Impact of Oral Chlorhexidine on Bloodstream Infection in Critically Ill Patients: Systematic Review and Meta-Analysis of Randomized Controlled Trials.

OBJECTIVES: Oropharyngeal overgrowth of microorganisms in the critically ill is a risk factor for lower respiratory tract infection and subsequent invasion of the bloodstream. Oral chlorhexidine has been used to prevent pneumonia, but its effect on bloodstream infection never has been assessed in meta-analyses. The authors explored the effect of oral chlorhexidine on the incidence of bloodstream infection, the causative microorganism, and on all-cause mortality in critically ill patients. DESIGN: Systematic review and meta-analysis of published studies. SETTING: Intensive care unit. PARTICIPANTS: The study comprised critically ill patients receiving oral chlorhexidine (test group) and placebo or standard oral care (control group). INTERVENTIONS: PubMed and the Cochrane Register of Controlled Trials were searched. Odds ratios (ORs) were pooled using the random-effects model. MEASUREMENTS AND MAIN RESULTS: Five studies including 1,655 patients (832 chlorhexidine and 823 control patients) were identified. The majority of information was from studies at low or unclear risk bias; 1 study was at high risk of bias. Bloodstream infection and mortality were not reduced significantly by chlorhexidine (OR 0.74; 95% confidence interval [CI] 0.37-1.50 and OR 0.69; 95% CI 0.31-1.53, respectively). In the subgroup of surgical, mainly cardiac, patients, chlorhexidine reduced bloodstream infection (OR 0.47; 95% CI 0.22-0.97). Chlorhexidine did not affect any microorganism significantly. CONCLUSION: In critically ill patients, oropharyngeal chlorhexidine did not reduce bloodstream infection and mortality significantly and did not affect any microorganism involved. The presence of a high risk of bias in 1 study and unclear risk of bias in others may have affected the robustness of these findings.

Selective Digestive Decontamination Attenuates Organ Dysfunction in Critically Ill Burn Patients.

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.

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.

Long-term use of selective decontamination of the digestive tract does not increase antibiotic resistance: a 5-year prospective cohort study.

PURPOSE: Despite the evidence, the use of selective decontamination of the digestive tract (SDD) remains controversial, largely because of concerns that it may promote the emergence of antibiotic-resistant strains. The purpose of this study was to evaluate the long-term incidence of carriage of antibiotic-resistant bacteria (ARB), its clinical impact on developing infections and to explore risk factors of acquiring resistance. METHODS: This study was conducted in one 18-bed medical-surgical intensive care unit (ICU). All consecutive patients admitted to the ICU who were expected to require tracheal intubation for longer than 48 h were given a 4-day course of intravenous cefotaxime, and enteral polymyxin E, tobramycin, amphotericin B in an oropharyngeal paste and digestive solution. Oropharyngeal and rectal swabs were obtained on admission and once a week. Diagnostic samples were obtained on clinical indication. RESULTS: During 5 years 1,588 patients were included in the study. The incidence density of ARB was stable: 18.91 carriers per 1,000 patient-days. The incidence of resistant Enterobacteriaceae was stable; the resistance of Pseudomonas aeruginosa to tobramycin, amikacin and ciprofloxacin was strongly reduced; there was an increase of P. aeruginosa resistant to ceftazidime and imipenem, associated with the increase in imipenem consumption; the incidence of other nonfermenter bacilli and oxacillin-resistant Staphylococcus aureus was close to zero. Ninety-seven patients developed 101 infections caused by ARB: 23 pneumonias, 20 bloodstream infections and 58 urinary tract infections. Abdominal surgery was the only risk factor associated with ARB acquisition [risk ratio 1.56 (1.10-2.19)]. CONCLUSIONS: Long-term use of SDD is not associated with an increase in acquisition of resistant flora.