Changing bacterial ecology during a five-year period of selective intestinal decontamination

Rebound Inverts the Staphylococcus aureus Bacteremia Prevention Effect of Antibiotic Based Decontamination Interventions in ICU Cohorts with Prolonged Length of Stay

Could rebound explain the paradoxical lack of prevention effect against Staphylococcus aureus blood stream infections (BSIs) with antibiotic-based decontamination intervention (BDI) methods among studies of ICU patients within the literature? Two meta-regression models were applied, each versus the group mean length of stay (LOS). Firstly, the prevention effects against S. aureus BSI [and S. aureus VAP] among 136 studies of antibiotic-BDI versus other interventions were analyzed. Secondly, the S. aureus BSI [and S. aureus VAP] incidence in 268 control and intervention cohorts from studies of antibiotic-BDI versus that among 165 observational cohorts as a benchmark was modelled. In model one, the meta-regression line versus group mean LOS crossed the null, with the antibiotic-BDI prevention effect against S. aureus BSI at mean LOS day 7 (OR 0.45; 0.30 to 0.68) inverted at mean LOS day 20 (OR 1.7; 1.1 to 2.6). In model two, the meta-regression line versus group mean LOS crossed the benchmark line, and the predicted S. aureus BSI incidence for antibiotic-BDI groups was 0.47; 0.09-0.84 percentage points below versus 3.0; 0.12-5.9 above the benchmark in studies with 7 versus 20 days mean LOS, respectively. Rebound within the intervention groups attenuated and inverted the prevention effect of antibiotic-BDI against S. aureus VAP and BSI, respectively. This explains the paradoxical findings.

Prevention of severe infectious complications after colorectal surgery using preoperative orally administered antibiotic prophylaxis (PreCaution): study protocol for a randomized controlled trial

BACKGROUND

Colorectal surgery is frequently complicated by surgical site infections (SSIs). The most important consequences of SSIs are prolonged hospitalization, an increased risk of surgical reintervention and an increase in mortality. Perioperative intravenously administered antibiotic prophylaxis is the standard of care to reduce the risk of SSIs. In the last few decades, preoperative orally administered antibiotics have been suggested as additional prophylaxis to further reduce the risk of infection, but are currently not part of routine practice in most hospitals. The objective of this study is to evaluate the efficacy of a preoperative orally administered antibiotic prophylaxis (Pre-OP) in addition to intravenously administered perioperative antibiotic prophylaxis to reduce the incidence of deep SSIs and/or mortality after elective colorectal surgery.

METHODS/DESIGN

The PreCaution trial is designed as a multicenter, double-blind, randomized, placebo-controlled clinical trial that will be carried out in The Netherlands. Adult patients who are scheduled for elective colorectal surgery are eligible to participate. In total, 966 patients will be randomized to receive the study medication. This will either be Pre-OP, a solution that consists of tobramycin and colistin sulphate, or a placebo solution. The study medication will be administered four times daily during the 3 days prior to surgery. Perioperative intravenously administered antibiotic prophylaxis will be administered to all patients in accordance with national infection control guidelines. The primary endpoint of the study is the cumulative incidence of deep SSIs and/or mortality within 30 days after surgery. Secondary endpoints include both infectious and non-infectious complications of colorectal surgery, and will be evaluated 30 days and/or 6 months after surgery.

DISCUSSION

To date, conclusive evidence on the added value of preoperative orally administered antibiotic prophylaxis in colorectal surgery is lacking. The PreCaution trial should determine the effects of orally administered antibiotics in preventing infectious complications in elective colorectal surgery.

TRIAL REGISTRATION

Netherlands Trial Register, ID: NTR6113 . Registered on 11 October 2016; EudraCT 2015-005736-17.

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.

Effect of probiotics on the incidence of ventilator-associated pneumonia in critically ill patients: a randomized controlled multicenter trial

PURPOSE

To evaluate the potential preventive effect of probiotics on ventilator-associated pneumonia (VAP).

METHODS

This was an open-label, randomized, controlled multicenter trial involving 235 critically ill adult patients who were expected to receive mechanical ventilation for ≥48 h. The patients were randomized to receive (1) a probiotics capsule containing live Bacillus subtilis and Enterococcus faecalis (Medilac-S) 0.5 g three times daily through a nasogastric feeding tube plus standard preventive strategies or (2) standard preventive strategies alone, for a maximum of 14 days. The development of VAP was evaluated daily, and throat swabs and gastric aspirate were cultured at baseline and once or twice weekly thereafter.

RESULTS

The incidence of microbiologically confirmed VAP in the probiotics group was significantly lower than that in the control patients (36.4 vs. 50.4 %, respectively; P = 0.031). The mean time to develop VAP was significantly longer in the probiotics group than in the control group (10.4 vs. 7.5 days, respectively; P = 0.022). The proportion of patients with acquisition of gastric colonization of potentially pathogenic microorganisms (PPMOs) was lower in the probiotics group (24 %) than the control group (44 %) (P = 0.004). However, the proportion of patients with eradication PPMO colonization on both sites of the oropharynx and stomach were not significantly different between the two groups. The administration of probiotics did not result in any improvement in the incidence of clinically suspected VAP, antimicrobial consumption, duration of mechanical ventilation, mortality and length of hospital stay.

CONCLUSION

Therapy with the probiotic bacteria B. Subtilis and E. faecalis are an effective and safe means for preventing VAP and the acquisition of PPMO colonization in the stomach.

The Japanese guidelines for the management of sepsis

This is a guideline for the management of sepsis, developed by the Sepsis Registry Committee of The Japanese Society of Intensive Care Medicine (JSICM) launched in March 2007. This guideline was developed on the basis of evidence-based medicine and focuses on unique treatments in Japan that have not been included in the Surviving Sepsis Campaign guidelines (SSCG), as well as treatments that are viewed differently in Japan and in Western countries. Although the methods in this guideline conform to the 2008 SSCG, the Japanese literature and the results of the Sepsis Registry Survey, which was performed twice by the Sepsis Registry Committee in intensive care units (ICUs) registered with JSICM, are also referred. This is the first and original guideline for sepsis in Japan and is expected to be properly used in daily clinical practice.

This article is translated from Japanese, originally published as “The Japanese Guidelines for the Management of Sepsis” in the Journal of the Japanese Society of Intensive Care Medicine (J Jpn Soc Intensive Care Med), 2013; 20:124–73. The original work is at http://dx.doi.org/10.3918/jsicm.20.124.

Probiotic/synbiotic therapy for treating critically ill patients from a gut microbiota perspective

The gut is an important target organ for stress caused by severe insults such as sepsis, trauma, burn, shock, bleeding and infection. Severe insult to the gut is considered to have an important role in promoting infectious complications and multiple organ dysfunction syndrome. These are sequelae of interactions between deteriorated intestinal epithelium, the immune system and commensal bacteria. The gut is the "motor" of multiple organ failure, and now it is recognized that gut dysfunction is a causative factor in disease progression. The gut flora and environment are significantly altered in critically ill patients, and the number of obligate anaerobes is associated with prognosis. Synbiotic therapy is a combination of probiotics and prebiotics. Probiotic, prebiotic and synbiotic treatment has been shown to be a promising therapy to maintain and repair the gut microbiota and gut environment. In the critically ill, such as major abdominal surgery, trauma and ICU patients, synbiotic therapy has been shown to significantly reduce septic complications. Further basic and clinical research would clarify the underlying mechanisms of the therapeutic effect of probiotic/synbiotic treatment and define the appropriate conditions for use.

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.

Selective digestive tract decontamination in critically ill patients

INTRODUCTION

Selective decontamination of the digestive tract (SDD) has been proposed to prevent endogenous and exogenous infections and to reduce mortality in critically ill patients. Although the efficacy of SDD has been confirmed by randomized controlled trials (RCTs) and systematic reviews, SDD has been the subject of intense controversy, based mainly on an insufficient evidence of efficacy and on concerns about resistance.

AREAS COVERED

This article reviews the philosophy, the current evidence on the efficacy of SDD and the issue of emergence of resistance. All SDD RCTs were searched using Embase and Medline, with no restriction of language, gender or age. Personal archives were also explored, including abstracts from major scientific meetings; references in papers and published meta-analyses on SDD were crosschecked. Up-to-date evidence of the impact of SDD on carriage, infections and mortality is presented, and the efficacy of SDD in selected patient groups was investigated, along with the problem of the emergence of resistance.

EXPERT OPINION

SDD significantly reduces the number of infections of the lower respiratory tract and bloodstream, multiple organ failure and mortality. It also controls resistance, particularly when the full protocol of parenteral and enteral antimicrobials is used.

Clinical practice guidelines for hospital-acquired pneumonia and ventilator-associated pneumonia in adults

Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) are important causes of morbidity and mortality, with mortality rates approaching 62%. HAP and VAP are the second most common cause of nosocomial infection overall, but are the most common cause documented in the intensive care unit setting. In addition, HAP and VAP produce the highest mortality associated with nosocomial infection. As a result, evidence-based guidelines were prepared detailing the epidemiology, microbial etiology, risk factors and clinical manifestations of HAP and VAP. Furthermore, an approach based on the available data, expert opinion and current practice for the provision of care within the Canadian health care system was used to determine risk stratification schemas to enable appropriate diagnosis, antimicrobial management and nonantimicrobial management of HAP and VAP. Finally, prevention and risk-reduction strategies to reduce the risk of acquiring these infections were collated. Future initiatives to enhance more rapid diagnosis and to effect better treatment for resistant pathogens are necessary to reduce morbidity and improve survival.

Prevention of ventilator-associated pneumonia, mortality and all intensive care unit acquired infections by topically applied antimicrobial or antiseptic agents: a meta-analysis of randomized controlled trials in intensive care units

INTRODUCTION

Given the high morbidity and mortality attributable to ventilator-associated pneumonia (VAP) in intensive care unit (ICU) patients, prevention plays a key role in the management of patients undergoing mechanical ventilation. One of the candidate preventive interventions is the selective decontamination of the digestive or respiratory tract (SDRD) by topical antiseptic or antimicrobial agents. We performed a meta-analysis to investigate the effect of topical digestive or respiratory tract decontamination with antiseptics or antibiotics in the prevention of VAP, of mortality and of all ICU-acquired infections in mechanically ventilated ICU patients.

METHODS

A meta-analysis of randomised controlled trials was performed. The U.S. National Library of Medicine's MEDLINE database, Embase, and Cochrane Library computerized bibliographic databases, and reference lists of selected studies were used. Selection criteria for inclusion were: randomised controlled trials (RCTs); primary studies; examining the reduction of VAP and/or mortality and/or all ICU-acquired infections in ICU patients by prophylactic use of one or more of following topical treatments: 1) oropharyngeal decontamination using antiseptics or antibiotics, 2) gastrointestinal tract decontamination using antibiotics, 3) oropharyngeal plus gastrointestinal tract decontamination using antibiotics and 4) respiratory tract decontamination using antibiotics; reported enough data to estimate the odds ratio (OR) or risk ratio (RR) and their variance; English language; published through June 2010.

RESULTS

A total of 28 articles met all inclusion criteria and were included in the meta-analysis. The overall estimate of efficacy of topical SDRD in the prevention of VAP was 27% (95% CI of efficacy = 16% to 37%) for antiseptics and 36% (95% CI of efficacy = 18% to 50%) for antibiotics, whereas in none of the meta-analyses conducted on mortality was a significant effect found. The effect of topical SDRD in the prevention of all ICU-acquired infections was statistically significant (efficacy = 29%; 95% CI of efficacy = 14% to 41%) for antibiotics whereas the use of antiseptics did not show a significant beneficial effect.

CONCLUSIONS

Topical SDRD using antiseptics or antimicrobial agents is effective in reducing the frequency of VAP in ICU. Unlike antiseptics, the use of topical antibiotics seems to be effective also in preventing all ICU-acquired infections, while the effectiveness on mortality of these two approaches needs to be investigated in further research.

Hypothermia does not increase the risk of infection: a case control study

Introduction

Hypothermia may improve outcome in patients after traumatic brain injury, especially when hypothermia is maintained for more than 48 hours. In the acute phase, patients with severe brain injury are more vulnerable to infections. Prolonged hypothermic treatment may further enhance the risk of infection. Selective decontamination of the digestive tract (SDD) reduces the risk of respiratory tract infections. The aim of this study was to investigate the incidence of infections in patients treated with hypothermia and normothermia while receiving SDD.

Methods

In this retrospective case control study 35 patients treated with prolonged hypothermia (cases) were identified and 169 patients with severe brain injury were included (controls). Propensity score matching was performed to correct for differences in baseline characteristics and clinical parameters. Primary outcome was the incidence of infection. The secondary endpoints were the micro-organisms found in the surveillance cultures and infection. In addition, a number of clinical characteristics were assessed.

Results

The demographic and clinical data indicated that the cases and controls were well matched. The overall risk of infection during ICU stay was 20% in the hypothermia groups versus 34.4% in the normothermia group (P = 0.388). Pneumonia was diagnosed in 11.4% of patients in both groups (P = 1.000). The incidence of meningitis, wound infection, bacteremia, and urinary tract infection was low and comparable between the groups. SDD surveillance cultures indicated a higher colonization with gram-negative bacteria in the rectal samples of the hypothermia patients.

Conclusions

Hypothermia does not increase the risk of infection in patients treated with SDD.

Antibiotics or probiotics as preventive measures against ventilator-associated pneumonia: a literature review

Introduction

Mechanically ventilated critically ill patients frequently develop ventilator-associated pneumonia (VAP), a life-threatening complication. Proposed preventive measures against VAP include, but are not restricted to, selective decontamination of the digestive tract (SDD), selective oropharyngeal decontamination (SOD) and the use of probiotics. Probiotics are live bacteria that could have beneficial effects on the host by altering gastrointestinal flora. Similar to SDD and SOD, a prescription of probiotics aims at the prevention of secondary colonization of the upper and/or lower digestive tract.

Methods

We performed a literature review to describe the differences and similarities between SDD/SOD and probiotic preventive strategies, focusing on (a) efficacy, (b) risks, and (c) the routing of these strategies.

Results

Reductions in the incidence of VAP have been achieved with SDD and SOD. Two large randomized controlled trials even showed reduced mortality with these preventive strategies. Randomized controlled trials of probiotic strategies also showed a reduction of the incidence of VAP, but trials were too small to draw firm conclusions. Preventive strategies with antibiotics and probiotics may be limited due to the risk of emerging resistance to the locally applied antibiotics and the risk of probiotic-related infections, respectively. The majority of trials of SDD and SOD did not exhaustively address the issue of emerging resistance. Likewise, trials of probiotic strategies did not adequately address the risk of colonization with probiotics and probiotic-related infection. In studies of SDD and SOD the preventive strategy aimed at decontamination of the oral cavity, throat, stomach and intestines, and the oral cavity and throat, respectively. In the vast majority of studies of probiotic therapy the preventive strategy aimed at decontamination of the stomach and intestines.

Conclusions

Prophylactic use of antibiotics in critically ill patients is effective in reducing the incidence of VAP. Probiotic strategies deserve consideration in future well-powered trials. Future studies are needed to determine if preventive antibiotic and probiotic strategies are safe with regard to development of antibiotic resistance and probiotic infections. It should be determined whether the efficacy of probiotics improves when these agents are provided to the mouth and the intestines simultaneously.

Paradoxical ventilator associated pneumonia incidences among selective digestive decontamination studies versus other studies of mechanically ventilated patients: benchmarking the evidence base

Introduction

Selective digestive decontamination (SDD) appears to have a more compelling evidence base than non-antimicrobial methods for the prevention of ventilator associated pneumonia (VAP). However, the striking variability in ventilator associated pneumonia-incidence proportion (VAP-IP) among the SDD studies remains unexplained and a postulated contextual effect remains untested for.

Methods

Nine reviews were used to source 45 observational (benchmark) groups and 137 component (control and intervention) groups of studies of SDD and studies of three non-antimicrobial methods of VAP prevention. The logit VAP-IP data were summarized by meta-analysis using random effects methods and the associated heterogeneity (tau²) was measured. As group level predictors of logit VAP-IP, the mode of VAP diagnosis, proportion of trauma admissions, the proportion receiving prolonged ventilation and the intervention method under study were examined in meta-regression models containing the benchmark groups together with either the control (models 1 to 3) or intervention (models 4 to 6) groups of the prevention studies.

Results

The VAP-IP benchmark derived here is 22.1% (95% confidence interval; 95% CI; 19.2 to 25.5; tau² 0.34) whereas the mean VAP-IP of control groups from studies of SDD and of non-antimicrobial methods, is 35.7 (29.7 to 41.8; tau² 0.63) versus 20.4 (17.2 to 24.0; tau² 0.41), respectively (P < 0.001). The disparity between the benchmark groups and the control groups of the SDD studies, which was most apparent for the highest quality studies, could not be explained in the meta-regression models after adjusting for various group level factors. The mean VAP-IP (95% CI) of intervention groups is 16.0 (12.6 to 20.3; tau² 0.59) and 17.1 (14.2 to 20.3; tau² 0.35) for SDD studies versus studies of non-antimicrobial methods, respectively.

Conclusions

The VAP-IP among the intervention groups within the SDD evidence base is less variable and more similar to the benchmark than among the control groups. These paradoxical observations cannot readily be explained. The interpretation of the SDD evidence base cannot proceed without further consideration of this contextual effect.

Selective decontamination of the digestive tract reduces pneumonia and mortality

Selective decontamination of the digestive tract (SDD) has been subject of numerous randomized controlled trials in critically ill patients. Almost all clinical trials showed SDD to prevent pneumonia. Nevertheless, SDD has remained a controversial strategy. One reason for why clinicians remained reluctant to implement SDD into daily practice could be that mortality was reduced in only 2 trials. Another reason could be the heterogeneity of trials of SDD. Indeed, many different prophylactic antimicrobial regimes were tested, and dissimilar diagnostic criteria for pneumonia were applied amongst the trials. This heterogeneity impeded interpretation and comparison of trial results. Two other hampering factors for implementation of SDD have been concerns over the risk of antimicrobial resistance and fear for escalation of costs associated with the use of prophylactic antimicrobials. This paper describes the concept of SDD, summarizes the results of published trials of SDD in mixed medical-surgical intensive care units, and rationalizes the risk of antimicrobial resistance and rise of costs associated with this potentially life-saving preventive strategy.

Physicians' and nurses' opinions on selective decontamination of the digestive tract and selective oropharyngeal decontamination: a survey

Introduction

Use of selective decontamination of the digestive tract (SDD) and selective oropharyngeal decontamination (SOD) in intensive care patients has been controversial for years. Through regular questionnaires we determined expectations concerning SDD (effectiveness) and experience with SDD and SOD (workload and patient friendliness), as perceived by nurses and physicians.

Methods

A survey was embedded in a group-randomized, controlled, cross-over multicenter study in the Netherlands in which, during three 6-month periods, SDD, SOD or standard care was used in random order. At the end of each study period, all nurses and physicians from participating intensive care units received study questionnaires.

Results

In all, 1024 (71%) of 1450 questionnaires were returned by nurses and 253 (82%) of 307 by physicians. Expectations that SDD improved patient outcome increased from 71% and 77% of respondents after the first two study periods to 82% at the end of the study (P = 0.004), with comparable trends among nurses and physicians. Nurses considered SDD to impose a higher workload (median 5.0, on a scale from 1 (low) to 10 (high)) than SOD (median 4.0) and standard care (median 2.0). Both SDD and SOD were considered less patient friendly than standard care (medians 4.0, 4.0 and 6.0, respectively). According to physicians, SDD had a higher workload (median 5.5) than SOD (median 5.0), which in turn was higher than standard care (median 2.5). Furthermore, physicians graded patient friendliness of standard care (median 8.0) higher than that of SDD and SOD (both median 6.0).

Conclusions

Although perceived effectiveness of SDD increased as the trial proceeded, both among physicians and nurses, SOD and SDD were, as compared to standard care, considered to increase workload and to reduce patient friendliness. Therefore, education about the importance of oral care and on the effects of SDD and SOD on patient outcomes will be important when implementing these strategies.

Trial registration

ISRCTN35176830.

Current Concepts in the Prevention and Treatment of Ventilator-Associated Pneumonia

Ventilator-associated pneumonia (VAP) is one of the most common causes of infection in intensive care unit (ICU) patients. Efforts to prevent VAP have focused on both pharmacologic and nonpharmacologic strategies. Two of the more controversial pharmacologic approaches included selective decontamination of the digestive tract (SDD) and decontamination of the oropharynx using topical antimicrobials or antiseptics including chlorhexidine (CHX). Additionally, avoidance of pharmacotherapy-related risk factors is hypothesized to reduce VAP rates. Successful treatment of VAP is becoming increasingly difficult in the era of antibiotic resistance. Utilization of local antibiograms, implementation of standardized treatment pathways, and optimization of pharmacodynamic-based dosing offer methods to improve empiric therapy selections. De-escalation of therapy should be a constant focus in an attempt to reduce overall antibiotic consumption and the selection pressure on ICU flora, thus minimizing the development and spread of antimicrobial resistance in the ICU.

Ecological effects of selective decontamination on resistant gram-negative bacterial colonization

RATIONALE

Selective digestive tract decontamination (SDD) and selective oropharyngeal decontamination (SOD) eradicate gram-negative bacteria (GNB) from the intestinal and respiratory tract in intensive care unit (ICU) patients, but their effect on antibiotic resistance remains controversial.

OBJECTIVES

We quantified the effects of SDD and SOD on bacterial ecology in 13 ICUs that participated in a study, in which SDD, SOD, or standard care was used during consecutive periods of 6 months (de Smet AM, Kluytmans JA, Cooper BS, Mascini EM, Benus RF, van der Werf TS, van der Hoeven JG, Pickkers P, Bogaers-Hofman D, van der Meer NJ, et al. N Engl J Med 2009;360:20-31).

METHODS

Point prevalence surveys of rectal and respiratory samples were performed once monthly in all ICU patients (receiving or not receiving SOD/SDD). Effects of SDD on rectal, and of SDD/SOD on respiratory tract, carriage of GNB were determined by comparing results from consecutive point prevalence surveys during intervention (6 mo for SDD and 12 mo for SDD/SOD) with consecutive point prevalence data in the pre- and postintervention periods.

MEASUREMENTS AND MAIN RESULTS

During SDD, average proportions of patients with intestinal colonization with GNB resistant to either ceftazidime, tobramycin, or ciprofloxacin were 5, 7, and 7%, and increased to 15, 13, and 13% postintervention (P < 0.05). During SDD/SOD resistance levels in the respiratory tract were not more than 6% for all three antibiotics but increased gradually (for ceftazidime; P < 0.05 for trend) during intervention and to levels of 10% or more for all three antibiotics postintervention (P < 0.05).

CONCLUSIONS

SOD and SDD have marked effects on the bacterial ecology in an ICU, with rising ceftazidime resistance prevalence rates in the respiratory tract during intervention and a considerable rebound effect of ceftazidime resistance in the intestinal tract after discontinuation of SDD.

[Selective decontamination of the digestive tract: repercussions on microbiology laboratory workload and costs, and antibiotic resistance trends]

INTRODUCTION

This study determines the workload and cost of implementing selective digestive decontamination in the microbiology laboratory, and reports the impact on microbial flora and bacterial resistance trends in the intensive care unit (ICU).

METHODS

The total microbiological workload and cost were quantified, as well as the part charged to the petitioning service, in the year before and the year after introducing the procedure. Changes in microbial flora were evaluated and bacterial resistance trends were analyzed over 12 years in 21 sentinel antimicrobial/microorganism combinations.

RESULTS

The workload ascribed to the ICU increased by 10% and cost increased by 1.8% in the period after introduction of the procedure (non-significant differences). The increased workload resulting from epidemiological surveillance cultures was compensated by significant reductions in quantitative endotracheal aspirate cultures, blood cultures, exudate cultures, identification tests with antibiograms, and serologies. The procedure has been associated with a significant decrease in Acinetobacter isolates and a significant increase in Enterococcus. Three significant trends of increased resistance were detected, all of them in Pseudomonas aeruginosa (imipenem, tobramycin, and ciprofloxacin).

CONCLUSIONS

In our hospital, implementation of selective digestive decontamination did not cause a significant increase in the workload or costs in the microbiology laboratory. Selective digestive decontamination was associated with a significant decrease in Acinetobacter, an increase in Enterococcus, and higher resistance to imipenem, tobramycin and ciprofloxacin in P. aeruginosa.

Decontamination of the digestive tract and oropharynx in ICU patients

BACKGROUND

Selective digestive tract decontamination (SDD) and selective oropharyngeal decontamination (SOD) are infection-prevention measures used in the treatment of some patients in intensive care, but reported effects on patient outcome are conflicting.

METHODS

We evaluated the effectiveness of SDD and SOD in a crossover study using cluster randomization in 13 intensive care units (ICUs), all in The Netherlands. Patients with an expected duration of intubation of more than 48 hours or an expected ICU stay of more than 72 hours were eligible. In each ICU, three regimens (SDD, SOD, and standard care) were applied in random order over the course of 6 months. Mortality at day 28 was the primary end point. SDD consisted of 4 days of intravenous cefotaxime and topical application of tobramycin, colistin, and amphotericin B in the oropharynx and stomach. SOD consisted of oropharyngeal application only of the same antibiotics. Monthly point-prevalence studies were performed to analyze antibiotic resistance.

RESULTS

A total of 5939 patients were enrolled in the study, with 1990 assigned to standard care, 1904 to SOD, and 2045 to SDD; crude mortality in the groups at day 28 was 27.5%, 26.6%, and 26.9%, respectively. In a random-effects logistic-regression model with age, sex, Acute Physiology and Chronic Health Evaluation (APACHE II) score, intubation status, and medical specialty used as covariates, odds ratios for death at day 28 in the SOD and SDD groups, as compared with the standard-care group, were 0.86 (95% confidence interval [CI], 0.74 to 0.99) and 0.83 (95% CI, 0.72 to 0.97), respectively.

CONCLUSIONS

In an ICU population in which the mortality rate associated with standard care was 27.5% at day 28, the rate was reduced by an estimated 3.5 percentage points with SDD and by 2.9 percentage points with SOD. (Controlled Clinical Trials number, ISRCTN35176830.)

Impact of Selective Decontamination of the Digestive Tract on Carriage and Infection Due to Gram-Negative and Gram-Positive Bacteria: A Systematic Review of Randomised Controlled Trials

Meta-analyses of randomised controlled trials of selective digestive decontamination have clinical outcome measures, mainly pneumonia and mortality. This meta-analysis has a microbiological endpoint and explores the impact of selective digestive decontamination on Gram-negative and Gram-positive carriage and severe infections. We searched electronic databases, Cochrane Register of Controlled Trials, previous meta-analyses and conference proceedings with no language restrictions. We included randomised controlled trials which compared the selective digestive decontamination protocol with no treatment or placebo. Three reviewers independently applied selection criteria, performed the quality assessment and extracted the data. The outcome measures were carriage and severe infection due to Gram-negative and Gram-positive bacteria. Odds ratios were pooled with the random effect model. Fifty-four randomised controlled trials comprising 9473 patients were included; 4672 patients received selective digestive decontamination and 4801 were controls. Selective digestive decontamination significantly reduced oropharyngeal carriage (odds ratio [OR] 0.13, 95% confidence interval [CI] 0.07 to 0.23), rectal carriage (OR 0.15, 95% CI 0.07 to 0.31), overall infection (OR 0.17, 95% CI 0.10 to 0.28), lower respiratory tract infection (OR 0.11, 95% CI 0.06 to 0.20) and bloodstream infection (OR 0.35, 95% CI 0.21 to 0.67) due to Gram-negative bacteria. Reduction in Gram-positive carriage was not significant. Gram-positive lower airway infections were significantly reduced (OR 0.52, 95% CI 0.34 to 0.78). Gram-positive bloodstream infections were not significantly increased (OR 1.03, 95% CI 0.75 to 1.41). The association of parenteral and enteral antimicrobials was superior to enteral antimicrobials in reducing carriage and severe infections due to Gram-negative bacteria. This meta-analysis confirms that selective digestive decontamination mainly targets Gram-negative bacteria; it does not show a significant increase in Gram-positive infection.

Guidelines for the management of hospital-acquired pneumonia in the UK: report of the working party on hospital-acquired pneumonia of the British Society for Antimicrobial Chemotherapy

These evidence-based guidelines have been produced after a systematic literature review of a range of issues involving prevention, diagnosis and treatment of hospital-acquired pneumonia (HAP). Prevention is structured into sections addressing general issues, equipment, patient procedures and the environment, whereas in treatment, the structure addresses the use of antimicrobials in prevention and treatment, adjunctive therapies and the application of clinical protocols. The sections dealing with diagnosis are presented against the clinical, radiological and microbiological diagnosis of HAP. Recommendations are also made upon the role of invasive sampling and quantitative microbiology of respiratory secretions in directing antibiotic therapy in HAP/ventilator-associated pneumonia.

Antibiotic Prescribing in Critical Care: Specific Indications

This article outlines recommendations for the treatment of specific infections occurring in the setting of critical care. In the interests of brevity, a limited number of infections are discussed and recommendations are largely confined to empirical therapy. Basic principles of diagnosis and treatment apply in all cases, including appropriate de-escalation when an organism is identified. These aspects of treatment have been dealt with in part one of this article – ‘Antibiotic prescribing in critical care: general principles' published in the winter 2007 edition of JICS.

[Selective digestive decontamination. Why don't we apply the evidence in the clinical practice?]

Selective digestive decontamination (SDD) is a prophylactic strategy whose objective is to reduce the incidence of infections, mainly mechanical ventilation associated pneumonia in patients who require intensive cares, preventing or eradicating the oropharyngeal and gastrointestinal carrier state of potentially pathogenic microorganisms. Fifty-four randomized clinical trials (RCTs) and 9 meta-analysis have evaluated SDD. Thirty eight RCTs show a significant reduction of the infections and 4 of mortality. All the meta-analyses show a significant reduction of the infections and 5 out of the 9 meta-analyses report a significant reduction in mortality. Thus, 5 patients from the ICU with SDD must be treated to prevent pneumonia and 12 patients from the ICU should be treated to prevent one death. The data that show benefit of the SDD on mortality have an evidence grade 1 or recommendation grade A (supported by at least two level 1 investigations). The aim of this review is to explain the pathogeny of infections in critical patients, describe selective digestive decontamination, analyze the evidence available on it efficacy and the potential adverse effects and discuss the reasons published by the experts who advise against the use of SDD, even though it is recognized as the best intervention evaluated in intensive cares to reduce morbidity and mortality of the infections.

Article Commentary: Strategies in the Prevention and Management of Ventilator-Associated Pneumonia

Ventilator-associated pneumonia (VAP) is a leading cause of morbidity and mortality in the intensive care unit. Prevention of VAP is possible through the use of several evidence-based strategies intended to minimize intubation, the duration of mechanical ventilation, and the risk of aspiration of oropharyngeal pathogens. Current data favor the quantitative analysis of lower respiratory tract cultures for the diagnosis of VAP, accompanied by the initiation of broad-spectrum empiric antimicrobial therapy based on patient risk factors for infection with multi-drug-resistant pathogens and data from unit-specific antibiograms. Eventual choice of antibiotic and duration of therapy are selected based on culture results and patient stability, with an emphasis on minimization of unnecessary antibiotic use.

Relative effects of barrier precautions and topical antibiotics on nosocomial bacterial transmission: results of multi-compartment models

Nosocomial bacterial infections in critically ill patients are generally preceded by asymptomatic carriage (i.e. colonization) at one, or even several, body sites such as the skin, the gastro-intestinal and the respiratory tract. Different routes of transmission between the colonized sites create a complex epidemiology, which is additionally complicated by the smallness of the patient population size and the rapid patient turnover, characteristic for intensive care units (ICUs). Naturally occurring large fluctuations in the prevalence of colonization make it very difficult to determine the efficacy of control measures that aim to reduce the prevalence of antibiotic-resistant bacteria in ICUs. Theoretical models can sharpen our intuition through carefully designed thought experiments. In this spirit, we introduce and investigate two models that incorporate the fact that patients may be colonized at multiple body sites. Our study can be applied to several pathogens commonly found in ICUs, such Pseudomonas Aeruginosa, enteric Gram-negative bacteria, MRSA and enterococci. We evaluate the effects of barrier precautions (improved hygiene, use of gloves and gowns, etc.) and of administration of nonabsorbable antibiotics on the prevalence of colonization in ICUs and find that the effect of the controversial, though widely used, antibiotic prophylaxis can only be substantial if the patient-to-patient transmission has already been reduced to a subcritical level by barrier precautions. Taking into account that the very use of antibiotics may increase the selection for resistant strains and may thereby only add to the ever increasing problem of antibiotic resistance, our findings hence represent a firm theoretical argument against the routine use of topical antimicrobial prophylaxis for infection control.

Reducing susceptibility to bacteremia after experimental burn injury: a role for selective decontamination of the digestive tract

We proposed that selective decontamination of the digestive tract (SDD) initiated after experimental burn injury would decrease myocardial inflammation and dysfunction after a second insult such as septic challenge. Rats were divided into eight experimental groups. Groups included sham burn plus sham sepsis, burn alone, sepsis alone, and burn plus sepsis given either water by oral gavage for 5 days after burn (or sham burn) or given oral antibiotics (polymyxin E, 15 mg; tobramycin, 6 mg; 5-flucytosin, 100 mg given by oral gavage, 2x daily for 5 days after burn or sham burn). Cardiac function and inflammation were studied 24 h after septic challenge. In the absence of SDD, burn alone, sepsis alone, or burn plus septic challenge promoted cardiac myocyte secretion of TNF-alpha (burn, 174+/-11; sepsis, 269+/-19; burn+sepsis, 453+/-14 pg/ml), IL-1beta (burn, 35+/-2; sepsis, 29+/-1; burn+sepsis, 48+/-7 pg/ml), and IL-6 (burn, 143+/-18; sepsis, 116+/-3; burn+sepsis, 248+/-12 pg/ml) compared with values measured in sham (TNF-alpha, 3+/-1; IL-1beta, 1+/-0.4; IL-6, 6+/-1.5 pg/ml) (P<0.05). Impaired ventricular contraction and relaxation responses were evident in the absence of SDD [burn+sepsis: left ventricular pressure (LVP), 65+/-4 mmHg; rate of LVP rise (+dP/dt), 1,320+/-131 mmHg/s compared with values measured in sham: LVP, 96+/-4 mmHg; +dP/dt, 2,095+/-99 mmHg/s, P<0.05]. SDD treatment of experimental burn attenuated septic challenge-related inflammatory responses and improved myocardial contractile responses, producing cardiac TNF-alpha, IL-1beta, and IL-6 levels, LVP, +dP/dt, and rate of LVP fall (-dP/dt) values that were significantly better (P<0.05) than values measured in burn plus sepsis in the absence of SDD. This work confirms that endogenous gut organisms contribute to sensitivity to subsequent infectious challenge.

Selective decontamination of the digestive tract reduces bacterial bloodstream infection and mortality in critically ill patients. Systematic review of randomized, controlled trials

A systematic review and meta-analysis of randomized controlled trials (RCTs) of selective decontamination of the digestive tract (SDD) was undertaken to evaluate the impact of this procedure on bacterial bloodstream infection and mortality. Data sources were Medline, Embase, Cochrane Register of Controlled Trials, previous meta-analyses, and conference proceedings, without restriction of language or publication status. RCTs were retrieved that compared oropharyngeal and/or intestinal administration of antibiotics as part of the SDD protocol, with or without a parenteral component, with no treatment or placebo in the controls. The three outcome measures were patients with bloodstream infection, causative micro-organisms, and total mortality. Fifty-one RCTs conducted between 1987 and 2005, comprising 8065 critically ill patients were included in the review; 4079 patients received SDD and 3986 were controls. SDD significantly reduced overall bloodstream infections [odds ratio (OR), 0.73; 95% confidence interval (CI), 0.59-0.90; P=0.0036], gram-negative bloodstream infections (OR, 0.39; 95% CI, 0.24-0.63; P<0.001) and overall mortality (OR, 0.80; 95% CI, 0.69-0.94; P=0.0064), without affecting gram-positive bloodstream infections (OR, 1.06; 95% CI, 0.77-1.47). The subgroup analysis showed an even larger impact of SDD using parenteral and enteral antimicrobials on overall bloodstream infections, bloodstream infections due to gram-negative bacteria and overall mortality with ORs of 0.63 (95% CI, 0.46-0.87; P=0.005), 0.30 (95% CI, 0.16-0.56; P<0.001), and 0.74 (95% CI, 0.61-0.91; P=0.0034), respectively. Twenty patients need to be treated with SDD to prevent one gram-negative bloodstream infection and 22 patients to prevent one death.

The effect of selective decontamination of the digestive tract on mortality in multiple trauma patients: a multicenter randomized controlled trial

OBJECTIVE

Evaluation of selective decontamination of the digestive tract (SDD) on late mortality in ventilated trauma patients in an intensive care unit (ICU).

METHODS

A multicenter, randomized controlled trial was undertaken in 401 trauma patients with Hospital Trauma Index-Injury Severity Score of 16 or higher. Patients were randomized to control (n=200) or SDD (n=201), using polymyxin E, tobramycin, and amphotericin B in throat and gut throughout ICU treatment combined with cefotaxime for 4 days. Primary endpoint was late mortality excluding early death from hemorrhage or craniocerebral injury. Secondary endpoints were infection and organ dysfunction.

RESULTS

Mortality was 20.9% with SDD and 22.0% in controls. Overall late mortality was 15.3% (57/372) as 29 patients died from cerebral injury, 16 SDD and 13 control. The odds ratio (95% confidence intervals) of late mortality for SDD relative to control was 0.75 (0.40-1.37), corresponding to estimates of 13.4% SDD and 17.2% control. The overall infection rate was reduced in the test group (48.8% vs. 61.0%). SDD reduced lower airway infections (30.9% vs. 50.0%) and bloodstream infections due to aerobic Gram-negative bacilli (2.5% vs. 7.5%). No difference in organ dysfunction was found.

CONCLUSION

This study demonstrates that SDD significantly reduces infection in multiple trauma, although this RCT in 401 patients was underpowered to detect a mortality benefit.

Ventilator-associated pneumonia: diagnosis, treatment, and prevention

While critically ill patients experience a life-threatening illness, they commonly contract ventilator-associated pneumonia. This nosocomial infection increases morbidity and likely mortality as well as the cost of health care. This article reviews the literature with regard to diagnosis, treatment, and prevention. It provides conclusions that can be implemented in practice as well as an algorithm for the bedside clinician and also focuses on the controversies with regard to diagnostic tools and approaches, treatment plans, and prevention strategies.

Selective Digestive Tract Decontamination—Will It Prevent Infection with Multidrug-Resistant Gram-Negative Pathogens but Still Be Applicable in Institutions where Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococci Are Endemic?

The purposes of selective decontamination of the digestive tract are to treat infections that may be incubating at the time a patient is admitted to an intensive care unit (ICU), by intravenous administration of antibiotics during the first days of a stay in the ICU, and to prevent ICU-acquired infections, by topical application of antibiotics in the oropharynx and the gastrointestinal tract. Despite multiple trials in which a considerable reduction in the incidence of ventilator-associated pneumonia was demonstrated, major objections against the routine use of selective decontamination of the digestive tract have included a lack of demonstrated reductions in mortality rates and in length of stay (in individual trials), a lack of cost-efficacy data, and the threat of selection of multidrug-resistant bacteria. Recently, 2 controlled, randomized studies reported significant reductions in mortality rates among patients in ICUs who underwent selective decontamination of the digestive tract in combination with reduced selection of antibiotic-resistant pathogens. However, those studies were performed in settings where levels of antibiotic resistance are low, and some methodological issues remain unresolved. If these beneficial results are confirmed, the question of how to balance these benefits against the expected enhanced selection of methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and, possibly, multidrug-resistant gram-negative bacteria will emerge.

Effects of long-term routine use of selective digestive decontamination on antimicrobial resistance

OBJECTIVE

To assess the distribution of bacterial species and antimicrobial resistance in an ICU during long-term use of selective digestive decontamination (SDD) in the context of national reference data.

DESIGN AND SETTING

Five-year prospective observational study in a 24-bed interdisciplinary surgical ICU of a university hospital (study ICU) participating in the project "Surveillance of Antimicrobial Use and Antimicrobial Resistance in German Intensive Care Units" (SARI; reference ICUs).

PATIENTS

Resistance data were obtained from all patients; patients intubated for at least 2 days received SDD (colistin, tobramycin, amphotericin B).

INTERVENTIONS AND MEASUREMENTS

SDD was performed in 1,913 of 7,270 patients. Antimicrobial resistance was examined in 4,597 (study ICU) and 46,346 (reference ICUs) isolates.

RESULTS

Methicillin-resistant Staphylococcus aureus (MRSA) remained stable (2.76 and 2.58 isolates/1000 patient days) in the study ICU; this was below the German average (4.26 isolates/1000 patient days). Aminoglycoside- and betalactam-resistant Gram-negative rods did not increase during SDD use. Aminoglycoside resistance of Pseudomonas aeruginosa was 50% below the mean value of SARI (0.24 vs. 0.52 isolates/1,000 patient days). The relative frequency of enterococci and coagulase-negative staphylococci (CNS) was higher than in the SARI ICUs (23.2% vs. 17.3%, and 25.0% vs. 20.6%, respectively).

CONCLUSION

Routine 5-year-use of SDD was not associated with increased antimicrobial resistance in our ICU with low baseline resistance rates. Vigorous surveillance and control measures to search and destroy MRSA were considered a mandatory component of the SDD program. The relative increase in enterococci and CNS is of concern requiring further investigation.

Ventilator associated pneumonia and infection control

Ventilator associated pneumonia (VAP) is the leading cause of morbidity and mortality in intensive care units. The incidence of VAP varies from 7% to 70% in different studies and the mortality rates are 20-75% according to the study population. Aspiration of colonized pathogenic microorganisms on the oropharynx and gastrointestinal tract is the main route for the development of VAP. On the other hand, the major risk factor for VAP is intubation and the duration of mechanical ventilation. Diagnosis remains difficult, and studies showed the importance of early initiation of appropriate antibiotic for prognosis. VAP causes extra length of stay in hospital and intensive care units and increases hospital cost. Consequently, infection control policies are more rational and will save money.

Nosocomial pneumonia: state of the science

Nosocomial pneumonia is the leading cause of mortality due to hospital-acquired infections. A thorough understanding of the most recent developments in evaluating and managing nosocomial pneumonia is critical for infection control professionals and hospital epidemiologists, given the incidence and cost of this important patient safety problem. We review the evidence on pathogenesis, diagnosis, treatment, and prevention of both ventilator-associated and nonventilator-associated pneumonia. Key recommendations are then provided for diagnostic testing strategies, antibiotic selection, and treatment duration. We also summarize the most recent data on how to prevent hospital-acquired infection, in general, and nosocomial pneumonia, in particular.

Small intestinal bacterial overgrowth: roles of antibiotics, prebiotics, and probiotics

Small intestinal bacterial overgrowth is common in intestinal failure. Its occurrence relates to alterations in intestinal anatomy, motility, and gastric acid secretion. Its presence may contribute to symptoms, mucosal injury, and malnutrition. Relationships between bacterial overgrowth and systemic sepsis are of potential importance in the intestinal failure patient because the direct translocation of bacteria across the intestinal epithelium may contribute to systemic sepsis: a phenomenon that has been well established in experimental animal models. The accurate diagnosis of bacterial overgrowth continues to present a number of challenges in clinical practice and especially so among patients with intestinal failure. The management of patients with bacterial overgrowth remains, for the most part, primarily empiric and comprises antibiotic therapy and correction of any associated nutritional deficiencies. Although evidence from experimental animal studies consistently indicates that probiotics exert barrier-enhancing, antibacterial, immune-modulating, and anti-inflammatory effects, which all could be benefits in small intestinal bacterial overgrowth and intestinal failure, their role in human beings remains to be evaluated adequately.

A prospective study of septicaemia on a paediatric oncology unit: A three-year experience at The Royal Liverpool Children’s Hospital, Alder Hey, UK

Septicaemia in neutropaenic patients is predominantly due to gut translocation [endogenous septicaemia] and contamination of the central venous catheter by microorganisms not carried by the patient [exogenous septicaemia]. To control both types of infection, a protocol was implemented based on pre 1990's parenteral and enteral antimicrobials together with strict hygiene. Surveillance cultures of throat/rectum were taken to distinguish exogenous from endogenous septicaemia and enteral non-absorbable antibiotics are administered as part of selective decontamination of the digestive tract (SDD). This protocol was evaluated in a 14-bedded paediatric oncology unit over a period of 3 years. 313 Septicaemia episodes were recorded in 131 children. 28.4% of the septicaemias were caused by microorganisms associated with the unit, equivalent to 0.82 episodes per 100 patient days. Low-level pathogens such as coagulase-negative staphylococci caused more than 70% of infections. Amongst the potential pathogens, Pseudomonas species (7.8%) and Staphylococcus aureus (5.5%) were predominant. Antibiotic resistance was rare with no superinfections or outbreaks. Four patients (3%) died, two due to Candida species and two due to Pseudomonas aeruginosa. We believe that the addition of enteral non-absorbable antibiotics to systemic antibiotics maintained a low level of resistance and mortality but a randomised controlled trial is indicated to confirm these observations.

Impact of selective decontamination of the digestive tract on fungal carriage and infection: systematic review of randomized controlled trials

OBJECTIVE

To determine the impact of the antifungal component of selective decontamination of the digestive tract on fungal carriage, infection and fungaemia.

DESIGN

Meta-analysis of randomized controlled trials of selective decontamination of the digestive tract.

STUDY SELECTION

Data sources included Medline, Embase, Cochrane Register of Controlled Trials, previous meta-analyses, personal communications and conference proceedings, without restriction of language or publication status. All randomized trials were selected that compared oropharyngeal and/or intestinal administration of antifungals amphotericin B or nystatin, as part of selective decontamination protocol, with no treatment in the controls. There were 42 randomized controlled trials with a total of 6,075 critically ill patients.

METHODS

Three reviewers independently applied selection criteria, performed quality assessment and extracted the data. The main outcome measures were patients with fungal carriage, patients with fungal infections and patients with fungaemia. Odds ratios were pooled with the random effect model.

MEASUREMENTS AND RESULTS

Enteral antifungals significantly reduced fungal carriage (odds ratio 0.32, 95% confidence interval 0.19-0.53) and overall fungal infections (0.30, 0.17-0.53). Fungaemia was not significantly reduced in the treatment group (0.89, 0.16-4.95).

CONCLUSIONS

Antifungals, as part of selective decontamination of the digestive tract, reduce fungal carriage and infection but not fungaemia in critically ill patients and may justify the inclusion of an antifungal component in the decontamination protocol.

[Selective digestive decontamination: the light as changed from red to green]

OBJECTIVES

To study the efficacy of selective digestive decontamination (SDD) for the prevention of nosocomial infections, particularly pneumonia, as well as its impact on the emergence of multiresistant bacteria.

DATA SOURCES

Data collected from the Pubmed: original articles, review articles and editorial published on SDD. The keywords were: selective digestive decontamination, pneumonia, intensive care unit, infection.

DATA SELECTION

Ten randomized clinical trials performed since 1995 in mechanically ventilated adult patients hospitalized in intensive care unit.

RESULTS

The rationale for the use of SDD consists on the parenteral administration of a short course of antibiotic associated with the topical use of non-absorbable antibiotics directed against Gram negative bacteria. Five randomized studies described a reduction in the incidence of pneumonia associated with SDD. Only one study has showed a decrease in mortality rate. The other five studies, which present some methodological limitations, concluded the lack of efficacy of SDD. Regarding the emergence of multiresistant bacteria, the literature underlines the role of environment. The use of SDD seems to trigger the resistance in endemic areas, while these are softened in the units with a good control of their ecology.

CONCLUSION

The data from the literature provide arguments to use SDD in targeted patient populations like multiple traumas in intensive care units, which have a low rate of multiresistant bacteria.