Clinical cure of ventilator-associated pneumonia treated with piperacillin/tazobactam administered by continuous or intermittent infusion

Clinical outcomes with alternative dosing strategies for piperacillin/tazobactam: a systematic review and meta-analysis

Objectives

A better dosing strategy can improve clinical outcomes for patients. We sought to compare the extended or continuous infusion with conventional intermittent infusion of piperacillin/tazobactam, investigating which approach is better and worthy of recommendation for clinical use.

Methods

Articles were gathered from PubMed, Web of Science, ProQuest, Science Direct, Cochrane, two Chinese literature databases (CNKI, Wan Fang Data) and related ICAAC and ACCP conferences. Randomized controlled and observational studies that compared extended or continuous infusion with conventional intermittent infusion of piperacillin/tazobactam were identified from the databases above and analyzed. Two reviewers independently extracted and investigated the data. A meta-analysis was performed using Revman 5.2 software. The quality of each study was assessed. Sensitivity analysis and publication bias were evaluated.

Results

Five randomized controlled trials and nine observational studies were included in this study. All included studies had high quality and no publication bias was found. Compared to the conventional intermittent infusion approach, the extended or continuous infusion group had a significantly higher clinical cure rate (OR 1.88, 95% CI 1.29-2.73, P = 0.0009) and a lower mortality rate (OR 0.67, 95% CI 0.50-0.89, P = 0.005). No statistical difference was observed for bacteriologic cure (OR 1.40, 95% CI 0.82-2.37, P = 0.22) between the two dosing regimens. The sensitivity analysis showed the results were stable.

Conclusions

Our systematic review and meta-analysis suggested that the extended or continuous infusion strategy of piperacillin/tazobactam should be recommended for clinical use considering its higher clinical cure rate and lower mortality rate in comparison with conventional intermittent strategy. Data from this study could be extrapolated for other β-lactam antimicrobials. Therefore, this dosing strategy could be considered in clinical practice.

Trends in multidrug-resistant gram-negative bacilli and the role of prolonged β-lactam infusion in the intensive care unit

Multidrug-resistant gram-negative bacilli are emerging threats in the intensive care unit setting worldwide. Extended-spectrum β-lactamases, AmpC β-lactamases, and carbapenem-resistant Enterobacteriaceae are increasing at an alarming rate, leaving limited therapeutic options. In addition, multidrug resistance among Pseudomonas aeruginosa and Acinetobacter baumannii has widely disseminated and become a frequent cause of nosocomial infections within many intensive care units. Therefore, resistance is increasing to all currently available antibiotics, including cephalosporins, penicillins, aztreonam, carbapenems, fluoroquinolones, and aminoglycosides. Some multidrug-resistant gram-negative bacteria remain susceptible to only a few antibiotics such as tigecycline, fosfomycin, and polymyxins. The steady trend of increasing resistance coupled with the lack of novel antibiotics targeting resistant gram-negative bacilli has forced clinicians to increasingly apply more aggressive dosing strategies, such as prolonged and continuous infusion of β-lactam antibiotics to address the challenges associated with these difficult-to-treat pathogens. Nurses who have a thorough understanding of antibiotic resistance patterns, infection control procedures, and appropriate antibiotic use and dosing regimens, particularly the method of administration, are essential in the battle to preserve the usefulness of antibiotics and prevent further antibiotic resistance.

Doripenem population pharmacokinetics and dosing requirements for critically ill patients receiving continuous venovenous haemodiafiltration

OBJECTIVES

Doripenem is a newer carbapenem with little data available to guide effective dosing during renal replacement therapy in critically ill patients. The objective of this study was to determine the population pharmacokinetics of doripenem in critically ill patients undergoing continuous venovenous haemodiafiltration (CVVHDF) for acute kidney injury (AKI).

METHODS

This was an observational pharmacokinetic study in 12 infected critically ill adult patients with AKI undergoing CVVHDF and receiving 500 mg of doripenem intravenously every 8 h as a 60 min infusion. Serial blood samples were taken on 2 days of treatment and used for population pharmacokinetic analysis with S-ADAPT.

RESULTS

The median (IQR) age was 62 (53-71) years, the median (IQR) weight was 77 (67-96) kg and the median (IQR) APACHE II score was 29 (19-32). The median blood, dialysate and replacement fluid rates were 200, 1000 and 1000 mL/h, respectively. A two-compartment linear model with doripenem clearance described by CVVHDF, renal or non-renal mechanisms was most appropriate. The mean value for total doripenem clearance was 4.46 L/h and volume of distribution was 38.0 L. Doripenem clearance by CVVHDF was significantly correlated with the replacement fluid flow rate and accounted for ∼30%-37% of total clearance. A dose of 500 mg intravenously every 8 h achieved favourable pharmacokinetic/pharmacodynamics for all patients up to an MIC of 4 mg/L.

CONCLUSIONS

This is the first paper describing the pharmacokinetics/pharmacodynamics of doripenem in critically ill patients with AKI receiving CVVHDF. A dose of 500 mg intravenously every 8 h was appropriate for our CVVHDF settings for infections caused by susceptible bacteria.

Prolonged infusion versus intermittent boluses of β-lactam antibiotics for treatment of acute infections: a meta-analysis

The clinical advantages of prolonged (extended/continuous) infusion remain controversial. Previous studies and reviews have failed to show consistent clinical benefits of extending the infusion time. This meta-analysis sought to determine whether prolonged β-lactam infusions were associated with a reduction in mortality and improvement in clinical success. A search of PubMed, EMBASE and The Cochrane Library for randomised controlled trials (RCTs) and observational studies comparing prolonged infusion with intermittent bolus administration of the same antibiotic in hospitalised adult patients was conducted. Primary outcomes evaluated were mortality and clinical success. A total of 29 studies with 2206 patients (18 RCTs and 11 observational studies) were included in the meta-analysis. Compared with intermittent boluses, use of prolonged infusion appeared to be associated with a significant reduction in mortality [pooled relative risk (RR) = 0.66, 95% confidence interval (CI) 0.53-0.83] and improvement in clinical success (RR = 1.12, 95% CI 1.03-1.21). Statistically significant benefit was supported by non-randomised studies (mortality, RR = 0.57, 95% CI 0.43-0.76; clinical success, RR = 1.34, 95% CI 1.02-1.76) but not by RCTs (mortality, RR = 0.83, 95% CI 0.57-1.21; clinical success, RR = 1.05, 95% CI 0.99-1.12). The positive results from observational studies, especially in the face of increasing antibiotic resistance, serve to justify the imperative need to conduct a large-scale, well-designed, multicentre RCT involving critically ill patients infected with high minimum inhibitory concentration pathogens to clearly substantiate this benefit.

Bugs, hosts and ICU environment: countering pan-resistance in nosocomial microbiota and treating bacterial infections in the critical care setting

ICUs are areas where resistance problems are the largest, and these constitute a major problem for the intensivist's clinical practice. Main resistance phenotypes among nosocomial microbiota are (i) vancomycin-resistance/heteroresistance and tolerance in grampositives (MRSA, enterococci) and (ii) efflux pumps/enzymatic resistance mechanisms (ESBLs, AmpC, metallo-betalactamases) in gramnegatives. These phenotypes are found at different rates in pathogens causing respiratory (nosocomial pneumonia/ventilator-associated pneumonia), bloodstream (primary bacteremia/catheter-associated bacteremia), urinary, intraabdominal and surgical wound infections and endocarditis in the ICU. New antibiotics are available to overcome non-susceptibility in grampositives; however, accumulation of resistance traits in gramnegatives has led to multidrug resistance, a worrisome problem nowadays. This article reviews microorganism/infection risk factors for multidrug resistance, suggesting adequate empirical treatments. Drugs, patient and environmental factors all play a role in the decision to prescribe/recommend antibiotic regimens in the specific ICU patient, implying that intensivists should be familiar with available drugs, environmental epidemiology and patient factors.

Optimal dosing of antibiotics in critically ill patients by using continuous/extended infusions: a systematic review and meta-analysis

Introduction

The aim of this study was to determine whether using pharmacodynamic-based dosing of antimicrobials, such as extended/continuous infusions, in critically ill patients is associated with improved outcomes as compared with traditional dosing methods.

Methods

We searched Medline, HealthStar, EMBASE, Cochrane Clinical Trial Registry, and CINAHL from inception to September 2013 without language restrictions for studies comparing the use of extended/continuous infusions with traditional dosing. Two authors independently selected studies, extracted data on methodology and outcomes, and performed quality assessment. Meta-analyses were performed by using random-effects models.

Results

Of 1,319 citations, 13 randomized controlled trials (RCTs) (n = 782 patients) and 13 cohort studies (n = 2,117 patients) met the inclusion criteria. Compared with traditional non-pharmacodynamic-based dosing, RCTs of continuous/extended infusions significantly reduced clinical failure rates (relative risk (RR) 0.68; 95% confidence interval (CI) 0.49 to 0.94, P = 0.02) and intensive care unit length of stay (mean difference, −1.5; 95% CI, −2.8 to −0.2 days, P = 0.02), but not mortality (RR, 0.87; 95% CI, 0.64 to 1.19; P = 0.38). No significant between-trial heterogeneity was found for these analyses (I² = 0). Reduced mortality rates almost achieved statistical significance when the results of all included studies (RCTs and cohort studies) were pooled (RR, 0.83; 95% CI, 0.69 to 1.00; P = 0.054).

Conclusions

Pooled results from small RCTs suggest reduced clinical failure rates and intensive care unit length-of-stay when using continuous/extended infusions of antibiotics in critically ill patients. Reduced mortality rates almost achieved statistical significance when the results of RCTs were combined with cohort studies. These results support the conduct of adequately powered RCTs to define better the utility of continuous/extended infusions in the era of antibiotic resistance.

An alternate pathophysiologic paradigm of sepsis and septic shock: implications for optimizing antimicrobial therapy

The advent of modern antimicrobial therapy following the discovery of penicillin during the 1940s yielded remarkable improvements in case fatality rate of serious infections including septic shock. Since then, pathogens have continuously evolved under selective antimicrobial pressure resulting in a lack of significant improvement in clinical effectiveness in the antimicrobial therapy of septic shock despite ever more broad-spectrum and potent drugs. In addition, although substantial effort and money has been expended on the development novel non-antimicrobial therapies of sepsis in the past 30 years, clinical progress in this regard has been limited. This review explores the possibility that the current pathophysiologic paradigm of septic shock fails to appropriately consider the primacy of the microbial burden of infection as the primary driver of septic organ dysfunction. An alternate paradigm is offered that suggests that has substantial implications for optimizing antimicrobial therapy in septic shock. This model of disease progression suggests the key to significant improvement in the outcome of septic shock may lie, in great part, with improvements in delivery of existing antimicrobials and other anti-infectious strategies. Recognition of the role of delays in administration of antimicrobial therapy in the poor outcomes of septic shock is central to this effort. However, therapeutic strategies that improve the degree of antimicrobial cidality likely also have a crucial role.

Continuous versus intermittent infusion of cefepime in neurosurgical patients with post-operative intracranial infections

Cefepime is administered as an intermittent infusion (II); however, continuous infusion (CI) may be advantageous because β-lactam antibiotics exhibit time-dependent antibacterial activity. This retrospective, non-randomised, comparative study included 68 neurosurgical patients with post-operative intracranial infections treated with 4g/day cefepime over 24h as a CI (n=34) or 2g every 12h as II (n=34). CI controlled the intracranial infection more rapidly and effectively than II (6.6±1.9 days vs. 7.8±2.6 days; P=0.036). By considering the minimum inhibitory concentrations (MICs) to be 4μg/mL and 8μg/mL, the percentage of time when the cefepime plasma or CSF concentrations were higher than the MIC (%T>MIC) was calculated for each patient. For plasma cefepime concentrations, the %T(>MIC) in the CI group was higher than in the II group (for MICs of 8μg/mL, 100% vs. 75%, respectively). The mean calculated area under the curve (AUC) in the CI group was similar to the II group (1197.99±72.15μgh/mL vs. 890.84±140.78μgh/mL; P=0.655). For CSF cefepime concentrations, the %T(>MIC) in the CI group was higher than in the II group (for MICs of 4μg/mL and 8μg/mL, 83.3% and 75% vs. 25% and 0%, respectively). The mean calculated AUC for the CI group was higher than the II group (220.56±13.59μgh/mL vs. 86.34±5.69μgh/mL; P=0.003). Therefore, CI of cefepime significantly enhanced the antibacterial effect and reduced the treatment duration in neurosurgical patients with post-operative intracranial infections.

Management and prevention of ventilator-associated pneumonia caused by multidrug-resistant pathogens

Ventilator-associated pneumonia (VAP) due to multidrug-resistant (MDR) pathogens is a leading healthcare-associated infection in mechanically ventilated patients. The incidence of VAP due to MDR pathogens has increased significantly in the last decade. Risk factors for VAP due to MDR organisms include advanced age, immunosuppression, broad-spectrum antibiotic exposure, increased severity of illness, previous hospitalization or residence in a chronic care facility and prolonged duration of invasive mechanical ventilation. Methicillin-resistant Staphylococcus aureus and several different species of Gram-negative bacteria can cause MDR VAP. Especially difficult Gram-negative bacteria include Pseudomonas aeruginosa, Acinetobacter baumannii, carbapenemase-producing Enterobacteraciae and extended-spectrum β-lactamase producing bacteria. Proper management includes selecting appropriate antibiotics, optimizing dosing and using timely de-escalation based on antiimicrobial sensitivity data. Evidence-based strategies to prevent VAP that incorporate multidisciplinary staff education and collaboration are essential to reduce the burden of this disease and associated healthcare costs.

β-lactam pharmacokinetics and pharmacodynamics in critically ill patients and strategies for dose optimization: a structured review

1. Infections and related sepsis are two of the most prevalent issues in the care of critically ill patients, with mortality as high as 70%. Appropriate antibiotic selection, as well as adequate dosing, is important to improve the clinical outcome for these patients. 2. β-Lactams are the most common antibiotic class used in critically ill sepsis patients because of their broad spectrum of activity and high tolerability. β-Lactams exhibit time-dependent antibacterial activity. Therefore, concentrations need to be maintained above the minimum inhibitory concentration (MIC) of pathogenic bacteria. β-Lactams are hydrophilic antibiotics with small distribution volumes similar to extracellular water and are predominantly excreted through the renal system. 3. Critically ill patients experience a myriad of physiological changes that result in changes in the pharmacokinetics (PK) of hydrophilic drugs such as β-lactams. A different approach to dosing with β-lactams may increase the likelihood of positive outcomes considering the pharmacodynamics (PD) of β-lactams, as well as the changes in PK in critically ill patients. 4. The present review describes the strategies for dose optimization of β-lactams in critically ill patients in line with the PK and PD of these drugs.

2013 WSES guidelines for management of intra-abdominal infections

Despite advances in diagnosis, surgery, and antimicrobial therapy, mortality rates associated with complicated intra-abdominal infections remain exceedingly high.The 2013 update of the World Society of Emergency Surgery (WSES) guidelines for the management of intra-abdominal infections contains evidence-based recommendations for management of patients with intra-abdominal infections.

Continuous infusion of piperacillin/tazobactam in septic critically ill patients--a multicenter propensity matched analysis

The clinical efficacy of continuous infusion of piperacillin/tazobactam in critically ill patients with microbiologically documented infections is currently unknown. We conducted a retrospective multicenter cohort study in 7 Portuguese intensive care units (ICU). We included 569 critically ill adult patients with a documented infection and treated with piperacillin/tazobactam admitted to one of the participating ICU between 2006 and 2010. We successfully matched 173 pairs of patients according to whether they received continuous or conventional intermittent dosing of piperacillin/tazobactam, using a propensity score to adjust for confounding variables. The majority of patients received 16g/day of piperacillin plus 2g/day of tazobactam. The 28-day mortality rate was 28.3% in both groups (p = 1.0). The ICU and in-hospital mortality were also similar either in those receiving continuous infusion or intermittent dosing (23.7% vs. 20.2%, p = 0.512 and 41.6% vs. 40.5%, p = 0.913, respectively). In the subgroup of patients with a Simplified Acute Physiology Score (SAPS) II>42, the 28-day mortality rate was lower in the continuous infusion group (31.4% vs. 35.2%) although not reaching significance (p = 0.66). We concluded that the clinical efficacy of piperacillin/tazobactam in this heterogeneous group of critically ill patients infected with susceptible bacteria was independent of its mode of administration, either continuous infusion or intermittent dosing.

Continuous beta-lactam infusion in critically ill patients: the clinical evidence

There is controversy over whether traditional intermittent bolus dosing or continuous infusion of beta-lactam antibiotics is preferable in critically ill patients. No significant difference between these two dosing strategies in terms of patient outcomes has been shown yet. This is despite compelling in vitro and in vivo pharmacokinetic/pharmacodynamic (PK/PD) data. A lack of significance in clinical outcome studies may be due to several methodological flaws potentially masking the benefits of continuous infusion observed in preclinical studies. In this review, we explore the methodological shortcomings of the published clinical studies and describe the criteria that should be considered for performing a definitive clinical trial. We found that most trials utilized inconsistent antibiotic doses and recruited only small numbers of heterogeneous patient groups. The results of these trials suggest that continuous infusion of beta-lactam antibiotics may have variable efficacy in different patient groups. Patients who may benefit from continuous infusion are critically ill patients with a high level of illness severity. Thus, future trials should test the potential clinical advantages of continuous infusion in this patient population. To further ascertain whether benefits of continuous infusion in critically ill patients do exist, a large-scale, prospective, multinational trial with a robust design is required.

Continuous infusion of antibiotics in the critically ill: The new holy grail for beta-lactams and vancomycin?

The alarming global rise of antimicrobial resistance combined with the lack of new antimicrobial agents has led to a renewed interest in optimization of our current antibiotics. Continuous infusion (CI) of time-dependent antibiotics has certain theoretical advantages toward efficacy based on pharmacokinetic/pharmacodynamic principles. We reviewed the available clinical studies concerning continuous infusion of beta-lactam antibiotics and vancomycin in critically ill patients. We conclude that CI of beta-lactam antibiotics is not necessarily more advantageous for all patients. Continuous infusion is only likely to have clinical benefits in subpopulations of patients where intermittent infusion is unable to achieve an adequate time above the minimal inhibitory concentration (T > MIC). For example, in patients with infections caused by organisms with elevated MICs, patients with altered pharmacokinetics (such as the critically ill) and possibly also immunocompromised patients. For vancomycin CI can be chosen, not always for better clinical efficacy, but because it is practical, cheaper, associated with less AUC_24h (area under the curve >24 h)-variability, and easier to monitor.

Continuous versus intermittent administration of piperacillin-tazobactam in intensive care unit patients with ventilator-associated pneumonia

BACKGROUND AND AIMS

Ventilator-associated pneumonia (VAP) is one of the most common Intensive Care Unit (ICU)-acquired infection. The aim of this study was to compare the clinical outcome of continuous and intermittent administration of piperacillin-tazobactam by serial measurements of the Clinical Pulmonary Infection Score (CPIS).

SUBJECTS AND METHODS

Groups were designed as parallel and the study was designed as quasi-experimental and conducted at a semi-closed ICU between September 2008 and May 2010. Patients received 3.375 g (piperacillin 3 g/tazobactam 0.375 g) either through intermittent infusion every 6 h for 30 min [Intermittent Infusion (II) group; n = 30] or through continuous infusion every 8 h for 4 h [Continuous Infusion (CI) group; n = 31]. CPIS was used to assess the clinical diagnosis and outcome of VAP patients.

RESULTS

Sex, age, Acute Physiology and Chronic Health Evaluation II II score on ICU admission, diagnosis and underlying disease of VAP patients were not significantly different in the CI (n = 31) and II (n = 30) groups. Duration of mechanical ventilation, length of stay, total number of antibiotics used per patient and duration of piperacillin/tazobactam treatment were similar in both groups. Mortality rates of VAP patients were similar between both groups during hospitalization.

CONCLUSION

There was no significant difference in clinical outcomes of patients receiving piperacillin-tazobactam via CI or II when measured by serial CPIS score.

Impact of antibiotic MIC on infection outcome in patients with susceptible Gram-negative bacteria: a systematic review and meta-analysis

The objective of this study was to analyze the impact of MIC values within the susceptible range of antibiotics on the outcomes of patients with Gram-negative infections. The PubMed and Scopus electronic databases were searched. We identified 13 articles (1,469 patients) that studied the impact of antibiotic MICs on the outcomes of infections; β-lactams were studied in 10 of them. Infections due to Salmonella enterica strains with high fluoroquinolone MICs were associated with more treatment failures than those due to strains with low MICs (relative risk [RR], 5.75; 95% confidence interval [CI], 1.77 to 18.71). Among non-Salmonella enterobacteriaceae, there was no difference in treatment failures depending on the MIC value (RR, 1.18; 95% CI, 0.71 to 1.97); however, a higher all-cause mortality was observed for patients infected with strains with high MICs (RR, 2.03; 95% CI, 1.05 to 3.92). More treatment failures were observed for patients infected with nonfermentative Gram-negative bacilli when strains had high MICs (RR, 5.54; 95% CI, 2.72 to 11.27). The mortality rate for patients with infections with Gram-negative nonfermentative bacilli with high MICs was also higher than for those with low MICs (RR, 2.39; 95% CI, 1.19 to 4.81). The limited available data suggest that there is an association between high MICs, within the susceptible range, and adverse outcomes for patients with Gram-negative infections.

Advances in the management of sepsis and the understanding of key immunologic defects

Anesthesiologists are increasingly confronting the difficult problem of caring for patients with sepsis in the operating room and in the intensive care unit. Sepsis occurs in more than 750,000 patients in the United States annually and is responsible for more than 210,000 deaths. Approximately 40% of all intensive care unit patients have sepsis on admission to the intensive care unit or experience sepsis during their stay in the intensive care unit. There have been significant advances in the understanding of the pathophysiology of the disorder and its treatment. Although deaths attributable to sepsis remain stubbornly high, new treatment algorithms have led to a reduction in overall mortality. Thus, it is important for anesthesiologists and critical care practitioners to be aware of these new therapeutic regimens. The goal of this review is to include practical points on important advances in the treatment of sepsis and provide a vision of future immunotherapeutic approaches.

Continuous infusion of piperacillin/tazobactam in ventilator-associated pneumonia: a pilot study on efficacy and costs

Ventilator-associated pneumonia (VAP) occurs in nearly one-third of mechanically ventilated patients in the Intensive Care Unit. Piperacillin/tazobactam (TZP) is currently recommended in the empirical treatment of VAP, but intermittent dosing may result in inadequate serum concentrations. The efficacy and costs of continuous infusion (CI) of TZP, using therapeutic drug monitoring for real-time dose adjustment, was assessed in a prospective pilot study of 16 patients with VAP. TZP was given as a loading dose of 2.0/0.25 g followed by a CI of 10.0/1.25g daily. Rapid antimicrobial susceptibility testing was used to determine the minimum inhibitory concentration (MIC) of the pathogens. TZP concentrations were determined by high-pressure liquid chromatography before and at 1, 6, 12, 24, 48, 72 and 96 h after the onset of administration. Dosages were adjusted to maintain piperacillin concentrations four-fold above the MIC (T>4 × MIC) of the pathogen, with a maximum dose of 16.0/2.0 g. The cost of the total TZP administered was compared with the cost of a standard TZP regimen (16.0/2.0 g) if given over the same period of time. The median MIC for TZP was 1 μg/mL (range 0.025-32 μg/mL). TZP concentrations were adequate for 71% of pathogens on the first day of therapy. Clinical cure was achieved in 9/10 patients who had adequate drug concentrations and in 3/6 patients with insufficient levels. The daily dose of TZP received by CI was 37.5% less than that of a standard regimen, which corresponds to a saving of €15 on daily therapy costs compared with the standard regimen. In conclusion, CI of TZP achieved optimal drug concentrations in most patients with VAP, with a favourable impact on costs. Adequate drug concentrations were achieved for MIC ≤ 4 μg/mL, but higher dosages should be considered for the treatment of pathogens with low susceptibility thresholds.

Appraising contemporary strategies to combat multidrug resistant gram-negative bacterial infections--proceedings and data from the Gram-Negative Resistance Summit

The emerging problem of antibiotic resistance, especially among Gram-negative bacteria (GNB), has become a serious threat to global public health. Very few new antibacterial classes with activity against antibiotic-resistant GNB have been brought to market. Renewed and growing attention to the development of novel compounds targeting antibiotic-resistant GNB, as well as a better understanding of strategies aimed at preventing the spread of resistant bacterial strains and preserving the efficacy of existing antibiotic agents, has occurred. The Gram-Negative Resistance Summit convened national opinion leaders for the purpose of analyzing current literature, epidemiologic trends, clinical trial data, therapeutic options, and treatment guidelines related to the management of antibiotic-resistant GNB infections. After an in-depth analysis, the Summit investigators were surveyed with regard to 4 clinical practice statements. The results then were compared with the same survey completed by 138 infectious disease and critical care physicians and are the basis of this article.

Does prolonged β-lactam infusions improve clinical outcomes compared to intermittent infusions? A meta-analysis and systematic review of randomized, controlled trials

Background

The emergence of multi-drug resistant Gram-negatives (MDRGNs) coupled with an alarming scarcity of new antibiotics has forced the optimization of the therapeutic potential of available antibiotics. To exploit the time above the minimum inhibitory concentration mechanism of β-lactams, prolonging their infusion may improve outcomes. The primary objective of this meta-analysis was to determine if prolonged β-lactam infusion resulted in decreased mortality and improved clinical cure compared to intermittent β-lactam infusion.

Methods

Relevant studies were identified from searches of MEDLINE, EMBASE, and CENTRAL. Heterogeneity was assessed qualitatively, in addition to I² and Chi-square statistics. Pooled relative risks (RR) and 95% confidence intervals (CI) were calculated using Mantel-Haenszel random-effects models.

Results

Fourteen randomized controlled trials (RCTs) were included. Prolonged infusion β-lactams were not associated with decreased mortality (n= 982; RR 0.92; 95% CI:0.61-1.37) or clinical cure (n = 1380; RR 1.00 95% CI:0.94-1.06) compared to intermittent infusions. Subgroup analysis for β-lactam subclasses and equivalent total daily β-lactam doses yielded similar results. Most studies had notable methodological flaws.

Conclusions

No clinical advantage was observed for prolonged infusion β-lactams. The limited number of studies with MDRGNs precluded evaluation of prolonged infusion of β-lactams for this subgroup. A large, multicenter RCT with critically ill patients infected with MDRGNs is needed.

WSES consensus conference: Guidelines for first-line management of intra-abdominal infections

Intra-abdominal infections are still associated with high rate of morbidity and mortality.A multidisciplinary approach to the management of patients with intra-abdominal infections may be an important factor in the quality of care. The presence of a team of health professionals from various disciplines, working in concert, may improve efficiency, outcome, and the cost of care.A World Society of Emergency Surgery (WSES) Consensus Conference was held in Bologna on July 2010, during the 1st congress of the WSES, involving surgeons, infectious disease specialists, pharmacologists, radiologists and intensivists with the goal of defining recommendations for the early management of intra-abdominal infections.This document represents the executive summary of the final guidelines approved by the consensus conference.

Empiric therapy for gram-negative pathogens in nosocomial and health care-associated pneumonia: starting with the end in mind

Nosocomial pneumonia is a major cause of morbidity and mortality for hospitalized patients. Antimicrobial resistance is increasing, creating a strain between ensuring the provision of adequate empiric therapy and slowing the development of antimicrobial resistance. Excessive antimicrobial therapy places patients are at greater risk of drug interactions, adverse events, and superinfections. Ways to maximize adequate empiric therapy include (1) categorizing each patient's risk of being infected with a multidrug-resistant pathogen and knowledge of local susceptibility patterns, (2) de-escalating antimicrobial therapy to decrease the rates of superinfections such as Clostridium difficile, and (3) limiting the duration of therapy to decrease the likelihood of adverse events, drug interactions, and antimicrobial resistance. Pharmacodynamically enhanced dosing regimens also have the potential to improve clinical outcomes and slow the development of antimicrobial resistance. Drugs whose killing is optimized by the percentage time above the minimum inhibitory concentration (MIC), such as beta-lactams, can be given by continuous or extended infusion to provide superior pharmacodynamic (PD) target attainment rates compared with traditional regimens. Drugs whose killing is optimized with a high-peak plasma concentration to MIC ratio (eg, aminoglycosides) should be administered once daily to maximize the likelihood of achieve optimal target attainment rates. Drugs whose killing is optimized by the ratio of the area under the curve (AUC) to MIC ratio (eg, fluoroquinolones) depend on the total daily dose as opposed to the dosing schedule or infusion time. Determining the optimal drug dosing schedules for obese patients remains critical because these patients have may have significantly increased volumes of distribution and clearance rates compared to normal weight patients. Optimizing the use of current antimicrobials is paramount to ensure quality treatment options are available, given the lack of gram-negative antimicrobials in the pipeline.

Harmonization of antimicrobial susceptibility testing breakpoints in Europe: implications for reporting intermediate susceptibility

Harmonization of antimicrobial susceptibility testing breakpoints across Europe has resulted in the reintroduction of the intermediate susceptibility categorization into the BSAC susceptibility testing method for a wide range of antibiotic pathogen test pairs. The implications of this, for laboratories and prescribers, are discussed.

Bench-to-bedside review: Appropriate antibiotic therapy in severe sepsis and septic shock--does the dose matter?

Appropriate antibiotic therapy in patients with severe sepsis and septic shock should mean prompt achievement and maintenance of optimal exposure at the infection site with broad-spectrum antimicrobial agents administered in a timely manner. Once the causative pathogens have been identified and tested for in vitro susceptibility, subsequent de-escalation of antimicrobial therapy should be applied whenever feasible. The goal of appropriate antibiotic therapy must be pursued resolutely and with continuity, in view of the ongoing explosion of antibiotic-resistant infections that plague the intensive care unit setting and of the continued decrease in new antibiotics emerging. This article provides some principles for the correct handling of antimicrobial dosing regimens in patients with severe sepsis and septic shock, in whom various pathophysiological conditions may significantly alter the pharmacokinetic behaviour of drugs.