Décontamination Digestive Sélective Résultats D'une Étude Chez Le Polytraumatisé

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.

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.

Unusually High Incidences of Staphylococcus aureus Infection within Studies of Ventilator Associated Pneumonia Prevention Using Topical Antibiotics: Benchmarking the Evidence Base

Selective digestive decontamination (SDD, topical antibiotic regimens applied to the respiratory tract) appears effective for preventing ventilator associated pneumonia (VAP) in intensive care unit (ICU) patients. However, potential contextual effects of SDD on Staphylococcus aureus infections in the ICU remain unclear. The S. aureus ventilator associated pneumonia (S. aureus VAP), VAP overall and S. aureus bacteremia incidences within component (control and intervention) groups within 27 SDD studies were benchmarked against 115 observational groups. Component groups from 66 studies of various interventions other than SDD provided additional points of reference. In 27 SDD study control groups, the mean S. aureus VAP incidence is 9.6% (95% CI; 6.9–13.2) versus a benchmark derived from 115 observational groups being 4.8% (95% CI; 4.2–5.6). In nine SDD study control groups the mean S. aureus bacteremia incidence is 3.8% (95% CI; 2.1–5.7) versus a benchmark derived from 10 observational groups being 2.1% (95% CI; 1.1–4.1). The incidences of S. aureus VAP and S. aureus bacteremia within the control groups of SDD studies are each higher than literature derived benchmarks. Paradoxically, within the SDD intervention groups, the incidences of both S. aureus VAP and VAP overall are more similar to the benchmarks.

Impact of selective digestive decontamination on respiratory tract Candida among patients with suspected ventilator-associated pneumonia. A meta-analysis

The purpose here is to establish the incidence of respiratory tract colonization with Candida (RT Candida) among ICU patients receiving mechanical ventilation within studies in the literature. Also of interest is its relationship with candidemia and the relative importance of topical antibiotic (TA) use as within studies of selective digestive decontamination (SDD) versus other candidate risk factors towards it. The incidence of RT Candida was extracted from component (control and intervention) groups decanted from studies of various TA and non-TA ICU infection prevention methods with summary estimates derived using random effects. A benchmark RT Candida incidence to provide overarching calibration was derived using (observational) groups from studies without any prevention method under study. A multi-level regression model of group level data was undertaken using generalized estimating equation (GEE) methods. RT Candida data were sourced from 113 studies. The benchmark RT Candida incidence is 1.3; 0.9-1.8 % (mean and 95 % confidence intervals). Membership of a concurrent control group of a study of SDD (p = 0.02), the group-wide presence of candidemia risk factors (p < 0.001), and proportion of trauma admissions (p = 0.004), but neither the year of study publication, nor membership of any other component group, nor the mode of respiratory sampling are predictive of the RT Candida incidence. RT Candida and candidemia incidences are correlated. RT Candida incidence can serve as a basis for benchmarking. Several relationships have been identified. The increased incidence among concurrent control groups of SDD studies cannot be appreciated in any single study examined in isolation.

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.

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.

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.

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.

Antibiotic prophylaxis to reduce respiratory tract infections and mortality in adults receiving intensive care

BACKGROUND

Pneumonia is an important cause of mortality in intensive care units (ICUs). The incidence of pneumonia in ICU patients ranges between 7% and 40%, and the crude mortality from ventilator-associated pneumonia may exceed 50%. Although not all deaths in patients with this form of pneumonia are directly attributable to pneumonia, it has been shown to contribute to mortality in ICUs independently of other factors that are also strongly associated with such deaths.

OBJECTIVES

To assess the effects of prophylactic antibiotic regimens, such as selective decontamination of the digestive tract (SDD) for the prevention of respiratory tract infections (RTIs) and overall mortality in adults receiving intensive care.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, issue 1), which contains the Cochrane Acute Respiratory Infections (ARI) Group's Specialised Register; MEDLINE (January 1966 to March 2009); and EMBASE (January 1990 to March 2009).

SELECTION CRITERIA

Randomised controlled trials (RCTs) of antibiotic prophylaxis for RTIs and deaths among adult ICU patients.

DATA COLLECTION AND ANALYSIS

At least two review authors independently extracted data and assessed trial quality.

MAIN RESULTS

We included 36 trials involving 6914 people. There was variation in the antibiotics used, patient characteristics and risk of RTIs and mortality in the control groups. In trials comparing a combination of topical and systemic antibiotics, there was a significant reduction in both RTIs (number of studies = 16, odds ratio (OR) 0.28, 95% confidence interval (CI) 0.20 to 0.38) and total mortality (number of studies = 17, OR 0.75, 95% CI 0.65 to 0.87) in the treated group. In trials comparing topical antimicrobials alone (or comparing topical plus systemic versus systemic alone) there was a significant reduction in RTIs (number of studies = 17, OR 0.44, 95% CI 0.31 to 0.63) but not in total mortality (number of studies = 19, OR 0.97, 95% CI 0.82 to 1.16) in the treated group.

AUTHORS' CONCLUSIONS

A combination of topical and systemic prophylactic antibiotics reduces RTIs and overall mortality in adult patients receiving intensive care. Treatment based on the use of topical prophylaxis alone reduces respiratory infections but not mortality. The risk of resistance occurring as a negative consequence of antibiotic use was appropriately explored only in one trial which did not show any such effect.

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.

[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.

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.

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.

Antibiotic prophylaxis to reduce respiratory tract infections and mortality in adults receiving intensive care

BACKGROUND

Pneumonia is an important cause of mortality in intensive care units. The incidence of pneumonia in such patients ranges between 7% and 40%, and the crude mortality from ventilator associated pneumonia may exceed 50%. Although not all deaths in patients with this form of pneumonia are directly attributable to pneumonia, it has been shown to contribute to mortality in intensive care units independently of other factors that are also strongly associated with such deaths.

OBJECTIVES

The objective of this review was to assess the effects of antibiotics for preventing respiratory tract infections and overall mortality in adults receiving intensive care.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (issue 3, 2003), which contains the Acute Respiratory Infections (ARI) Group specialised trials register; MEDLINE (January 1966 to September 2003); EMBASE (January 1990 to September 2003); proceedings of scientific meetings and reference lists of articles from January 1984 to December 2002. We also contacted investigators in the field.

SELECTION CRITERIA

Randomised trials of antibiotic prophylaxis for respiratory tract infections and deaths among adult intensive care unit patients.

DATA COLLECTION AND ANALYSIS

At least two reviewers independently extracted data and assessed trial quality.

MAIN RESULTS

Overall 36 trials involving 6922 people were included. There was variation in the antibiotics used, patient characteristics and risk of respiratory tract infections and mortality in the control groups. In 17 trials (involving 4295 patients) that tested a combination of topical and systemic antibiotic, the average rates of respiratory tract infections and deaths in the control group were 36% and 29% respectively. There was a significant reduction of both respiratory tract infections (odds ratio 0.35, 95% confidence interval 0.29 to 0.41) and total mortality (odds ratio 0.78, 95% confidence interval 0.68 to 0.89) in the treated group. On average 5 patients needed to be treated to prevent one infection and 21 patients to prevent one death. In 17 trials (involving 2664 patients) that tested topical antimicrobials alone (or comparing topical plus systemic versus systemic alone) the rates of respiratory tract infections and deaths in the control groups were 30% and 26% respectively. There was a significant reduction of respiratory tract infections (odds ratio 0.52, 95% confidence interval 0.43 to 0.63) but not in total mortality (odds ratio 0.97, 95% confidence interval 0.81 to 1.16) in the treated group.

REVIEWER'S CONCLUSIONS

A combination of topical and systemic prophylactic antibiotics reduces respiratory tract infections and overall mortality in adult patients receiving intensive care. A treatment based on the use of topical prophylaxis alone reduces respiratory infections but not mortality. The risk of occurrence of resistance as a negative consequence of antibiotic use was appropriately explored only in the most recent trial by de Jonge which did not show any such effect.