Nosocomial pneumonia: state of the science

Infectious diseases and infection control prevention strategies in adult and pediatric population on ECMO

As survival after ECMO improves and use of ECMO support increases in both pediatric and adult population, there is a need to focus on both the morbidities and complications associated with ECMO and how to manage and prevent them. Infectious complications during ECMO often have a significant clinical impact, resulting in increased morbidity or mortality irrespective of the underlying etiology necessitating cardiorespiratory support. In this review article, we discuss the prevention, management, challenges, and differences of infectious complications in adult and pediatric patients receiving ECMO support.

Lung infection by Pseudomonas aeruginosa induces neuroinflammation and blood-brain barrier dysfunction in mice

BACKGROUND

Severe lung infection can lead to brain dysfunction and neurobehavioral disorders. The mechanisms that regulate the lung-brain axis of inflammatory response to respiratory infection are incompletely understood. This study examined the effects of lung infection causing systemic and neuroinflammation as a potential mechanism contributing to blood-brain barrier (BBB) leakage and behavioral impairment.

METHODS

Lung infection in mice was induced by instilling Pseudomonas aeruginosa (PA) intratracheally. We determined bacterial colonization in tissue, microvascular leakage, expression of cytokines and leukocyte infiltration into the brain.

RESULTS

Lung infection caused alveolar-capillary barrier injury as indicated by leakage of plasma proteins across pulmonary microvessels and histopathological characteristics of pulmonary edema (alveolar wall thickening, microvessel congestion, and neutrophil infiltration). PA also caused significant BBB dysfunction characterized by leakage of different sized molecules across cerebral microvessels and a decreased expression of cell-cell junctions (VE-cadherin, claudin-5) in the brain. BBB leakage peaked at 24 h and lasted for 7 days post-inoculation. Additionally, mice with lung infection displayed hyperlocomotion and anxiety-like behaviors. To test whether cerebral dysfunction was caused by PA directly or indirectly, we measured bacterial load in multiple organs. While PA loads were detected in the lungs up to 7 days post-inoculation, bacteria were not detected in the brain as evidenced by negative cerebral spinal fluid (CSF) cultures and lack of distribution in different brain regions or isolated cerebral microvessels. However, mice with PA lung infection demonstrated increased mRNA expression in the brain of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), chemokines (CXCL-1, CXCL-2) and adhesion molecules (VCAM-1 and ICAM-1) along with CD11b + CD45+ cell recruitment, corresponding to their increased blood levels of white cells (polymorphonuclear cells) and cytokines. To confirm the direct effect of cytokines on endothelial permeability, we measured cell-cell adhesive barrier resistance and junction morphology in mouse brain microvascular endothelial cell monolayers, where administration of IL-1β induced a significant reduction of barrier function coupled with tight junction (TJ) and adherens junction (AJ) diffusion and disorganization. Combined treatment with IL-1β and TNFα augmented the barrier injury.

CONCLUSIONS

Lung bacterial infection is associated with BBB disruption and behavioral changes, which are mediated by systemic cytokine release.

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.

Lung infection by P. aeruginosa induces neuroinflammation and blood-brain barrier dysfunction in mice

Background Severe lung infection can lead to brain dysfunction and neurobehavioral disorders. The mechanisms that regulate the lung-brain axis of inflammatory response to respiratory infection are incompletely understood. This study examined the effects of lung infection causing systemic and neuroinflammation as a potential mechanism contributing to blood-brain barrier (BBB) leakage and behavioral impairment. Methods Pneumonia was induced in adult C57BL/6 mice by intratracheal inoculation of Pseudomonas aeruginosa (PA). Solute extravasation, histology, immunofluorescence, RT-PCR, multiphoton imaging and neurological testing were performed in this study. Results Lung infection caused alveolar-capillary barrier injury as indicated by leakage of plasma proteins across pulmonary microvessels and histopathological characteristics of pulmonary edema (alveolar wall thickening, microvessel congestion, and neutrophil infiltration). PA also caused significant BBB dysfunction characterized by leakage of different sized molecules across cerebral microvessels and a decreased expression of cell-cell junctions (VE-cadherin, claudin-5) in the brain. BBB leakage peaked at 24 hours and lasted for 7 days post-inoculation. Additionally, mice with lung infection displayed hyperlocomotion and anxiety-like behaviors. To test whether cerebral dysfunction was caused by PA directly or indirectly, we measured bacterial load in multiple organs. While PA loads were detected in the lungs up to 7 days post-inoculation, bacteria were not detected in the brain as evidenced by negative cerebral spinal fluid (CSF) cultures and lack of distribution in different brain regions or isolated cerebral microvessels. However, mice with PA lung infection demonstrated increased mRNA expression in the brain of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), chemokines (CXCL-1, CXCL-2) and adhesion molecules (VCAM-1 and ICAM-1) along with CD11b + cell recruitment, corresponding to their increased blood levels of white cells (polymorphonuclear cells) and cytokines. To confirm the direct effect of cytokines on endothelial permeability, we measured cell-cell adhesive barrier resistance and junction morphology in mouse brain microvascular endothelial cell monolayers, where administration of IL-1β induced a significant reduction of barrier function coupled with tight junction (TJ) diffusion and disorganization. Combined treatment with IL-1β and TNFα augmented the barrier injury. Conclusions These results suggest that lung bacterial infection causes cerebral microvascular leakage and neuroinflammation via a mechanism involving cytokine-induced BBB injury.

Lung infection by P. aeruginosa induces neuroinflammation and blood-brain barrier dysfunction in mice

Background

Severe lung infection can lead to brain dysfunction and neurobehavioral disorders. The mechanisms that regulate the lung-brain axis of inflammatory response to respiratory infection are incompletely understood. This study examined the effects of lung infection causing systemic and neuroinflammation as a potential mechanism contributing to blood-brain barrier (BBB) leakage and behavioral impairment.

Methods

Pneumonia was induced in adult C57BL/6 mice by intratracheal inoculation of Pseudomonas aeruginosa (PA). Solute extravasation, histology, immunofluorescence, RT-PCR, multiphoton imaging and neurological testing were performed in this study.

Results

Lung infection caused alveolar-capillary barrier injury as indicated by leakage of plasma proteins across pulmonary microvessels and histopathological characteristics of pulmonary edema (alveolar wall thickening, microvessel congestion, and neutrophil infiltration). PA also caused significant BBB dysfunction characterized by leakage of different sized molecules across cerebral microvessels and a decreased expression of cell-cell junctions (VE-cadherin, claudin-5) in the brain. BBB leakage peaked at 24 hours and lasted for 7 days post-inoculation. Additionally, mice with lung infection displayed hyperlocomotion and anxiety-like behaviors. To test whether cerebral dysfunction was caused by PA directly or indirectly, we measured bacterial load in multiple organs. While PA loads were detected in the lungs up to 7 days post-inoculation, bacteria were not detected in the brain as evidenced by negative cerebral spinal fluid (CSF) cultures and lack of distribution in different brain regions or isolated cerebral microvessels. However, mice with PA lung infection demonstrated increased mRNA expression in the brain of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), chemokines (CXCL-1, CXCL-2) and adhesion molecules (VCAM-1 and ICAM-1) along with CD11b+ cell recruitment, corresponding to their increased blood levels of white cells (polymorphonuclear cells) and cytokines. To confirm the direct effect of cytokines on endothelial permeability, we measured cell-cell adhesive barrier resistance and junction morphology in mouse brain microvascular endothelial cell monolayers, where administration of IL-1β induced a significant reduction of barrier function coupled with tight junction (TJ) diffusion and disorganization. Combined treatment with IL-1β and TNFα augmented the barrier injury.

Conclusions

These results suggest that lung bacterial infection causes cerebral microvascular leakage and neuroinflammation via a mechanism involving cytokine-induced BBB injury.

Interventions to reduce the incidence of medical error and its financial burden in health care systems: A systematic review of systematic reviews

Background and aim

Improving health care quality and ensuring patient safety is impossible without addressing medical errors that adversely affect patient outcomes. Therefore, it is essential to correctly estimate the incidence rates and implement the most appropriate solutions to control and reduce medical errors. We identified such interventions.

Methods

We conducted a systematic review of systematic reviews by searching four databases (PubMed, Scopus, Ovid Medline, and Embase) until January 2021 to elicit interventions that have the potential to decrease medical errors. Two reviewers independently conducted data extraction and analyses.

Results

Seventysix systematic review papers were included in the study. We identified eight types of interventions based on medical error type classification: overall medical error, medication error, diagnostic error, patients fall, healthcare-associated infections, transfusion and testing errors, surgical error, and patient suicide. Most studies focused on medication error (66%) and were conducted in hospital settings (74%).

Conclusions

Despite a plethora of suggested interventions, patient safety has not significantly improved. Therefore, policymakers need to focus more on the implementation considerations of selected interventions.

Microbiologic pattern and clinical outcome of non-ICU-acquired pneumonia: Korean HAP registry analysis

BACKGROUND/AIMS

Most studies on hospital-acquired pneumonia (HAP) have been conducted in intensive care unit (ICU) settings. This study aimed to investigate the microbiological and clinical characteristics of non-ICU-acquired pneumonia (NIAP) and to identify the factors affecting clinical outcomes in Korea.

METHODS

This multicenter retrospective cohort study was conducted in patients admitted to 13 tertiary hospitals between July 1, 2019 and December 31, 2019. Patients diagnosed with NIAP were included in this study. To assess the prognostic factors of NIAP, the study population was classified into treatment success and failure groups.

RESULTS

Of 526 patients with HAP, 379 were diagnosed with NIAP. Overall, the identified causative pathogen rate was 34.6% in the study population. Among the isolated organisms (n = 113), gram-negative bacilli were common pathogens (n = 91), such as Pseudomonas aeruginosa (n = 25), Acinetobacter baumannii (n = 23), and Klebsiella pneumoniae (n = 21). The multidrug resistance rates of A. baumannii, P. aeruginosa, and K. pneumoniae were 91.3%, 76.0%, and 57.1%, respectively. Treatment failure was significantly associated with K. pneumoniae (odds ratio [OR], 3.50; 95% confidence interval [CI], 1.35 to 9.05; p = 0.010), respiratory viruses (OR, 3.81; 95% CI, 1.34 to 10.82; p = 0.012), hematological malignancies (OR, 3.54; 95% CI, 1.57 to 8.00; p = 0.002), and adjunctive corticosteroid treatment (OR, 2.40; 95% CI, 1.27 to 4.52; p = 0.007).

CONCLUSION

The causative pathogens of NIAP in Korea are predominantly gram-negative bacilli with a high rate of multidrug resistance. These were not different from the common pathogens of ICU-acquired pneumonia.

d-Amino Acid-Based Metabolic Labeling Enables a Fast Antibiotic Susceptibility Test of Both Isolated Bacteria and Bronchoalveolar Lavage Fluid

The threat of multidrug-resistant bacteria has escalated rapidly, increasing the demand for accurate antibiotic susceptibility tests (ASTs). Traditional bacterial growth yield-based ASTs often take overnight to report, delaying the timely guidance of antibiotic use. Here, a fluorescent d-amino acid (FDAA) labeling-based AST (FaAST) is reported, which can quickly provide accurate minimum inhibitory concentrations (MICs). The FDAA-labeling signals that reflect the bacterial metabolic status underlie the flow cytometry-based strategy for MIC determination. Resistant bacteria show a reluctant decline in FDAA-labeling (inhibited metabolism) after treatment with the corresponding antibiotics, whereas susceptible bacteria demonstrate quick responses to low doses of drugs. The MICs are determined based on the changing trends in labeling. After testing 23 clinical isolates and laboratory strains of the most critical drug-resistant bacteria against a panel of representative antibiotics, FaAST shows a high susceptibility category with an accuracy of 98.13%. Moreover, FaAST can also make quick and accurate diagnosis against bronchoalveolar lavage fluids collected from hospital-acquired pneumonia patients, saving 2-4 days in guiding antibiotic use for this life-threatening infection. Thus, the speed, accuracy, and broad applicability of FaAST will be valuable in informing antibiotic decisions when treating critical infections caused by drug-resistant bacteria.

Pretreatment with 6-Gingerol Ameliorates Sepsis-Induced Immune Dysfunction by Regulating the Cytokine Balance and Reducing Lymphocyte Apoptosis

Sepsis is characterized by an initial net hyperinflammatory response, followed by a period of immunosuppression, termed immunoparalysis. During this immunosuppressive phase, patients may have difficulty eradicating invading pathogens and are susceptible to life-threatening secondary hospital-acquired infections. Due to progress in antimicrobial treatment and supportive care, most patients survive early sepsis. Mortality is more frequently attributed to subsequent secondary nosocomial infections and multiorgan system failure. 6-Gingerol is the major pharmacologically active component of ginger. Although it is known to exhibit a variety of biological activities, including anti-inflammation and antioxidation, the role of 6-gingerol in sepsis-induced immune dysfunction remains elusive. Thus, we investigated whether 6-gingerol improves septic host response to infections during sepsis. 6-Gingerol-treated mice showed significantly lower mortality in polymicrobial sepsis induced by cecal ligation and puncture LPS via enhanced bacterial clearance in the peritoneum, blood, and organs (liver, spleen, and kidney) and inhibited the production of TNF-α and IL-6 in TLR2 and/or TLR4-stimulated macrophages. In addition, we demonstrated that survival improvement of secondary infection following septic insult was associated with an initial response of enhanced neutrophil numbers and function at the infection site, reduced apoptosis of immune cells, and a shift from a T helper cell type 2 (Th2) to a T helper cell type 1 (Th1) cytokine balance in the hypoinflammation phase. Our overall findings suggest that 6-gingerol potentially restores sepsis-induced immune dysfunction by shifting the balance of Th1/Th2 and by regulating apoptosis of immune cells.

What is the future of Periodontal Medicine?

In the last five decades, considerable progress has been made towards understanding the etiology and pathogenesis of periodontal diseases and their interactions with the host. The impact of an individual periodontal condition on systemic homeostasis became more evident because of this knowledge and prompted advances in studies that associate periodontitis with systemic diseases and conditions. The term Periodontal Medicine describes how periodontal infection/inflammation can affect extraoral health. This review presents the current scientific evidence on the most investigated associations between periodontitis and systemic diseases and conditions, such as cardiovascular diseases, diabetes, preterm birth and low birth weight, and pneumonia. Additionally, other associations between periodontitis and chronic inflammatory bowel disease, colorectal cancer, and Alzheimer's disease that were recently published and are still poorly studied were described. Thus, the aim of this review was to answer the following question: What is the future of Periodontal Medicine? Epidemiological evidence and the evidence of biological plausibility between periodontitis and general health reinforce the rationale that the study of Periodontal Medicine should continue to advance, along with improvements in the epidemiological method, highlighting the statistical power of the studies, the method for data analysis, the case definition of periodontitis, and the type of periodontal therapy to be applied in intervention studies.

Research on the economic loss of hospital-acquired pneumonia caused by Klebsiella pneumonia base on propensity score matching

BACKGROUND

Hospital-acquired pneumonia (HAP) caused by Klebsiella pneumonia (KP) is a common nosocomial infection (NI). However, the reports on the economic burden of hospital-acquired pneumonia caused by Klebsiella pneumonia (KP-HAP) were scarce. The study aims to study the direct economic loss caused by KP-HAP with the method of propensity score matching (PSM) to provide a basis for the cost accounting of NI and provide references for the formulation of infection control measures.

METHODS

A retrospective investigation was conducted on the hospitalization information of all patients discharged from a tertiary group hospital in Shenzhen, Guangdong province, China, from June 2016 to August 2019. According to the inclusion and exclusion criteria, patients were divided into the HAP group and noninfection group, the extended-spectrum beta-lactamases (ESBLs) positive KP infection group, and the ESBLs-negative KP infection group. After the baselines of each group were balanced with the PSM, length of stay (LOS) and hospital cost of each group were compared.

RESULTS

After the PSM, there were no differences in the baselines of each group. Compared with the noninfection group, the median LOS in the KP-HAP group increased by 15 days (2.14 times), and the median hospital costs increased by 7329 yuan (0.89 times). Compared with the ESBLs-negative KP-HAP group, the median LOS in the ESBLs-positive KP-HAP group increased by 7.5 days (0.39 times), and the median hospital costs increased by 22,424 yuan (1.90 times).

CONCLUSION

KP-HAP prolonged LOS and increased hospital costs, and HAP caused by ESBLs-positive KP had more economic losses than ESBLs-negative, which deserves our attention and should be controlled by practical measures.

Evaluation of Bacteria Causing Ventilator-Associated Pneumonia in Patients Admitted to Internal ICUs and Internal Wards at Shiraz Teaching Hospitals, 2017 - 2018

Background: Ventilator-associated pneumonia (VAP), a subset of hospital infections, occurs in patients who have been mechanically ventilated for at least 48 hours. Objectives: Our study aimed at determining the frequency and antibiotic susceptibility patterns of bacteria causing VAP in teaching hospitals of Shiraz. Methods: This was a descriptive cross-sectional study conducted in Shiraz for eight months (November 2017 to June 2018). Samples were detected according to diagnostic bacteriologic tests, and antibiotic susceptibility tests were performed by the disk diffusion (Kirby-Bauer) method based on the Clinical and Laboratory Standards Institute (CLSI). Results: A total of 51 patients with VAP were examined, of whom 10 and eight patients had a chronic obstructive pulmonary disease and acute respiratory distress syndrome, respectively. The late-onset VAP rate (61.7%) was higher than the early-onset VAP rate (38.3%). In our study, 45.2% of patients with VAP received antibiotics before the incidence of pneumonia, of whom 31.6% died. Of the remaining 54.8%, only 8.7% died. In other words, patients who received antibiotics before the incidence of pneumonia had higher mortality. The most frequently used antibiotics were meropenem (76.6%) and vancomycin (78.7%). Among 59 bacteria isolated, Acinetobacter and Pseudomonas were the most prevalent organisms. Conclusions: Our results showed that most of the isolates (40%) belonged to multi-drug resistant (MDR) pathogens. Probably, antimicrobial treatment before the onset of VAP led to the selection of these MDR pathogens.

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.

Disturbance in the oropharyngeal microbiota in relation to antibiotic and proton pump inhibitor medication and length of hospital stay

The aim of this study was to investigate the appearance of a disturbed oropharyngeal microbiota during hospitalization and explore the patient characteristics that maybe associated with such a disturbance. Oropharyngeal swabs were collected from 134 patients at hospital admission and every 3-4 days thereafter. The samples were cultivated to determine the presence of a disturbed microbiota, which, in turn, was subcategorized into respiratory tract pathogens, gut microbiota and yeast species. Demographics, medical history data and hospitalization events were compared. The percentage of disturbed oropharyngeal microbiota increased significantly with length of stay (LOS). Receiving antibiotic treatment during the hospitalization tended to be associated with a disturbed microbiota (OR 2.75 [0.99-7.60]). Proton pump inhibitor (PPI) medication and receiving antibiotics before hospitalization were associated with the development of a disturbed oropharyngeal microbiota with colonization of gut pathogens (OR 3.49 [1.19-10.2] and OR 4.52 [1.13-18.1], respectively), while acute hospital admission was associated with a lower risk of colonization of gut pathogens (OR: 0.23 [0.074-0.72]). The risk of developing a disturbed oropharyngeal microbiota increased with LOS in hospitalized patients. PPI medication and receiving antibiotics before hospitalization were independent risk factors for developing oropharyngeal colonization of gut pathogens.

Non-ventilator health care-associated pneumonia (NV-HAP): Long-term care

Nonventilator health care-associated pneumonia (NV-HAP) is costly and preventable with significant impact on patient morbidity and mortality. This chapter outlines the increased risk of NV-HAP among individuals residing in long-term care facilities and the incidence of pneumonia in this health care setting which accounts for up to 18% of all persons admitted to acute care hospital for pneumonia. A description of prevention strategies with detail on modifiable and Nonmodifiable risk factors for acquiring pneumonia are presented along with the need for a robust interdisciplinary team and approach for this vulnerable population. In addition, the lack of active surveillance and infection prevention expertise may result in the spread of pathogens that can cause NVHAP outbreaks.

Sustaining Quality Improvement: Long-Term Reduction of Nonventilator Hospital-Acquired Pneumonia

BACKGROUND

Hospital-acquired pneumonia is now the number one hospital-acquired infection. Hospitals have addressed ventilator-associated pneumonia; however, patients not on a ventilator acquire more pneumonia with significant associated mortality rates.

LOCAL PROBLEM

In our hospital, non-ventilator-associated pneumonia was occurring on all types of units.

METHODS

The Influencer Model was used to reduce nonventilator hospital-acquired pneumonia rates. Statistical process control R and X-bar-charts were monitored monthly.

INTERVENTIONS

After a gap analysis, an interdisciplinary team implemented enhanced oral care before surgery and on the units, changed tube management, and monitored stress ulcer medication.

RESULTS

We achieved a statistically significantly reduction (P = .01) in pneumonia rates that have been sustained over 4 years.

CONCLUSIONS

Sustaining change requires (a) a continued team-based, collaborative approach, (b) ongoing stakeholder and executive leadership engagement, (c) monitoring that easy-to-use protocols and required equipment remain in place, and (d) embedded analytics to monitor results over a prolonged period.

Anti-PD-1 Antibody Administration following Hip Fracture Surgery Reverses Immune Dysfunction and Decreases Susceptibility to Infection

The aim of this investigation was to assess expression of programmed death-1 (PD-1) and inflammatory status after hip fracture surgery in aged mice and to evaluate the effect of anti-PD-1 antibody intervention. Male C57BL/6 mice aged 22-28 months underwent hip fracture and femoral intramedullary pinning or a sham procedure. Expression of PD-1 was measured on CD4⁺ and CD8⁺ T cells. Additionally, the effects of anti-PD-1 antibody on lymphocyte apoptosis, cytokine production, bacterial clearance, and survival were determined. Expression of PD-1 on T cells was upregulated in mice after hip fracture and surgery compared to sham controls. Administration of anti-PD-1 antibody prevented T lymphocyte apoptosis, increased IFN-γ production in splenocytes, and decreased systemic inflammation. Antibody blockade of PD-1 significantly decreased susceptibility to bacteria and improved survival rates of aged mice after hip fracture and surgery followed by the induction of Pseudomonas aeruginosa pneumonia. This study showed that hip fracture and surgical trauma cause significant increases in PD-1 expression in aged mice. Antibody blockade of PD-1 partially reverses T cell apoptosis, decreases the systemic inflammatory response and susceptibility to bacteria, and reduces mortality.

Partial Depletion of Regulatory T Cells Enhances Host Inflammatory Response Against Acute Pseudomonas aeruginosa Infection After Sepsis

Immune dysfunction contributes to secondary infection and worse outcomes in sepsis. Regulatory T cells (Tregs) have been implicated in sepsis-induced immunosuppression. Nevertheless, the role of Tregs in secondary infection after sepsis remains to be determined. In the present study, a two-hit model which mimics clinical conditions was used and the potential role of Tregs in secondary Pseudomonas aeruginosa infection post-sepsis was investigated. Results showed that mice were susceptible to secondary P. aeruginosa infection 3 days, but not 7 days, post-cecal ligation and puncture (CLP). The levels of IL-17A, IL-1β, and IL-6 remained low in CLP mice after P. aeruginosa infection, while the levels of IL-10 increased significantly. Additionally, increased number of Tregs in both lung and spleen was observed in "two-hit" mice. Injection with PC61 (anti-CD25) mAb reduced the number of Tregs by 50% in spleen and 60% in lung of septic mice. This partial depletion of Tregs elevated IL-17A, IL-1β, and IL-6 production and decreased IL-10 levels in septic mice with P. aeruginosa infection, leading to lower bacterial load, attenuation of lung injury, and improvement of survival. The present findings demonstrate that Tregs play a crucial role in secondary P. aeruginosa infection after sepsis by modulating the inflammatory response.

Early bronchoalveolar lavage for intubated trauma patients with TBI or chest trauma

PURPOSE

To evaluate the efficacy of an early bronchoalveolar lavage (E-BAL) protocol. BAL was performed within 48 h for intubated patients with traumatic brain injury or chest trauma. We hypothesized that E-BAL would decrease antibiotic use and improve outcomes compared to late BAL (L-BAL) triggered by clinical signs of pneumonia.

METHODS

Retrospective cohort analysis of 132 patients with quantitative BAL and ≥1 risk factor: head Abbreviated Injury Score ≥2, ≥3 rib fractures, or radiographic signs of aspiration or pulmonary contusion. E-BAL (n=71) was compared to L-BAL (n=61). Pneumonia was defined as ≥10⁴ organisms on BAL or Clinical Pulmonary Infection Score >6.

RESULTS

There were no significant differences in age, injury severity, initial Pao₂:Fio₂, or smoking status between E-BAL and L-BAL groups. 52% and 61% of the E-BAL and L-BAL cultures were positive, respectively. E-BAL patients had fewer antibiotic days (7.3 vs 9.2, P=.034), ventilator days (11 vs 15, P=.002), tracheostomies (49% vs 75%, P=.002), and shorter intensive care unit and hospital length of stay (13 vs 17 days (P=.007), 18 vs 22 days (P=.041)).

CONCLUSIONS

More than half of all E-BAL patients had pneumonia present early after admission. E-BAL was associated with fewer days on antibiotics and better outcomes than L-BAL.

Prevention of hospital-acquired pneumonia in non-ventilated adult patients: a narrative review

Background

Pneumonia is one of the leading hospital-acquired infections worldwide and has an important impact. Although preventive measures for ventilator-associated pneumonia (VAP) are well known, less is known about appropriate measures for prevention of hospital-acquired pneumonia (HAP).

Aim

The purpose of this narrative review is to provide an overview of the current standards for preventing HAP in non-ventilated adult patients.

Methods

A search of the literature up to May 2015 was conducted using Medline for guidelines published by national professional societies or professional medical associations. In addition, a comprehensive search for the following preventive measures was performed: hand hygiene, oral care, bed position, mobilization, diagnosis and treatment of dysphagia, aspiration prevention, viral infections and stress bleeding prophylaxis.

Findings

Regarding international guidelines, several measures were recommended for VAP, whilst no specific recommendations for HAP prevention in non-ventilated patients are available. There is reasonable evidence available that oral care is associated with a reduction in HAP. Early mobilization interventions, swift diagnosis and treatment of dysphagia, and multimodal programmes for the prevention of nosocomial influenza cross-infection, have a positive impact on HAP reduction. The impact of bed position and stress bleeding prophylaxis remains uncertain. Systematic antibiotic prophylaxis for HAP prevention should be avoided.

Conclusion

Scant literature and little guidance is available for the prevention of HAP among non-ventilated adult patients. In addition, the criteria used for the diagnosis of HAP and the populations targeted in the studies selected are heterogeneous. Oral care was the most studied measure and was commonly associated with a decrease in HAP rate, although a broad range of interventions are proposed. No robust evidence is available for other measures. Further high-quality studies are required to evaluate the impact of specific measures on HAP prevention in non-ventilated adult patients.

Inducible epithelial resistance protects mice against leukemia-associated pneumonia

Despite widespread infection prevention efforts, pneumonia remains the leading cause of death among patients with acute leukemia, due to complex disease- and treatment-dependent immune defects. We have reported that a single inhaled treatment with a synergistic combination of Toll-like receptor 2/6 (TLR 2/6) and TLR9 agonists (Pam2-ODN) induces protective mucosal defenses in mice against a broad range of pathogens. As Pam2-ODN-induced protection persists despite depletion of several leukocyte populations, we tested whether it could prevent pneumonia in a mouse model of acute myeloid leukemia (AML) remission induction therapy. Pam2-ODN prevented death due to pneumonia caused by Pseudomonas aeruginosa, Streptococcus pneumoniae, and Aspergillus fumigatus when mice were heavily engrafted with leukemia cells, had severe chemotherapy-induced neutropenia or both. Pam2-ODN also extended survival of pneumonia in NSG mice engrafted with primary human AML cells. Protection was associated with rapid pathogen killing in the lungs at the time of infection and with reduced pathogen burdens at distant sites at the end of observation. Pathogen killing was inducible directly from isolated lung epithelial cells and was not abrogated by the presence of leukemia cells or cytotoxic agents. Pam2-ODN had no discernible effect on replication rate, total tumor population, or killing by chemotherapy of mouse or human leukemia cells, either in vitro or in vivo. Taken together, we report that therapeutic stimulation of lung epithelial defenses robustly protects against otherwise lethal pneumonias despite the profound immune dysfunction associated with acute leukemia and its treatment. These findings may suggest an opportunity to protect this population during periods of peak vulnerability.

Periodontal systemic associations: review of the evidence

AIM

To critically appraise recent research into associations between periodontal disease and systemic diseases and conditions specifically respiratory disease, chronic kidney disease, rheumatoid arthritis, cognitive impairment, obesity, metabolic syndrome and cancer.

METHODS

A MEDLINE literature search of papers published between 2002 and April 2012 was conducted. Studies that included periodontitis as an exposure were identified. Cross-sectional epidemiological investigations on large samples, prospective studies and systematic reviews formed the basis of the narrative review. A threshold set for the identification of periodontitis was used to identify those studies that contributed to the conclusions of the review.

RESULTS

Many of the investigations were cross-sectional secondary analyses of existing data sets in particular the NHANES studies. There were a small number of systematic reviews and prospective studies. There was substantial variability in the definitions of exposure to periodontitis. A small number of studies met the threshold set for periodontitis and supported associations; however, in some of the chronic diseases there were no such studies. There was strong evidence from randomized controlled trials that interventions, which improve oral hygiene have positive effects on the prevention of nosocomial pneumonias.

CONCLUSIONS

There was substantial heterogeneity in the definitions used to identify periodontitis and very few studies met a stringent threshold for periodontitis. Published evidence supports modest associations between periodontitis and some, although not all, of the diseases and conditions reviewed. There is a need to reach a consensus on what constitutes periodontitis for future studies of putative associations with systemic diseases.

Periodontal systemic associations: review of the evidence

AIM

To critically appraise recent research into associations between periodontal disease and systemic diseases and conditions specifically respiratory disease, chronic kidney disease, rheumatoid arthritis, cognitive impairment, obesity, metabolic syndrome and cancer.

METHODS

A MEDLINE literature search of papers published between 2002 and April 2012 was conducted. Studies that included periodontitis as an exposure were identified. Cross-sectional epidemiological investigations on large samples, prospective studies and systematic reviews formed the basis of the narrative review. A threshold set for the identification of periodontitis was used to identify those studies that contributed to the conclusions of the review.

RESULTS

Many of the investigations were cross-sectional secondary analyses of existing data sets in particular the NHANES studies. There were a small number of systematic reviews and prospective studies. There was substantial variability in the definitions of exposure to periodontitis. A small number of studies met the threshold set for periodontitis and supported associations; however, in some of the chronic diseases there were no such studies. There was strong evidence from randomized controlled trials that interventions, which improve oral hygiene have positive effects on the prevention of nosocomial pneumonias.

CONCLUSIONS

There was substantial heterogeneity in the definitions used to identify periodontitis and very few studies met a stringent threshold for periodontitis. Published evidence supports modest associations between periodontitis and some, although not all, of the diseases and conditions reviewed. There is a need to reach a consensus on what constitutes periodontitis for future studies of putative associations with systemic diseases.

Non-Intensive Care Unit Acquired Pneumonia: A New Clinical Entity?

Hospital-acquired pneumonia (HAP) is a frequent cause of nosocomial infections, responsible for great morbidity and mortality worldwide. The majority of studies on HAP have been conducted in patients hospitalized in the intensive care unit (ICU), as mechanical ventilation represents a major risk factor for nosocomial pneumonia and specifically for ventilator-associated pneumonia. However, epidemiological data seem to be different between patients acquiring HAP in the ICU vs. general wards, suggesting the importance of identifying non ICU-acquired pneumonia (NIAP) as a clinical distinct entity in terms of both etiology and management. Early detection of NIAP, along with an individualized management, is needed to reduce antibiotic use and side effects, bacterial resistance and mortality. The present article reviews the pathophysiology, diagnosis, treatment and prevention of NIAP.

A realist analysis of hospital patient safety in Wales: applied learning for alternative contexts from a multisite case study

Background

Hospital patient safety is a major social problem. In the UK, policy responses focus on the introduction of improvement programmes that seek to implement evidence-based clinical practices using the Model for Improvement, Plan-Do-Study-Act cycle. Empirical evidence that the outcomes of such programmes vary across hospitals demonstrates that the context of their implementation matters. However, the relationships between features of context and the implementation of safety programmes are both undertheorised and poorly understood in empirical terms.

Objectives

This study is designed to address gaps in conceptual, methodological and empirical knowledge about the influence of context on the local implementation of patient safety programmes.

Design

We used concepts from critical realism and institutional analysis to conduct a qualitative comparative-intensive case study involving 21 hospitals across all seven Welsh health boards. We focused on the local implementation of three focal interventions from the 1000 Lives+patient safety programme: Improving Leadership for Quality Improvement, Reducing Surgical Complications and Reducing Health-care Associated Infection. Our main sources of data were 160 semistructured interviews, observation and 1700 health policy and organisational documents. These data were analysed using the realist approaches of abstraction, abduction and retroduction.

Setting

Welsh Government and NHS Wales.

Participants

Interviews were conducted with 160 participants including government policy leads, health managers and professionals, partner agencies with strategic oversight of patient safety, advocacy groups and academics with expertise in patient safety.

Main outcome measures

Identification of the contextual factors pertinent to the local implementation of the 1000 Lives+patient safety programme in Welsh NHS hospitals.

Results

An innovative conceptual framework harnessing realist social theory and institutional theory was produced to address challenges identified within previous applications of realist inquiry in patient safety research. This involved the development and use of an explanatory intervention–context–mechanism–agency–outcome (I-CMAO) configuration to illustrate the processes behind implementation of a change programme. Our findings, illustrated by multiple nested I-CMAO configurations, show how local implementation of patient safety interventions are impacted and modified by particular aspects of context: specifically, isomorphism, by which an intervention becomes adapted to the environment in which it is implemented; institutional logics, the beliefs and values underpinning the intervention and its source, and their perceived legitimacy among different groups of health-care professionals; and the relational structure and power dynamics of the functional group, that is, those tasked with implementing the initiative. This dynamic interplay shapes and guides actions leading to the normalisation or the rejection of the patient safety programme.

Conclusions

Heightened awareness of the influence of context on the local implementation of patient safety programmes is required to inform the design of such interventions and to ensure their effective implementation and operationalisation in the day-to-day practice of health-care teams. Future work is required to elaborate our conceptual model and findings in similar settings where different interventions are introduced, and in different settings where similar innovations are implemented.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Evaluation of Synergistic Interactions Between Cell-Free Supernatant of Lactobacillus Strains and Amikacin and Genetamicin Against Pseudomonas aeruginosa

BACKGROUND

The indiscriminate use of antibiotics in the treatment of infectious diseases can increase the development of antibiotic resistance. Therefore, there is a big demand for new sources of antimicrobial agents and alternative treatments for reduction of antibiotic dosage required to decrease the associated side effects.

OBJECTIVES

In this study, the synergistic action of aminoglycoside antibiotics and cell-free supernatant (CFS) of probiotic (Lactobacillus rahmnosus and L. casei) against Pseudomonas aeruginosa PTCC 1430 was evaluated.

MATERIALS AND METHODS

A growth medium for culturing of probiotic bacteria was separated by centrifugation. The antimicrobial effects of CFS of probiotic bacteria were evaluated using the agar well diffusion assay. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated using the micro dilution method. Finally, an interaction between CFS and amikacin or gentamicin against P. aeruginosa PTCC 1430 was examined through the checkerboard method and fractional inhibitory concentration (FIC). Furthermore, CFSs from Lactobacillus strains were analyzed by reversed phase HPLC (RP-HPLC) for antimicrobial compounds.

RESULTS

The results showed a significant effect of CFS on the growth of P. aeruginosa. The MIC and MBC of CFS from L. casei were 62.5 µL⁄mL while the MIC and MBC of CFS from L. rhamnosus were 62.5 μL⁄mL and 125 μL⁄mL, respectively. Using the FIC indices, synergistic interactions were observed in combination of CFS and antibiotics. Fractional Inhibitory Concentration indices of CFS from L. casei and aminoglycoside antibiotics were 0.124 and 0.312 while FIC indices of CFS from L. rhamnosus and aminoglycoside antibiotics were 0.124 and 0.56, respectively showing a synergism effect. The results of RP-HPLC showed that CFS of Lactobacillus strains contained acetic acid, lactic acid and hydrogen peroxide (H2O2).

CONCLUSIONS

Our findings indicate that probiotic bacterial strains of Lactobacillus have a significant inhibitory effect on the growth of P. aeruginosa PTCC 1430. The antimicrobial potency of this combination can be useful for designing and developing alternative therapeutic strategies against P. aeruginosa infections.

Time to Guideline-Based Empiric Antibiotic Therapy in the Treatment of Pneumonia in a Community Hospital: A Retrospective Review

PURPOSE

The 2005 American Thoracic Society/Infectious Diseases Society of America (ATS/IDSA) guidelines for hospital-acquired pneumonia (HAP), ventilator-associated pneumonia (VAP), and health care-associated pneumonia (HCAP) stress the importance of initiating prompt appropriate empiric antibiotic therapy. This study's purpose was to determine the percentage of patients with HAP, VAP, and HCAP who received guideline-based empiric antibiotic therapy and to determine the average time to receipt of an appropriate empiric regimen.

METHODS

A retrospective chart review of adults with HAP, VAP, or HCAP was conducted at a community hospital in suburban Birmingham, Alabama. The hospital's electronic medical record system utilized International Classification of Diseases, Ninth Revision (ICD-9) codes to identify patients diagnosed with pneumonia. The percentage of patients who received guideline-based empiric antibiotic therapy was calculated. The mean time from suspected diagnosis of pneumonia to initial administration of the final antibiotic within the empiric regimen was calculated for patients who received guideline-based therapy.

RESULTS

Ninety-three patients met the inclusion criteria. The overall guideline adherence rate for empiric antibiotic therapy was 31.2%. The mean time to guideline-based therapy in hours:minutes was 7:47 for HAP and 28:16 for HCAP. For HAP and HCAP combined, the mean time to appropriate therapy was 21:55.

CONCLUSION

Guideline adherence rates were lower and time to appropriate empiric therapy was greater for patients with HCAP compared to patients with HAP.

Oral health disparities in older adults: oral bacteria, inflammation, and aspiration pneumonia

Poor oral hygiene has been suggested to be a risk factor for aspiration pneumonia in the institutionalized and disabled elderly. Control of oral biofilm formation in these populations reduces the numbers of potential respiratory pathogens in the oral secretions, which in turn reduces the risk for pneumonia. Together with other preventive measures, improved oral hygiene helps to control lower respiratory infections in frail elderly hospital and nursing home patients.

Risk factors for infection with multidrug-resistant bacteria in non-ventilated patients with hospital-acquired pneumonia

OBJECTIVE:

To identify risk factors for the development of hospital-acquired pneumonia (HAP) caused by multidrug-resistant (MDR) bacteria in non-ventilated patients.

METHODS:

This was a retrospective observational cohort study conducted over a three-year period at a tertiary-care teaching hospital. We included only non-ventilated patients diagnosed with HAP and presenting with positive bacterial cultures. Categorical variables were compared with chi-square test. Logistic regression analysis was used to determine risk factors for HAP caused by MDR bacteria.

RESULTS:

Of the 140 patients diagnosed with HAP, 59 (42.1%) were infected with MDR strains. Among the patients infected with methicillin-resistant Staphylococcus aureus and those infected with methicillin-susceptible S. aureus, mortality was 45.9% and 50.0%, respectively (p = 0.763). Among the patients infected with MDR and those infected with non-MDR gram-negative bacilli, mortality was 45.8% and 38.3%, respectively (p = 0.527). Univariate analysis identified the following risk factors for infection with MDR bacteria: COPD; congestive heart failure; chronic renal failure; dialysis; urinary catheterization; extrapulmonary infection; and use of antimicrobial therapy within the last 10 days before the diagnosis of HAP. Multivariate analysis showed that the use of antibiotics within the last 10 days before the diagnosis of HAP was the only independent predictor of infection with MDR bacteria (OR = 3.45; 95% CI: 1.56-7.61; p = 0.002).

CONCLUSIONS:

In this single-center study, the use of broad-spectrum antibiotics within the last 10 days before the diagnosis of HAP was the only independent predictor of infection with MDR bacteria in non-ventilated patients with HAP.

Respiratory medicine

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Upper respiratory infections are commonplace, especially in young people, and are often contagious

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Lower respiratory infections are often contagious and some are potentially fatal

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Asthma is common and may be life-threatening

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Chronic obstructive pulmonary disease is common and disabling

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Tuberculosis worldwide is an important infection, affecting people with HIV/AIDS or malnutrition particularly

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Lung cancer is common and usually has a poor prognosis

Partially-desulfated heparin improves survival in Pseudomonas pneumonia by enhancing bacterial clearance and ameliorating lung injury

Nosocomial pneumonia (NP, or hospital-acquired pneumonia) is associated with infections originating from hospital-borne pathogens. Persistent microbial presence and acute lung injury are common features of these infections, contributing to the high mortality rates and excessive financial burden for these patients. Pseudomonas aeruginosa (PA), a gram-negative opportunistic pathogen, is one of the prominent pathogens associated with NP. PA pneumonia is characterized by excessive secretion of inflammatory cytokines, neutrophil infiltration, and subsequent lung damage. The persistent presence of PA along with overwhelming inflammatory response is suggestive of impairment in innate immunity. High mobility group box 1 (HMGB1), a recently discovered potent pro-inflammatory cytokine, plays an important role in PA lung infections by compromising innate immunity via impairing phagocyte function through toll-like receptors (TLR) TLR2 and TLR4. ODSH (2-O, 3-O-desulfated heparin), a heparin derivative with significant anti-inflammatory properties but minimal anti-coagulatory effects, has been shown to reduce neutrophilic lung injury in the absence of active microbial infections. This study examined the effects of ODSH on PA pneumonia. This study demonstrates that ODSH not only reduced PA-induced lung injury, but also significantly increased bacterial clearance. The ameliorated lung injury, together with the increased bacterial clearance, resulted in marked improvement in the survival of these animals. The resulting attenuation in lung injury and improvement in bacterial clearance were associated with decreased levels of airway HMGB1. Furthermore, binding of HMGB1 to its receptors TLR2 and TLR4 was blunted in the presence of ODSH. These data suggest that ODSH provides a potential novel approach in the adjunctive treatment of PA pneumonia.

Systemic inflammatory responses and lung injury following hip fracture surgery increases susceptibility to infection in aged rats

Pulmonary infections frequently occur following hip fracture surgery in aged patients. However, the underlying reasons are not fully understood. The present study investigates the systemic inflammatory response and pulmonary conditions following hip fracture surgery as a means of identifying risk factors for lung infections using an aged rodent model. Aged, male Sprague-Dawley rats (8 animals per group) underwent a sham procedure or hip fracture plus femoral intramedullary pinning. Animals were sacrificed 1, 3, and 7 days after the injury. Markers of systemic inflammation and pulmonary injury were analyzed. Both sham-operated and injured/surgical group animals underwent intratracheal inoculation with Pseudomonas aeruginosa 1, 3, and 7 days after surgery. P. aeruginosa counts in blood and bronchoalveolar lavage (BAL) fluid and survival rates were recorded. Serum TNF-α, IL-6, IL-1β, and IL-10 levels and markers of pulmonary injury were significantly increased at 1 and 3 days following hip fracture and surgery. Animals challenged with P. aeruginosa at 1 and 3 days after injury had a significantly decreased survival rate and more P. aeruginosa recovered from blood and BAL fluid. This study shows that hip fracture and surgery in aged rats induced a systemic inflammatory response and lung injury associated with increased susceptibility to infection during the acute phase after injury and surgery.

Modest reduction in risk for ventilator-associated pneumonia in critically ill patients receiving mechanical ventilation following topical oral chlorhexidine

SUBJECTS

The sample (N = 547) included patients older than 18 years (328 men and 219 women from a total population of 10,913) admitted to 3 intensive care units (ICUs) (medical, surgical/trauma, and neuroscience) at Virginia Commonwealth University Medical Center. The sample size required to detect an interaction (ie, the effect of chlorhexidine and toothbrushing in combination) was determined to be larger than that required to detect main effects (ie, chlorhexidine alone or toothbrushing alone) for a test at a given level of significance. The study was designed to detect an interactive effect resulting in a 0.755 difference in mean Clinical Pulmonary Infection Score (CPIS) at a power of 80% and a significance level of .05. An interim analysis was done and a Bonferroni adjustment was used to avoid inflation in the overall significance level related to interim analyses; for this reason, the level of significance for final analysis was .025. This was a randomized controlled clinical trial with a 2 × 2 factorial design. Patients were randomized to treatment within each ICU according to a permuted block design developed by the biostatistician before the start of the study. Staff who performed interventions (oral care) had no knowledge of patients' CPIS. Patients receiving mechanical ventilation were enrolled within 24 hours of intubation and were followed for up to 14 days. Dates of recruitment were not disclosed.

KEY EXPOSURE/STUDY FACTOR

Lung infection, resulting from aspiration of potential bacterial pathogens, such as Staphylococcus aureus, Streptococcus pneumoniae, or gram-negative rods that first colonize the oral cavity and oropharynx. Oral topical 0.12 % chlorhexidine gluconate, toothbrushing, or both (applied 4 times per day) were tested to determine their impact, if any, on incidence of lung infection in this cohort.

MAIN OUTCOME MEASURE

The CPIS was assessed as the primary outcome variable. This score consists of the sum of points assigned to 6 clinical and laboratory variables (yielding a score from 0 to 12): temperature, white blood cell count, tracheal secretions, oxygenation (calculated as PaO2 divided by the fraction of inspired oxygen), findings on chest radiographs (no infiltrate, diffuse infiltrate, localized infiltrate), and results of culturing of tracheal aspirates (microscopic examination and semiquantitative culture of tracheal secretions). Analysis used in this study examined the effect of interventions on both the range of CPIS scores and on dichotomous categories of the presence (CPIS ≥6) or absence (CPIS <6) of VAP.

MAIN RESULTS

When data on all patients were analyzed together, mixed models analysis indicated no effect of either chlorhexidine (P = .29) or toothbrushing (P = .95); however, chlorhexidine significantly reduced the incidence of pneumonia on day 3 (CPIS ≥6) among patients who had a CPIS less than 6 at baseline (P = .006). Toothbrushing had no effect on CPIS and did not enhance the effect of chlorhexidine.

CONCLUSIONS

Chlorhexidine oral swabbing was effective in reducing early ventilator-associated pneumonia (VAP) (after 3 days of intervention) in patients in medical, surgical/trauma, and neuroscience ICUs who did not have evidence of lung infection at baseline. This effect was not observed after day 3. Toothbrushing did not reduce the incidence of VAP, and combining toothbrushing and chlorhexidine did not provide additional benefit over use of chlorhexidine alone.

TLR3 agonist improves survival to secondary pneumonia in a double injury model

BACKGROUND

Toll-like receptors (TLR) can initiate various immune responses and are therefore activated under diverse infectious states. Previous studies have focused on TLR3 primarily as an antiviral pathway. However, recent research has demonstrated its efficacy in bacterial infection. Having developed a murine double injury model of cecal ligation and puncture (CLP) followed by Pseudomonas aeruginosa (Pa), we hypothesized that targeted administration of Poly I:C, a TLR3 agonist, would protect mice against secondary pneumonia.

MATERIAL AND METHODS

B6 mice underwent CLP followed 4 d afterward by an intranasal dose of Pa. Animals were given Poly I:C or vehicle (phosphate-buffered saline) intranasally 24 h post CLP and every day thereafter for a total of 6 d. For acute studies, mice were sacrificed at two time points, 4 d post CLP and 1 d post pneumonia (Pa).

RESULTS

Poly I:C treatment led to a significant improvement in survival (69% versus 33%). Cytokine analysis from bronchioalveolar lavage displayed significant differences both immediately before and after pneumonia. Bronchioalveolar lavage cultures taken at 24 h post double injury showed significantly higher colony counts in the lungs of control animals compared with those of Poly I:C animals. Measurements of TLR3 expression showed significant increases within both the immune and lung epithelial cells of Poly I:C-treated mice. Finally, the lungs of treated animals had significant increases in lymphocytes and innate cells.

CONCLUSIONS

The prophylactic treatment applied in this clinically relevant model further illustrates the overarching hypothesis of immune dysfunction and the possibility of corrective immune modulation within the setting of sepsis.

Ventilator-associated pneumonia: a review

Ventilator-associated pneumonia (VAP) is the most common infection seen in intensive care units (ICUs); it accounts for one-fourth of the infections occurring in critically ill patients and is the reason for half of antibiotic prescriptions in mechanically ventilated patients. In addition to being a financial burden on ICUs, it continues to contribute significantly to the morbidity and mortality of ICU patients, with an estimated attributable mortality rate of 8% to 15%. While the pathophysiology of VAP remains relatively unchanged, diagnostic techniques and preventive measures are constantly evolving. The focus of this article is on recent trends in VAP epidemiology, modifiable risk factors, diagnostic techniques, challenges in management, and current data on the prevention of VAP. Important messages that the reader should take away include: 1) There is no gold standard for the diagnosis of VAP; whenever VAP is suspected, if feasible, a quantitative culture should be obtained by invasive or noninvasive methods (whichever is more readily available before initiation of antibiotics); 2) Suspicion based on clinical features should prompt the initiation of a broad spectrum of antibiotics depending on suspected pathogens; 3) Close attention should be paid to de-escalation of antibiotics once microbiological results become available or as the patient starts responding clinically; the ideal duration of treatment should be 8 days instead of the conventional 10 to 14 days, except in situations where Pseudomonas may be suspected or the patient's comorbidities dictate otherwise; and 4) Prevention remains the key to reducing the burden of VAP. We promote the proven preventive measures of using noninvasive ventilation when possible, semirecumbent patient positioning, continuous aspiration of subglottic secretions, and oral chlorhexidine washes along with stress ulcer prophylaxis only after careful assessment of the risks versus benefits.

Oxygen therapy for pneumonia in adults

BACKGROUND

Oxygen therapy is widely used in the treatment of lung diseases. However, the effectiveness of oxygen therapy as a treatment for pneumonia is not well known.

OBJECTIVES

To determine the effectiveness and safety of oxygen therapy in the treatment of pneumonia in adults older than 18 years.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) 2011, Issue 4, part of The Cochrane Library, www.thecochranelibrary.com (accessed 9 December 2011), which includes the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE (1948 to November week 3, 2011) and EMBASE (1974 to December 2011).

SELECTION CRITERIA

Randomised controlled trials (RCTs) of oxygen therapy for adults with community-acquired pneumonia (CAP) and nosocomial (hospital-acquired) pneumonia (HAP or NP) in intensive care units (ICU).

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed abstracts and assessed data for methodological quality.

MAIN RESULTS

Three RCTs met our inclusion criteria. The studies enrolled 151 participants with CAP or immunosuppressed patients with pulmonary infiltrates. Overall, we found that non-invasive ventilation can reduce the risk of death in the ICU, odd ratio (OR) 0.28, 95% confidence interval (CI) 0.09 to 0.88; endotracheal intubation, OR 0.26, 95% CI 0.11 to 0.61; complications, OR 0.23, 95% CI 0.08 to 0.70; and shorten ICU length of stay, mean duration (MD) -3.28, 95% CI -5.41 to -1.61.Non-invasive ventilation and standard oxygen supplementation via a Venturi mask were similar when measuring mortality in hospital, OR 0.54, 95% CI 0.11 to 2.68; two-month survival, OR 1.67, 95% CI 0.53 to 5.28; duration of hospital stay, MD -1.00, 95% CI -2.05 to 0.05; and duration of mechanical ventilation, standard MD -0.26, 95% CI -0.66 to 0.14. Some outcomes and complications of non-invasive ventilation were varied according to different participant populations. We also found that some subgroups had a high level of heterogeneity when conducting pooled analyses.

AUTHORS' CONCLUSIONS

Non-invasive ventilation can reduce the risk of death in the ICU, endotracheal intubation, shorten ICU stay and length of intubation. Some outcomes and complications of non-invasive ventilation were varied according to different participant populations. Other than the oxygen therapy, we must mention the importance of standard treatment by physicians. The evidence is weak and we did not include participants with pulmonary tuberculosis and cystic fibrosis. More RCTs are required to answer these clinical questions. However, the review indicates that non-invasive ventilation may be more beneficial than standard oxygen supplementation via a Venturi mask for pneumonia.

[Risk factors of nosocomial pneumonia caused by methicillin-resistant Staphylococcus aureus]

BACKGROUND AND OBJECTIVE

To include a specific antibiotic in the empiric therapy, it is necessary to predict when a nosocomial pneumonia (NP) is caused by methicillin-resistant Staphylococcus aureus (MRSA). We have developed a model for the prediction of the probability of a NP being caused by MRSA, when the carrier status and the microbiological diagnosis are unknown.

PATIENTS AND METHODS

A retrospective case-control study (1999-2005) was designed. A univariate and multivariate logistic regression was performed to identify the risk factors for suffering a NP due to MRSA. Demographic factors, related to hospitalization, immunosuppression or neutropenia, to medication and severity were included.

RESULTS

Three hundred and sixty three patients (121 cases and 242 controls) were studied. The final model of multivariate logistic regression included an age>14 years (OR 7.4, CI 95% 1.5-37.4, P<.015), NP appearance>6 days after admittance (OR 4.1, CI 95% 2.4-7,1, P<.001), NP development excluding summers (OR 2.5, CI 95% 1.2-5.2, P<.015), respiratory diseases (OR 4.9, CI 95% 1.5-15.8, P<.007) and multilobar involvement (OR 4, CI 95% 2.3-7.2, P<.001).The probability of developing a pneumonia due to MRSA was studied for each of the possible combinations and subsequently classified in minor and major criteria.

CONCLUSIONS

MRSA coverage should be included in the empirical treatment of NP when: a) an adult patient (>14 years old) presents, at least, 2 major criteria or 1 major criterion together with 2 minor criteria, and b) a patient <14 years-old has 2 major criteria as well as 2 minor criteria.

Guideline-adherent initial intravenous antibiotic therapy for hospital-acquired/ventilator-associated pneumonia is clinically superior, saves lives and is cheaper than non guideline adherent therapy

INTRODUCTION

Hospital-acquired pneumonia (HAP) often occurring as ventilator-associated pneumonia (VAP) is the most frequent hospital infection in intensive care units (ICU). Early adequate antimicrobial therapy is an essential determinant of clinical outcome. Organisations like the German PEG or ATS/ IDSA provide guidelines for the initial calculated treatment in the absence of pathogen identification. We conducted a retrospective chart review for patients with HAP/VAP and assessed whether the initial intravenous antibiotic therapy (IIAT) was adequate according to the PEG guidelines.

MATERIALS AND METHODS

We collected data from 5 tertiary care hospitals. Electronic data filtering identified 895 patients with potential HAP/VAP. After chart review we finally identified 221 patients meeting the definition of HAP/VAP. Primary study endpoints were clinical improvement, survival and length of stay. Secondary endpoints included duration of mechanical ventilation, total costs, costs incurred on the intensive care unit (ICU), costs incurred on general wards and drug costs.

RESULTS

We found that 107 patients received adequate initial intravenous antibiotic therapy (IIAT) vs. 114 with inadequate IIAT according to the PEG guidelines. Baseline characteristics of both groups revealed no significant differences and good comparability. Clinical improvement was 64% over all patients and 82% (85/104) in the subpopulation with adequate IIAT while only 47% (48/103) inadequately treated patients improved (p< 0.001). The odds ratio of therapeutic success with GA versus NGA treatment was 5.821 (p<0.001, [95% CI: 2.712-12.497]). Survival was 80% for the total population (n = 221), 86% in the adequately treated (92/107) and 74% in the inadequately treated subpopulation (84/114) (p = 0.021). The odds ratio of mortality for GA vs. NGA treatment was 0.565 (p=0.117, [95% CI: 0.276-1.155]). Adequately treated patients had a significantly shorter length of stay (LOS) (23.9 vs. 28.3 days; p = 0.022), require significantly less hours of mechanical ventilation (175 vs. 274; p = 0.001), incurred lower total costs (EUR 28,033 vs. EUR 36,139, p = 0.006) and lower ICU-related costs (EUR 13,308 vs. EUR 18,666, p = 0.003). Drug costs for the hospital stay were also lower (EUR 4,069 vs. EUR 4,833) yet not significant. The most frequent types of inadequate therapy were monotherapy instead of combination therapy, wrong type of penicillin and wrong type of cephalosporin.

DISCUSSION

These findings are consistent with those from other studies analyzing the impact of guideline adherence on survival rates, clinical success, LOS and costs. However, inadequately treated patients had a higher complicated pathogen risk score (CPRS) compared to those who received adequate therapy. This shows that therapy based on local experiences may be sufficient for patients with low CPRS but inadequate for those with high CPRS. Linear regression models showed that single items of the CPRS like extrapulmonary organ failure or late onset had no significant influence on the results.

CONCLUSION

Guideline-adherent initial intravenous antibiotic therapy is clinically superior, saves lives and is less expensive than non guideline adherent therapy. Using a CPRS score can be a useful tool to determine the right choice of initial intravenous antibiotic therapy. The net effect on the German healthcare system per year is estimated at up to 2,042 lives and EUR 125,819,000 saved if guideline-adherent initial therapy for HAP/VAP were established in all German ICUs.

Ventilator-associated pneumonia: the importance of oral care in intubated adults

Ventilator-associated pneumonia (VAP) occurs within 24 hours of intubation and mechanical ventilation. Health care costs related to increased patient mortality, extended length of stay, and patient well-being make treatment of VAP a priority in all health care settings. The Institute for Healthcare Improvements has developed the Ventilator Bundle as a group of interventions linked to ventilator care with demonstrated outcome improvements; removal of subglottic secretions is one of these recommendations. Dental plaque and bacterial colonization of pathogens is directly related to microaspiration of bacteria into the lungs. A moist environment in the mouth maintains normal oropharyngeal bacteria, preventing overgrowth of pathogenic bacteria. Frequent oral care to include twice-a-day brushing of the teeth found a 69% reduction in respiratory tract infections.

The relationship between hospital size and ICU type on select adverse patient outcomes

The authors examined the relationships among hospital size and unit type, the prevalence of pressure ulcers, and rates of ventilator-associated pneumonia and catheter-related bloodstream infections in 25 intensive care units (ICUs) in 8 hospitals. Data came from the American Hospital Association survey, and nursing and infection control databases. Multiple regression was the main statistical technique. Pressure ulcer prevalence and catheter-related bloodstream infection rates were higher in large hospitals; ventilator-associated pneumonia rates were higher in surgical ICUs. Future researchers should include factors often hidden within hospital and unit characteristics to expose possible relationships that may be incorporated into interventions to prevent adverse outcomes.

"Does periodontal therapy reduce the risk for systemic diseases?"

Periodontal disease is treated by various approaches, including simple oral hygiene practices, professional mechanical debridement, antimicrobial therapy and periodontal surgery. There is evidence to associate periodontal disease with several systemic diseases and conditions, including myocardial infarction, adverse pregnancy outcomes, diabetes mellitus, and respiratory disease. This article reviews the published literature that describes the effects of periodontal treatment on cardiovascular diseases, adverse pregnancy outcomes, diabetes mellitus, and respiratory disease. While some progress has been made, further research is required to understand the value of periodontal interventions in the prevention of systemic diseases.

Characterization and modulation of the immunosuppressive phase of sepsis

Sepsis continues to cause significant morbidity and mortality in critically ill patients. Studies of patients and animal models have revealed that changes in the immune response during sepsis play a decisive role in the outcome. Using a clinically relevant two-hit model of sepsis, i.e., cecal ligation and puncture (CLP) followed by the induction of Pseudomonas aeruginosa pneumonia, we characterized the host immune response. Second, AS101 [ammonium trichloro(dioxoethylene-o,o')tellurate], a compound that blocks interleukin 10 (IL-10), a key mediator of immunosuppression in sepsis, was tested for its ability to reverse immunoparalysis and improve survival. Mice subjected to pneumonia following CLP had different survival rates depending upon the timing of the secondary injury. Animals challenged with P. aeruginosa at 4 days post-CLP had approximately 40% survival, whereas animals challenged at 7 days had 85% survival. This improvement in survival was associated with decreased lymphocyte apoptosis, restoration of innate cell populations, increased proinflammatory cytokines, and restoration of gamma interferon (IFN-gamma) production by stimulated splenocytes. These animals also showed significantly less P. aeruginosa growth from blood and bronchoalveolar lavage fluid. Importantly, AS101 improved survival after secondary injury 4 days following CLP. This increased survival was associated with many of the same findings observed in the 7-day group, i.e., restoration of IFN-gamma production, increased proinflammatory cytokines, and decreased bacterial growth. Collectively, these studies demonstrate that immunosuppression following initial septic insult increases susceptibility to secondary infection. However, by 7 days post-CLP, the host's immune system has recovered sufficiently to mount an effective immune response. Modulation of the immunosuppressive phase of sepsis may aid in the development of new therapeutic strategies.

Inhaled therapeutics for prevention and treatment of pneumonia

The lungs are the most common site of serious infection owing to their large surface area exposed to the external environment and minimum barrier defense. However, this architecture makes the lungs readily available for topical therapy. Therapeutic aerosols include those directed towards improving mucociliary clearance of pathogens, stimulation of innate resistance to microbial infection, cytokine stimulation of immune function and delivery of antibiotics. In our opinion inhaled antimicrobials are underused, especially in patients with difficult-to-treat lung infections. The use of inhaled antimicrobial therapy has become an important part of the treatment of airway infection with Pseudomonas aeruginosa in cystic fibrosis and the prevention of invasive fungal infection in patients undergoing heart and lung transplantation. Cytokine inhaled therapy has also been explored in the treatment of neoplastic and infectious disease. The choice of pulmonary drug delivery systems remains critical as air-jet and ultrasonic nebulizer may deliver sub-optimum drug concentration if not used properly. In future development of this field, we recommend an emphasis on the study of the use of aerosolized hypertonic saline solution to reduce pathogen burden in the airways of subjects infected with microbes of low virulence, stimulation of innate resistance to prevent pneumonia in immunocompromised subjects using cytokines or synthetic pathogen-associated molecular pattern analogues and more opportunities for the use of inhaled antimicrobials. These therapeutics are still in their infancy but show great promise.