Prevention of ventilator-associated pneumonia with oral antiseptics: a systematic review and meta-analysis

Facilitating Nitrite-Derived S-Nitrosothiol Formation in the Upper Gastrointestinal Tract in the Therapy of Cardiovascular Diseases

Cardiovascular diseases (CVDs) are often associated with impaired nitric oxide (NO) bioavailability, a critical pathophysiological alteration in CVDs and an important target for therapeutic interventions. Recent studies have revealed the potential of inorganic nitrite and nitrate as sources of NO, offering promising alternatives for managing various cardiovascular conditions. It is now becoming clear that taking advantage of enzymatic pathways involved in nitrite reduction to NO is very relevant in new therapeutics. However, recent studies have shown that nitrite may be bioactivated in the acidic gastric environment, where nitrite generates NO and a variety of S-nitrosating compounds that result in increased circulating S-nitrosothiol concentrations and S-nitrosation of tissue pharmacological targets. Moreover, transnitrosation reactions may further nitrosate other targets, resulting in improved cardiovascular function in patients with CVDs. In this review, we comprehensively address the mechanisms and relevant effects of nitrate and nitrite-stimulated gastric S-nitrosothiol formation that may promote S-nitrosation of pharmacological targets in various CVDs. Recently identified interfering factors that may inhibit these mechanisms and prevent the beneficial responses to nitrate and nitrite therapy were also taken into consideration.

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.

Efficacy of preventive interventions against ventilator-associated pneumonia in critically ill patients: an umbrella review of meta-analyses

Many meta-analyses have assessed the efficacy of preventive interventions against ventilator-associated pneumonia (VAP) in critically ill patients. However, there has been no comprehensive analysis of the strength and quality of evidence to date. Systematic reviews of randomized and quasi-randomized controlled trials, which evaluated the effect of preventive strategies on the incidence of VAP in critically ill patients receiving mechanical ventilation for at least 48 h, were included in this article. We identified a total of 34 interventions derived from 31 studies. Among these interventions, 19 resulted in a significantly reduced incidence of VAP. Among numerous strategies, only selective decontamination of the digestive tract (SDD) was supported by highly suggestive (Class II) evidence (risk ratio (RR)=0.439, 95% CI: 0.362-0.532). Based on data from the sensitivity analysis, the evidence for the efficacy of non-invasive ventilation in weaning from mechanical ventilation (NIV) was upgraded from weak (Class IV) to highly suggestive (Class II) (RR=0.32, 95% CI: 0.22-0.46). All preventive interventions were not supported by robust evidence for reducing mortality. Early mobilization exhibited suggestive (Class III) evidence in shortening both intensive length of stay (LOS) in the intensive care unit (ICU) (mean difference (MD)=-0.85, 95% CI: -1.21 to -0.49) and duration of mechanical ventilation (MD=-1.02, 95% CI: -1.41 to -0.63). In conclusion, SDD and NIV are supported by robust evidence for prevention against VAP, while early mobilization has been shown to significantly shorten the LOS in the ICU and the duration of mechanical ventilation. These three strategies are recommendable for inclusion in the ventilator bundle to lower the risk of VAP and improve the prognosis of critically ill patients.

Is Zero Ventilator-Associated Pneumonia Achievable? Updated Practical Approaches to Ventilator-Associated Pneumonia Prevention

Ventilator-associated pneumonia (VAP) remains a significant clinical entity with reported incidence rates of 7% to 15%. Given the considerable adverse consequences associated with this infection, VAP prevention became a core measure required in most US hospitals. Many institutions took pride in implementing effective VAP prevention bundles that combined at least head of bed elevation, hand hygiene, chlorhexidine oral care, and subglottic drainage. Spontaneous breathing and awakening trials have also consistently been shown to shorten the duration of mechanical ventilation and secondarily reduce the occurrence of VAP.

Effects of preoperative oral care on bacterial colonisation and halitosis in patients undergoing elective surgery: A randomised controlled study

OBJECTIVES

To evaluate the effects of single-dose chlorhexidine oral care on bacterial colonisation and halitosis in patients undergoing elective surgery.

RESEARCH METHODOLOGY

We conducted a two-arm parallel, single-blinded, randomised controlled trial. The intervention group (n = 102) received preoperative oral care with 0.12% chlorhexidine gluconate, and the control group (n = 105) received standard care. The data of the microbiological cultures between the groups were compared at the time of tracheal intubation, at extubation and 30 min after surgery. The presence of halitosis was measured using a survey questionnaire administered to the anaesthesia nurses assigned to the patients.

RESULTS

At baseline, no significant differences were found between the intervention and control groups for bacterial colonisation or halitosis. After the intervention, there was no significant difference in microbiological culture, including gram-positive, gram-negative bacilli and cocci results, between the two groups (p > 0.05). The presence of halitosis in the intervention group was significantly lower than in the control group during intubation (p < 0.0001) and at 30 min after surgery (p < 0.02). Regression analysis indicated that receiving oral was protective towards halitosis, while poor oral health was a risk factor.

CONCLUSIONS

Preoperative oral care using a single dose of chlorhexidine significantly improved the patients' halitosis in the perioperative period, but no significant effect was found on bacterial colonisation. Further studies are needed regarding the safe use of chlorhexidine for oral care.

IMPLICATION FOR CLINICAL PRACTICE

Oral hygiene using chlorhexidine could be beneficial in improving halitosis for anaesthesia personnel who take care of intubated adult patients undergoing elective surgery with general anaesthesia.

Revisiting Oral Antiseptics, Microorganism Targets and Effectiveness

A good oral health status is mostly dependent on good oral hygiene habits, which knowingly impacts systemic health. Although controversial, chemical oral antiseptics can be useful in adjunct use to mechanical dental plaque control techniques in the prevention and management of local and overall health and well-being. This review aims to revisit, gather and update evidence-based clinical indications for the use of the most popular oral antiseptics, considering different types, microorganism targets and effectiveness in order to establish updated clinical recommendations.

Poor Oral Health in the Etiology and Prevention of Aspiration Pneumonia

Aspiration pneumonia (AP), inflammation of the lung parenchyma initiated by aspirated microorganisms into the lower airways from proximal sites, including the oral cavity, is prevalent in, and problematic for, the elderly, especially those in institutions, and for those with several important risk factors. Many factors influence the pathogenesis of AP, including dysphagia, poor oral hygiene, diminished host defense, and underlying medical conditions. This article reviews the epidemiology, microbiology, pathogenesis, and prevention of AP, focusing on the role of poor oral health as a risk factor for, and on dental care for the prevention and management of, this important infection.

Effect of an educational intervention on compliance with care bundle items to prevent ventilator-associated pneumonia

OBJECTIVES

We aimed to evaluate the effectiveness of our ventilator-associated pneumonia prevention bundle implemented by education of the nursing staff, and to describe the tendency of knowledge retention.

RESEARCH METHODOLOGY

A prospective, before-and-after study was performed. The ventilator-associated pneumonia prevention bundle was implemented through a single educational intervention of the nursing staff. The risk of ventilator-associated pneumonia over time was estimated using a Cox proportional cause-specific hazard model. Compliance to preventive measures was assessed at three time-points: before education, at three months and 12 months after education.

SETTING

A 29-bed mixed medical-surgical intensive care unit.

MAIN OUTCOME MEASURES

Ventilator-associate pneumonia incidence densities, the risk of ventilator-associated pneumonia, and compliance to preventive measures in the pre-implementation and post-implementation periods.

RESULTS

We analyzed the data of 251 patients. The incidence density of pneumonia decreased from 29.3/1000 to 15.3/1000 ventilator-days after the implementation of the prevention program. Patients in the post-implementation period had significantly lower risk to develop pneumonia (hazard ratio 0.34, 95 % confidence interval 0.19-0.61, p = 0.001). At 3 months of implementation, a significant improvement was detected to all the individual bundle components. Complete compliance increased from 16.2 % to 62.2 % (p < 0.001). Compliance with bundle components decreased to baseline levels after 12 months of implementation apart from head-of-bed elevation.

CONCLUSION

This study supports existing evidence that educational interventions improve compliance. The gained knowledge was well translated into clinical practice reflected by the decreasing ventilator-associated pneumonia rate. It may be assumed that a refresher educational session within 12 months after implementation is needed.

Staphylococcus aureus hitchhiking from colonization to bacteremia via Candida within ICU infection prevention studies: a proof of concept modelling

Whether Candida within the patient microbiome drives the pathogenesis of Staphylococcus aureus bacteremia, described as microbial hitchhiking, cannot be directly studied. Group-level observations from studies of various decontamination and non-decontamination-based ICU infection prevention interventions and studies without study interventions (observational groups) collectively enable tests of this interaction within causal models. Candidate models of the propensity for Staphylococcus aureus bacteremia to arise with versus without various antibiotic, anti-septic, and antifungal exposures, each identified as singleton exposures, were tested using generalized structural equation modelling (GSEM) techniques with Candida and Staphylococcus aureus colonization appearing as latent variables within the models. Each model was tested by confrontation against blood and respiratory isolate data, obtained from 467 groups within 284 infection prevention studies. Introducing an interaction term between Candida colonization and Staphylococcus aureus colonization substantially improved GSEM model fit. Model-derived coefficients for singular exposure to anti-septic agents (- 1.28; 95% confidence interval; - 2.05 to - 0.5), amphotericin (- 1.49; - 2.3 to - 0.67), and topical antibiotic prophylaxis (TAP; + 0.93; + 0.15 to + 1.71) as direct effects versus Candida colonization were similar in magnitude but contrary in direction. By contrast, the coefficients for singleton exposure to TAP, as with anti-septic agents, versus Staphylococcus colonization were weaker or non-significant. Topical amphotericin would be predicted to halve both candidemia and Staphylococcus aureus bacteremia incidences versus literature derived benchmarks for absolute differences of < 1 percentage point. Using ICU infection prevention data, GSEM modelling validates the postulated interaction between Candida and Staphylococcus colonization facilitating bacteremia.

Structural equation modelling the impact of antimicrobials on the human microbiome. Colonization resistance versus colonization susceptibility as case studies

The impact of antimicrobials on the human microbiome and its relationship to human health are of great interest. How antimicrobial exposure might drive change within specific constituents of the microbiome to effect clinically relevant endpoints is difficult to study. Clinical investigation of each step within a network of causation would be challenging if done 'step-by-step'. An analytic tool of great potential to clinical microbiome research is structural equation modelling (SEM), which has a long history of applications to research questions arising within subject areas as diverse as psychology and econometrics. SEM enables postulated models based on a network of causation to be tested en bloc by confrontation with data derived from the literature. Case studies for the potential application of SEM techniques are colonization resistance (CR) and its counterpart, colonization susceptibility (CS), wherein specific microbes within the microbiome are postulated to either impede (CR) or facilitate (CS) invasive infection with pathogenic bacteria. These postulated networks have three causation steps: exposure to specific antimicrobials are key drivers, clinically relevant infection endpoints are the measurable observables and the activity of key microbiome constituents mediating CR or CS, which may be unobservable, appear as latent variables in the model. SEM methods have potential application towards evaluating the activity of specific antimicrobial agents within postulated networks of causation using clinically derived data.

Anti-Inflammatory and Anti-Bacterial Effects of Mouthwashes in Intensive Care Units: A Systematic Review and Meta-Analysis

Mouthwashes are used as oral care for critical care patients to prevent infections. However, there are conflicting data concerning whether mouthwashes are needed as a part of daily oral care for critical care patients. This study aimed to evaluate the anti-inflammatory and anti-bacterial effects of mouthwashes for critical care patients. The PubMed, EMBASE, CENTRAL, and grey literature databases were searched by descriptors combining population (intensive care unit patients) and intervention (mouthwashes). After the screening, only randomized controlled trials (RCTs) evaluating the anti-inflammatory and anti-bacterial effects of mouthwashes in patient critical care were included. From the 1531 articles, 16 RCTs satisfied the eligibility criteria for systematic review and 10 were included in the meta-analyses. A significant difference was found in the incidence of ventilator associated pneumonia (VAP) (odds ratio [OR] 0.53, 95% confidential interval [95% CI] 0.33 to 0.86) between the mouthwash and placebo groups, while no significant difference was found in the mortality (OR 1.49, 95%CI 0.92 to 2.40); the duration of mechanical ventilation (weighted mean difference [WMD] -0.10, 95%CI -2.01 to 1.81); and the colonization of Staphylococcus aureus (OR 0.88, 95%CI 0.34 to 2.30), Escherichia coli (OR 1.19, 95%CI 0.50 to 2.82), and Pseudomonas aeruginosa (OR 1.16, 95%CI 0.27 to 4.91) between the two groups. In conclusion, mouthwashes were effective in decreasing the incidence of VAP. Thus, mouthwashes can be used as part of daily oral care for critical care patients.

Effects of Perioperative Oral Management in Patients with Cancer

Perioperative oral management (POM) is used to prevent pneumonia in patients with cancer. However, the factors that expose hospitalized patients to increased risk of developing pneumonia remain unclear. For example, no study to date has compared the incidence of pneumonia in hospitalized patients by cancer primary lesion, or POM implementation, or not. We determined which patients were most likely to benefit from POM and examined the effects of POM on pneumonia prevention and mortality. In a total of 9441 patients with cancer who underwent surgery during hospitalization, there were 8208 patients in the No POM group, and 1233 in the POM group. We examined between-group differences in the incidence of pneumonia and associated outcomes during hospitalization. There was no significant between-group difference in the incidence of pneumonitis, however, patients with lung, or head and neck cancers, demonstrated a lower incidence of postoperative pneumonia. Among patients with lung and pancreatic cancers, mortality was significantly lower in the POM group. POM appears effective at reducing the risk of postoperative pneumonia in patients with certain cancers. Further, mortality was significantly lower in patients with lung and pancreatic cancers who received POM; hence, POM may be an effective adjuvant therapy for patients with cancer.

Candida and the Gram-positive trio: testing the vibe in the ICU patient microbiome using structural equation modelling of literature derived data

Background

Whether Candida interacts with Gram-positive bacteria, such as Staphylococcus aureus, coagulase negative Staphylococci (CNS) and Enterococci, to enhance their invasive potential from the microbiome of ICU patients remains unclear. Several effective anti-septic, antibiotic, anti-fungal, and non-decontamination based interventions studied for prevention of ventilator associated pneumonia (VAP) and other ICU acquired infections among patients receiving prolonged mechanical ventilation (MV) are known to variably impact Candida colonization. The collective observations within control and intervention groups from numerous ICU infection prevention studies enables tests of these postulated microbial interactions in the clinical context.

Methods

Four candidate generalized structural equation models (GSEM), each with Staphylococcus aureus, CNS and Enterococci colonization, defined as latent variables, were confronted with blood culture and respiratory tract isolate data derived from 460 groups of ICU patients receiving prolonged MV from 283 infection prevention studies.

Results

Introducing interaction terms between Candida colonization and each of S aureus (coefficient + 0.40; 95% confidence interval + 0.24 to + 0.55), CNS (+ 0.68; + 0.34 to + 1.0) and Enterococcal (+ 0.56; + 0.33 to + 0.79) colonization (all as latent variables) improved the fit for each model. The magnitude and significance level of the interaction terms were similar to the positive associations between exposure to topical antibiotic prophylaxis (TAP) on Enterococcal (+ 0.51; + 0.12 to + 0.89) and Candida colonization (+ 0.98; + 0.35 to + 1.61) versus the negative association of TAP with S aureus (− 0.45; − 0.70 to − 0.20) colonization and the negative association of anti-fungal exposure and Candida colonization (− 1.41; − 1.6 to − 0.72).

Conclusions

GSEM modelling of published ICU infection prevention data enables the postulated interactions between Candida and Gram-positive bacteria to be tested using clinically derived data. The optimal model implies interactions occurring in the human microbiome facilitating bacterial invasion and infection. This interaction might also account for the paradoxically high bacteremia incidences among studies of TAP in ICU patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12982-022-00116-9.

GSEM modelling of published ICU infection prevention data from > 250 studies enables a test of and provides support to the interaction between Candida and Gram-positive bacteria.

The various ICU infection prevention interventions may each broadly impact the patient microbiome.

Effectiveness of Continuous Cuff Pressure Control in Preventing Ventilator-Associated Pneumonia: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVES

Microaspiration of subglottic secretions is the main pathogenic mechanism for ventilator-associated pneumonia (VAP). Adequate inflation of the endotracheal cuff is pivotal to providing an optimal seal of the extraluminal airway. However, cuff pressure substantially fluctuates due to patient or tube movements, which can induce microaspiration. Therefore, devices for continuous cuff pressure control (CCPC) have been developed in recent years. The purpose of this systematic review and meta-analysis is to assess the effectiveness of CCPC in VAP prevention.

DATA SOURCES

A systematic search of Embase, the Cochrane Central Register of Controlled Trials, and the International Clinical Trials Registry Platform was conducted up to February 2022.

STUDY SELECTION

Eligible studies were randomized controlled trials (RCTs) and quasi-RCTs comparing the impact of CCPC versus intermittent cuff pressure control on the occurrence of VAP.

DATA EXTRACTION

Random-effects meta-analysis was used to calculate odds ratio (OR) and 95% CI for VAP incidence between groups. Secondary outcome measures included mortality and duration of mechanical ventilation (MV) and ICU stay. The certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation approach.

DATA SYNTHESIS

Eleven RCTs with 2,092 adult intubated patients were included. The use of CCPC was associated with a reduced risk of VAP (OR, 0.51). Meta-analyses of secondary endpoints showed no significant difference in mortality but significant differences in durations of MV (mean difference, -1.07 d) and ICU stay (mean difference, -3.41 d) in favor of CCPC. However, the risk of both reporting and individual study bias was considered important. The main issues were the lack of blinding, potential commercial conflicts of interest of study authors and high heterogeneity due to methodological differences between studies, differences in devices used for CCPC and in applied baseline preventive measures. Certainty of the evidence was considered "very low."

CONCLUSIONS

The use of CCPC was associated with a reduction in VAP incidence; however, this was based on very low certainty of evidence due to concerns related to risk of bias and inconsistency.

Nosocomial Pneumonia in the Mechanically Ventilated Patient

Ventilator-associated pneumonia (VAP) is a common complication occurring in critically ill patients who are mechanically ventilated and is the leading cause of nosocomial infection-related death. Etiologic agents for VAP widely differ based on the population of intensive care unit patients, duration of hospital stay, and prior antimicrobial therapy. VAP due to multidrug-resistant pathogens is associated with the highest morbidity and mortality, likely due to delays in appropriate antimicrobial treatment. International guidelines are currently available to guide diagnostic and therapeutic strategies. VAP can be prevented through various pharmacological and non-pharmacological interventions, which are more effective when grouped as bundles. When VAP is clinically suspected, diagnostic strategies should include early collection of respiratory samples to guide antimicrobial therapy. Empirical treatment should be based on the most likely etiologic microorganisms and antibiotics likely to be active against these microorganisms. Response to therapy should be reassessed after 3 to 5 days and antimicrobials adjusted or de-escalated to reduce the burden of the disease. Finally, considering that drug resistance is increasing worldwide, several novel antibiotics are being tested to efficiently treat VAP in the coming decades.

Healthcare-associated infections in adult intensive care unit patients: Changes in epidemiology, diagnosis, prevention and contributions of new technologies

Patients in intensive care units (ICUs) are at high risk for healthcare-acquired infections (HAI) due to the high prevalence of invasive procedures and devices, induced immunosuppression, comorbidity, frailty and increased age. Over the past decade we have seen a successful reduction in the incidence of HAI related to invasive procedures and devices. However, the rate of ICU-acquired infections remains high. Within this context, the ongoing emergence of new pathogens, further complicates treatment and threatens patient outcomes. Additionally, the SARS-CoV-2 (COVID-19) pandemic highlighted the challenge that an emerging pathogen provides in adapting prevention measures regarding both the risk of exposure to caregivers and the need to maintain quality of care. ICU nurses hold a special place in the prevention and management of HAI as they are involved in basic hygienic care, steering and implementing quality improvement initiatives, correct microbiological sampling, and aspects antibiotic stewardship. The emergence of more sensitive microbiological techniques and our increased knowledge about interactions between critically ill patients and their microbiota are leading us to rethink how we define HAIs and best strategies to diagnose, treat and prevent these infections in the ICU. This multidisciplinary expert review, focused on the ICU setting, will summarise the recent epidemiology of ICU-HAI, discuss the place of modern microbiological techniques in their diagnosis, review operational and epidemiological definitions and redefine the place of several controversial preventive measures including antimicrobial-impregnated medical devices, chlorhexidine-impregnated washcloths, catheter dressings and chlorhexidine-based mouthwashes. Finally, general guidance is suggested that may reduce HAI incidence and especially outbreaks in ICUs.

Management of Ventilator-Associated Pneumonia: Quality Assessment of Clinical Practice Guidelines and Variations in Recommendations on Drug Therapy for Prevention and Treatment

Purpose: To assess the quality of clinical practice guidelines (CPGs) related to drug therapy for prevention and control of ventilator-associated pneumonia (VAP) and compare the differences and similarities between recommendations.

Methods: Electronic databases (including PubMed, Cochrane library, Embase, Web of Science), guideline development organizations, and professional societies were searched to identify CPGs for VAP from 20 January 2012 to 20 January 2022. The Appraisal of Guidelines Research & Evaluation (AGREE) II instrument was used to evaluate the quality of the guidelines. The recommendations on drug therapy for prevention and treatment for each guideline were extracted, and then a descriptive synthesis was performed to analyze the scope/topic, and consistency of the recommendations.

Results: Thirteen CPGs were included. The median score and interquartile range (IQR) in each domain are shown below: scope and purpose 72.22% (63.89%,83.33%); stakeholder involvement 44.44% (38.89%,52.78%); rigor of development 43.75% (31.25%,57.29%); clarity and presentation 94.44% (77.78%,94.44%); applicability 20.83 (8.34%,33.34%) and editorial independence 50% (33.33%,66.67%). We extracted 21 recommendations on drug therapy for prevention of VAP and 51 recommendations on drugs used for treatment. Some controversies remained among the included guidelines.

Conclusion: There is considerable variability in the development processes and reporting of VAP guidelines. Despite many similarities, the recommendations still had some inconsistencies in the details. For the prevention and treatment of VAP, local microbial epidemiology and antibiotic sensitivity must be considered, and recommendations should be regularly revised as new evidence emerges.

Should oral chlorhexidine remain in ventilator-associated pneumonia prevention bundles?

Ventilator-associated pneumonia (VAP) is related with high mortality, duration of mechanical ventilation and costs. Recent studies have questioned the safety and effectiveness of oral chlorhexidine to prevent VAP. We sought to verify whether the adverse effects of this substance outweigh its benefits. We searched several databases and selected studies that investigated the use of oral chlorhexidine and its impact on mortality. No association between oral chlorhexidine and lower VAP rates was found on meta-analyses of double-blind randomized trials, however significant increase in mortality was reported. It is speculated that chlorhexidine can cause damage to several organic sectors and cytotoxicity. Although it still can be beneficial in specific settings, robust evidence to recommend its routine application for all mechanically ventilated patients is lacking; therefore, given the possibility of harm, it would be better to follow the principle of non-maleficence until more studies becomes available.

Oral health status and the etiology and prevention of nonventilator hospital-associated pneumonia

Nonventilator hospital-associated pneumonia has recently emerged as an important preventable hospital-associated infection, and is a leading cause of healthcare-associated infection. Substantial accumulated evidence links poor oral health with an increased risk of pneumonia, which can be caused by bacterial, viral, or fungal pathogens, each with their own distinct mechanisms of transmission and host susceptibility. These infections are frequently polymicrobial, and often include microbes from biofilms in the oral cavity. Evidence documenting the importance of oral care to prevent nonventilator hospital-associated pneumonia is continuing to emerge. Reduction of oral biofilm in these populations will reduce the numbers of potential respiratory pathogens in the oral secretions that can be aspirated, which in turn can reduce the risk for pneumonia. This review summarizes up-to-date information on the role of oral care in the prevention of nonventilator hospital-associated pneumonia.

Reduced chlorhexidine susceptibility is associated with tetracycline resistance tet genes in clinical isolates of Escherichia coli

Chlorhexidine is a widely used antiseptic in hospital and community healthcare. Decreased susceptibility to this compound has been recently described in Klebsiella pneumoniae and Pseudomonas aeruginosa, together with cross-resistance to colistin. Surprisingly, few data are available for Escherichia coli, the main species responsible for community and healthcare-associated infections. In order to decipher chlorhexidine resistance mechanisms in E. coli, we studied both in vitro derived and clinical isolates through whole-genome sequence analysis. Comparison of strains grown in vitro under chlorhexidine pressure identified mutations in the gene mlaA coding for a phospholipid transport system. Phenotypic analyses of single-gene mutant from the Keio collection confirmed the role of this mutation in the decreased susceptibility to chlorhexidine. However, mutations in mlaA were not found in isolates from large clinical collections. In contrast, genome wide association studies (GWAS) showed that, in clinical strains, chlorhexidine reduced susceptibility was associated with the presence of tetA genes of class B coding for efflux pumps and located in a Tn10 transposon. Construction of recombinant strains in E. coli K-12 confirmed the role of tetA determinant in acquired resistance to both chlorhexidine and tetracycline. Our results reveal two different evolutionary paths leading to chlorhexidine decreased susceptibility: one restricted to in vitro evolution conditions and involving a retrograde phospholipid transport system; the other observed in clinical isolates associated with efflux pump TetA. None of these mechanisms provides cross-resistance to colistin. This work demonstrates the GWAS power to identify new resistance mechanisms in bacterial species.

Structural equation modelling the relationship between anti-fungal prophylaxis and Pseudomonas bacteremia in ICU patients

Purpose

Animal models implicate candida colonization facilitating invasive bacterial infections. The clinical relevance of this microbial interaction remains undefined and difficult to study directly. Observations from studies of anti-septic, antibiotic, anti-fungal, and non-decontamination-based interventions to prevent ICU acquired infection collectively serve as a natural experiment.

Methods

Three candidate generalized structural equation models (GSEM), with Candida and Pseudomonas colonization as latent variables, were confronted with blood culture and respiratory tract isolate data derived from 464 groups from 279 studies including studies of combined antibiotic and antifungal exposures within selective digestive decontamination (SDD) interventions.

Results

Introducing an interaction term between Candida colonization and Pseudomonas colonization substantially improved GSEM model fit. Model derived coefficients for singular exposure to anti-septic agents (− 1.23; − 2.1 to − 0.32), amphotericin (− 1.78; − 2.79 to − 0.78) and topical antibiotic prophylaxis (TAP; + 1.02; + 0.11 to + 1.93) versus Candida colonization were similar in magnitude but contrary in direction. By contrast, the model-derived coefficients for singular exposure to TAP, as with anti-septic agents, versus Pseudomonas colonization were weaker or non-significant. Singular exposure to amphotericin would be predicted to more than halve candidemia and Pseudomonas bacteremia incidences versus literature benchmarks for absolute differences of approximately one percentage point or less.

Conclusion

GSEM modelling of published data supports the postulated interaction between Candida and Pseudomonas colonization towards promoting bacteremia among ICU patients. This would be difficult to detect without GSEM modelling. The model indicates that anti-fungal agents have greater impact in preventing Pseudomonas bacteremia than TAP, which has no impact.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40635-022-00429-8.

Oral care for intensive care unit patients without mechanical ventilation: protocol for a systematic review and meta-analysis

BACKGROUND

Infection is a common problem and a major cause of morbidity and mortality for patients in intensive care units (ICUs). According to published meta-analyses, oral care has been found to reduce the risk of nosocomial pneumonia, and has been recommended to improve the oral environment for patients in ICUs. However, relatively little information is available about the effects of oral care in patients without ventilatory support in ICUs. Therefore, this review proposes to evaluate the effectiveness of oral care in preventing pneumonia in non-ventilated ICU patients.

METHODS

Eight databases will be searched for relevant literature, including four Chinese and four English online databases, from their inception to the protocol publication date. Records obtained will be managed and screened via Endnote X7. All literature will be selected following pre-established inclusion criteria by two independent review authors to obtain quality trials. The quality of the included records will be evaluated according to the "risk of bias table", recommended by the Cochrane Handbook for Systematic Reviews of Interventions. All the data will be extracted by one author and checked by another. If there is any disagreement, a final agreement will be reached with a third reviewer via consultation. If there are missing data, the original authors will be emailed to ask for it. If enough data were collected, the data synthesis will be performed using Review Manager (RevMan5.3). Both a random effect model and a fixed effect model will be undertaken. A Bayesian meta-analysis will also be performed to estimate the magnitude of the heterogeneity variance and comparing it with the distribution using the WinBUGS software. Otherwise, the results will be reported narratively. The sources of heterogeneity will be determined using meta-regression and subgroup analysis if there is significant heterogeneity. A funnel plot will be used to assess publication bias if there are enough records included. The Cochrane Handbook for Systematic Reviews of Interventions will be followed throughout the system evaluation process.

CONCLUSION

This review will provide evidence of oral care for intensive care unit patients without mechanical ventilation to prevent nosocomial pneumonia.

TRIAL REGISTRATION

PROSPERO Research registration identifying number: CRD42020146932.

Management of pneumonia in critically ill patients

Severe pneumonia is associated with high mortality (short and long term), as well as pulmonary and extrapulmonary complications. Appropriate diagnosis and early initiation of adequate antimicrobial treatment for severe pneumonia are crucial in improving survival among critically ill patients. Identifying the underlying causative pathogen is also critical for antimicrobial stewardship. However, establishing an etiological diagnosis is challenging in most patients, especially in those with chronic underlying disease; those who received previous antibiotic treatment; and those treated with mechanical ventilation. Furthermore, as antimicrobial therapy must be empiric, national and international guidelines recommend initial antimicrobial treatment according to the location's epidemiology; for patients admitted to the intensive care unit, specific recommendations on disease management are available. Adherence to pneumonia guidelines is associated with better outcomes in severe pneumonia. Yet, the continuing and necessary research on severe pneumonia is expansive, inviting different perspectives on host immunological responses, assessment of illness severity, microbial causes, risk factors for multidrug resistant pathogens, diagnostic tests, and therapeutic options.

Effectiveness of chlorhexidine in preventing infections among patients undergoing cardiac surgeries: a meta-analysis and systematic review

Background

Although several meta-analyses reported the impact of chlorhexidine (CHX) use in patients undergoing various types of surgery, no meta-analysis summarized the overall effectiveness of CHX specifically for cardiac surgery. This meta-analysis aimed to examine the impact of CHX on infections after cardiac surgery compared with other cleansers or antiseptics.

Methods

PubMed, Embase, and the Cochrane Library were searched from inception up to October 2020 for potentially eligible studies: (1) population: patients who underwent cardiac surgery; (2) intervention or exposure: any type of CHX use in the treatment or exposed group; (3) outcome: number of patients with infections; (4) comparison: placebo or other antiseptic agents; (5) English. The primary outcome was surgical site infection (SSI).

Results

Fourteen studies were included, with 8235 and 6901 patients in the CHX and control groups. CHX was not protective against SSI (OR = 0.77, 95% CI: 0.57–1.04, P = 0.090). CHX was protective for superficial wound infection (OR = 0.42, 95% CI: 0.26–0.70, P = 0.001), but not with deep wound infection (P = 0.509). CHX was not protective against urinary tract of infection (P = 0.415) but was protective for bloodstream infection (OR = 0.36, 95% CI: 0.16–0.80, P = 0.012), nosocomial infections (OR = 0.55, 95% CI: 0.44–0.69, P < 0.001), and pneumonia (OR = 0.26, 95% CI: 0.11–0.61, P = 0.002).

Conclusions

In patients undergoing cardiac surgery, CHX does not protect against SSI, deep wound infection, and urinary tract infections but might protect against superficial SSI, bloodstream infection, nosocomial infections, and pneumonia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-021-01009-3.

Effect of oral chlorhexidine de-adoption and implementation of an oral care bundle on mortality for mechanically ventilated patients in the intensive care unit (CHORAL): a multi-center stepped wedge cluster-randomized controlled trial

Purpose

Oral chlorhexidine is used widely for mechanically ventilated patients to prevent pneumonia, but recent studies show an association with excess mortality. We examined whether de-adoption of chlorhexidine and parallel implementation of a standardized oral care bundle reduces intensive care unit (ICU) mortality in mechanically ventilated patients.

Methods

A stepped wedge cluster-randomized controlled trial with concurrent process evaluation in 6 ICUs in Toronto, Canada. Clusters were randomized to de-adopt chlorhexidine and implement a standardized oral care bundle at 2-month intervals. The primary outcome was ICU mortality. Secondary outcomes were time to infection-related ventilator-associated complications (IVACs), oral procedural pain and oral health dysfunction. An exploratory post hoc analysis examined time to extubation in survivors.

Results

A total of 3260 patients were enrolled; 1560 control, 1700 intervention. ICU mortality for the intervention and control periods were 399 (23.5%) and 330 (21.2%), respectively (adjusted odds ratio [aOR], 1.13; 95% confidence interval [CI] 0.82 to 1.54; P = 0.46). Time to IVACs (adjusted hazard ratio [aHR], 1.06; 95% CI 0.44 to 2.57; P = 0.90), time to extubation (aHR 1.03; 95% CI 0.85 to 1.23; P = 0.79) (survivors) and oral procedural pain (aOR, 0.62; 95% CI 0.34 to 1.10; P = 0.10) were similar between control and intervention periods. However, oral health dysfunction scores (− 0.96; 95% CI − 1.75 to − 0.17; P = 0.02) improved in the intervention period.

Conclusion

Among mechanically ventilated ICU patients, no benefit was observed for de-adoption of chlorhexidine and implementation of an oral care bundle on ICU mortality, IVACs, oral procedural pain, or time to extubation. The intervention may improve oral health.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-021-06475-2.

Preliminary model assessing the cost-effectiveness of preoperative chlorhexidine mouthwash at reducing postoperative pneumonia among abdominal surgery patients in South Africa

Background

Pneumonia is a common and severe complication of abdominal surgery, it is associated with increased length of hospital stay, healthcare costs, and mortality. Further, pulmonary complication rates have risen during the SARS-CoV-2 pandemic. This study explored the potential cost-effectiveness of administering preoperative chlorhexidine mouthwash versus no-mouthwash at reducing postoperative pneumonia among abdominal surgery patients.

Methods

A decision analytic model taking the South African healthcare provider perspective was constructed to compare costs and benefits of mouthwash versus no-mouthwash-surgery at 30 days after abdominal surgery. We assumed two scenarios: (i) the absence of COVID-19; (ii) the presence of COVID-19. Input parameters were collected from published literature including prospective cohort studies and expert opinion. Effectiveness was measured as proportion of pneumonia patients. Deterministic and probabilistic sensitivity analyses were performed to assess the impact of parameter uncertainties. The results of the probabilistic sensitivity analysis were presented using cost-effectiveness planes and cost-effectiveness acceptability curves.

Results

In the absence of COVID-19, mouthwash had lower average costs compared to no-mouthwash-surgery, $3,675 (R 63,770) versus $3,958 (R 68,683), and lower proportion of pneumonia patients, 0.029 versus 0.042 (dominance of mouthwash intervention). In the presence of COVID-19, the increase in pneumonia rate due to COVID-19, made mouthwash more dominant as it was more beneficial to reduce pneumonia patients through administering mouthwash. The cost-effectiveness acceptability curves shown that mouthwash surgery is likely to be cost-effective between $0 (R0) and $15,000 (R 260,220) willingness to pay thresholds.

Conclusions

Both the absence and presence of SARS-CoV-2, mouthwash is likely to be cost saving intervention for reducing pneumonia after abdominal surgery. However, the available evidence for the effectiveness of mouthwash was extrapolated from cardiac surgery; there is now an urgent need for a robust clinical trial on the intervention on non-cardiac surgery.

Oral mucosal mouthwash with chlorhexidine does not reduce the incidence of ventilator-associated pneumonia in critically ill children: A randomised controlled trial

BACKGROUND

Ventilator-associated pneumonia (VAP) is one of the most frequently encountered causes of hospital-acquired infection and results in high morbidity among intubated patients. Few trials have investigated the efficacy of oral care with chlorhexidine (CHX) mouthwash for the prevention of VAP in the paediatric population.

OBJECTIVES

The objective of this study was to assess the efficacy of CHX mouthwash in the prevention of VAP and to determine risk factors for VAP in children aged 1 month to 18 years admitted to the paediatric intensive care unit (PICU).

METHODS

This was a prospective, randomised, controlled, double-blind trial performed in the PICU. Patients were randomised into two groups receiving CHX (0.12%) (n = 88) or placebo (0.9% NaCl) (n = 86) and were followed up for VAP development. The main outcome measures were incidence of VAP, duration of hospital stay, duration of PICU stay, duration of ventilation, mortality, and the characteristics of organisms isolated in cases with VAP.

RESULTS

No difference was observed in the incidence of VAP and the type and distribution of organisms in the two groups (p > 0.05). In the CHX and placebo groups, we identified 21 and 22 patients with VAP, respectively. Incidence per 1000 ventilation days was 29.5 events in the CHX group and 35.1 events in the placebo group. Gram-negative bacteria were most common (71.4% in CHX vs. 54.5% in placebo). The use of 0.12% CHX did not influence hospital stay, PICU stay, ventilation, and mortality (p > 0.05). Multivariate analysis identified duration of ventilation as the only independent risk factor for VAP (p = 0.001).

CONCLUSION

The use of 0.12% CHX did not reduce VAP frequency among critically ill children. The only factor that increased VAP frequency was longer duration on ventilation. It appears that low concentration of CHX is not effective for VAP prevention, especially in the presence of multiresistant bacteria. CLINICALTRIALS.

GOV IDENTIFIER

NCT04527276.

Rapid-flow expulsion maneuver in subglottic secretion clearance to prevent ventilator-associated pneumonia: a randomized controlled study

Background

Following endotracheal intubation, clearing secretions above the endotracheal tube cuff decreases the incidence of ventilator-associated pneumonia (VAP); therefore, subglottic secretion drainage (SSD) is widely advocated. Our group developed a novel technique to remove the subglottic secretions, the rapid-flow expulsion maneuver (RFEM). The objective of this study was to explore the effectiveness and safety of RFEM compared with SSD.

Methods

This study was a single-center, prospective, randomized and controlled trial, conducted at Respiratory Intensive Care Unit (ICU) of Beijing Chao-Yang Hospital, a university-affiliated tertiary hospital. The primary outcome was the incidence of VAP, assessed for non-inferiority.

Results

Patients with an endotracheal tube allowing drainage of subglottic secretions (n = 241) were randomly assigned to either the RFEM group (n = 120) or SSD group (n = 121). Eleven patients (9.17%) in the RFEM group and 13 (10.74%) in the SSD group developed VAP (difference, − 1.59; 95% confidence interval [CI] [− 9.20 6.03]), as the upper limit of 95% CI was not greater than the pre-defined non-inferiority limit (10%), RFEM was declared non-inferior to SSD. There were no statistically significant differences in the duration of mechanical ventilation, ICU mortality, or ICU length of stay and costs between groups. In terms of safety, no accidental extubation or maneuver-related barotrauma occurred in the RFEM group. The incidence of post-extubation laryngeal edema and reintubation was similar in both groups.

Conclusions

RFEM is effective and safe, with non-inferiority compared to SSD in terms of the incidence of VAP. RFEM could be an alternative method in first-line treatment of respiratory ICU patients.

Trial registration This study has been registered on ClinicalTrials.gov (Registration Number: NCT02032849, https://clinicaltrials.gov/ct2/show/NCT02032849); registered on January 2014

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00887-5.

Preventive Effects of Sustainable and Developmental Perioperative Oral Management Using the "Oral Triage" System on Postoperative Pneumonia after Cancer Surgery

Perioperative oral management is widely recognized in the healthcare system of Japan. Conventionally, the surgeon refers patients with oral problems to a dental or oral surgery clinic in the hospital. However, frequent in-house referrals were found to increase the number of incoming patients resulting in unsustainable situations due to an insufficient workforce. In 2011, the Center for Perioperative Medicine was established at our hospital to function as a management gateway for patients scheduled to undergo surgery under general anesthesia. The “oral triage” system, wherein a dental hygienist conducts an oral screening to select patients who need preoperative oral hygiene and functional management, was established in 2012. A total of 37,557 patients who underwent surgery at our hospital from April 2010 to March 2019 (two years before and seven years after introducing the system) were evaluated in this study. The sustainability and effectiveness of introducing the system were examined in 7715 cancer surgery patients. An oral management intervention rate of 20% and a significant decrease in the incidence of postoperative pneumonia (aOR = 0.50, p = 0.03) indicated that this system could be useful as a sustainable and developmental oral management strategy to manage surgical patients with minimal human resources.

Efficacy of Chinese Herbal Injections for Elderly Patients With pneumonia-A Bayesian Network Meta-analysis of Randomized Control Trials

Background: Pneumonia is a prevalent and complicated disease among adults, elderly people in particular, and the debate on the optimal Chinese herbal injections (CHIs) is ongoing. Our objective is to investigate the comparative effectiveness of various CHIs strategies for elderly patients with pneumonia. Methods: A comprehensive search strategy was executed to identify relevant randomized controlled trials (RCTs) by browsing through several databases from their inception to first, Feb 2020; All of the direct and indirect evidence included was rated by Network meta-analysis under a Bayesian framework. Results: We ultimately identified 34 eligible randomized controlled trials that involved 3,111 elderly participants and investigated 4 CHIs combined with Western medicine (WM) (Xiyanping injection [XYP]+WM, Yanhuning injection [YHN]+WM, Tanreqing injection [TRQ]+WM, Reduning injection [RDN]+WM), contributing 34 direct comparisons between CHIs. Seen from the outcome of Clinical effective rate and time for defervescence, patients taking medicine added with CHIs [Clinical effective rate, XYP + WM(Odd ratio (OR): 0.74, 95%Credible intervals (CrIs):0.55-0.98), YHN + WM(OR: 0.66, 95%CrI: 0.45-0.95), TRQ + WM(OR: 0.65, 95%CrI: 0.50-0.83), RDN + WM(OR: 0.60, 95%CrI: 0.40-0.89); Time for defervescence, YHN + WM(Mean difference (MD): -2.11, 95%CrI: -3.26 to -0.98), XYP + WM(MD: -2.06, 95%CrI: -3.08 to -1.09), RDN + WM(MD: -1.97, 95%CrI: -3.61 to -0.35), TRQ + WM(MD: -1.69, 95%CrI: -2.27 to -1.04)] showed statistically better effect compared with participants in the Control group (CG) who only took WM. Meanwhile, based on the time for disappearance of cough, 3 out of 4 CHIs [TRQ + WM(MD: -2.56, 95%CrI: -3.38 to -1.54), YHN + WM(MD: -2.36, 95%CrI: -3.86 to -1.00) and XYP + WM(MD: -2.21, 95%CrI: -3.72 to -1.10)] strategies indicated improvement of clinical symptoms. Only XYP + WM(MD -1.78, 95%CrI: -3.29 to -0.27) and TRQ + WM (MD: -1.71, 95%CrI: -2.71 to -0.73) could significantly shorten the time for disappearance of pulmonary rales. Conclusion: According to the statistical effect size (The surface under the cumulative ranking), we found that XYP + WM was presumably to be the preferable treatment for treating elderly patients with pneumonia compared with WM alone in terms of clinical effective rate. Our findings were based on very limited evidence and thus should be interpreted with caution. The application of the findings requires further research.

Poor Oral Health in the Etiology and Prevention of Aspiration Pneumonia

Aspiration pneumonia (AP), inflammation of the lung parenchyma initiated by aspirated microorganisms into the lower airways from proximal sites, including the oral cavity, is prevalent in, and problematic for, the elderly, especially those in institutions, and for those with several important risk factors. Many factors influence the pathogenesis of AP, including dysphagia, poor oral hygiene, diminished host defense, and underlying medical conditions. This article reviews the epidemiology, microbiology, pathogenesis, and prevention of AP, focusing on the role of poor oral health as a risk factor for, and on dental care for the prevention and management of, this important infection.

Network meta-analysis from a pairwise meta-analysis design: to assess the comparative effectiveness of oral care interventions in preventing ventilator-associated pneumonia in critically ill patients

OBJECTIVE

In this research, we assessed the usefulness of network meta-analysis (NMA), in creating a hierarchy to define the most effective oral care intervention for the prevention and management of ventilation-associated pneumonia (VAP).

MATERIALS AND METHODS

We applied NMA to a previously published robust pairwise meta-analysis. Statistical analyses were based on comparing rates of total VAP events between intervention groups and placebo-usual care groups. We synthesized a netgraph, reported the ranking order of the interventions, and summarized output by a forest plot with a reference treatment placebo/usual care.

RESULTS

The results of this NMA are from the low and high risk of bias studies, and hence, we strongly recommend not to use findings of this NMA for clinical treatment needs, but based on results of the NMA, we highly recommend for future clinical trials. With our inclusion and exclusion criteria for the NMA, we extracted 25 studies (4473 subjects). The NMA included 16 treatments, 29 pairwise comparisons, and 15 designs. Based on results of NMA frequentist-ranking P scores, tooth brushing (P fixed-0.94, P random-0.89), tooth brushing with povidone-iodine (P fixed-0.90, P random-0.88), and furacillin (P fixed-0.88, P random-0.84) were the best three interventions for preventing VAP.

CONCLUSIONS

Any conclusion drawn from this NMA should be taken with caution and recommend future clinical trials with the results.

CLINICAL RELEVANCE

NMA appeared to be an effective platform from which multiple interventions reported in disparate clinical trials could be compared to derive a hierarchical assessment of efficacy in VAP intervention.

Oral hygiene care for critically ill patients to prevent ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) is defined as pneumonia developing in people who have received mechanical ventilation for at least 48 hours. VAP is a potentially serious complication in these patients who are already critically ill. Oral hygiene care (OHC), using either a mouthrinse, gel, swab, toothbrush, or combination, together with suction of secretions, may reduce the risk of VAP in these patients.

OBJECTIVES

To assess the effects of oral hygiene care (OHC) on incidence of ventilator-associated pneumonia in critically ill patients receiving mechanical ventilation in hospital intensive care units (ICUs).

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 25 February 2020), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2020, Issue 1), MEDLINE Ovid (1946 to 25 February 2020), Embase Ovid (1980 to 25 February 2020), LILACS BIREME Virtual Health Library (1982 to 25 February 2020) and CINAHL EBSCO (1937 to 25 February 2020). We also searched the VIP Database (January 2012 to 8 March 2020). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) evaluating the effects of OHC (mouthrinse, gel, swab, toothbrush or combination) in critically ill patients receiving mechanical ventilation for at least 48 hours.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed search results, extracted data and assessed risk of bias in included studies. We contacted study authors for additional information. We reported risk ratio (RR) for dichotomous outcomes and mean difference (MD) for continuous outcomes, using the random-effects model of meta-analysis when data from four or more trials were combined.

MAIN RESULTS

We included 40 RCTs (5675 participants), which were conducted in various countries including China, USA, Brazil and Iran. We categorised these RCTs into five main comparisons: chlorhexidine (CHX) mouthrinse or gel versus placebo/usual care; CHX mouthrinse versus other oral care agents; toothbrushing (± antiseptics) versus no toothbrushing (± antiseptics); powered versus manual toothbrushing; and comparisons of other oral care agents used in OHC (other oral care agents versus placebo/usual care, or head-to-head comparisons between other oral care agents). We assessed the overall risk of bias as high in 31 trials and low in two, with the rest being unclear. Moderate-certainty evidence from 13 RCTs (1206 participants, 92% adults) shows that CHX mouthrinse or gel, as part of OHC, probably reduces the incidence of VAP compared to placebo or usual care from 26% to about 18% (RR 0.67, 95% confidence intervals (CI) 0.47 to 0.97; P = 0.03; I2 = 66%). This is equivalent to a number needed to treat for an additional beneficial outcome (NNTB) of 12 (95% CI 7 to 128), i.e. providing OHC including CHX for 12 ventilated patients in intensive care would prevent one patient developing VAP. There was no evidence of a difference between interventions for the outcomes of mortality (RR 1.03, 95% CI 0.80 to 1.33; P = 0.86, I2 = 0%; 9 RCTs, 944 participants; moderate-certainty evidence), duration of mechanical ventilation (MD -1.10 days, 95% CI -3.20 to 1.00 days; P = 0.30, I2 = 74%; 4 RCTs, 594 participants; very low-certainty evidence) or duration of intensive care unit (ICU) stay (MD -0.89 days, 95% CI -3.59 to 1.82 days; P = 0.52, I2 = 69%; 5 RCTs, 627 participants; low-certainty evidence). Most studies did not mention adverse effects. One study reported adverse effects, which were mild, with similar frequency in CHX and control groups and one study reported there were no adverse effects. Toothbrushing (± antiseptics) may reduce the incidence of VAP (RR 0.61, 95% CI 0.41 to 0.91; P = 0.01, I2 = 40%; 5 RCTs, 910 participants; low-certainty evidence) compared to OHC without toothbrushing (± antiseptics). There is also some evidence that toothbrushing may reduce the duration of ICU stay (MD -1.89 days, 95% CI -3.52 to -0.27 days; P = 0.02, I2 = 0%; 3 RCTs, 749 participants), but this is very low certainty. Low-certainty evidence did not show a reduction in mortality (RR 0.84, 95% CI 0.67 to 1.05; P = 0.12, I2 = 0%; 5 RCTs, 910 participants) or duration of mechanical ventilation (MD -0.43, 95% CI -1.17 to 0.30; P = 0.25, I2 = 46%; 4 RCTs, 810 participants).

AUTHORS' CONCLUSIONS

Chlorhexidine mouthwash or gel, as part of OHC, probably reduces the incidence of developing ventilator-associated pneumonia (VAP) in critically ill patients from 26% to about 18%, when compared to placebo or usual care. We did not find a difference in mortality, duration of mechanical ventilation or duration of stay in the intensive care unit, although the evidence was low certainty. OHC including both antiseptics and toothbrushing may be more effective than OHC with antiseptics alone to reduce the incidence of VAP and the length of ICU stay, but, again, the evidence is low certainty. There is insufficient evidence to determine whether any of the interventions evaluated in the studies are associated with adverse effects.

Pulmonary infections complicating ARDS

Pulmonary infection is one of the main complications occurring in patients suffering from acute respiratory distress syndrome (ARDS). Besides traditional risk factors, dysregulation of lung immune defenses and microbiota may play an important role in ARDS patients. Prone positioning does not seem to be associated with a higher risk of pulmonary infection. Although bacteria associated with ventilator-associated pneumonia (VAP) in ARDS patients are similar to those in patients without ARDS, atypical pathogens (Aspergillus, herpes simplex virus and cytomegalovirus) may also be responsible for infection in ARDS patients. Diagnosing pulmonary infection in ARDS patients is challenging, and requires a combination of clinical, biological and microbiological criteria. The role of modern tools (e.g., molecular methods, metagenomic sequencing, etc.) remains to be evaluated in this setting. One of the challenges of antimicrobial treatment is antibiotics diffusion into the lungs. Although targeted delivery of antibiotics using nebulization may be interesting, their place in ARDS patients remains to be explored. The use of extracorporeal membrane oxygenation in the most severe patients is associated with a high rate of infection and raises several challenges, diagnostic issues and pharmacokinetics/pharmacodynamics changes being at the top. Prevention of pulmonary infection is a key issue in ARDS patients, but there is no specific measure for these high-risk patients. Reinforcing preventive measures using bundles seems to be the best option.

Should oral chlorhexidine remain in ventilator-associated pneumonia prevention bundles?

Ventilator-associated pneumonia (VAP) is related with high mortality, duration of mechanical ventilation and costs. Recent studies have questioned the safety and effectiveness of oral chlorhexidine to prevent VAP. We sought to verify whether the adverse effects of this substance outweigh its benefits. We searched several databases and selected studies that investigated the use of oral chlorhexidine and its impact on mortality. No association between oral chlorhexidine and lower VAP rates was found on meta-analyses of double-blind randomized trials, however significant increase in mortality was reported. It is speculated that chlorhexidine can cause damage to several organic sectors and cytotoxicity. Although it still can be beneficial in specific settings, robust evidence to recommend its routine application for all mechanically ventilated patients is lacking; therefore, given the possibility of harm, it would be better to follow the principle of non-maleficence until more studies becomes available.

British Association of Critical Care Nurses: Evidence-based consensus paper for oral care within adult critical care units

BACKGROUND

Patients who are critically ill are at increased risk of hospital acquired pneumonia and ventilator associated pneumonia. Effective evidence based oral care may reduce the incidence of such iatrogenic infection.

AIM

To provide an evidence-based British Association of Critical Care Nurses endorsed consensus paper for best practice relating to implementing oral care, with the intention of promoting patient comfort and reducing hospital acquired pneumonia and ventilator associated pneumonia in critically ill patients.

DESIGN

A nominal group technique was adopted. A consensus committee of adult critical care nursing experts from the United Kingdom met in 2018 to evaluate and review the literature relating to oral care, its application in reducing pneumonia in critically ill adults and to make recommendations for practice. An elected national board member for the British Association of Critical Care Nurses chaired the round table discussion.

METHODS

The committee focused on 5 aspects of oral care practice relating to critically ill adult patients. The evidence was evaluated for each practice within the context of reducing pneumonia in the mechanically ventilated patient or pneumonia in the non-ventilated patient. The five practices included the frequency for oral care; tools for oral care; oral care technique; solutions used and oral care in the non-ventilated patient who is critically ill and is at risk of aspiration. The group searched the best available evidence and evaluated this using the Grading of Recommendations Assessment, Development, and Evaluation system to assess the quality of evidence from high to very low, and to formulate recommendations as strong, moderate, weak, or best practice consensus statement when applicable.

RESULTS

The consensus group generated recommendations, delineating an approach to best practice for oral care in critically ill adult patients. Recommendations included guidance for frequency and procedure for oral assessment, toothbrushing, and moisturising the mouth. Evidence on the use of chlorhexidine is not consistent and caution is advised with its routine use.

CONCLUSION

Oral care is an important part of the care of critically ill patients, both ventilated and non-ventilated. An effective oral care programme reduces the incidence of pneumonia and promotes patient comfort.

RELEVANCE TO CLINICAL PRACTICE

Effective oral care is integral to safe patient care in critical care.

Antiseptic mouthwash, the nitrate-nitrite-nitric oxide pathway, and hospital mortality: a hypothesis generating review

Meta-analyses and several large cohort studies have demonstrated that antiseptic mouthwashes are associated with mortality in hospitalized patients. A clear pathogenic mechanism is lacking, leading to controversy and a reluctance to abandon or limit the use of antiseptic mouthwashes. Here, we generate the hypothesis that a disturbance in nitric oxide homeostasis by antiseptic mouthwashes may be responsible for the observed increase in mortality risk. Nitric oxide is essential in multiple physiological processes, and a reduction in nitric oxide bioavailability is associated with the occurrence or worsening of pathologies, such as atherosclerosis, diabetes, and sepsis. Oral facultative anaerobic bacteria are essential for the enterosalivary nitrate–nitrite–nitric oxide pathway due to their capacity to reduce nitrate to nitrite. Nitrate originates from dietary sources or from the active uptake by salivary glands of circulating nitrate, which is then excreted in the saliva. Because antiseptic mouthwashes eradicate the oral bacterial flora, this nitric oxide-generating pathway is abolished, which may result in nitric oxide-deficient conditions potentially leading to life-threatening complications such as ischaemic heart events or sepsis.

Analysis of oral risk factors for ventilator-associated pneumonia in critically ill patients

Objective

This a cross-sectional study to evaluate the association between oral health findings and ventilator-associated pneumonia (VAP) among critically ill patients in intensive care units (ICU).

Material and methods

Data were collected from medical records, and a detailed oral physical examination was performed on 663 critically ill patients on mechanical ventilation. Data were statistically analysed using univariate and logistic regression models relating the development of VAP with the oral findings.

Results

At oral physical examination, the most frequent findings were tooth loss (568–85.67%), coated tongue (422–63.65%) and oral bleeding (192–28.96%). Patients with a coated tongue or oral bleeding on the first day of ICU hospitalization developed more VAP than did patients without these conditions (20.14 vs 13.69%, p = 0.02; 23.44 vs 15.50%, p = 0.01, respectively). In the logistic regression, a coated tongue and oral bleeding were considered independent risk factors for VAP development (OR = 1.61 (1.03–2.51) and OR = 1.69 (1.08–2.66), respectively).

Conclusions

The presence of a coated tongue and oral bleeding in ICU admission could be considered markers for the development of VAP.

Clinical relevance

The results of this paper reinforce the importance of proper maintenance of oral hygiene before intubation, which may lead to a decrease in the incidence of VAP in the ICU.

Effects of Diluents, Saliva and Other Organics on the Microbicidal Activity of Cetylpyridinium Chloride and Povidone-iodine

Povidone-iodine (PVP-I) is used for infection control and preoperative sterilization of the oral and pharyngeal regions. Marketed preparations containing cetylpyridinium chloride (CPC) are used to inhibit growth of oral bacteria. We conducted an in vitro study of the sterilizing effects of these microbicides on 10 oral bacterial strains and fungi related to pneumonia and periodontal disease, after dilution with phosphate-buffered saline (PBS), saliva, and components in saliva. The CPC solution was evaluated at 50 mg/100 mL, which is the concentration used in products. CPC sterilized all strains within 1 minute. Prolongation of the sterilization time associated with dilution was more gradual in comparison to PVP-I solution. CPC sterilized 7 of 10 microbial strains within 3 minutes at 3 mg/100 mL. At 500 mg/100 mL, which is near the upper limit of the concentration that is actually used, PVP-I solution sterilized 7 microbial strains within 3 minutes. However, PVP-I had no sterilization effect when diluted to 100 mg/100 mL or lower. With addition of saliva, PVP-I sterilized 2 microbial strains within 3 minutes at 500 mg/100 mL, whereas CPC solution sterilized 9 microbial strains within 1 minute at 50 mg/100 mL. Our results show that in use influenced by dilution with saliva, CPC is likely to maintain a strong sterilization effect, whereas PVP-I may have a reduced effect.

Structural equation modeling the "control of gut overgrowth" in the prevention of ICU-acquired Gram-negative infection

BACKGROUND

Conceptually, the "control of gut overgrowth" (COGO) is key in mediating prevention against infection with Gram-negative bacilli by topical antibiotic prophylaxis, a common constituent of selective digestive decontamination (SDD) regimens. However, the relative importance of the other SDD components, enteral and protocolized parenteral antibiotic prophylaxis, versus other methods of infection prevention and versus other contextual exposures cannot be resolved within individual studies.

METHODS

Seven candidate generalized structural equation models founded on COGO concepts were confronted with Pseudomonas and Acinetobacter bacteremia as well as ventilator-associated pneumonia data derived from > 200 infection prevention studies. The following group-level exposures were included in the models: use and mode of antibiotic prophylaxis, anti-septic and non-decontamination methods of infection prevention; proportion receiving mechanical ventilation; trauma ICU; mean length of ICU stay; and concurrency versus non-concurrency of topical antibiotic prophylaxis study control groups.

RESULTS

In modeling Pseudomonas and Acinetobacter gut overgrowth as latent variables, anti-septic interventions had the strongest negative effect against Pseudomonas gut overgrowth but no intervention was significantly negative against Acinetobacter gut overgrowth. Strikingly, protocolized parenteral antibiotic prophylaxis and concurrency each have positive effects in the model, enteral antibiotic prophylaxis is neutral, and Acinetobacter bacteremia incidences are high within topical antibiotic prophylaxis studies, moreso with protocolized parenteral antibiotic prophylaxis exposure. Paradoxically, topical antibiotic prophylaxis (moreso with protocolized parenteral antibiotic prophylaxis) appears to provide the strongest summary prevention effects against overall bacteremia and overall VAP.

CONCLUSIONS

Structural equation modeling of published Gram-negative bacillus infection data enables a test of the COGO concept. Paradoxically, Acinetobacter and Pseudomonas bacteremia incidences are unusually high among studies of topical antibiotic prophylaxis.

Evaluation of effects of perioperative oral care intervention on hospitalization stay and postoperative infection in patients undergoing lung cancer intervention

PURPOSE

This retrospective study investigated the effect of perioperative oral care intervention on postoperative outcomes in patients undergoing lung cancer resection, in terms of the length of postoperative hospital stay and the incidence of postoperative respiratory infections.

METHODS

In total, 585 patients underwent lung resection for lung cancer, 397 received perioperative oral care intervention, whereas the remaining 188 did not. This study retrospectively investigated the demographic and clinical characteristics (including postoperative complications and postoperative hospital stay) of each group. To determine whether perioperative oral care intervention was independently associated with either postoperative hospital stay or postoperative respiratory infections, multivariate analysis, multiple regression analysis, and multivariate logistic regression analysis were conducted.

RESULTS

Parameters significantly associated with a prolonged postoperative hospital stay in lung cancer surgery patients were older age, postoperative complications, increased intraoperative bleeding, more invasive operative approach (e.g., open surgery), and lack of perioperative oral care intervention (standard partial regression coefficient (ß) = 0.083, p = 0.027). Furthermore, older age and longer operative time were significant independent risk factors for the occurrence of postoperative respiratory infections. Lack of perioperative oral care intervention was a potential risk factor for the occurrence of postoperative respiratory infections, although not statistically significant (odds ratio = 2.448, 95% confidence interval = 0.966-6.204, p = 0.059).

CONCLUSION

These results highlight the importance of perioperative oral care intervention prior to lung cancer surgery, in order to shorten postoperative hospital stay and reduce the risk of postoperative respiratory infections.

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.

Topical povidone iodine inhibits bacterial growth in the oral cavity of patients on mechanical ventilation: a randomized controlled study

Background

Topical 0.12% chlorhexidine has been used widely to prevent ventilator-associated pneumonia in patients undergoing mechanical ventilation. However, it is not approved for mucosal application in Japan. The aims of this study were to investigate if topical povidone iodine (i) inhibits bacterial growth and (ii) disrupts the balance of the oral microbiota.

Methods

This randomized controlled clinical trial included 23 patients who underwent mechanical ventilation in the intensive care unit. The patients were divided randomly into two groups: the intervention group (n = 16) and the control group (n = 7). All patients received oral cleaning with 3% hydrogen peroxide, followed by irrigation with tap water. The patients in the intervention group received 10% povidone iodine applied topically to the oral cavity. The concentration of total bacteria in the oropharyngeal fluid were determined before, immediately after, 1 h, 2 h, and 3 h after oral care using the Rapid Oral Bacteria Quantification System, which is based on dielectrophoresis and impedance measurements. The number of streptococci, methicillin-resistant Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, Porphyromonas gingivalis, and Candida albicans before, immediately after, 1 h, and 3 h after oral care were estimated based on real-time polymerase chain reaction data.

Results

After irrigation of the oral cavity, the number of bacteria decreased, but increased again at 1 h after oral care in the control group; however, in the intervention group, the concentration of bacteria was significantly lower than that in the control group at 1 hour (p = 0.009), 2 h (p = 0.001), and 3 h (p = 0.001) after oral care. The growth of all bacterial species tested was inhibited in the intervention group at 3 h after oral care, suggesting that povidone iodine did not disturb the balance of the oral microbiota.

Conclusions

Topical application of povidone iodine after cleaning and irrigation of the oral cavity inhibited bacterial growth in the oropharyngeal fluid of patients on mechanical ventilation while not disrupting the balance of the oral microbiota.

Trial registration

University Hospitals Medical Information Network Clinical Trials Registry (UMIN-CTR), UMIN000028307. Registered 1 September 2017.