Influence of combined intravenous and topical antibiotic prophylaxis on the incidence of infections, organ dysfunctions, and mortality in critically ill surgical patients: a prospective, stratified, randomized, double-blind, placebo-controlled clinical trial

Efficacy of probiotics or synbiotics in critically ill patients: A systematic review and meta-analysis

BACKGROUND

This latest systematic review and meta-analysis aim to examine the effects of probiotic and synbiotic supplementation in critically ill patients.

METHODS

Relevant articles were retrieved from PubMed, Embase, the Cochrane Database, and the Web of Science. The primary output measure was the incident of ventilator-associated pneumonia, and the secondary outputs were diarrhea, Clostridium diffusion infection (CDI), incident of sepsis, incident of hospital acquired pneumonia, duration of mechanical exploitation, ICU mortality rate, length of ICU stay, in hospital mortality, and length of hospital stay. Data were pooled and expressed as Relative Risk(RR) and Standardized Mean Difference (SMD) with a 95 % confidence interval (CI).

RESULTS

33 studies were included in this systematic review and meta-analysis, with 4065 patients who received probiotics or synbiotics (treatment group) and 3821 patients who received standard care or placebo (control group). The pooled data from all included studies demonstrated that the treatment group has significantly reduced incidence of ventilation-associated pneumonia (VAP) (RR = 0.80; 95 % CI: 0.67-0.96; p = 0.021, I2 = 52.5 %) and sepsis (RR = 0.97; 95 % CI: 0.66-1.42; p = 0.032, I2 = 54.4 %), As well as significantly increased duration of mechanical exploitation (SMD = -0.47; 95 % CI: -0.74-0.20, p = 0.012, I2 = 63.4 %), ICU mobility (RR = 0.95; 95 % CI: 0.71-1.27; p = 0.004, I2 = 62.8 %), length of ICU stay (SMD = -0.29; 95 % CI: -0.58-0.01; p = 0.000, I2 = 82.3 %) and length of hospital stay (SMD = -0.33; 95 % CI: -0.57-0.08, p = 0.000, I2 = 74.2 %) than the control group. There were no significant differences in diarrhea, CDI, incidence of hospital acquired pneumonia, and in hospital mortality between the two groups.

CONCLUSION

Our meta-analysis showed that probiotic and synbiotic supplements are beneficial for critically ill patients as they significantly reduce the incidence of ventilator associated pneumonia and sepsis, as well as the duration of mechanical exploitation, length of hospital stay, length of ICU stay, and ICU mortality. However, this intervention has minimal impact on diarrhea, CDI, incidence of hospital acquired pneumonia, and in hospital mortality in critically ill patients.

Selective decontamination of the digestive tract: concept and application

Selective digestive decontamination (SDD) is a prophylactic strategy aimed at preventing or eradicating bacterial overgrowth in the intestinal flora that precedes the development of most infections in the Intensive Care Unit. SDD prevents serious infections, reduces mortality, is cost-effective, has no adverse effects, and its short- or long-term use is not associated with any significant increase in antimicrobial resistance. SDD is one of the most widely evaluated interventions in critically ill patients, yet its use is not widespread. The present article offers a narrative review of the most relevant evidence and an update of the pathophysiological concepts of infection control supporting the use of SDD.

Quality indicators in intensive care medicine for Germany - fourth edition 2022

The measurement of quality indicators supports quality improvement initiatives. The German Interdisciplinary Society of Intensive Care Medicine (DIVI) has published quality indicators for intensive care medicine for the fourth time now. After a scheduled evaluation after three years, changes in several indicators were made. Other indicators were not changed or only minimally. The focus remained strongly on relevant treatment processes like management of analgesia and sedation, mechanical ventilation and weaning, and infections in the ICU. Another focus was communication inside the ICU. The number of 10 indicators remained the same. The development method was more structured and transparency was increased by adding new features like evidence levels or author contribution and potential conflicts of interest. These quality indicators should be used in the peer review in intensive care, a method endorsed by the DIVI. Other forms of measurement and evaluation are also reasonable, for example in quality management. This fourth edition of the quality indicators will be updated in the future to reflect the recently published recommendations on the structure of intensive care units by the DIVI.

Association Between Selective Decontamination of the Digestive Tract and In-Hospital Mortality in Intensive Care Unit Patients Receiving Mechanical Ventilation: A Systematic Review and Meta-analysis

Importance

The effectiveness of selective decontamination of the digestive tract (SDD) in critically ill adults receiving mechanical ventilation is uncertain.

Objective

To determine whether SDD is associated with reduced risk of death in adults receiving mechanical ventilation in intensive care units (ICUs) compared with standard care.

Data Sources

The primary search was conducted using MEDLINE, EMBASE, and CENTRAL databases until September 2022.

Study Selection

Randomized clinical trials including adults receiving mechanical ventilation in the ICU comparing SDD vs standard care or placebo.

Data Extraction and Synthesis

Data extraction and risk of bias assessments were performed in duplicate. The primary analysis was conducted using a bayesian framework.

Main Outcomes and Measures

The primary outcome was hospital mortality. Subgroups included SDD with an intravenous agent compared with SDD without an intravenous agent. There were 8 secondary outcomes including the incidence of ventilator-associated pneumonia, ICU-acquired bacteremia, and the incidence of positive cultures of antimicrobial-resistant organisms.

Results

There were 32 randomized clinical trials including 24 389 participants in the analysis. The median age of participants in the included studies was 54 years (IQR, 44-60), and the median proportion of female trial participants was 33% (IQR, 25%-38%). Data from 30 trials including 24 034 participants contributed to the primary outcome. The pooled estimated risk ratio (RR) for mortality for SDD compared with standard care was 0.91 (95% credible interval [CrI], 0.82-0.99; I2 = 33.9%; moderate certainty) with a 99.3% posterior probability that SDD reduced hospital mortality. The beneficial association of SDD was evident in trials with an intravenous agent (RR, 0.84 [95% CrI, 0.74-0.94]), but not in trials without an intravenous agent (RR, 1.01 [95% CrI, 0.91-1.11]) (P value for the interaction between subgroups = .02). SDD was associated with reduced risk of ventilator-associated pneumonia (RR, 0.44 [95% CrI, 0.36-0.54]) and ICU-acquired bacteremia (RR, 0.68 [95% CrI, 0.57-0.81]). Available data regarding the incidence of positive cultures of antimicrobial-resistant organisms were not amenable to pooling and were of very low certainty.

Conclusions and Relevance

Among adults in the ICU treated with mechanical ventilation, the use of SDD compared with standard care or placebo was associated with lower hospital mortality. Evidence regarding the effect of SDD on antimicrobial resistance was of very low certainty.

Ecological effects of selective oral decontamination on multidrug-resistance bacteria acquired in the intensive care unit: a case-control study over 5 years

Purpose

This case–control study investigated the long-term evolution of multidrug-resistant bacteria (MDRB) over a 5-year period associated with the use of selective oropharyngeal decontamination (SOD) in the intensive care unit (ICU). In addition, effects on health care-associated infections and ICU mortality were analysed.

Methods

We investigated patients undergoing mechanical ventilation > 48 h in 11 adult ICUs located at 3 campuses of a university hospital. Administrative, clinical, and microbiological data which were routinely recorded electronically served as the basis. We analysed differences in the rates and incidence densities (ID, cases per 1000 patient-days) of MDRB associated with SOD use in all patients and stratified by patient origin (outpatient or inpatient). After propensity score matching, health-care infections and ICU mortality were compared.

Results

5034 patients were eligible for the study. 1694 patients were not given SOD. There were no differences in the incidence density of MDRB when SOD was used, except for more vancomycin-resistant Enterococcus faecium (0.72/1000 days vs. 0.31/1000 days, p < 0.01), and fewer ESBL-producing Klebsiella pneumoniae (0.22/1000 days vs. 0.56/1000 days, p < 0.01). After propensity score matching, SOD was associated with lower incidence rates of ventilator-associated pneumonia and death in the ICU but not with ICU-acquired bacteremia or urinary tract infection.

Conclusions

Comparisons of the ICU-acquired MDRB over a 5-year period revealed no differences in incidence density, except for lower rate of ESBL-producing Klebsiella pneumoniae and higher rate of vancomycin-resistant Enterococcus faecium with SOD. Incidence rates of ventilator-associated pneumonia and death in the ICU were lower in patients receiving SOD.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-022-06826-7.

Rescuing the Last-Line Polymyxins: Achievements and Challenges

Antibiotic resistance is a major global health challenge and, worryingly, several key Gram negative pathogens can become resistant to most currently available antibiotics. Polymyxins have been revived as a last-line therapeutic option for the treatment of infections caused by multidrug-resistant Gram negative bacteria, in particular Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacterales. Polymyxins were first discovered in the late 1940s but were abandoned soon after their approval in the late 1950s as a result of toxicities (e.g., nephrotoxicity) and the availability of "safer" antibiotics approved at that time. Therefore, knowledge on polymyxins had been scarce until recently, when enormous efforts have been made by several research teams around the world to elucidate the chemical, microbiological, pharmacokinetic/pharmacodynamic, and toxicological properties of polymyxins. One of the major achievements is the development of the first scientifically based dosage regimens for colistin that are crucial to ensure its safe and effective use in patients. Although the guideline has not been developed for polymyxin B, a large clinical trial is currently being conducted to optimize its clinical use. Importantly, several novel, safer polymyxin-like lipopeptides are developed to overcome the nephrotoxicity, poor efficacy against pulmonary infections, and narrow therapeutic windows of the currently used polymyxin B and colistin. This review discusses the latest achievements on polymyxins and highlights the major challenges ahead in optimizing their clinical use and discovering new-generation polymyxins. To save lives from the deadly infections caused by Gram negative "superbugs," every effort must be made to improve the clinical utility of the last-line polymyxins. SIGNIFICANCE STATEMENT: Antimicrobial resistance poses a significant threat to global health. The increasing prevalence of multidrug-resistant (MDR) bacterial infections has been highlighted by leading global health organizations and authorities. Polymyxins are a last-line defense against difficult-to-treat MDR Gram negative pathogens. Unfortunately, the pharmacological information on polymyxins was very limited until recently. This review provides a comprehensive overview on the major achievements and challenges in polymyxin pharmacology and clinical use and how the recent findings have been employed to improve clinical practice worldwide.

Topical antibiotic prophylaxis to reduce respiratory tract infections and mortality in adults receiving mechanical ventilation

BACKGROUND

Patients treated with mechanical ventilation in intensive care units (ICUs) have a high risk of developing respiratory tract infections (RTIs). Ventilator-associated pneumonia (VAP) has been estimated to affect 5% to 40% of patients treated with mechanical ventilation for at least 48 hours. The attributable mortality rate of VAP has been estimated at about 9%. Selective digestive decontamination (SDD), which consists of the topical application of non-absorbable antimicrobial agents to the oropharynx and gastroenteric tract during the whole period of mechanical ventilation, is often used to reduce the risk of VAP. A related treatment is selective oropharyngeal decontamination (SOD), in which topical antibiotics are applied to the oropharynx only. This is an update of a review first published in 1997 and updated in 2002, 2004, and 2009.

OBJECTIVES

To assess the effect of topical antibiotic regimens (SDD and SOD), given alone or in combination with systemic antibiotics, to prevent mortality and respiratory infections in patients receiving mechanical ventilation for at least 48 hours in ICUs.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Acute Respiratory Infections (ARI) Group's Specialised Register, PubMed, and Embase on 5 February 2020. We also searched the WHO ICTRP and ClinicalTrials.gov for ongoing and unpublished studies on 5 February 2020. All searches included non-English language literature. We handsearched references of topic-related systematic reviews and the included studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and cluster-RCTs assessing the efficacy and safety of topical prophylactic antibiotic regimens in adults receiving intensive care and mechanical ventilation. The included studies compared topical plus systemic antibiotics versus placebo or no treatment; topical antibiotics versus no treatment; and topical plus systemic antibiotics versus systemic antibiotics.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included a total of 41 trials involving 11,004 participants (five new studies were added in this update). The minimum duration of mechanical ventilation ranged from 2 (19 studies) to 6 days (one study). Thirteen studies reported the mean length of ICU stay, ranging from 11 to 33 days. The percentage of immunocompromised patients ranged from 0% (10 studies) to 22% (1 study). The reporting quality of the majority of included studies was very poor, so we judged more than 40% of the studies as at unclear risk of selection bias. We judged all studies to be at low risk of performance bias, though 47.6% were open-label, because hospitals usually have standardised infection control programmes, and possible subjective decisions on who should be tested for the presence or absence of RTIs are unlikely in an ICU setting. Regarding detection bias, we judged all included studies as at low risk for the outcome mortality. For the outcome RTIs, we judged all double-blind studies as at low risk of detection bias. We judged five open-label studies as at high risk of detection bias, as the diagnosis of RTI was not based on microbiological exams; we judged the remaining open-label studies as at low risk of detection bias, as a standardised set of diagnostic criteria, including results of microbiological exams, were used. Topical plus systemic antibiotic prophylaxis reduces overall mortality compared with placebo or no treatment (risk ratio (RR) 0.84, 95% confidence interval (CI) 0.73 to 0.96; 18 studies; 5290 participants; high-certainty evidence). Based on an illustrative risk of 303 deaths in 1000 people this equates to 48 (95% CI 15 to 79) fewer deaths with topical plus systemic antibiotic prophylaxis. Topical plus systemic antibiotic prophylaxis probably reduces RTIs (RR 0.43, 95% CI 0.35 to 0.53; 17 studies; 2951 participants; moderate-certainty evidence). Based on an illustrative risk of 417 RTIs in 1000 people this equates to 238 (95% CI 196 to 271) fewer RTIs with topical plus systemic antibiotic prophylaxis. Topical antibiotic prophylaxis probably reduces overall mortality compared with no topical antibiotic prophylaxis (RR 0.96, 95% CI 0.87 to 1.05; 22 studies, 4213 participants; moderate-certainty evidence). Based on an illustrative risk of 290 deaths in 1000 people this equates to 19 (95% CI 37 fewer to 15 more) fewer deaths with topical antibiotic prophylaxis. Topical antibiotic prophylaxis may reduce RTIs (RR 0.57, 95% CI 0.44 to 0.74; 19 studies, 2698 participants; low-certainty evidence). Based on an illustrative risk of 318 RTIs in 1000 people this equates to 137 (95% CI 83 to 178) fewer RTIs with topical antibiotic prophylaxis. Sixteen studies reported adverse events and dropouts due to adverse events, which were poorly reported with sparse data. The certainty of the evidence ranged from low to very low.

AUTHORS' CONCLUSIONS

Treatments based on topical prophylaxis probably reduce respiratory infections, but not mortality, in adult patients receiving mechanical ventilation for at least 48 hours, whereas a combination of topical and systemic prophylactic antibiotics reduces both overall mortality and RTIs. However, we cannot rule out that the systemic component of the combined treatment provides a relevant contribution in the observed reduction of mortality. No conclusion can be drawn about adverse events as they were poorly reported with sparse data.

Cost-effectiveness of selective digestive decontamination (SDD) versus selective oropharyngeal decontamination (SOD) in intensive care units with low levels of antimicrobial resistance: an individual patient data meta-analysis

OBJECTIVE

To determine the cost-effectiveness of selective digestive decontamination (SDD) as compared to selective oropharyngeal decontamination (SOD) in intensive care units (ICUs) with low levels of antimicrobial resistance.

DESIGN

Post-hoc analysis of a previously performed individual patient data meta-analysis of two cluster-randomised cross-over trials.

SETTING

24 ICUs in the Netherlands.

PARTICIPANTS

12 952 ICU patients who were treated with ≥1 dose of SDD (n=6720) or SOD (n=6232).

INTERVENTIONS

SDD versus SOD.

PRIMARY AND SECONDARY OUTCOME MEASURES

The incremental cost-effectiveness ratio (ICER; ie, costs to prevent one in-hospital death) was calculated by comparing differences in direct healthcare costs and in-hospital mortality of patients treated with SDD versus SOD. A willingness-to-pay curve was plotted to reflect the probability of cost-effectiveness of SDD for a range of different values of maximum costs per prevented in-hospital death.

RESULTS

The ICER resulting from the fixed-effect meta-analysis, adjusted for clustering and differences in baseline characteristics, showed that SDD significantly reduced in-hospital mortality (adjusted absolute risk reduction 0.0195, 95% CI 0.0050 to 0.0338) with no difference in costs (adjusted cost difference €62 in favour of SDD, 95% CI -€1079 to €935). Thus, SDD yielded significantly lower in-hospital mortality and comparable costs as compared with SOD. At a willingness-to-pay value of €33 633 per one prevented in-hospital death, SDD had a probability of 90.0% to be cost-effective as compared with SOD.

CONCLUSION

In Dutch ICUs, SDD has a very high probability of cost-effectiveness as compared to SOD. These data support the implementation of SDD in settings with low levels of antimicrobial resistance.

Clinical epidemiology and outcomes of ventilator-associated pneumonia in critically ill adult patients: protocol for a large-scale systematic review and planned meta-analysis

BACKGROUND

An increasing number of studies have investigated the clinical epidemiology and outcomes of ventilator-associated pneumonia (VAP) in intensive care units. However, these findings have not been clearly defined in broad subgroups of mechanically ventilated adults. Hence, this protocol for a systematic review and meta-analysis is designed to better understand the clinical and epidemiological features of VAP in these patient populations by establishing its overall prognosis of and risk factors for morbidity and mortality and to determine the differences in clinical and economic outcomes between VAP and non-VAP patients.

METHODS

This present review will systematically search available full-text articles without date and language restrictions and indexed in PubMed, CENTRAL, CINAHL, Web of Science, and EMBASE databases. In addition, reference lists and citations of retrieved articles and relevant medical and nursing journals will be manually reviewed. Supplementary search in other databases involving trials, reviews, and grey literatures, including conference proceedings, theses, and dissertations, will be performed. Study investigators will be contacted to clarify missing or unpublished data. All prognostic studies meeting the pre-defined eligibility criteria will be included. The study selection, risk of bias assessment, data extraction, and grading of the quality of evidence will be carried out in duplicate, involving independent evaluation by two investigators with consensus or a third-party adjudication. The degree of inter-rater agreement will be calculated using the kappa statistic. For meta-analysis, dichotomous and continuous outcome measures will be pooled using odds ratios and standardized mean differences with 95% confidence intervals, respectively. The Mantel-Haenszel or inverse variance methods with random effects model will be used as a guide for analysis. The heterogeneity of each outcome measure will be assessed using both X2 and I2 statistics. In addition, sensitivity and subgroup analyses will be performed to ensure consistency of pooled results. The review protocol described herein is in accordance with the PRISMA-P standards.

DISCUSSION

The investigation of the epidemiological profiles, prognostic factors, and outcomes associated with VAP is critical for the identification of high-risk groups of mechanically ventilated patients and evaluation of possible clinical endpoints. This may provide substantial links for improved VAP prevention practices targeting modifiable risk factors. Implications for future research directions are discussed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017048158.

IL (Interleukin)-33 Suppresses Abdominal Aortic Aneurysm by Enhancing Regulatory T-Cell Expansion and Activity

Objective- Inflammation occurs during the progression of abdominal aortic aneurysm (AAA). IL (interleukin)-33 is a pleiotropic cytokine with multiple immunomodulatory effects, yet its role in AAA remains unknown. Approach and Results- Immunoblot, immunohistochemistry, and immunofluorescent staining revealed increased IL-33 expression in adventitia fibroblasts from mouse AAA lesions. Daily intraperitoneal administration of recombinant IL-33 or transgenic IL-33 expression ameliorated periaorta CaPO4 injury- and aortic elastase exposure-induced AAA in mice, as demonstrated by blunted aortic expansion, reduced aortic wall elastica fragmentation, enhanced AAA lesion collagen deposition, attenuated T-cell and macrophage infiltration, reduced inflammatory cytokine production, skewed M2 macrophage polarization, and reduced lesion MMP (matrix metalloproteinase) expression and cell apoptosis. Flow cytometry analysis, immunostaining, and immunoblot analysis showed that exogenous IL-33 increased CD4+Foxp3+ regulatory T cells in spleens, blood, and aortas in periaorta CaPO4-treated mice. Yet, ST2 deficiency muted these IL-33 activities. Regulatory T cells from IL-33-treated mice also showed significantly stronger activities in suppressing smooth muscle cell inflammatory cytokine and chemokine expression, macrophage MMP expression, and in increasing M2 macrophage polarization than those from vehicle-treated mice. In contrast, IL-33 failed to prevent AAA and lost its beneficial activities in CaPO4-treated mice after selective depletion of regulatory T cells. Conclusions- Together, this study established a role of IL-33 in protecting mice from AAA formation by enhancing ST2-dependent aortic and systemic regulatory T-cell expansion and their immunosuppressive activities.

Carriage of antibiotic-resistant Gram-negative bacteria after discontinuation of selective decontamination of the digestive tract (SDD) or selective oropharyngeal decontamination (SOD)

Background

Selective decontamination of the digestive tract (SDD) and selective oropharyngeal decontamination (SOD) reduce colonization with antibiotic-resistant Gram-negative bacteria (ARGNB), incidence of nosocomial infections and improve survival in ICU patients. The effect on bacterial gut colonization might be caused by growth suppression by antibiotics during SDD/SOD. We investigated intestinal colonization with ARGNB after discharge from ICU and discontinuation of SDD or SOD.

Methods

We performed a prospective, observational follow-up study in regular hospital wards of three teaching hospitals in the Netherlands in patients discharged from the ICU, who were participating in a cluster randomized trial comparing SDD with SOD. We determined rectal carriage with ARGNB at ICU discharge (time (T) = 0) and 3, 6 and 10 days after discharge. The primary endpoint was time to first colonization with ARGNB that was not present at T = 0. Bacteria that are intrinsically resistant to antibiotics were not included in the primary analysis, but were included in post-hoc analysis.

Results

Of 1370 patients screened for inclusion, 996 patients had samples at T = 0 (507 after SDD and 489 after SOD). At ICU discharge, the prevalence of intestinal carriage with any ARGNB was 22/507 (4.3%) after SDD and 87/489 (17.8%) after SOD (p < 0.0001): 426 (SDD) and 409 (SOD) patients had at least one follow-up sample for analysis. The hazard rate for acquiring carriage of ARGNB after discontinuation of SDD, compared to SOD, in the ICU was 0.61 (95% CI 0.40–0.91, p = 0.02), and cumulative risks of acquisition of at least one ARGNB until day 10 were 13% (SDD) and 18% (SOD). At day 10 after ICU discharge, the prevalence of intestinal carriage with ARGNB was 11.3% (26/230 patients) after SDD and 12.5% (28/224 patients) after SOD (p = 0.7). In post-hoc analysis of all ARGNB, including intrinsically resistant bacteria, colonization at ICU discharge was lower after SDD (4.9 vs. 22.3%, p < 0.0001), but acquisition rates after ICU discharge were similar in both groups.

Conclusions

Intestinal carriage at ICU discharge and the acquisition rate of ARGNB after ICU discharge are lower after SDD than after SOD. The prevalence of intestinal carriage with ARGNB at 10 days after ICU discharge was comparable in both groups, suggesting rapid clearance of ARGNB from the gut after ICU discharge.

Trial registration

Netherlands Trial Registry, NTR3311. Registered on 28 february 2012.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2170-2) contains supplementary material, which is available to authorized users.

Interventions for preventing upper gastrointestinal bleeding in people admitted to intensive care units

BACKGROUND

Upper gastrointestinal (GI) bleeding due to stress ulcers contributes to increased morbidity and mortality in people admitted to intensive care units (ICUs). Stress ulceration refers to GI mucosal injury related to the stress of being critically ill. ICU patients with major bleeding as a result of stress ulceration might have mortality rates approaching 48.5% to 65%. However, the incidence of stress-induced GI bleeding in ICUs has decreased, and not all critically ill patients need prophylaxis. Stress ulcer prophylaxis can result in adverse events such as ventilator-associated pneumonia; therefore, it is necessary to evaluate strategies that safely decrease the incidence of GI bleeding.

OBJECTIVES

To assess the effect and risk-benefit profile of interventions for preventing upper GI bleeding in people admitted to ICUs.

SEARCH METHODS

We searched the following databases up to 23 August 2017, using relevant search terms: MEDLINE; Embase; the Cochrane Central Register of Controlled Trials; Latin American Caribbean Health Sciences Literature; and the Cochrane Upper Gastrointestinal and Pancreatic Disease Group Specialised Register, as published in the Cochrane Library (2017, Issue 8). We searched the reference lists of all included studies and those from relevant systematic reviews and meta-analyses to identify additional studies. We also searched the World Health Organization International Clinical Trials Registry Platform search portal and contacted individual researchers working in this field, as well as organisations and pharmaceutical companies, to identify unpublished and ongoing studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs with participants of any age and gender admitted to ICUs for longer than 48 hours. We excluded studies in which participants were admitted to ICUs primarily for the management of GI bleeding and studies that compared different doses, routes, and regimens of one drug in the same class because we were not interested in intraclass effects of drugs.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as recommended by Cochrane.

MAIN RESULTS

We identified 2292 unique records.We included 129 records reporting on 121 studies, including 12 ongoing studies and two studies awaiting classification.We judged the overall risk of bias of two studies as low. Selection bias was the most relevant risk of bias domain across the included studies, with 78 studies not clearly reporting the method used for random sequence generation. Reporting bias was the domain with least risk of bias, with 12 studies not reporting all outcomes that researchers intended to investigate.Any intervention versus placebo or no prophylaxisIn comparison with placebo, any intervention seems to have a beneficial effect on the occurrence of upper GI bleeding (risk ratio (RR) 0.47, 95% confidence interval (CI) 0.39 to 0.57; moderate certainty of evidence). The use of any intervention reduced the risk of upper GI bleeding by 10% (95% CI -12.0% to -7%). The effect estimate of any intervention versus placebo or no prophylaxis with respect to the occurrence of nosocomial pneumonia, all-cause mortality in the ICU, duration of ICU stay, duration of intubation (all with low certainty of evidence), the number of participants requiring blood transfusions (moderate certainty of evidence), and the units of blood transfused was consistent with benefits and harms. None of the included studies explicitly reported on serious adverse events.Individual interventions versus placebo or no prophylaxisIn comparison with placebo or no prophylaxis, antacids, H2 receptor antagonists, and sucralfate were effective in preventing upper GI bleeding in ICU patients. Researchers found that with H2 receptor antagonists compared with placebo or no prophylaxis, 11% less developed upper GI bleeding (95% CI -0.16 to -0.06; RR 0.50, 95% CI 0.36 to 0.70; 24 studies; 2149 participants; moderate certainty of evidence). Of ICU patients taking antacids versus placebo or no prophylaxis, 9% less developed upper GI bleeding (95% CI -0.17 to -0.00; RR 0.49, 95% CI 0.25 to 0.99; eight studies; 774 participants; low certainty of evidence). Among ICU patients taking sucralfate versus placebo or no prophylaxis, 5% less had upper GI bleeding (95% CI -0.10 to -0.01; RR 0.53, 95% CI 0.32 to 0.88; seven studies; 598 participants; moderate certainty of evidence). The remaining interventions including proton pump inhibitors did not show a significant effect in preventing upper GI bleeding in ICU patients when compared with placebo or no prophylaxis.Regarding the occurrence of nosocomial pneumonia, the effects of H2 receptor antagonists (RR 1.12, 95% CI 0.85 to 1.48; eight studies; 945 participants; low certainty of evidence) and of sucralfate (RR 1.33, 95% CI 0.86 to 2.04; four studies; 450 participants; low certainty of evidence) were consistent with benefits and harms when compared with placebo or no prophylaxis. None of the studies comparing antacids versus placebo or no prophylaxis provided data regarding nosocomial pneumonia.H2 receptor antagonists versus proton pump inhibitorsH2 receptor antagonists and proton pump inhibitors are most commonly used in practice to prevent upper GI bleeding in ICU patients. Proton pump inhibitors significantly more often prevented upper GI bleeding in ICU patients compared with H2 receptor antagonists (RR 2.90, 95% CI 1.83 to 4.58; 18 studies; 1636 participants; low certainty of evidence). When taking H2 receptor antagonists, 4.8% more patients might experience upper GI bleeding (95% CI 2.1% to 9%). Nosocomial pneumonia occurred in similar proportions of participants taking H2 receptor antagonists and participants taking proton pump inhibitors (RR 1.02, 95% CI 0.77 to 1.35; 10 studies; 1256 participants; low certainty of evidence).

AUTHORS' CONCLUSIONS

This review shows that antacids, sucralfate, and H2 receptor antagonists might be more effective in preventing upper GI bleeding in ICU patients compared with placebo or no prophylaxis. The effect estimates of any treatment versus no prophylaxis on nosocomial pneumonia were consistent with benefits and harms. Evidence of low certainty suggests that proton pump inhibitors might be more effective than H2 receptor antagonists. Therefore, patient-relevant benefits and especially harms of H2 receptor antagonists compared with proton pump inhibitors need to be assessed by larger, high-quality RCTs to confirm the results of previously conducted, smaller, and older studies.

Eradication of P. aeruginosa biofilm in endotracheal tubes based on lock therapy: results from an in vitro study

Background

Despite the several strategies available for the management of biofilm-associated ventilator-associated pneumonia, data regarding the efficacy of applying antibiotics to the subglottic space (SS) are scarce. We created an in vitro model to assess the efficacy of antibiotic lock therapy (ALT) applied in the SS for eradication of Pseudomonas aeruginosa biofilm in endotracheal tubes (ETTs).

Methods

We applied 2 h of ALT to a P. aeruginosa biofilm in ETTs using a single dose (SD) and a 5-day therapy model (5D). We used sterile saline lock therapy (SLT) as the positive control. We compared colony count and the percentage of live cells between both models.

Results

The median (IQR) cfu counts/ml and percentage of live cells in the SD-ALT and SD-SLT groups were, respectively, 3.12 × 10⁵ (9.7 × 10⁴-0) vs. 8.16 × 10⁷ (7.0 × 10⁷-0) (p = 0.05) and 53.2% (50.9%-57.2%) vs. 91.5% (87.3%-93.9%) (p < 0.001). The median (IQR) cfu counts/ml and percentage of live cells in the 5D-ALT and 5D-SLT groups were, respectively, 0 (0-0) vs. 3.2 × 10⁷ (2.32 × 10⁷-0) (p = 0.03) and 40.6% (36.6%-60.0%) vs. 90.3% (84.8%-93.9%) (p < 0.001).

Conclusion

We demonstrated a statistically significant decrease in the viability of P. aeruginosa biofilm after application of 5D-ALT in the SS. Future clinical studies to assess ALT in patients under mechanical ventilation are needed.

The function of probiotics on the treatment of ventilator-associated pneumonia (VAP): facts and gaps

Probiotics have been used for centuries in making fermented dairy products. The health benefits related to probiotics consumption are well recognized and they are generally regarded as safe (GRAS). Their therapeutic effects are due to the production of a variety of antimicrobial compounds, such as short-chain fatty acids, organic acids (such as lactic, acetic, formic, propionic and butyric acids), ethanol, hydrogen peroxide and bacteriocins. Ventilator-associated pneumonia (VAP) is a nosocomial infection associated with high mortality in intensive care units. VAP can result from endotracheal intubation and mechanical ventilation. These interventions increase the risk of infection as patients lose the natural barrier between the oropharynx and the trachea, which in turn facilitates the entry of pathogens through the aspiration of oropharyngeal secretions containing bacteria into the lung. In order to prevent this, probiotics have been used extensively against VAP. This review is an update containing information extracted from recent studies on the use of probiotics to treat VAP. In addition, probiotic safety, the therapeutic properties of probiotics, the probiotic strains used and the action of the probiotics mechanism are reviewed. Furthermore, the therapeutic effects of probiotic treatment procedures for VAP are compared to those of antibiotics. Finally, the influences of bacteriocin on the growth of human pathogens, and the side-effects and limitations of using probiotics for the treatment of VAP are addressed.

Quality indicators in intensive care medicine for Germany - third edition 2017

Quality improvement in medicine is depending on measurement of relevant quality indicators. The quality indicators for intensive care medicine of the German Interdisciplinary Society of Intensive Care Medicine (DIVI) from the year 2013 underwent a scheduled evaluation after three years. There were major changes in several indicators but also some indicators were changed only minimally. The focus on treatment processes like ward rounds, management of analgesia and sedation, mechanical ventilation and weaning, as well as the number of 10 indicators were not changed. Most topics remained except for early mobilization which was introduced instead of hypothermia following resuscitation. Infection prevention was added as an outcome indicator. These quality indicators are used in the peer review in intensive care, a method endorsed by the DIVI. A validity period of three years is planned for the quality indicators.

Prophylactic Antibiotic Therapy for Preventing Poststroke Infection

Infections, in particular pneumonia, are common complications in patients with acute stroke and are associated with a less favorable neurologic and functional outcome. Patients with severe stroke and dysphagia are at highest risk of infection. Experimental and clinical data suggest stroke-induced immunodeficiency as a major factor contributing to the high incidence of infection after stroke. Preclinical studies support the potential benefit of preventive antibiotic therapy in acute stroke for lowering the incidence of infection and improving clinical outcome. Several smaller clinical trials on preventive antibiotic therapy in patients with stroke conducted during the last 10 years yielded inconclusive results. Recently, 2 large, open-label, controlled trials failed to demonstrate an improved clinical outcome after preventive antibiotic therapy in patients with acute stroke treated in specialized stroke units. In the "Preventive Antibiotics in Stroke Study", antibiotic therapy lowered the rate of infection but did not influence outcome. In the STROKE-INF study, performed in patients with dysphagia after stroke, antibiotic therapy did not lower the incidence of pneumonia and had no prognostic significance. At present, preventive antibiotic therapy cannot be recommended as a therapeutic option for acute stroke.

Selective intestinal decontamination for the prevention of early bacterial infections after liver transplantation

Bacterial infection in the first month after liver transplantation is a frequent complication that poses a serious risk for liver transplant recipients as contributes substantially to increased length of hospitalization and hospital costs being a leading cause of death in this period. Most of these infections are caused by gram-negative bacilli, although gram-positive infections, especially Enterococcus sp. constitute an emerging infectious problem. This high rate of early postoperative infections after liver transplant has generated interest in exploring various prophylactic approaches to surmount this problem. One of these approaches is selective intestinal decontamination (SID). SID is a prophylactic strategy that consists of the administration of antimicrobials with limited anaerobicidal activity in order to reduce the burden of aerobic gram-negative bacteria and/or yeast in the intestinal tract and so prevent infections caused by these organisms. The majority of studies carried out to date have found SID to be effective in the reduction of gram-negative infection, but the effect on overall infection is limited due to a higher number of infection episodes by pathogenic enterococci and coagulase-negative staphylococci. However, difficulties in general extrapolation of the favorable results obtained in specific studies together with the potential risk of selection of multirresistant microorganisms has conditioned controversy about the routinely application of these strategies in liver transplant recipients.

Inapparent Outbreaks of Ventilator-Associated Pneumonia An Ecologic Analysis of Prevention and Cohort Studies

Objective:

To compare ventilator-associated pneumonia (VAP) rates and patterns of isolates across studies of antibiotic and non-antibiotic methods for preventing VAP.

Design:

With the use of 42 cohort study groups as the reference standard, the prevalence of VAP was modeled in two linear regressions: one with the control groups and the other with the intervention groups of 96 VAP prevention studies. The proportion of patients admitted with trauma and the VAP diagnostic criteria were used as ecologic correlates. Also, the patterns of pathogenic isolates were available for 117 groups.

Results:

In the first regression model, the VAP rates for the control groups of antibiotic-based prevention studies were at least 18 (CI95, 12 to 24) per 100 patients higher than those in the cohort study groups (P< .001). By contrast, comparisons of cohort study groups with all other control and intervention groups in the first and second regression models yielded differences that were less than 6 per 100 and not significant (P> .05). For control groups with VAP rates greater than 35%, the patterns of VAP isolates, such as the proportion ofStaphylococcus aureus,more closely resembled those in the corresponding intervention groups than in the cohort groups.

Conclusions:

The rates of VAP in the control groups of the antibiotic prevention studies were significantly higher than expected and the patterns of pathogenic isolates were unusual. These observations suggest that inapparent outbreaks of VAP occurred in these studies. The possibility remains that antibiotic-based VAP prevention presents a major cross-infection hazard.

Strategies to Prevent Ventilator-Associated Pneumonia in Acute Care Hospitals: 2014 Update

Previously published guidelines are available that provide comprehensive recommendations for detecting and preventing healthcare-associated infections (HAIs). The intent of this document is to highlight practical recommendations in a concise format to assist acute care hospitals in implementing and prioritizing strategies to prevent ventilator-associated pneumonia (VAP) and other ventilator-associated events (VAEs) and to improve outcomes for mechanically ventilated adults, children, and neonates. This document updates "Strategies to Prevent Ventilator-Associated Pneumonia in Acute Care Hospitals," published in 2008. This expert guidance document is sponsored by the Society for Healthcare Epidemiology of America (SHEA) and is the product of a collaborative effort led by SHEA, the Infectious Diseases Society of America (IDSA), the American Hospital Association (AHA), the Association for Professionals in Infection Control and Epidemiology (APIC), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise. The list of endorsing and supporting organizations is presented in the introduction to the 2014 updates.

Fighting antibiotic resistance in the intensive care unit using antibiotics

Antibiotic resistance is a global and increasing problem that is not counterbalanced by the development of new therapeutic agents. The prevalence of antibiotic resistance is especially high in intensive care units with frequently reported outbreaks of multidrug-resistant organisms. In addition to classical infection prevention protocols and surveillance programs, counterintuitive interventions, such as selective decontamination with antibiotics and antibiotic rotation have been applied and investigated to control the emergence of antibiotic resistance. This review provides an overview of selective oropharyngeal and digestive tract decontamination, decolonization of methicillin-resistant Staphylococcus aureus and antibiotic rotation as strategies to modulate antibiotic resistance in the intensive care unit.

Selective decontamination and antibiotic resistance in ICUs

Selective digestive decontamination (SDD) and selective oropharyngeal decontamination (SOD) have been associated with reduced mortality and lower ICU-acquired bacteremia and ventilator-associated pneumonia rates in areas with low levels of antibiotic resistance. However, the effect of selective decontamination (SDD/SOD) in areas where multidrug-resistant Gram-negative bacteria are endemic is less clear. It will be important to determine whether SDD/SOD improves patient outcome in such settings and how these measures affect the epidemiology of multidrug-resistant Gram-negative bacteria. Here we review the current evidence on the effects of SDD/SOD on antibiotic resistance development in individual ICU patients as well as the effect on ICU ecology, the latter including both ICU-level antibiotic resistance and antibiotic resistance development during long-term use of SDD/SOD.

Strategies to prevent ventilator-associated pneumonia in acute care hospitals: 2014 update

Previously published guidelines are available that provide comprehensive recommendations for detecting and preventing healthcare-associated infections (HAIs). The intent of this document is to highlight practical recommendations in a concise format to assist acute care hospitals in implementing and prioritizing strategies to prevent ventilator-associated pneumonia (VAP) and other ventilator-associated events (VAEs) and to improve outcomes for mechanically ventilated adults, children, and neonates. This document updates “Strategies to Prevent Ventilator-Associated Pneumonia in Acute Care Hospitals,” published in 2008. This expert guidance document is sponsored by the Society for Healthcare Epidemiology of America (SHEA) and is the product of a collaborative effort led by SHEA, the Infectious Diseases Society of America (IDSA), the American Hospital Association (AHA), the Association for Professionals in Infection Control and Epidemiology (APIC), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise. The list of endorsing and supporting organizations is presented in the introduction to the 2014 updates.

Colistin and tobramycin resistance during long- term use of selective decontamination strategies in the intensive care unit: a post hoc analysis

Introduction

Selective decontamination of the digestive tract (SDD) and selective oropharyngeal decontamination (SOD) have been shown to improve intensive care unit (ICU) patients’ outcomes. The aim of this study was to determine the effects of long-term use of SDD and SOD on colistin and tobramycin resistance among gram-negative bacteria.

Methods

We performed a post hoc analysis of two consecutive multicentre cluster-randomised trials with crossover of interventions. SDD and SOD were alternately but continuously used during 7 years in five Dutch ICUs participating in two consecutive cluster-randomised trials. In both trials, to measure colistin and tobramycin resistance among gram-negative bacteria, rectal and respiratory samples were obtained monthly from all patients present in the ICU.

Results

The prevalence of tobramycin resistance in respiratory and rectal samples decreased significantly during long-term use of SOD and SDD. (rectal samples risk ratio (RR) 0.35 (0.23 to 0.53); respiratory samples RR 0.48 (0.32 to 0.73), SDD compared to standard care). Colistin resistance in rectal and respiratory samples did not change (rectal samples RR 0.63 (0.29 to 1.38); respiratory samples RR 1.26 (0.35 to 4.57), SDD compared to standard care).

Conclusions

In this study, in a setting with low antimicrobial resistance rates, the prevalence of resistance against colistin and tobramycin among gram-negative isolates did not increase during a mean of 7 years of SDD or SOD use.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-0838-4) contains supplementary material, which is available to authorized users.

Prehospital oral chlorhexidine does not reduce the rate of ventilator-associated pneumonia among critically ill trauma patients: A prospective concurrent-control study

PURPOSE

The purpose of the study was to test the hypothesis that prehospital oral chlorhexidine administered to intubated trauma patients will decrease the Clinical Pulmonary Infection Score (CPIS) during the first 2 days of hospitalization.

MATERIALS AND METHODS

Prospective interventional concurrent-control study of all intubated adult trauma patients transported by air ambulance to a 711-bed Midwestern academic trauma center over a 1-year period. Patients transported by 2 university-based helicopters were treated with oral chlorhexidine after intubation, and the control group was patients transported by other air transport services.

RESULTS

Sixty-seven patients were enrolled, of which 23 received chlorhexidine (9 patients allocated to the intervention were not treated). The change in CPIS score was no different between the intervention and control groups by intention to treat (1.06- vs 1.40-point reduction, P = .520), and no difference was observed in tracheal colonization (29.0% vs 36.7%, P = .586). No differences were observed in the rate of clinical pneumonia (8.7% vs 8.6%, P = .987) or mortality (P = .196) in the per-protocol chlorhexidine group.

CONCLUSIONS

The prehospital administration of oral chlorhexidine does not reduce the CPIS score over the first 48 hours of admission for intubated trauma patients. Further study should explore other prehospital strategies of reducing complications of critical illness.

Topical antibiotics as a major contextual hazard toward bacteremia within selective digestive decontamination studies: a meta-analysis

BACKGROUND

Among methods for preventing pneumonia and possibly also bacteremia in intensive care unit (ICU) patients, Selective Digestive Decontamination (SDD) appears most effective within randomized concurrent controlled trials (RCCT's) although more recent trials have been cluster randomized. However, of the SDD components, whether protocolized parenteral antibiotic prophylaxis (PPAP) is required, and whether the topical antibiotic actually presents a contextual hazard, remain unresolved. The objective here is to compare the bacteremia rates and patterns of isolates in SDD-RCCT's versus the broader evidence base.

METHODS

Bacteremia incidence proportion data were extracted from component (control and intervention) groups decanted from studies investigating antibiotic (SDD) or non-antibiotic methods of VAP prevention and summarized using random effects meta-analysis of study and group level data. A reference category of groups derived from purely observational studies without any prevention method under study provided a benchmark incidence.

RESULTS

Within SDD RCCTs, the mean bacteremia incidence among concurrent component groups not exposed to PPAP (27 control; 17.1%; 13.1-22.1% and 12 intervention groups; 16.2%; 9.1-27.3%) is double that of the benchmark bacteremia incidence derived from 39 benchmark groups (8.3; 6.8-10.2%) and also 20 control groups from studies of non-antibiotic methods (7.1%; 4.8 - 10.5). There is a selective increase in coagulase negative staphylococci (CNS) but not in Pseudomonas aeruginosa among bacteremia isolates within control groups of SDD-RCCT's versus benchmark groups with data available.

CONCLUSIONS

The topical antibiotic component of SDD presents a major contextual hazard toward bacteremia against which the PPAP component partially mitigates.

Impact of pretransplant rifaximin therapy on early post-liver transplant infections

Bacterial and fungal infections are major causes of morbidity and mortality after liver transplantation (LT). The role of intestinal decontamination in the prevention of post-LT infections is controversial. Rifaximin is widely used for the treatment of hepatic encephalopathy. The effect of rifaximin on post-LT infections is unknown. The aim of our study was to determine the effect of rifaximin therapy in the pretransplant period on early bacterial infections (EBIs) and fungal infections within the first 30 days after LT. All adult patients who underwent LT at our institution (January 2009 to July 2011) were included in this retrospective cohort study. Patients receiving antibiotics other than pretransplant protocol antibiotics were excluded. Patients were stratified into 2 groups based on the presence or absence of rifaximin therapy for at least 2 days before LT. Infections were defined by the isolation of any bacterial or fungal organisms within 30 days of LT. Multivariate regression analysis, Student t tests, and Pearson's chi-square tests were used to compare the 2 groups. Two hundred sixty-eight patients were included, and 71 of these patients (26.5%) were on rifaximin at the time of LT. The 2 groups were comparable with respect to age, sex, race, and Model for End-Stage Liver Disease score. There were no significant differences in the rates of EBIs (30% for the non-rifaximin group and 25% for the rifaximin group, P = 0.48) or fungal infections between the 2 groups. There was no increase in antimicrobial resistance among the infecting organisms. There was no difference in survival between the rifaximin and non-rifaximin groups (98% versus 97%, P = 0.36). In conclusion, the use of rifaximin in the pre-LT period was not associated with an increased risk of bacterial or fungal infections in the early post-LT period.

Selective digestive or oropharyngeal decontamination and topical oropharyngeal chlorhexidine for prevention of death in general intensive care: systematic review and network meta-analysis

OBJECTIVES

To determine the effect on mortality of selective digestive decontamination, selective oropharyngeal decontamination, and topical oropharyngeal chlorhexidine in adult patients in general intensive care units and to compare these interventions with each other in a network meta-analysis.

DESIGN

Systematic review, conventional meta-analysis, and network meta-analysis. Medline, Embase, and CENTRAL were searched to December 2012. Previous meta-analyses, conference abstracts, and key journals were also searched. We used pairwise meta-analyses to estimate direct evidence from intervention-control trials and a network meta-analysis within a Bayesian framework to combine direct and indirect evidence.

INCLUSION CRITERIA

Prospective randomised controlled trials that recruited adult patients in general intensive care units and studied selective digestive decontamination, selective oropharyngeal decontamination, or oropharyngeal chlorhexidine compared with standard care or placebo.

RESULTS

Selective digestive decontamination had a favourable effect on mortality, with a direct evidence odds ratio of 0.73 (95% confidence interval 0.64 to 0.84). The direct evidence odds ratio for selective oropharyngeal decontamination was 0.85 (0.74 to 0.97). Chlorhexidine was associated with increased mortality (odds ratio 1.25, 1.05 to 1.50). When each intervention was compared with the other, both selective digestive decontamination and selective oropharyngeal decontamination were superior to chlorhexidine. The difference between selective digestive decontamination and selective oropharyngeal decontamination was uncertain.

CONCLUSION

Selective digestive decontamination has a favourable effect on mortality in adult patients in general intensive care units. In these patients, the effect of selective oropharyngeal decontamination is less certain. Both selective digestive decontamination and selective oropharyngeal decontamination are superior to chlorhexidine, and there is a possibility that chlorhexidine is associated with increased mortality.

Infection control in the intensive care unit

Nosocomial infections are common in many hospital departments, but particularly so on the intensive care unit, where they affect some 20 to 30% of patients. While early diagnosis and appropriate treatment are, of course, important, perhaps the greatest challenge is in the application of techniques to limit the development of such infections. This review will briefly discuss some of the background pathophysiology and epidemiology of nosocomial infection, and then focus on general and infection-specific preventative strategies individually and as part of broader infection-control programs with infection surveillance.

Isolation and characterization of antimicrobial compounds in plant extracts against multidrug-resistant Acinetobacter baumannii

The number of fully active antibiotic options that treat nosocomial infections due to multidrug-resistant Acinetobacter baumannii (A. baumannii) is extremely limited. Magnolia officinalis, Mahonia bealei, Rabdosia rubescens, Rosa rugosa, Rubus chingii, Scutellaria baicalensis, and Terminalia chebula plant extracts were previously shown to have growth inhibitory activity against a multidrug-resistant clinical strain of A. baumannii. In this study, the compounds responsible for their antimicrobial activity were identified by fractionating each plant extract using high performance liquid chromatography, and determining the antimicrobial activity of each fraction against A. baumannii. The chemical structures of the fractions inhibiting >40% of the bacterial growth were elucidated by liquid chromatography/mass spectrometry analysis and nuclear magnetic resonance spectroscopy. The six most active compounds were identified as: ellagic acid in Rosa rugosa; norwogonin in Scutellaria baicalensis; and chebulagic acid, chebulinic acid, corilagin, and terchebulin in Terminalia chebula. The most potent compound was identified as norwogonin with a minimum inhibitory concentration of 128 µg/mL, and minimum bactericidal concentration of 256 µg/mL against clinically relevant strains of A. baumannii. Combination studies of norwogonin with ten anti-Gram negative bacterial agents demonstrated that norwogonin did not enhance the antimicrobial activity of the synthetic antibiotics chosen for this study. In conclusion, of all identified antimicrobial compounds, norwogonin was the most potent against multidrug-resistant A. baumannii strains. Further studies are warranted to ascertain the prophylactic and therapeutic potential of norwogonin for infections due to multidrug-resistant A. baumannii.

Effect of selective decontamination on antimicrobial resistance in intensive care units: a systematic review and meta-analysis

BACKGROUND

Many meta-analyses have shown reductions in infection rates and mortality associated with the use of selective digestive decontamination (SDD) or selective oropharyngeal decontamination (SOD) in intensive care units (ICUs). These interventions have not been widely implemented because of concerns that their use could lead to the development of antimicrobial resistance in pathogens. We aimed to assess the effect of SDD and SOD on antimicrobial resistance rates in patients in ICUs.

METHODS

We did a systematic review of the effect of SDD and SOD on the rates of colonisation or infection with antimicrobial-resistant pathogens in patients who were critically ill. We searched for studies using Medline, Embase, and Cochrane databases, with no limits by language, date of publication, study design, or study quality. We included all studies of selective decontamination that involved prophylactic application of topical non-absorbable antimicrobials to the stomach or oropharynx of patients in ICUs, with or without additional systemic antimicrobials. We excluded studies of interventions that used only antiseptic or biocide agents such as chlorhexidine, unless antimicrobials were also included in the regimen. We used the Mantel-Haenszel model with random effects to calculate pooled odds ratios.

FINDINGS

We analysed 64 unique studies of SDD and SOD in ICUs, of which 47 were randomised controlled trials and 35 included data for the detection of antimicrobial resistance. When comparing data for patients in intervention groups (those who received SDD or SOD) versus data for those in control groups (who received no intervention), we identified no difference in the prevalence of colonisation or infection with Gram-positive antimicrobial-resistant pathogens of interest, including meticillin-resistant Staphylococcus aureus (odds ratio 1·46, 95% CI 0·90-2·37) and vancomycin-resistant enterococci (0·63, 0·39-1·02). Among Gram-negative bacilli, we detected no difference in aminoglycoside-resistance (0·73, 0·51-1·05) or fluoroquinolone-resistance (0·52, 0·16-1·68), but we did detect a reduction in polymyxin-resistant Gram-negative bacilli (0·58, 0·46-0·72) and third-generation cephalosporin-resistant Gram-negative bacilli (0·33, 0·20-0·52) in recipients of selective decontamination compared with those who received no intervention.

INTERPRETATION

We detected no relation between the use of SDD or SOD and the development of antimicrobial-resistance in pathogens in patients in the ICU, suggesting that the perceived risk of long-term harm related to selective decontamination cannot be justified by available data. However, our study indicates that the effect of decontamination on ICU-level antimicrobial resistance rates is understudied. We recommend that future research includes a non-crossover, cluster randomised controlled trial to assess long-term ICU-level changes in resistance rates.

FUNDING

None.

Colistin resistance in gram-negative bacteria during prophylactic topical colistin use in intensive care units

PURPOSE

Topical use of colistin as part of selective digestive decontamination (SDD) and selective oropharyngeal decontamination (SOD) has been associated with improved patient outcome in intensive care units (ICU), yet little is known about the risks of colistin resistance. We quantified effects of selective decontamination on acquisition of colistin-resistant gram-negative bacteria (GNB) using data from a cluster-randomized study and a single-centre cohort.

METHODS

Acquisition of colistin-resistant GNB and conversion from susceptible to resistance in GNB was determined in respiratory samples [from patients receiving SDD (n = 455), SOD (n = 476), or standard care (SC) (n = 315)], and in rectal swabs from 1,840 SDD-patients. Genotyping of converting isolates was performed where possible.

RESULTS

The respiratory tract acquisition rates of colistin-resistant GNB were comparable during SDD, SOD, and SC and ranged from 0.7 to 1.1/1,000 patient-days at risk. Rectal acquisition rates during SDD were <3.3/1,000 days at risk. In patients with respiratory tract GNB carriage, conversion rates were 3.6 and 1.1/1,000 patient-days at risk during SDD and SC, respectively, (p > 0.05). In patients with rectal GNB carriage conversion rates during SDD were 5.4 and 3.2/1,000 days at risk and 15.5 and 12.6/1,000 days at risk when colonized with tobramycin-resistant GNB.

CONCLUSIONS

Acquisition rates with colistin-resistant GNB in the respiratory tract were low and comparable with and without topical use of colistin. Rates of acquisition of colistin-resistant GNB during SDD were--in ICUs with low endemicity of antibiotic resistance--<2.5/1,000 days at risk, but were fivefold higher during persistent GNB colonization and 15-fold higher during carriage with tobramycin-resistant GNB.

Selective decontamination of the digestive tract: the mechanism of action is control of gut overgrowth

PURPOSE

Gut overgrowth is the pathophysiological event in the critically ill requiring intensive care. In relation to the risk of developing a clinically important outcome, gut overgrowth is defined as ≥10(5) potential pathogens including 'abnormal' aerobic Gram-negative bacilli (AGNB), 'normal' bacteria and yeasts, per mL of digestive tract secretion. Surveillance samples of throat and gut are the only samples to detect overgrowth. Gut overgrowth is the crucial event which precedes both primary and secondary endogenous infection, and a risk factor for the development of de novo resistance. Selective decontamination of the digestive tract (SDD) is an antimicrobial prophylaxis designed to control overgrowth.

METHODS

There have been 65 randomised controlled trials of SDD in 15,000 patients over 25 years and 11 meta-analyses, which are reviewed.

RESULTS AND CONCLUSIONS

These trials demonstrate that the full SDD regimen using parenteral and enteral antimicrobials reduces lower airway infection by 72 %, blood stream infection by 37 %, and mortality by 29 %. Resistance is also controlled. Parenteral cefotaxime which reaches high salivary and biliary concentrations eradicates overgrowth of 'normal' bacteria such as Staphylococcus aureus in the throat. Enteral polyenes control 'normal' Candida species. Enteral polymyxin and tobramycin, eradicate, or prevent gut overgrowth of 'abnormal' AGNB. Enteral vancomycin controls overgrowth of 'abnormal' methicillin-resistant S. aureus. SDD controls overgrowth by achieving high antimicrobial concentrations effective against 'normal' and 'abnormal' potential pathogens rather than by selectivity.

Ventilator-associated pneumonia: a review

Ventilator-associated pneumonia (VAP) is the most common infection seen in intensive care units (ICUs); it accounts for one-fourth of the infections occurring in critically ill patients and is the reason for half of antibiotic prescriptions in mechanically ventilated patients. In addition to being a financial burden on ICUs, it continues to contribute significantly to the morbidity and mortality of ICU patients, with an estimated attributable mortality rate of 8% to 15%. While the pathophysiology of VAP remains relatively unchanged, diagnostic techniques and preventive measures are constantly evolving. The focus of this article is on recent trends in VAP epidemiology, modifiable risk factors, diagnostic techniques, challenges in management, and current data on the prevention of VAP. Important messages that the reader should take away include: 1) There is no gold standard for the diagnosis of VAP; whenever VAP is suspected, if feasible, a quantitative culture should be obtained by invasive or noninvasive methods (whichever is more readily available before initiation of antibiotics); 2) Suspicion based on clinical features should prompt the initiation of a broad spectrum of antibiotics depending on suspected pathogens; 3) Close attention should be paid to de-escalation of antibiotics once microbiological results become available or as the patient starts responding clinically; the ideal duration of treatment should be 8 days instead of the conventional 10 to 14 days, except in situations where Pseudomonas may be suspected or the patient's comorbidities dictate otherwise; and 4) Prevention remains the key to reducing the burden of VAP. We promote the proven preventive measures of using noninvasive ventilation when possible, semirecumbent patient positioning, continuous aspiration of subglottic secretions, and oral chlorhexidine washes along with stress ulcer prophylaxis only after careful assessment of the risks versus benefits.

For whom should we use selective decontamination of the digestive tract?

PURPOSE OF REVIEW

This review discusses the relevant studies on selective decontamination of the digestive tract (SDD) published between 2009 and mid-2011.

RECENT FINDINGS

In a multicenter cluster-randomized cross-over study in the Netherlands, SDD and selective oropharyngeal decontamination (SOD) were associated with higher survival at day 28, with a lower incidence of ICU-acquired bacteremia and with less acquisition of respiratory tract colonization with antibiotic resistant pathogens, compared to standard care. A post-hoc analysis of this study suggests that SDD might be more effective in surgical patients and SOD in nonsurgical patients. In a randomized study perioperative use of SDD in patients undergoing gastrointestinal surgery was associated with lower incidences of anastomotic leakages. A Cochrane meta-analysis, not including any of the before mentioned studies, reported a reduction of respiratory tract infections in studies by using topical antibiotics only and higher survival rates when topical antibiotics were combined with parenteral antibiotics.

SUMMARY

Recent studies show that in ICUs with low levels of antibiotic resistance, SDD and SOD improved patient outcome and reduced infections and carriage with antibiotic-resistant pathogens. The effect in settings with higher levels of antibiotic resistance remains to be determined as well as the efficacy of SDD and SOD in specific patient groups.