Selective oropharyngeal decontamination versus selective digestive decontamination in critically ill patients: a meta-analysis of randomized controlled trials

Selective decontamination of the digestive tract: concept and application

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

Asymmetric Effects of Decontamination Using Topical Antibiotics for the ICU Patient

There are several antiseptic, antibiotic and non-decontamination-based interventions for preventing intensive care unit (ICU) acquired infection. These have been evaluated in >200 studies. Infection prevention using topical antibiotic prophylaxis (TAP) appears to be the most effective. Whether antibiotic use in the ICU may influence the risk of infection among concurrent control patients within the same ICU and result in asymmetrical herd effects cannot be resolved with individual studies examined in isolation. The collective observations within control and intervention groups from numerous ICU infection prevention studies simulates a multi-center natural experiment enabling the herd effects of antibiotics to be evaluated. Among the TAP control groups, the incidences for both ventilator associated pneumonia (VAP) and mortality are unusually high in comparison to literature-derived benchmarks. Paradoxically, amongst the TAP intervention groups, the incidences of mortality are also unusually high and the VAP incidences are similar (i.e., not lower) compared to the incidences among studies of other interventions. By contrast, the mortality incidences among the intervention groups of other studies are similar to those among the intervention groups of TAP studies. Using topical antibiotics to prevent infections acquired within the ICU environment may result in profoundly asymmetrical effects.

Pathogenesis-Targeted Preventive Strategies for Multidrug Resistant Ventilator-Associated Pneumonia: A Narrative Review

Ventilator-associated pneumonia (VAP) is the most common hospital-acquired infection in the intensive care unit (ICU), accounting for relevant morbidity and mortality among critically ill patients, especially when caused by multidrug resistant (MDR) organisms. The rising problem of MDR etiologies, which has led to a reduction in treatment options, have increased clinician’s attention to the employment of effective prevention strategies. In this narrative review we summarized the evidence resulting from 27 original articles that were identified through a systematic database search of the last 15 years, focusing on several pathogenesis-targeted strategies which could help preventing MDR-VAP. Oral hygiene with Chlorhexidine (CHX), CHX body washing, selective oral decontamination (SOD) and/or digestive decontamination (SDD), multiple decontamination regimens, probiotics, subglottic secretions drainage (SSD), special cuff material and shape, silver-coated endotracheal tubes (ETTs), universal use of gloves and contact isolation, alcohol-based hand gel, vaporized hydrogen peroxide, and bundles of care have been addressed. The most convincing evidence came from interventions directly addressed against the key factors of MDR-VAP pathogenesis, especially when they are jointly implemented into bundles. Further research, however, is warranted to identify the most effective combination.

Altering Routine Intensive Care Unit Practices to Support Commensalism

The gastrointestinal (GI) tract consists of trillions of organisms that support multiple functions in the body, from immunity, digestion, and absorption to drug metabolism. These microbes form an overall collection of microorganisms that form the body's microbiome. In critical illness, many of these functions are aberrant, and the microbiome is altered, leading to untoward effects. Some of the most common medications received by patients include antibiotics and proton pump inhibitors, which affect particular changes in the microbiome. In addition, patients receiving prolonged enteral and parenteral nutrition experience changes in the microbiological composition and diversity of their GI tracts. Research is ongoing to characterize the crosstalk between the microbiome and immune function as targets for drug and nutrition therapy.

Characterization of Postoperative Infection Risk in Cardiac Surgery Patients With Delayed Sternal Closure

OBJECTIVES

To compare the incidence of postoperative infection in cardiac surgery patients who had delayed sternal closure (DSC) with those who had primary sternal closure (PSC) and evaluate the effectiveness of antibiotic prophylaxis in DSC patients.

DESIGN

Retrospective, observational cohort study with propensity score matching.

SETTING

Single academic medical center.

PARTICIPANTS

Cardiothoracic surgery patients, excluding transplantation patients, from a single academic medical center who had DSC or PSC between November 2015 and November 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 2,685 patients who had cardiac surgery with cardiopulmonary bypass, 99 had DSC. Fifty-nine DSC patients met study inclusion criteria, and the final propensity score matched cohort included 57 patients with DSC and 57 patients with PSC. Propensity score matching reduced bias but was unable to balance all covariates. The most common indication for DSC was coagulopathy in 32 of the 57 patients. All patients in the PSC group received routine antibiotic prophylaxis for 48 hours after surgery. Patients in the DSC group received prolonged broadened prophylaxis until 48 hours after sternal closure. Despite prolonged broadened antibiotic prophylaxis, the DSC group had a higher rate of postoperative infection (31.6% v 3.5%; p < 0.005), mainly pneumonia (19.3% v 1.8%; p < 0.005), in the first 30 days after surgery. There was no difference in the incidence of sepsis (5.3% v 0%; p = 0.24), superficial skin and soft tissue infection (1.8% v 1.8%; p = 1), or mediastinitis/deep tissue infection (5.3% v 0%; p = 0.24) in patients with DSC. Seventy-seven percent of causative organisms for infection were Gram-negative bacteria in the matched cohort.

CONCLUSION

The incidence of postoperative infection, particularly pneumonia, is high in cardiothoracic surgery patients with DSC, even with prolonged broadened antibiotic prophylaxis, but the rate of mediastinitis/deep tissue infection did not appear to be greater with DSC. Additional research is needed into optimal antibiotic prophylaxis in this high-risk group of patients.

The Role of the Environment and Colonization in Healthcare-Associated Infections

Healthcare-associated infections (HAIs) can be caused by endogenous host microbial flora or by exogenous microbes, including those found in the hospital environment. Efforts to decrease endogenous pathogens via decolonization and skin antisepsis may decrease the risk of infection in some settings. Controlling the spread of potential pathogens from the environment requires meticulous attention to cleaning and disinfection practices. In addition to selection of the appropriate cleaning agent, use of tools that assess the adequacy of cleaning and addition of no-touch cleaning technology may decrease environmental contamination. Hand hygiene is also a critical component of preventing transmission of pathogens from the environment to patients via healthcare worker hands.

Can probiotics be an alternative to chlorhexidine for oral care in the mechanically ventilated patient? A multicentre, prospective, randomised controlled open trial

Background

Pathogenic enteric bacteria aspirated from the oropharynx are the main cause of ventilator-associated pneumonia (VAP). Using chlorhexidine (CHX) orally or selective decontamination has been shown to reduce VAP. In a pilot study we found that oral care with the probiotic bacterium Lactobacillus plantarum 299 (Lp299) was as effective as CHX in reducing enteric bacteria in the oropharynx. To confirm those results, in this expanded study with an identical protocol we increased the number of patients and participating centres.

Methods

One hundred and fifty critically ill patients on mechanical ventilation were randomised to oral care with either standard 0.1% CHX solution (control group) or a procedure comprising final application of an emulsion of Lp299. Samples for microbiological analyses were taken from the oropharynx and trachea at inclusion and subsequently at defined intervals.

Student’s t test was used for comparisons of parameters recorded daily and Fisher’s exact test was used to compare the results of microbiological cultures.

Results

Potentially pathogenic enteric bacteria not present at inclusion were identified in oropharyngeal samples from 29 patients in the CHX group and in 31 samples in the probiotic group. Considering cultures of tracheal secretions, enteric bacteria were found in 17 and 19 samples, respectively. Risk ratios show a difference in favour of the Lp group for fungi in oropharyngeal cultures. VAP was diagnosed in seven patients in the Lp group and in 10 patients among the controls.

Conclusions

In this multicentre study, we could not demonstrate any difference between Lp299 and CHX used in oral care procedures regarding their impact on colonisation with emerging potentially pathogenic enteric bacteria in the oropharynx and trachea.

Trial registration

ClinicalTrials.gov, NCT01105819. Registered on 9 April 2010.

First part: Current Controlled Trials, ISRCTN00472141. Registered on 22 November 2007 (published Critical Care 2008, 12:R136).

Impact of selective digestive decontamination without systemic antibiotics in a major heart surgery intensive care unit

PURPOSE

The incidence density of ventilator-associated pneumonia (VAP) is higher in patients undergoing major heart surgery than in other populations, despite the introduction of bundles of preventive measures, because many risk factors are not amenable to intervention. Selective digestive decontamination (SDD) has been shown to be efficacious for decreasing the frequency of VAP, although it has not been incorporated into the routine of most intensive care units. The objective of our study was to evaluate the efficacy of SDD without parenteral antibiotics for preventing VAP in a major heart surgery intensive care unit.

METHODS

We compared the incidence of VAP before the introduction of SDD (17 months) and during the 17 months after the introduction of SDD and examined its ecologic influence.

RESULTS

The rates of VAP in the overall population before and during the intervention were 16.26/1000 days and 6.80 episodes/1000 days of mechanical ventilation, respectively (P = .01). The rates of VAP in the 173 patients remaining under mechanical ventilation > 48 hours after surgery were, respectively, 25.85/1000 days of mechanical ventilation versus 12.06 episodes/1000 days of mechanical ventilation (P = .04). We found a significant reduction in the number of patients with multidrug-resistant microorganisms (P = .01) in the second period of the study.

CONCLUSIONS

Our study shows that SDD without parenteral antibiotics can reduce the incidence of VAP in high-risk patients after major heart surgery, with no significant ecologic influence.

EFFECT of daily antiseptic body wash with octenidine on nosocomial primary bacteraemia and nosocomial multidrug-resistant organisms in intensive care units: design of a multicentre, cluster-randomised, double-blind, cross-over study

INTRODUCTION

Nosocomial infections are serious complications that increase morbidity, mortality and costs and could potentially be avoidable. Antiseptic body wash is an approach to reduce dermal micro-organisms as potential pathogens on the skin. Large-scale trials with chlorhexidine as the antiseptic agent suggest a reduction of nosocomial infection rates. Octenidine is a promising alternative agent which could be more effective against Gram-negative organisms. We hypothesise that daily antiseptic body wash with octenidine reduces the risk of intensive care unit (ICU)-acquired primary bacteraemia and ICU-acquired multidrug-resistant organisms (MDRO) in a standard care setting.

METHODS AND ANALYSIS

EFFECT is a controlled, cluster-randomised, double-blind study. The experimental intervention consists in using octenidine-impregnated wash mitts for the daily routine washing procedure of the patients. This will be compared with using placebo wash mitts. Replacing existing washing methods is the only interference into clinical routine.Participating ICUs are randomised in an AB/BA cross-over design. There are two 15-month periods, each consisting of a 3-month wash-out period followed by a 12-month intervention and observation period. Randomisation determines only the sequence in which octenidine-impregnated or placebo wash mitts are used. ICUs are left unaware of what mitts packages they are using.The two coprimary endpoints are ICU-acquired primary bacteraemia and ICU-acquired MDRO. Endpoints are defined based on individual ward-movement history and microbiological test results taken from the hospital information systems without need for extra documentation. Data on clinical symptoms of infection are not collected. EFFECT aims at recruiting about 45 ICUs with about 225 000 patient-days per year.

ETHICS AND DISSEMINATION

The study was approved by the ethics committee of the University of Leipzig (number 340/16-ek) in November 2016. Findings will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

DRKS-ID: DRKS00011282.