriate and unnecessary use of antimicrobials, while improving the quality of patient care and locally helping prevent the development of antimicrobial resistance. An important aspect of AMS programmes is the qualitative assessment of prescribing through antimicrobial prescribing surveys (APS), which are able to provide information about the prescribing behaviour within institutions. Owing to lack of standardization of audit tools and the resources required, qualitative methods for the assessment of antimicrobial use are not often performed. The aim of this study was to design an audit tool that was appropriate for use in all Australian hospitals, suited to local user requirements and included an assessment of the overall appropriateness of the prescription. Methods: In November 2011, a pilot APS was conducted across 32 hospitals to assess the usability and generalizability of a newly designed audit tool. Following participant feedback, this tool was revised to reflect the requirements of the respondents. A second pilot study was then performed in November 2012 across 85 hospitals. Results: These surveys identified several areas that can be targets for quality improvement at a national level, including: documentation of indication; surgical prophylaxis prescribed for >24 h; compliance with prescribing guidelines; and the appropriateness of the prescription. Conclusions: By involving the end users in the design and evaluation, we have been able to provide a practical and relevant APS tool for quantitative and qualitative data collection in a wide range of Australian hospital settings.