Search

We undertook a prospective observational cohort study in intensive care unit (ICU) patients requiring mechanical ventilation for four days or more to evaluate normal and abnormal bacterial carriage on admission detected by surveillance cultures of throat and rectum. We assessed the importance of surveillance and diagnostic cultures for the early detection of resistance to third generation cephalosporins employed as the parenteral component of the selective decontamination of the digestive tract. Finally, we sought the risk factors of abnormal carriage on admission to the ICU. During the 58-month study 621 patients were included: 186 patients (30%) carried abnormal flora including methicillin-resistant Staphylococcus aureus (MRSA) and aerobic Gram negative bacilli (AGNB) on admission to the ICU Both MRSA and AGNB carriers were more commonly present in the hospital group of patients than in patients referred from the community (P < 0.001), although overgrowth was equally present both in community and in hospital patients. The incidence of infections during ICU stay was higher in abnormal (n=120, 64.5%) than in normal carriers (n=185, 42.5%) (P < 0.0001), with an odds ratio of 2.46 (95% confidence interval 1.72 to 3.51). Third generation cephalosporins covered ICU admission flora in 482 (78%) of the studied population. AGNB resistant to cephalosporins and MRSA were detected in surveillance cultures of 139 patients (22%), while the same resistant micro-organisms were identified only in 49 diagnostic samples (7.9%). Parenteral cephalosporins were modified in patients with abnormal flora (P < 0.0001). One hundred and ninety-six patients received antibiotics before admission to the ICU and 42% carried AGNB resistant to cephalosporins. Previous antibiotic use was the only risk factor for abnormal carriage in the multivariate analysis (OR 3.5; 95% confidence interval 2.1 to 5.8). The knowledge of carriage on admission using surveillance cultures may help intensivists to identify patients with abnormal carriage on admission and resistant bacterial strains at an early stage even when diagnostic samples are negative. Third generation cephalosporins covered admission flora in about 80% of the enrolled population and were modified in patients with abnormal flora who received antibiotic therapy before ICU admission. Our finding of overgrowth present on admission may justify the immediate administration of enteral antimicrobials. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective: To evaluate whether selective decontamination of the digestive tract (SDD) attenuates organ dysfunction in critically ill burn patients., Background: The effect of SDD on the development and progression of organ dysfunction, as an important determinant of mortality in burned patients, is still unknown. We asked whether organ dysfunction is mitigated by treatment with SDD., Methods: Patients with burns >20% of total body surface or suspected inhalation injury from a randomized placebo-controlled trial were analyzed to determine the relationship between treatment received (placebo or SDD) and the severity of organ dysfunction as measured by the area under the curve of the Sequential Organ Failure Assessment (SOFA) score (and its individual components) from day 1 to day 7 of admission., Results: One hundred seven patients (53 in the SDD group and 54 in the placebo group) were included. Survival was significantly higher in SDD-treated patients (48 of 53, 90.6%) than in placebo-treated patients (39 of 54, 72.2%, P = 0.013). Total (P < 0.01) and respiratory (P < 0.01), cardiovascular (P = 0.04) and hematological (not reaching statistical significance, P = 0.07) organ dysfunction was associated with mortality after adjusting for predicted mortality. In multivariate logistic regression, SDD treatment was independently associated with total (P < 0.01), respiratory (P = 0.02), and hematological (P < 0.01) dysfunction over the first week postinjury., Conclusions: The beneficial effect of SDD on mortality in critically ill burned patients is accompanied by a reduction in the degree of organ dysfunction. SDD seems to be a valuable therapeutic strategy to prevent organ dysfunction and, more specifically, respiratory and hematological dysfunction in severely ill burn patients.

Surveillance cultures are essential in the management of infection in the intensive care unit. They are crucial in the assessment of the efficacy of selective digestive decontamination.

We carried out a systematic review and meta-analysis of randomized trials to explore the effectiveness of oral chlorhexidine on nosocomial pneumonia, causative bacteria, and mortality. PubMed, Embase, and the Cochrane Register of Controlled Trials were searched for randomized trials in critically ill patients receiving oral chlorhexidine. Odds ratios (OR) were pooled with the random effects model. Twenty-two randomized trials including 4277 patients were identified. Chlorhexidine significantly reduced the incidence of nosocomial pneumonia (OR 0.66; 95% confidence interval [CI] 0.51-0.85) and ventilator-associated pneumonia (OR 0.68, 95% CI 0.53-0.87). There was a significant reduction of nosocomial pneumonia due to both Gram-positive (OR 0.41; 95% CI 0.19-0.85) and Gram-negative (OR 0.68; 95% CI 0.51-0.90) bacteria, but only pneumonia due to "normal" flora (OR 0.51; 95% CI 0.33-0.80). The subgroup analysis revealed a significant benefit of chlorhexidine on nosocomial pneumonia in surgical patients only (OR 0.52; 95% CI 0.33-0.82). Mortality was not affected. This review indicates that in critically ill, mainly surgical, patients, oral chlorhexidine reduces nosocomial pneumonia, ventilator-associated pneumonia, nosocomial pneumonia due to Gram-positive and Gram-negative bacteria, and due to "normal" flora, without affecting mortality. Further studies should explore the efficacy of oral chlorhexidine in non-surgical critically ill population.

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.

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.