Patterns of antimicrobial therapy in severe nosocomial infections: empiric choices, proportion of appropriate therapy, and adaptation rates--a multicentre, observational survey in critically ill patients

Antimicrobial infusion practices within intensive care units: Carbapenem infusion preparation and administration process errors

OBJECTIVE

To describe nurse preparation and administration of intermittent carbapenem infusions.

RESEARCH METHODOLOGY/DESIGN

This observational study documented the carbapenem infusion process to adult patients in three general intensive care units.

MAIN OUTCOME MEASURES

Timing and duration of infusions were observed. Volumetric analysis of infusion items was conducted to determine loss of reconstituted carbapenem during preparation and administration phases.

RESULTS

Carbapenem infusions (n = 223) administered to twenty adult patients were observed. Infusion duration guidance was variable, with two ICUs following current literature recommendations, and one ICU referring to medication package insert information. Within these parameters, only 60 % of infusions complied with infusion duration. Non-compliance with planned time of administration impacted on desired dosing intervals. Incomplete delivery of intended dose was found during: sub-optimal reconstitution of vials, incorrect number of vials reconstituted, failure to administer a dose (missed dose), and discarding antibiotic residue in infusion items. Volumetric analysis of infusion items showed mean dose losses of 4.9 % and 1.2 % in discarded vials and syringes. Mean drug losses of 6.3 % and 30.8 % occurred in discarded infusion bags and infusion lines respectively. No flushing guidance or practice was observed.

CONCLUSION

Incorrect nurse administration of antibiotics resulted in varying durations of infusions and the non-delivery of prescribed dose. Under-dosing has the potential to contribute to selection pressure for bacterial antibiotic resistance. The increasing frequency of intravenous delivery of antimicrobial agents through infusions requires an understanding of the required duration of administration and how to manage residual drug remaining in the intravenous line once the infusion is completed.

IMPLICATIONS FOR CLINICAL PRACTICE

Flushing of administration lines is not common practice following intermittent antimicrobial infusions. Although there are multi-factorial risk factors for antimicrobial resistance in the critical care arena, nurse infusion practice must ensure that patients receive intended antimicrobial treatment. Attention must be given to the potential for antimicrobial resistance from environmental contamination with the disposal of infusion items containing undelivered antimicrobial medication.

Associated Risk Factors and Clinical Outcomes of Bloodstream Infections among COVID-19 Intensive Care Unit Patients in a Tertiary Care Hospital

Introduction

The COVID-19 infection is an ongoing public health crisis causing millions of deaths worldwide. COVID-19 patients admitted to the intensive care unit (ICU) are more vulnerable to acquire secondary bloodstream infections (sBSIs) which cause a significant morbidity and mortality. Thus, we aim to assess the risk factors of sBSIs and outcomes in COVID-19 ICU patients.

Methods

One hundred blood culture samples with growth (cases) and other 100 blood culture with no growth(controls) were collected.. All the demographic data, laboratory data and antimicrobial resistance pattern were analysed . Blood culture bottle received in the Microbiology laboratory were loaded into Automated blood culture system. Flagged bottles were processed for final identification by MALDI TOF and automated antibiotic susceptibility testing. Flagged bottles were processed for final identification by MALDI TOF and automated antibiotic susceptibility testing.

Results

Raised C-reactive protein (CRP) (P = 0.0035), interleukin-6 (P = 0.0404), mechanical ventilation (MV) (P = 0.024), prior antimicrobial exposure (P = 0.002), longer ICU stay with median 11 days (P = 0.022), and higher mortality rate (P = 0.001) were significantly associated with the BSI. A significant proportion of BSIs were Gram-negative bacteria (n = 115) such as Acinetobacter baumannii 38 (33%) and Klebsiella pneumoniae 30 (26%). Monomicrobial organisms in blood yielded a higher proportion in our study 72 (72%). The highest resistance for Acinetobacter species (50) was observed with ceftazidime 29 (96.6%) amikacin 48 (96%), meropenem 48 (96%), cefotaxime 47 (94%), ciprofloxacin 46 (92%), and netilmicin 46 (92%). K. pneumoniae was highly resistant to cefotaxime 29 (96.6%), ceftazidime 29 (96.6%), ciprofloxacin 22 (73.3%), and cefuroxime 21 (70%). Among Gram-positive organisms, Enterococcus species showed that a resistance for high-level gentamicin and penicillin was 66.6%.

Conclusions

Raised CRP, need of MV, prior antimicrobial exposure, and longer ICU stay should alarm clinicians for BSI. Hence, our study highlights the associated risk factors for BSI and emphasizes adherence to hospital infection control policies and antibiotic stewardship program.

Epidemiology and risk factors for mortality in critically ill patients with pancreatic infection

Background

The AbSeS-classification defines specific phenotypes of patients with intra-abdominal infection based on the (1) setting of infection onset (community-acquired, early onset, or late-onset hospital-acquired), (2) presence or absence of either localized or diffuse peritonitis, and (3) severity of disease expression (infection, sepsis, or septic shock). This classification system demonstrated reliable risk stratification in intensive care unit (ICU) patients with intra-abdominal infection. This study aimed to describe the epidemiology of ICU patients with pancreatic infection and assess the relationship between the components of the AbSeS-classification and mortality.

Methods

This was a secondary analysis of an international observational study ("AbSeS") investigating ICU patients with intra-abdominal infection. Only patients with pancreatic infection were included in this analysis (n=165). Mortality was defined as ICU mortality within 28 days of observation for patients discharged earlier from the ICU. Relationships with mortality were assessed using logistic regression analysis and reported as odds ratio (OR) and 95% confidence interval (CI).

Results

The overall mortality was 35.2% (n=58). The independent risk factors for mortality included older age (OR=1.03, 95% CI: 1.0 to 1.1 P=0.023), localized peritonitis (OR=4.4, 95% CI: 1.4 to 13.9 P=0.011), and persistent signs of inflammation at day 7 (OR=9.5, 95% CI: 3.8 to 23.9, P<0.001) or after the implementation of additional source control interventions within the first week (OR=4.0, 95% CI: 1.3 to 12.2, P=0.013). Gram-negative bacteria were most frequently isolated (n=58, 49.2%) without clinically relevant differences in microbial etiology between survivors and non-survivors.

Conclusions

In pancreatic infection, a challenging source/damage control and ongoing pancreatic inflammation appear to be the strongest contributors to an unfavorable short-term outcome. In this limited series, essentials of the AbSeS-classification, such as the setting of infection onset, diffuse peritonitis, and severity of disease expression, were not associated with an increased mortality risk.ClinicalTrials.gov number: NCT03270345.

Microbiological profile of patients treated for postoperative peritonitis: temporal trends 1999-2019

BACKGROUND

Temporal changes in the microbiological resistance profile have been reported in several life-threatening infections. However, no data have ever assessed this issue in postoperative peritonitis (POP). Our purpose was to assess the rate of multidrug-resistant organisms (MDROs) in POP over a two-decade period and to analyse their influence on the adequacy of empirical antibiotic therapy (EAT).

METHODS

This retrospective monocentric analysis (1999-2019) addressed the changes over time in microbiologic data, including the emergence of MDROs and the adequacy of EAT for all intensive care unit adult patients treated for POP. The in vitro activities of 10 antibiotics were assessed to determine the most adequate EAT in the largest number of cases among 17 antibiotic regimens in patients with/without MDRO isolates. Our primary endpoint was to determine the frequency of MDRO and their temporal changes. Our second endpoint assessed the impact of MDROs on the adequacy of EAT per patient and their temporal changes based on susceptibility testing. In this analysis, the subgroup of patients with MDRO was compared with the subgroup of patients free of MDRO.

RESULTS

A total of 1,318 microorganisms were cultured from 422 patients, including 188 (45%) patients harbouring MDROs. The growing proportions of MDR Enterobacterales were observed over time (p = 0.016), including ESBL-producing strains (p = 0.0013), mainly related to Klebsiella spp (p < 0.001). Adequacy of EAT was achieved in 305 (73%) patients. Decreased adequacy rates were observed when MDROs were cultured [p = 0.0001 vs. MDRO-free patients]. Over the study period, decreased adequacy rates were reported for patients receiving piperacillin/tazobactam in monotherapy or combined with vancomycin and imipenem/cilastatin combined with vancomycin (p < 0.01 in the three cases). In patients with MDROs, the combination of imipenem/cilastatin + vancomycin + amikacin or ciprofloxacin reached the highest adequacy rates (95% and 91%, respectively) and remained unchanged over time.

CONCLUSIONS

We observed high proportions of MDRO in patients treated for POP associated with increasing proportions of MDR Enterobacterales over time. High adequacy rates were only achieved in antibiotic combinations involving carbapenems and vancomycin, while piperacillin/tazobactam is no longer a drug of choice for EAT in POP in infections involving MDRO.

Evaluation of intermittent antimicrobial infusion documentation practices in intensive care units: A cross-sectional study

OBJECTIVE

To observe nurse administration of carbapenem antibiotics, in the context of medication safety measures, in intensive care units.

RESEARCH METHODOLOGY/DESIGN

A quantitative study was conducted using observation principles.

SETTING

Three adult private and public Intensive Care Units in the health district of a capital city in KwaZulu-Natal, South Africa.

MAIN OUTCOME MEASURES

Nurse practices were observed for double-checking of the medication order, medication vial, and method of preparation and administration. Infusion bags were inspected for nurse labelling of medication and patient details. Patient medication treatment charts were inspected for nurse signature.

RESULTS

Carbapenem infusion administrations (n = 223) to twenty patients were observed. Adherence to the scheduled time occurred in 34.9% administrations, 5.4% doses were not given, and an incorrect dose given on 1.4% administrations. One hundred and forty-four (64.6%) infusion bags were inspected during the administrations: there was no medication label affixed to 21.5% bags, and only 8.3% of bags were labelled with essential details; the patient's name, drug, dose, date, time, signature of the nurse mixing and administering the dose, and signature of the secondary nurse.

CONCLUSION

There was a lack of compliance with accepted medication risk mitigation measures. Sub-optimal double-checking resulted in the incorrect dose given, missed dose, and non-adherence to scheduled administration time. This has implications for the optimal administration of antimicrobial medications, raising concerns about the efficacy of treatment for critically ill patients.

IMPLICATIONS FOR CLINICAL PRACTICE

Parenteral administration errors pose a challenge in acute care areas. Risk mitigation measures include double-checking of medications. If antimicrobial treatment is not administered at the prescribed dosing intervals, this may have implications for the efficacy of time-dependent broad-spectrum antibiotics such as carbapenems. Medication administration errors involving antimicrobial medications should therefore be considered as high-risk errors, with the potential to contribute towards antimicrobial resistance.

Informing antimicrobial stewardship with explainable AI

The accuracy and flexibility of artificial intelligence (AI) systems often comes at the cost of a decreased ability to offer an intuitive explanation of their predictions. This hinders trust and discourage adoption of AI in healthcare, exacerbated by concerns over liabilities and risks to patients' health in case of misdiagnosis. Providing an explanation for a model's prediction is possible due to recent advances in the field of interpretable machine learning. We considered a data set of hospital admissions linked to records of antibiotic prescriptions and susceptibilities of bacterial isolates. An appropriately trained gradient boosted decision tree algorithm, supplemented by a Shapley explanation model, predicts the likely antimicrobial drug resistance, with the odds of resistance informed by characteristics of the patient, admission data, and historical drug treatments and culture test results. Applying this AI-based system, we found that it substantially reduces the risk of mismatched treatment compared with the observed prescriptions. The Shapley values provide an intuitive association between observations/data and outcomes; the associations identified are broadly consistent with expectations based on prior knowledge from health specialists. The results, and the ability to attribute confidence and explanations, support the wider adoption of AI in healthcare.

Poor timing and failure of source control are risk factors for mortality in critically ill patients with secondary peritonitis

PURPOSE

To describe data on epidemiology, microbiology, clinical characteristics and outcome of adult patients admitted in the intensive care unit (ICU) with secondary peritonitis, with special emphasis on antimicrobial therapy and source control.

METHODS

Post hoc analysis of a multicenter observational study (Abdominal Sepsis Study, AbSeS) including 2621 adult ICU patients with intra-abdominal infection in 306 ICUs from 42 countries. Time-till-source control intervention was calculated as from time of diagnosis and classified into 'emergency' (< 2 h), 'urgent' (2-6 h), and 'delayed' (> 6 h). Relationships were assessed by logistic regression analysis and reported as odds ratios (OR) and 95% confidence interval (CI).

RESULTS

The cohort included 1077 cases of microbiologically confirmed secondary peritonitis. Mortality was 29.7%. The rate of appropriate empiric therapy showed no difference between survivors and non-survivors (66.4% vs. 61.3%, p = 0.1). A stepwise increase in mortality was observed with increasing Sequential Organ Failure Assessment (SOFA) scores (19.6% for a value ≤ 4-55.4% for a value > 12, p < 0.001). The highest odds of death were associated with septic shock (OR 3.08 [1.42-7.00]), late-onset hospital-acquired peritonitis (OR 1.71 [1.16-2.52]) and failed source control evidenced by persistent inflammation at day 7 (OR 5.71 [3.99-8.18]). Compared with 'emergency' source control intervention (< 2 h of diagnosis), 'urgent' source control was the only modifiable covariate associated with lower odds of mortality (OR 0.50 [0.34-0.73]).

CONCLUSION

'Urgent' and successful source control was associated with improved odds of survival. Appropriateness of empirical antimicrobial treatment did not significantly affect survival suggesting that source control is more determinative for outcome.

Healthcare-associated infections in adult intensive care unit patients: Changes in epidemiology, diagnosis, prevention and contributions of new technologies

Patients in intensive care units (ICUs) are at high risk for healthcare-acquired infections (HAI) due to the high prevalence of invasive procedures and devices, induced immunosuppression, comorbidity, frailty and increased age. Over the past decade we have seen a successful reduction in the incidence of HAI related to invasive procedures and devices. However, the rate of ICU-acquired infections remains high. Within this context, the ongoing emergence of new pathogens, further complicates treatment and threatens patient outcomes. Additionally, the SARS-CoV-2 (COVID-19) pandemic highlighted the challenge that an emerging pathogen provides in adapting prevention measures regarding both the risk of exposure to caregivers and the need to maintain quality of care. ICU nurses hold a special place in the prevention and management of HAI as they are involved in basic hygienic care, steering and implementing quality improvement initiatives, correct microbiological sampling, and aspects antibiotic stewardship. The emergence of more sensitive microbiological techniques and our increased knowledge about interactions between critically ill patients and their microbiota are leading us to rethink how we define HAIs and best strategies to diagnose, treat and prevent these infections in the ICU. This multidisciplinary expert review, focused on the ICU setting, will summarise the recent epidemiology of ICU-HAI, discuss the place of modern microbiological techniques in their diagnosis, review operational and epidemiological definitions and redefine the place of several controversial preventive measures including antimicrobial-impregnated medical devices, chlorhexidine-impregnated washcloths, catheter dressings and chlorhexidine-based mouthwashes. Finally, general guidance is suggested that may reduce HAI incidence and especially outbreaks in ICUs.

Epidemiology and Age-Related Mortality in Critically Ill Patients With Intra-Abdominal Infection or Sepsis: An International Cohort Study

BACKGROUND

The objective of this study is to describe the epidemiology and age-related mortality in older critically ill adults with intra-abdominal infections.

METHODS

This is a secondary analysis of a prospective, multinational, observational study (AbSeS, ClinicalTrials.gov #NCT03270345) including patients with intra-abdominal infection from 309 ICUs in 42 countries (January-December, 2016). Mortality was considered as ICU mortality with a minimum of 28 days of observation when patients were discharged earlier. Relationships with mortality were assessed by logistic regression analysis.

RESULTS

The cohort included 2337 patients. Four age groups were defined: middle-aged patients as reference category (40-59 years; n=659 [28.2%]), young-old (60-69 years; n=622 [26.6%]), middle-old (70-79 years; n=667 [28.5%]) and very-old patients (≥80 years; n=389 [16.6%]). Secondary peritonitis was the predominant infection (68.7%) and equally prevalent across age groups. Mortality increased with age: 20.9% in middle-aged patients, 30.5% in young-old, 31.2% in middle-old, and 44.7% in very-old patients (p<0.001). Compared to middle-aged patients, young-old age (OR 1.62, 95% CI 1.21-2.17), middle-old age (OR 1.80, 95% CI 1.35-2.41), and very-old age (OR 3.69, 95% CI 2.66-5.12) were independently associated with mortality. Other independent risk factors for mortality included late-onset hospital-acquired intra-abdominal infection, diffuse peritonitis, sepsis/septic shock, source control failure, liver disease, congestive heart failure, diabetes, and malnutrition.

CONCLUSIONS

For ICU patients with intra-abdominal infections, age above 60 years was associated with mortality while patients above 80 years had the worst prognosis. Comorbidities and overall disease severity further compromised survival. As all these factors are non-modifiable it remains unclear how to improve outcomes.

Personalized antibiograms for machine learning driven antibiotic selection

Background

The Centers for Disease Control and Prevention identify antibiotic prescribing stewardship as the most important action to combat increasing antibiotic resistance. Clinicians balance broad empiric antibiotic coverage vs. precision coverage targeting only the most likely pathogens. We investigate the utility of machine learning-based clinical decision support for antibiotic prescribing stewardship.

Methods

In this retrospective multi-site study, we developed machine learning models that predict antibiotic susceptibility patterns (personalized antibiograms) using electronic health record data of 8342 infections from Stanford emergency departments and 15,806 uncomplicated urinary tract infections from Massachusetts General Hospital and Brigham & Women’s Hospital in Boston. We assessed the trade-off between broad-spectrum and precise antibiotic prescribing using linear programming.

Results

We find in Stanford data that personalized antibiograms reallocate clinician antibiotic selections with a coverage rate (fraction of infections covered by treatment) of 85.9%; similar to clinician performance (84.3% p = 0.11). In the Boston dataset, the personalized antibiograms coverage rate is 90.4%; a significant improvement over clinicians (88.1% p < 0.0001). Personalized antibiograms achieve similar coverage to the clinician benchmark with narrower antibiotics. With Stanford data, personalized antibiograms maintain clinician coverage rates while narrowing 69% of empiric vancomycin+piperacillin/tazobactam prescriptions to piperacillin/tazobactam. In the Boston dataset, personalized antibiograms maintain clinician coverage rates while narrowing 48% of ciprofloxacin to trimethoprim/sulfamethoxazole.

Conclusions

Precision empiric antibiotic prescribing with personalized antibiograms could improve patient safety and antibiotic stewardship by reducing unnecessary use of broad-spectrum antibiotics that breed a growing tide of resistant organisms.

Antimicrobial Lessons From a Large Observational Cohort on Intra-abdominal Infections in Intensive Care Units

Severe intra-abdominal infection commonly requires intensive care. Mortality is high and is mainly determined by disease-specific characteristics, i.e. setting of infection onset, anatomical barrier disruption, and severity of disease expression. Recent observations revealed that antimicrobial resistance appears equally common in community-acquired and late-onset hospital-acquired infection. This challenges basic principles in anti-infective therapy guidelines, including the paradigm that pathogens involved in community-acquired infection are covered by standard empiric antimicrobial regimens, and second, the concept of nosocomial acquisition as the main driver for resistance involvement. In this study, we report on resistance profiles of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterococcus faecalis and Enterococcus faecium in distinct European geographic regions based on an observational cohort study on intra-abdominal infections in intensive care unit (ICU) patients. Resistance against aminopenicillins, fluoroquinolones, and third-generation cephalosporins in E. coli, K. pneumoniae and P. aeruginosa is problematic, as is carbapenem-resistance in the latter pathogen. For E. coli and K. pneumoniae, resistance is mainly an issue in Central Europe, Eastern and South-East Europe, and Southern Europe, while resistance in P. aeruginosa is additionally problematic in Western Europe. Vancomycin-resistance in E. faecalis is of lesser concern but requires vigilance in E. faecium in Central and Eastern and South-East Europe. In the subcohort of patients with secondary peritonitis presenting with either sepsis or septic shock, the appropriateness of empiric antimicrobial therapy was not associated with mortality. In contrast, failure of source control was strongly associated with mortality. The relevance of these new insights for future recommendations regarding empiric antimicrobial therapy in intra-abdominal infections is discussed.

Emergence of Nosocomial Pneumonia Caused by Colistin-Resistant Escherichia coli in Patients Admitted to Chest Intensive Care Unit

(1) Background: Colistin is a last-resort antibiotic used in treating multidrug-resistant Gram-negative infections. The growing emergence of colistin resistance in Escherichia coli (E. coli) represents a serious health threat, particularly to intensive care unit (ICU) patients. (2) Methods: In this work, we investigated the emergence of colistin resistance in 140 nosocomial E. coli isolated from patients with pneumonia and admitted to the chest ICU over 36 months. Virulence and resistance-related genes and E. coli pathotypes in colistin-resistant and colistin-sensitive isolates were determined. (3) Results: Colistin resistance was observed in 21/140 (15%) of the nosocomial E. coli isolates. The MIC₅₀ of the resistant strains was 4 mg/L, while MIC₉₀ was 16 mg/L. Colistin-resistant isolates were also co-resistant to amoxicillin, amoxicillin/clavulanic, aztreonam, ciprofloxacin, and chloramphenicol. The mechanism of colistin resistance was represented by the presence of mcr-1 in all resistant strains. Respectively, 42.9% and 36.1% of colistin-resistant and colistin-sensitive groups were extended-spectrum β-lactamase (ESBL) producers, while 23.8% and 21% were metallo β-lactamase (MBL) producers. bla_TEM-type was the most frequently detected ESBL gene, while bla_IMP-type was the most common MBL in both groups. Importantly, most resistant strains showed a significantly high prevalence of astA (76.2%), aggR (76.2%), and pic (52.4%) virulence-related genes. Enteroaggregative E. coli (76%) was the most frequently detected genotype among the colistin-resistant strains. (4) Conclusion: The high colistin resistance rate observed in E. coli strains isolated from patients with nosocomial pneumonia in our university hospital is worrisome. These isolates carry different drug resistance and virulence-related genes. Our results indicate the need for careful monitoring of colistin resistance in our university hospital. Furthermore, infection control policies restricting the unnecessary use of extended-spectrum cephalosporins and carbapenems are necessary.

[Evaluation of the Antimicrobial Effects of a Novel Visible Light-driven Photocatalyst in Vitro and in the Environment]

Environmental microorganisms can cause several infections in humans, especially in compromised hosts. Since there are many compromised hosts in a hospital setting, it is important to control environmental pathogens in such scenarios. To disinfect the environment, photocatalysts that produce reactive oxygen in response to light have attracted attention. In the present study, the effects of a visible-light-driven antimicrobial photocatalyst, silver (I) iodide and benzalkonium complex, on bacteria, viruses, and fungi were evaluated in vitro. In addition, uncoated panels and panels coated with the photocatalyst were set up at 11 points in a university campus for 6 months, and the adherent bacteria and fungi were measured. Bacteria, bacterial spores, viruses, and fungi were completely inactivated within 45 min on the photocatalyst-coated surface exposed to approximately 700-lux fluorescent light. In the university setting, there were fewer viable adherent bacteria and fungi on the coated plates. Our findings indicate that the silver (I) iodide and benzalkonium complex photocatalyst can decrease environmental bacteria in vitro and in actual environmental settings, and thus highlight its potential in controlling and disinfecting environmental pathogens.

Procalcitonin as a predictor of early antibiotic treatment failure in patients with gram-negative bloodstream infections caused by urinary tract infections

We retrospectively evaluated whether initial procalcitonin (PCT) levels can predict early antibiotic treatment failure (ATF) in patients with gram-negative bloodstream infections (GN-BSI) caused by urinary tract infections from January 2018 to November 2019. Early ATF was defined as the following: (1) hemodynamically unstable or febrile at Day 3; (2) the need for mechanical ventilation or continuous renal replacement therapy at Day 3; (3) patients who died within 3 days (date of blood culture: Day 0). The study included 189 patients; 42 showed early ATF. Independent risk factors for early ATF were initial admission to the intensive care unit (odds ratio: 7.735, 95% confidence interval: 2.567-23.311; P < 0.001) and PCT levels ≥30 ng/mL (odds ratio: 5.413, 95% confidence interval: 2.188-13.388; P < 0.001). Antibiotic factors were not associated with early ATF. Initial PCT levels may be helpful to predict early ATF in these patients.

Population pharmacokinetics and evaluation of the predictive performance of pharmacokinetic models in critically ill patients receiving continuous infusion meropenem: a comparison of eight pharmacokinetic models

Background

Several population pharmacokinetic (PopPK) models for meropenem dosing in ICU patients are available. It is not known to what extent these models can predict meropenem concentrations in an independent validation dataset when meropenem is infused continuously.

Patients and methods

A PopPK model was developed with concentration-time data collected from routine care of 21 ICU patients (38 samples) receiving continuous infusion meropenem. The predictability of this model and seven other published PopPK models was studied using an independent dataset that consisted of 47 ICU patients (161 samples) receiving continuous infusion meropenem. A statistical comparison of imprecision (mean square prediction error) and bias (mean prediction error) was conducted.

Results

A one-compartment model with linear elimination and creatinine clearance as a covariate of clearance best described our data. The mean ± SD parameter estimate for CL was 9.89 ± 3.71 L/h. The estimated volume of distribution was 48.1 L. The different PopPK models showed a bias in predicting serum concentrations from the validation dataset that ranged from -8.76 to 7.06 mg/L. Imprecision ranged from 9.90 to 42.1 mg/L.

Conclusions

Published PopPK models for meropenem vary considerably in their predictive performance when validated in an external dataset of ICU patients receiving continuous infusion meropenem. It is necessary to validate PopPK models in a target population before implementing them in a therapeutic drug monitoring program aimed at optimizing meropenem dosing.

Epidemiology of intra-abdominal infection and sepsis in critically ill patients: "AbSeS", a multinational observational cohort study and ESICM Trials Group Project

Purpose

To describe the epidemiology of intra-abdominal infection in an international cohort of ICU patients according to a new system that classifies cases according to setting of infection acquisition (community-acquired, early onset hospital-acquired, and late-onset hospital-acquired), anatomical disruption (absent or present with localized or diffuse peritonitis), and severity of disease expression (infection, sepsis, and septic shock).

Methods

We performed a multicenter (n = 309), observational, epidemiological study including adult ICU patients diagnosed with intra-abdominal infection. Risk factors for mortality were assessed by logistic regression analysis.

Results

The cohort included 2621 patients. Setting of infection acquisition was community-acquired in 31.6%, early onset hospital-acquired in 25%, and late-onset hospital-acquired in 43.4% of patients. Overall prevalence of antimicrobial resistance was 26.3% and difficult-to-treat resistant Gram-negative bacteria 4.3%, with great variation according to geographic region. No difference in prevalence of antimicrobial resistance was observed according to setting of infection acquisition. Overall mortality was 29.1%. Independent risk factors for mortality included late-onset hospital-acquired infection, diffuse peritonitis, sepsis, septic shock, older age, malnutrition, liver failure, congestive heart failure, antimicrobial resistance (either methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum beta-lactamase-producing Gram-negative bacteria, or carbapenem-resistant Gram-negative bacteria) and source control failure evidenced by either the need for surgical revision or persistent inflammation.

Conclusion

This multinational, heterogeneous cohort of ICU patients with intra-abdominal infection revealed that setting of infection acquisition, anatomical disruption, and severity of disease expression are disease-specific phenotypic characteristics associated with outcome, irrespective of the type of infection. Antimicrobial resistance is equally common in community-acquired as in hospital-acquired infection.

Electronic supplementary material

The online version of this article (10.1007/s00134-019-05819-3) contains supplementary material, which is available to authorized users.

Is systematic fecal carriage screening of extended-spectrum beta-lactamase-producing Enterobacteriaceae still useful in intensive care unit: a systematic review

BACKGROUND

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) are disseminating worldwide leading to increased hospital length of stay and mortality in intensive care units (ICU). ESBL-E dissemination was first due to outbreaks in hospital settings which led to the implementation of systematic fecal carriage screening to improve hygiene procedures by contact precautions. ESBLs have since spread in the community, and the relevance of contact precautions is questioned. ESBL-E dissemination led to an overuse of carbapenems triggering the emergence of carbapenem-resistant Enterobacteriaceae. Empirical antimicrobial therapy based on ESBL-E fecal carriage has been proposed but is debated as it could increase the consumption of carbapenems among ESBL-E carriers without any clinical benefit. Finally, selective decontamination among ESBL-E fecal carriers is evoked to decrease the risk for subsequent ESBL-E infection, but its efficacy remains debated. We propose to systematically review the evidence to recommend or not such systematic ESBL-E fecal carriage screening in adult ICU.

METHODS

Every article focusing on ESBL-E and ICU available on the MEDLINE database was assessed. Articles were included if focusing on cross-transmission, efficacy of hygiene procedures, link between ESBL-E colonization and infection or guidance of empirical therapy or selective decontamination efficacy.

RESULTS

Among 330 articles referenced on PubMed, 39 abstracts were selected for full-text assessment and 25 studies were included. Systematic screening of ESBL-E fecal carriage to guide contact precautions do not seem to decrease the rate of ESBL-E cross-transmission. It has a very good negative predictive value for subsequent ESBL-E infections but a positive predictive value between 40 and 50% and so does not help to spare carbapenems. Cessation of ESBL-E carriage systematic screening could decrease the use of carbapenems in ICU without any clinical harm. Nevertheless, further studies are needed to validate these results from monocentric before-after study. Selective decontamination strategy applied to ESBL-E fecal carriers could be helpful, but available data are conflicting.

CONCLUSION

Current knowledge lacks of high-quality evidence to strongly recommend in favor of or against a systematic ESBL-E fecal carriage screening policy for ICU patients in a non-outbreak situation. Further evaluation of selective decontamination or fecal microbiota transplantation among ESBL-E fecal carriers is needed.

Salivary Gland Extract from Aedes aegypti Improves Survival in Murine Polymicrobial Sepsis through Oxidative Mechanisms

Sepsis is a systemic disease with life-threatening potential and is characterized by a dysregulated immune response from the host to an infection. The organic dysfunction in sepsis is associated with the production of inflammatory cascades and oxidative stress. Previous studies showed that Aedes aegypti saliva has anti-inflammatory, immunomodulatory, and antioxidant properties. Considering inflammation and the role of oxidative stress in sepsis, we investigated the effect of pretreatment with salivary gland extract (SGE) from Ae. aegypti in the induction of inflammatory and oxidative processes in a murine cecum ligation and puncture (CLP) model. Here, we evaluated animal survival for 16 days, as well as bacterial load, leukocyte migration, and oxidative parameters. We found that the SGE pretreatment improved the survival of septic mice, reduced bacterial load and neutrophil influx, and increased nitric oxide (NO) production in the peritoneal cavity. With regard to oxidative status, SGE increased antioxidant defenses as measured by Trolox equivalent antioxidant capacity (TEAC) and glutathione (GSH), while reducing levels of the oxidative stress marker malondialdehyde (MDA). Altogether, these data suggest that SGE plays a protective role in septic animals, contributing to oxidative and inflammatory balance during sepsis. Therefore, Ae. aegypti SGE is a potential source for new therapeutic molecule(s) in polymicrobial sepsis, and this effect seems to be mediated by the control of inflammation and oxidative damage.

Surveillance of Antibiotic Prescribing in Intensive Care Units in Poland

Antibiotic use and microbial resistance in health care-associated infections are increasing globally and causing health care problems. Intensive Care Units (ICUs) represent the heaviest antibiotic burden within hospitals, and sepsis is the second noncardiac cause of mortality in ICUs. Optimizing appropriate antibiotic treatment in the management of the critically ill in ICUs became a major challenge for intensivists. We performed a surveillance study on the antibiotic consumption in 108 Polish ICUs. We determined which classes of antibiotics were most commonly consumed and whether they affected the length of ICU stay and the size and category of the hospital. A total of 292.389 defined daily doses (DDD) and 192.167 patient-days (pd) were identified. Antibiotic consumption ranged from 620 to 3960 DDD/1000 pd. The main antibiotic classes accounted for 59.6% of the total antibiotic consumption and included carbapenems (17.8%), quinolones (14%), cephalosporins (13.7%), penicillins (11.9%), and macrolides (2.2%), respectively, whereas the other antibiotic classes accounted for the remainder (40.4%) and included antifungals (34%), imidazoles (20%), aminoglycosides (18%), glycopeptides (15%), and polymyxins (6%). The most consumed antibiotic classes in Polish ICUs were carbapenems, quinolones, and cephalosporins, respectively. There was no correlation between antibiotic consumption in DDD/1000 patient-days, mean length of ICU stay, size of the hospital, size of the ICU, or the total amount of patient-days. It is crucial that surveillance systems are in place to guide empiric antibiotic treatment and to estimate the burden of resistance. Appropriate use of antibiotics in the ICU should be an important public health care issue.

Emergence of antimicrobial resistance to piperacillin/tazobactam or meropenem in the ICU: Intermittent versus continuous infusion. A retrospective cohort study

BACKGROUND

Prolonged infusion of beta-lactam antibiotics is broadly recognized as a strategy to optimize antibiotic therapy by achieving a higher percentage of time that concentrations remain above the minimal inhibitory concentration (% fT_>MIC), i.e. the pharmacokinetic/pharmacodynamic (PK/PD) index. However, %fT_>MIC may not be the PK/PD index of choice for inhibition of resistance emergence and it is therefore unsure what impact prolonged infusion of beta-lactam antibiotics may have on the emergence of resistance.

METHODS

A retrospective cohort study including 205 patients receiving either intermittent (101 patients) or continuous (104 patients) infusion of piperacillin/tazobactam or meropenem was conducted in the ICU of the Ghent University Hospital. Logistic regression analysis was used to develop a prediction model and to determine whether the mode of infusion was a predictor of emergence of antimicrobial resistance.

RESULTS

Resistant strains emerged in 24 out of the 205 patients (11.7%). The mode of infusion was no predictor of emergence of antimicrobial resistance. Infection with Pseudomonas aeruginosa was associated with a significantly higher risk for emergence of resistance.

CONCLUSIONS

In this retrospective cohort study, the emergence of antimicrobial resistance to piperacillin/tazobactam or meropenem was not related to the mode of infusion.

Population pharmacokinetics of continuous infusion of piperacillin in critically ill patients

Dosing recommendations for continuous infusion of piperacillin, a broad-spectrum beta-lactam antibiotic, are mainly guided by outputs from population pharmacokinetic models constructed with intermittent infusion data. However, the probability of target attainment in patients receiving piperacillin by continuous infusion may be overestimated when drug clearance estimates from population pharmacokinetic models based on intermittent infusion data are used, especially when higher doses (e.g. 16 g/24 h or more) are simulated. Therefore, the purpose of this study was to describe the population pharmacokinetics of piperacillin when infused continuously in critically ill patients. For this analysis, 270 plasma samples from 110 critically ill patients receiving piperacillin were available for population pharmacokinetic model building. A one-compartment model with linear clearance best described the concentration-time data. The mean ± standard deviation parameter estimates were 8.38 ± 9.91 L/h for drug clearance and 25.54 ± 3.65 L for volume of distribution. Creatinine clearance improved the model fit and was supported for inclusion as a covariate. In critically ill patients with renal clearance higher than 90 mL/min/1.73 m², a high-dose continuous infusion of 24 g/24 h is insufficient to achieve adequate exposure (pharmacokinetic/pharmacodynamic target of 100% fT_{>4 x MIC}) against susceptible Pseudomonas aerginosa isolates (MIC ≤16 mg/L). These findings suggest that merely increasing the dose of piperacillin, even with continuous infusion, may not always result in adequate piperacillin exposure. This should be confirmed by evaluating piperacillin target attainment rates in critically ill patients exhibiting high renal clearance.

Infections Caused by Antimicrobial Drug-Resistant Saprophytic Gram-Negative Bacteria in the Environment

Background

Drug-resistance genes found in human bacterial pathogens are increasingly recognized in saprophytic Gram-negative bacteria (GNB) from environmental sources. The clinical implication of such environmental GNBs is unknown.

Objectives

We conducted a systematic review to determine how often such saprophytic GNBs cause human infections.

Methods

We queried PubMed for articles published in English, Spanish, and French between January 2006 and July 2014 for 20 common environmental saprophytic GNB species, using search terms “infections,” “human infections,” “hospital infection.” We analyzed 251 of 1,275 non-duplicate publications that satisfied our selection criteria. Saprophytes implicated in blood stream infection (BSI), urinary tract infection (UTI), skin and soft tissue infection (SSTI), post-surgical infection (PSI), osteomyelitis (Osteo), and pneumonia (PNA) were quantitatively assessed.

Results

Thirteen of the 20 queried GNB saprophytic species were implicated in 674 distinct infection episodes from 45 countries. The most common species included Enterobacter aerogenes, Pantoea agglomerans, and Pseudomonas putida. Of these infections, 443 (66%) had BSI, 48 (7%) had SSTI, 36 (5%) had UTI, 28 (4%) had PSI, 21 (3%) had PNA, 16 (3%) had Osteo, and 82 (12%) had other infections. Nearly all infections occurred in subjects with comorbidities. Resistant strains harbored extended-spectrum beta-lactamase (ESBL), carbapenemase, and metallo-β-lactamase genes recognized in human pathogens.

Conclusion

These observations show that saprophytic GNB organisms that harbor recognized drug-resistance genes cause a wide spectrum of infections, especially as opportunistic pathogens. Such GNB saprophytes may become increasingly more common in healthcare settings, as has already been observed with other environmental GNBs such as Acinetobacter baumannii and Pseudomonas aeruginosa.

Rapid real-time recirculating PCR using localized surface plasmon resonance (LSPR) and piezo-electric pumping

Rapid detection and characterization of pathogens in patients with bloodstream infections (BSIs) is a persistent problem for modern medicine, as current techniques are slow or provide incomplete diagnostic information. Real-time polymerase chain reaction (qPCR) allows specific detection of a wide range of targets and quantification of pathogenic burdens to aid in treatment planning. However, new technological advances are required for a rapid and multiplex implementation of qPCR in clinical applications. In this paper, the feasibility of a novel microfluidic platform for qPCR is presented, integrating highly sensitive, label-free localized surface plasmon resonance (LSPR) imaging of DNA hybridization into a recirculating chip design for real-time analysis. Single target and multiplex detection of DNA target amplification are demonstrated, with a limit of detection of 5 fg μL^-1 of E. coli DNA for single target PCR, correlating with approximately 300 bacteria per mL. The results of this study demonstrate the potential of this platform for simultaneous real-time detection of multiple target genes within 15 minutes that could provide live saving benefits in patients with BSIs.

Targeted de-escalation rounds may effectively and safely reduce meropenem use

OBJECTIVE

Use of meropenem in our hospital has doubled in recent years. An audit in 2013 showed that although initiation of therapy with meropenem was generally appropriate, therapy was rarely subsequently reviewed and de-escalated where appropriate. Therefore, a structured stewardship initiative focussed on meropenem de-escalation was developed.

METHODS

A local guideline for review and de-escalation of meropenem was developed and approved by the Antimicrobial Stewardship Team. The guideline outlined clinical and microbiological criteria which when met should lead to recommendation for meropenem de-escalation. Implementation of the guideline was piloted for a period of 4 weeks by a consultant microbiologist and an antimicrobial pharmacist. Days of meropenem use and crude mortality in those in whom de-escalation was implemented were compared with those where de-escalation was not recommended or was recommended but not implemented.

RESULTS

Thirty-three patients were reviewed. Overall, a recommendation to de-escalate from meropenem to a specified alternative antibiotic was made for 18 (55 %) patients. This advice was followed for 12 (36 %) patients. The median days of meropenem use in patients where meropenem was de-escalated was 4.5 days (range 2-19) compared with 14 days (range 6-84) where de-escalation was not recommended or the recommendation was not implemented. There was no statistically significant difference in crude mortality between patients de-escalated from meropenem and those where meropenem was continued.

CONCLUSION

This pilot study suggests that targeted carbapenem de-escalation stewardship activity based on pre-determined criteria, while labour intensive, can effectively and safely reduce meropenem use in the acute hospital setting.

Beyond Blood Culture and Gram Stain Analysis: A Review of Molecular Techniques for the Early Detection of Bacteremia in Surgical Patients

BACKGROUND

Sepsis from bacteremia occurs in 250,000 cases annually in the United States, has a mortality rate as high as 60%, and is associated with a poorer prognosis than localized infection. Because of these high figures, empiric antibiotic administration for patients with systemic inflammatory response syndrome (SIRS) and suspected infection is the second most common indication for antibiotic administration in intensive care units (ICU)s. However, overuse of empiric antibiotics contributes to the development of opportunistic infections, antibiotic resistance, and the increase in multi-drug-resistant bacterial strains. The current method of diagnosing and ruling out bacteremia is via blood culture (BC) and Gram stain (GS) analysis.

METHODS

Conventional and molecular methods for diagnosing bacteremia were reviewed and compared. The clinical implications, use, and current clinical trials of polymerase chain reaction (PCR)-based methods to detect bacterial pathogens in the blood stream were detailed.

RESULTS

BC/GS has several disadvantages. These include: some bacteria do not grow in culture media; others do not GS appropriately; and cultures can require up to 5 d to guide or discontinue antibiotic treatment. PCR-based methods can be potentially applied to detect rapidly, accurately, and directly microbes in human blood samples.

CONCLUSIONS

Compared with the conventional BC/GS, particular advantages to molecular methods (specifically, PCR-based methods) include faster results, leading to possible improved antibiotic stewardship when bacteremia is not present.

Antimicrobial Justification form for Restricting Antibiotic Use in a Pediatric Intensive Care Unit

OBJECTIVE

To study whether introduction of an antimicrobial justification form deters clinicians from prescribing restricted antimicrobials and results in de-escalation of these antimicrobials.

METHODS

Clinicians were asked to fill a justification form if prescribing an antimicrobial from the pre-identified restricted group. Antimicrobial usage pattern over next year was compared with that in the one year preceding the introduction of justification form.

RESULTS

Significant overall decrease in antimicrobial usage (40.5% vs 34.6%) was noted in the post-intervention group along with a significant increase in the de-escalation of antibiotics.

CONCLUSION

Introduction of a justification form before prescribing antimicrobials or at the time of deferring de-escalation can be useful in restricting usage of antimicrobials.

An Argument for the Use of Aminoglycosides in the Empiric Treatment of Ventilator-Associated Pneumonia

BACKGROUND

Appropriate empiric antibiotic therapy for ventilator-associated pneumonia improves outcomes. Controversy exists regarding the inclusion of aminoglycosides in empiric therapeutic regimens.

METHODS

The Ovid and Cochrane databases were searched for relevant literature regarding the use of aminoglycosides in combination therapy for ventilator-associated pneumonia. The data supporting the use of aminoglycosides in certain populations and strategies to limit toxicity are summarized.

RESULTS

In patients at high risk of infection with antibiotic-resistant gram-negative bacilli and in those with severe illness, aminoglycosides improve clinical outcomes. In critically ill populations, short-duration therapy and high-dose extended-interval dosing of aminoglycosides can improve therapeutic efficacy while limiting nephrotoxicity.

CONCLUSIONS

In selected populations using appropriate dosing strategies, aminoglycosides should be considered for empiric treatment of ventilator-associated pneumonia.

Blood stream infections due to multidrug-resistant organisms among spinal cord-injured patients, epidemiology over 16 years and associated risks: a comparative study

STUDY DESIGN

Retrospective study.

OBJECTIVES

We aimed to describe the epidemiology of multidrug-resistant organisms (MDROs) during bloodstream infection (BSI) and identify associated risks of MDROs among patients with spinal cord injury (SCI).

SETTING

A teaching hospital, expert center in disability, in France.

METHODS

We studied a retrospective cohort of all BSIs occurring in SCI patients hospitalized over 16 years. We described the prevalence of MDRO BSI among this population and its evolution over time and compared the BSI population due to MDROs and due to non-MDROs.

RESULTS

A total of 318 BSIs occurring among 256 patients were included in the analysis. The most frequent primary sites of infection were urinary tract infection (34.0%), pressure sore (25.2%) and catheter line-associated bloodstream infection (11.3%). MDROs were responsible for 41.8% of BSIs, and this prevalence was stable over 16 years. No significant associated factor for MDRO BSI could be identified concerning sociodemographic and clinical characteristics, primary site of infection and bacterial species in univariate and multivariate analyses. BSI involving MDROs was not associated with initial severity of sepsis compared with infection without MDROs (43.8 vs 43.6%, respectively) and was not associated either with 30th-day mortality (6.2 vs 9%, respectively).

CONCLUSION

During BSI occurrence in an SCI population, MDROs are frequent but remain stable over years. No associated risk can be identified that would help optimize antibiotic treatment. Neither the severity of the episode nor the mortality is significantly different when an MDRO is involved.

Empirical antibiotic therapy for pneumonia in intensive care units: a multicentre, retrospective analysis of potentially pathogenic microorganisms identified by endotracheal aspirates cultures

The purpose of this investigation was to explore the presumed relationship between the days of hospitalisation and microorganisms identified by endotracheal aspirate cultures in relation to adequate empirical treatment strategies of pneumonia in the intensive care unit (ICU). All potentially pathogenic microorganisms identified by (surveillance) cultures of endotracheal aspirates obtained in the ICUs of two Dutch teaching hospitals in 2007 and 2012 were retrospectively collected and analysed. Antibiotic susceptibilities to 11 antibiotics were calculated for several time points (days or weeks) after hospital admission and expressed per patient-day. In total, 4184 potentially pathogenic microorganisms identified in 782 patients were analysed. Prevalence of the classic early-onset pneumonia-causing microorganisms decreased from 55 % on the first four days to 34 % on days 4–6 after hospital admission (p < 0.0001). Susceptibility to amoxicillin/clavulanic acid was below 70 % on all days. Except for days 0 and 12, susceptibility to ceftriaxone was below 80 %. The overall susceptibility to piperacillin/tazobactam was 1518/1973 (77 %) in 2007 vs. 727/1008 (67 %) in 2012 (p < 0.0001). After day 8 of hospital admission, susceptibility to piperacillin/tazobactam therapy was below 80 % in 2012. After one week of hospital admission, susceptibilities to antibiotics were lower in the hospital that included that antibiotic in the local empirical treatment protocols as compared to the hospitals in which that antibiotic was not or infrequently included: 90/434 (21 %) vs. 117/398 (29 %); p = 0.004 for amoxicillin/clavulanic acid and 203/433 (47 %) vs. 253/398 (64 %); p < 0.001 for ceftriaxone. No cut-off in the number of days after hospital admission could be identified to distinguish early-onset from late-onset pneumonia. Consequently, the choice of empirical antibiotics should probably not be based on the time of onset.

Procalcitonin algorithm in critically ill adults with undifferentiated infection or suspected sepsis. A randomized controlled trial

RATIONALE

The role of procalcitonin (PCT), a widely used sepsis biomarker, in critically ill patients with sepsis is undetermined.

OBJECTIVES

To investigate the effect of a low PCT cut-off on antibiotic prescription and to describe the relationships between PCT plasma concentration and sepsis severity and mortality.

METHODS

This was a multicenter (11 Australian intensive care units [ICUs]), prospective, single-blind, randomized controlled trial involving 400 patients with suspected bacterial infection/sepsis and expected to receive antibiotics and stay in ICU longer than 24 hours. The primary outcome was the cumulative number of antibiotics treatment days at Day 28.

MEASUREMENTS AND MAIN RESULTS

PCT was measured daily while in the ICU. A PCT algorithm, including 0.1 ng/ml cut-off, determined antibiotic cessation. Published guidelines and antimicrobial stewardship were used in all patients. Primary analysis included 196 (PCT) versus 198 standard care patients. Ninety-three patients in each group had septic shock. The overall median (interquartile range) number of antibiotic treatment days were 9 (6-21) versus 11 (6-22), P = 0.58; in patients with positive pulmonary culture, 11 (7-27) versus 15 (8-27), P = 0.33; and in patients with septic shock, 9 (6-22) versus 11 (6-24), P = 0.64; with an overall 90-day all-cause mortality of 35 (18%) versus 31 (16%), P = 0.54 in the PCT versus standard care, respectively. Using logistic regression, adjusted for age, ventilation status, and positive culture, the decline rate in log(PCT) over the first 72 hours independently predicted hospital and 90-day mortality (odds ratio [95% confidence interval], 2.76 [1.10-6.96], P = 0.03; 3.20 [1.30-7.89], P = 0.01, respectively).

CONCLUSIONS

In critically ill adults with undifferentiated infections, a PCT algorithm including 0.1 ng/ml cut-off did not achieve 25% reduction in duration of antibiotic treatment. Clinical trial registered with http://www.anzctr.org.au (ACTRN12610000809033).

Antibiotic stewardship programmes in intensive care units: Why, how, and where are they leading us

Antibiotic usage and increasing antimicrobial resistance (AMR) mount significant challenges to patient safety and management of the critically ill on intensive care units (ICU). Antibiotic stewardship programmes (ASPs) aim to optimise appropriate antibiotic treatment whilst minimising antibiotic resistance. Different models of ASP in intensive care setting, include “standard” control of antibiotic prescribing such as “de-escalation strategies”through to interventional approaches utilising biomarker-guided antibiotic prescribing. A systematic review of outcomes related studies for ASPs in an ICU setting was conducted. Forty three studies were identified from MEDLINE between 1996 and 2014. Of 34 non-protocolised studies, [1 randomised control trial (RCT), 22 observational and 11 case series], 29 (85%) were positive with respect to one or more outcome: These were the key outcome of reduced antibiotic use, or ICU length of stay, antibiotic resistance, or prescribing cost burden. Limitations of non-standard antibiotic initiation triggers, patient and antibiotic selection bias or baseline demographic variance were identified. All 9 protocolised studies were RCTs, of which 8 were procalcitonin (PCT) guided antibiotic stop/start interventions. Five studies addressed antibiotic escalation, 3 de-escalation and 1 addressed both. Six studies reported positive outcomes for reduced antibiotic use, ICU length of stay or antibiotic resistance. PCT based ASPs are effective as antibiotic-stop (de-escalation) triggers, but not as an escalation trigger alone. PCT has also been effective in reducing antibiotic usage without worsening morbidity or mortality in ventilator associated pulmonary infection. No study has demonstrated survival benefit of ASP. Ongoing challenges to infectious disease management, reported by the World Health Organisation global report 2014, are high AMR to newer antibiotics, and regional knowledge gaps in AMR surveillance. Improved AMR surveillance data, identifying core aspects of successful ASPs that are transferable, and further well-conducted trials will be necessary if ASPs are to be an effective platform for delivering desired patient outcomes and safety through best antibiotic policy.

Recent advances in multidisciplinary critical care

The intensive care unit is a work environment where superior dedication is crucial for optimizing patients' outcomes. As this demanding commitment is multidisciplinary in nature, it requires special qualities of health care workers and organizations. Thus research in the field covers a broad spectrum of activities necessary to deliver cutting-edge care. However, given the numerous research articles and education activities available, it is difficult for modern critical care clinicians to keep up with the latest progress and innovation in the field. This article broadly summarizes new developments in multidisciplinary intensive care. It provides elementary information about advanced insights in the field via brief descriptions of selected articles grouped by specific topics. Issues considered include care for heart patients, mechanical ventilation, delirium, nutrition, pressure ulcers, early mobility, infection prevention, transplantation and organ donation, care for caregivers, and family matters.

Prevalence of extensively drug-resistant gram negative bacilli in surgical intensive care in Egypt

Introduction

The prevalence of extensively drug resistant gram negative bacilli (XDR-GNB) is rapidly progressing; however in Egypt data are sparse. We conducted the present study to quantify the incidence, risk factors and outcome of patients harboring XDR-GNB.

Methods

A one year prospective study was done by collecting all the bacteriological reports for cultures sent from the surgical intensive care unit, Cairo university teaching hospital. XDR-GNB were defined as any gram negative bacilli resistant to three or more classes of antimicrobial agents. Patients with XDR-GNB compared with those sustaining non extensively drug-resistant infection. A multivariate logistic regression model was created to identify independent predictors of multi-resistance.

Results

During one-year study period, a total of 152 samples (65%) out of 234 gram negative bacilli samples developed extensively drug resistant infection. XDR strains were significantly higher in Acinetobacterspp (86%), followed by Pseudomonas (63%), then Proteus (61%), Klebsiella (52%), and E coli (47%). Fourth generation cephalosporine (Cefipime) had the lowest susceptibility (10%) followed by third generation cephalosporines (11%), Quinolones (31%), Amikacin (42%), Tazobactam (52%), Carbapinems (52%), and colistin (90%). Relaparotomy was the only significant risk factor for acquisition of XDR infection.

Conclusion

Extensively drug-resistant gram negative infections are frequent in our ICU. This is an alarming health care issue in Egypt which emphasizes the need to rigorously implement infection control practices.

Quantitative analysis and pharmacokinetics study of tigecycline in human serum using a validated sensitive liquid chromatography with tandem mass spectrometry method

Tigecycline, a novel intravenously administered glycylcycline antibiotic, currently plays a key role in the management of complicated multiorganism infections. However, current liquid chromatography with tandem mass spectrometry methods briefly describe parameters and the only reported internal standard was sometimes difficult to obtain. In our study, an updated liquid chromatography with tandem mass spectrometry method for the quantitative analysis of tigecycline in human serum was developed. Sample preparation involved precipitation with 20% trichloroacetic acid. Chromatographic separation of tigecycline and tetracycline (internal standard) was achieved on a Hypersil GOLD C18 column using gradient elution. The selected reaction monitoring transitions were performed at m/z 586.1→513.2 for tigecycline and m/z 445.1→410.2 for tetracycline. The assay was linear over the concentration range of 5-2000 ng/mL. The intra- and interday precisions at three concentration levels (10, 100, and 1600 ng/mL) were <15% and their accuracies were within the range of 95.1-106.1%. The mean recovery ranged from 94.3 to 105.6% and the matrix effect from 92.1 to 97.6%. Tigecycline was stable under all tested conditions. This validated method was successfully applied to a pharmacokinetic study in critically ill patients. The data demonstrated that our method allows quantification of tigecycline in serum in a quick and reliable manner for widespread application.

Prevalence, risk factors, and mortality for ventilator-associated pneumonia in middle-aged, old, and very old critically ill patients*

OBJECTIVE

We investigated the epidemiology of ventilator-associated pneumonia in elderly ICU patients. More precisely, we assessed prevalence, risk factors, signs and symptoms, causative bacterial pathogens, and associated outcomes.

DESIGN

Secondary analysis of a multicenter prospective cohort (EU-VAP project).

SETTING

Twenty-seven European ICUs.

PATIENTS

Patients who were mechanically ventilated for greater than or equal to 48 hours. We compared middle-aged (45-64 yr; n = 670), old (65-74 yr; n = 549), and very old patients (≥ 75 yr; n= 516).

MEASUREMENTS AND MAIN RESULTS

Ventilator-associated pneumonia occurred in 103 middle-aged (14.6%), 104 old (17.0%), and 73 very old patients (12.8%). The prevalence (n ventilator-associated pneumonia/1,000 ventilation days) was 13.7 in middle-aged patients, 16.6 in old patients, and 13.0 in very old patients. Logistic regression analysis could not demonstrate older age as a risk factor for ventilator-associated pneumonia. Ventilator-associated pneumonia in elderly patients was more frequently caused by Enterobacteriaceae (24% in middle-aged, 32% in old, and 43% in very old patients; p = 0.042). Regarding clinical signs and symptoms at ventilator-associated pneumonia onset, new temperature rise was less frequent among very old patients (59% vs 76% and 74% for middle-aged and old patients, respectively; p = 0.035). Mortality among patients with ventilator-associated pneumonia was higher among elderly patients: 35% in middle-aged patients versus 51% in old and very old patients (p = 0.036). Logistic regression analysis confirmed the importance of older age in the risk of death (adjusted odds ratio for old age, 2.1; 95% CI, 1.2-3.9 and adjusted odds ratio for very old age, 2.3; 95% CI, 1.2-4.4). Other risk factors for mortality in ventilator-associated pneumonia were diabetes mellitus, septic shock, and a high-risk pathogen as causative agent.

CONCLUSIONS

In this multicenter cohort study, ventilator-associated pneumonia did not occur more frequently among elderly, but the associated mortality in these patients was higher. New temperature rise was less common in elderly patients with ventilator-associated pneumonia, whereas more episodes among elderly patients were caused by Enterobacteriaceae.

Implementing a collaborative sepsis protocol on the time to antibiotics in an emergency department of a saudi hospital: quasi randomized study

Background. The objective of this study is to evaluate the impact of an ED sepsis protocol on the time to antibiotics for emergency department (ED) patients with severe sepsis. Methods. Quasiexperimental prospective study was conducted at the emergency department. Consecutive patients with severe sepsis were included before and after the implementation of a sepsis protocol. The outcome measures were time from recognition of severe sepsis/septic shock to first antibiotic dose delivery and the appropriateness of initial choice of antibiotics based on the presumed source of infection. Results. There were 47 patients in preintervention group and 112 patients in postintervention group. Before implementation, mean time from severe sepsis recognition to delivery of antibiotics was 140 ± 97 minutes. During the intervention period, the mean time was 68 ± 67 minutes, with an overall reduction of 72 minutes. The protocol resulted in an overall improvement of 37% in the compliance, as 62% received appropriate initial antibiotics for the presumed source of infection as compared to 25% before the start of protocol. Conclusion. Implementation of ED sepsis protocol improved the time from recognition of severe sepsis/septic shock to first antibiotic dose delivery as well as the appropriateness of initial antibiotic therapy.

The influence of acute kidney injury on antimicrobial dosing in critically ill patients: are dose reductions always necessary?

Optimal dosing of antimicrobial therapy is pivotal to increase the likelihood of survival in critically ill patients with sepsis. Drug exposure that maximizes bacterial killing, minimizes the development of antimicrobial resistance, and avoids concentration-related toxicities should be considered the target of therapy. However, antimicrobial dosing is problematic as pathophysiological factors inherent to sepsis that alter may result in reduced concentrations. Alternatively, sepsis may evolve to multiple-organ dysfunction including acute kidney injury (AKI). In this case, decreased clearance of renally cleared drugs is possible, which may lead to increased concentrations that may cause drug toxicities. Consequently, when dosing antibiotics in septic patients with AKI, one should consider factors that may lead to underdosing and overdosing. Drug-specific pharmacokinetic and pharmacodynamic data may be helpful to guide dosing in these circumstances. Yet, because of the high interpatient variability in pharmacokinetics of antibiotics during sepsis, this issue remains a significant challenge.

Insights and advances in multidisciplinary critical care: a review of recent research

The intensive care unit is a work environment where superior dedication is pivotal to optimize patients' outcomes. As this demanding commitment is multidisciplinary in nature, it requires special qualities of health care workers and organizations. Thus research in the field covers a broad spectrum of activities necessary to deliver cutting-edge care. However, given the abundance of research articles and education activities available, it is difficult for modern critical care clinicians to keep up with the latest progress and innovations in the field. This article broadly summarizes new developments in multidisciplinary intensive care, providing elementary information about advanced insights in the field by briefly describing selected articles bundled in specific topics. Issues considered include cardiovascular care, monitoring, mechanical ventilation, infection and sepsis, nutrition, education, patient safety, pain assessment and control, delirium, mental health, ethics, and outcomes research.

De-escalation of empirical therapy is associated with lower mortality in patients with severe sepsis and septic shock

PURPOSES

We set out to assess the safety and the impact on in-hospital and 90-day mortality of antibiotic de-escalation in patients admitted to the ICU with severe sepsis or septic shock.

METHODS

We carried out a prospective observational study enrolling patients admitted to the ICU with severe sepsis or septic shock. De-escalation was defined as discontinuation of an antimicrobial agent or change of antibiotic to one with a narrower spectrum once culture results were available. To control for confounding variables, we performed a conventional regression analysis and a propensity score (PS) adjusted-multivariable analysis.

RESULTS

A total of 712 patients with severe sepsis or septic shock at ICU admission were treated empirically with broad-spectrum antibiotics. Of these, 628 were evaluated (84 died before cultures were available). De-escalation was applied in 219 patients (34.9%). By multivariate analysis, factors independently associated with in-hospital mortality were septic shock, SOFA score the day of culture results, and inadequate empirical antimicrobial therapy, whereas de-escalation therapy was a protective factor [Odds-Ratio (OR) 0.58; 95% confidence interval (CI) 0.36-0.93). Analysis of the 403 patients with adequate empirical therapy revealed that the factor associated with mortality was SOFA score on the day of culture results, whereas de-escalation therapy was a protective factor (OR 0.54; 95% CI 0.33-0.89). The PS-adjusted logistic regression models confirmed that de-escalation therapy was a protective factor in both analyses. De-escalation therapy was also a protective factor for 90-day mortality.

CONCLUSIONS

De-escalation therapy for severe sepsis and septic shock is a safe strategy associated with a lower mortality. Efforts to increase the frequency of this strategy are fully justified.