Aspiration Pneumonia

Risk Factors for Home Care Discontinuation Among Older People With Dysphagia: A Two-Year Retrospective Cohort Study

BACKGROUND

Receiving home care improves the quality of life of older adults. Nonetheless, limited studies have examined factors influencing pneumonia onset and home care discontinuation in older adults living at home.

OBJECTIVE

To clarify the factors associated with home care discontinuation in older adults receiving home care for dysphagia and to identify risk factors for home care discontinuation.

METHODS

This study included 162 adults (≥ 65 years) with dysphagia who were receiving home care. Nutritional status, history of pneumonia, swallowing function, activities of daily living, and comorbidities were assessed. The study participants were followed up for 2 years. Factors associated with home care discontinuation (death and hospitalisation) were analysed using the Kaplan-Meier method and Cox proportional hazards model.

RESULTS

During the 2-year follow-up, 110 (67.9%) participants discontinued home care (35 due to pneumonia, 75 due to other causes). Severe dysphagia was the strongest risk factor for pneumonia-induced discontinuation (HR = 3.25, 95% CI: 1.35-7.83). Malnutrition (HR = 2.32, 95% CI: 0.93-5.76) and pneumonia history (HR = 2.00, 95% CI: 1.00-4.35) elevated pneumonia-related risk. Severe dysphagia (HR = 1.52, 95% CI: 0.65-3.55) and malnutrition (HR = 1.58, 95% CI: 0.95-2.64) were potential risk factors for non-pneumonia-induced discontinuation.

CONCLUSION

In older adults receiving home care, severe dysphagia was a major risk factor for home care discontinuation, with malnutrition and a history of pneumonia suggested as potential contributing factors. These findings indicate that improving nutritional status, maintaining and enhancing swallowing function and providing appropriate management for individuals with a history of pneumonia are crucial for ensuring continuous home care.

1, 8-Cineole Ameliorated Staphylococcus aureus-Induced Pneumonia through Modulation of TRP-KYN and Arginine-NO Reprogramming

1, 8-Cineole (Cin), a cyclic monoterpenoid derived from tea trees and eucalyptus species, exhibits diverse pharmacological properties. Yet, its therapeutic impact and underlying mechanism against Staphylococcus aureus (S. aureus) pneumonia remain to be elucidated. In this study, metabolomics based on UPLC-MS/MS was integrated with network pharmacology, molecular biology, and molecular docking to investigate the effects of Cin. The findings demonstrated that Cin markedly reduced mortality and lung bacterial load, lessened pulmonary damage while suppressing the levels of proinflammatory factors, including tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) in the bronchoalveolar lavage fluid (BALF) of infected mice. Additionally, 19 metabolites, primarily involved in tryptophan metabolism and arginine biosynthesis, were notably modified by Cin via suppressing the enzymatic activity of indoleamine 2, 3-dioxygenase 1 (IDO1) and inducible nitric oxide synthase (iNOS), thereby attenuating the inflammatory response. Notably, knockdown of IDO1 or iNOS significantly diminished the anti-inflammation effect of Cin. In conclusion, our study validates the therapeutic potential of Cin against S. aureus pneumonia via anti-inflammation by downregulating IDO1 and iNOS. Our results provide a theoretical basis of natural substances applied in bacterial pneumonia treatment.

Geriatric-Specific Considerations in the Care of Older Adults with Pulmonary/Respiratory Diseases

Older adult patients (age ≥ 65 years) frequently present to the emergency department with dyspnea, and the most common cause is pulmonary disease. Clinical presentation, examination findings, and existing diagnostic tests can be affected by the pathophysiological changes associated with aging and other comorbidities. As a result, to provide the highest quality care to older adult patients with pulmonary disease, physicians should understand these changes and their implications.

Comprehensive management of pneumonia in older patients

Pneumonia is a leading cause of death and functional decline in the older population. Diagnosis of pneumonia conventionally includes the presence of respiratory signs and symptoms, systemic signs of infection and a radiographic demonstration of lung involvement. Pneumonia diagnosis in the very old patient is compromised by atypical and unspecific presentation, resulting in a high proportion of false positive diagnosis. Chest radiograph is frequently of low quality and inconclusive in older patients. Computed tomography scan and chest ultrasound may provide valuable diagnostic confirmation in uncertain cases. Bacterial pneumonia has been mainly studied, but viruses, among which influenza, SARS-CoV-2, and respiratory syncytial virus, are increasingly recognized as major players. The decision to treat pneumonia is usually based on a triple assessment of diagnostic probability, disease severity and the general assessment of the patient (frailty, comorbidities, place of living, and goals of care). Antimicrobial treatment is probabilistic, targeting common pathogens. The optimal antibiotic treatment depends on epidemiological data, setting of acquisition, comorbidities, risk factors for methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, or aspiration pneumonia, and severity. Recent controlled trials have demonstrated the non-inferiority of short regimen in non-severe community acquired pneumonia, even in older individuals and a five-day antibiotic treatment is recommended in case of clinical improvement. Pneumonia management in older patients requires a comprehensive approach, including control of comorbidities (particularly cardiovascular), nutritional support, rehabilitation, and prevention of aspiration. Finally, pneumonia may be a pre-terminal event in many patients, requiring advanced-care planning and prompt instauration of palliative management.

Age-defying swallowing

Swallowing disorders, which are generally underdiagnosed, affect the elderly, leading to a decreased quality of life and complications, including aspiration pneumonia and death. Understanding the neurophysiology of swallowing and the causes of its dysfunction is a fundamental tool for the prevention, early diagnosis, and treatment of dysphagia. New technologies open a wide range of possibilities for the implementation of new care protocols for this disorder.

Antibiotics at life's end: key role in treating end-of-life pneumonia?

INTRODUCTION

Pneumonia is a common occurrence at the end of life (EOL). However, clear definitions and consensual guidelines for managing this condition are lacking. Diagnosing EOL pneumonia and deciding whether to treat it with antibiotics can be challenging.

AREA COVERED

This special report provides a narrative review of epidemiological data, diagnostic tools for EOL pneumonia, guidance on antibiotic use, and ethical considerations in this context. Literature from 2000 to 2024 was analyzed using PubMed and Cochrane databases.

EXPERT OPINION

At the EOL, respiratory symptoms must be managed to improve patients' quality of life. Bacterial pneumonia can be difficult to diagnose, and the benefits of antibiotics on respiratory symptoms remain uncertain. At an individual level, adverse events may impact EOL quality, while at a population level, overprescribing antibiotics contributes to antimicrobial resistance. A multidisciplinary approach is therefore essential. Treatment goals should be established with the patient or their healthcare representative. If antibiotics are prescribed, they should be initiated for a limited duration with daily reassessments. If the set goals are not achieved or if adverse events occur, antibiotics should be discontinued. Palliative care measures should also be introduced as early as possible.

Atomic Artificial Enzyme for Acute and Chronic Pneumonia

Pneumonia involves complex immunological and pathological processes leading to pulmonary dysfunction, which can be life-threatening yet lacks effective specialized medications. Natural enzymes can be used as biological agents for the treatment of oxidative stress-related diseases, but limiting to catalytic and environmental stability as well as high cost. Herein, an artificial enzyme, gold nanoclusters (Au NCs) with excellent stability, bioactivity, and renal clearance can be used as the next-generation biological agents for acute lung injury (ALI) and allergic lung disease (ALD). The Au25 clusters can mimic catalase (CAT) and glutathione peroxidase (GPx), and the Km of Au24Er1 with H2O2 reaches 1.28 mM, about 22 times higher than natural CAT (≈28.8 mM). The clusters inhibit the oxidative stress in the mitochondria and promote the synthesis of adenosine triphosphate (ATP). The molecular mechanism shows that the TLR4/MyD88/NF-κB pathway and M1 macrophage-mediated inflammatory response are suppressed in ALI and the Th1/Th2 imbalance in ovalbumin (OVA)-induced ALD is rescued. Further, the clusters can notably improve lung function in both ALI and ALD models which paves the way for immunomodulation and intervention for lung injury and can be used as a substitute for natural enzymes and potential biopharmaceuticals in the treatment of various types of pneumonia.

Pathway analysis of the impact of dysphagia on the prognosis of patients with stroke: Based on structural equation modeling

BACKGROUND AND AIMS

Dysphagia is significantly correlated with prognostic outcomes in patients with stroke; however, the intrinsic mechanism of action between the two remains unclear. This study aimed to model the intrinsic mechanism of action between dysphagia and prognostic outcomes in patients with stroke based on structural equation modeling.

METHODS

A retrospective analysis of 900 inpatients with stroke from three large hospitals was performed. AMOS software (version 23.0) was used to construct the structural equation modeling.

RESULTS

The overall model showed a good fit (chi-square = 27.3, root mean square error of approximation = 0.01, standardized root mean square residual = 0.032, comparative fit index = 0.98, and adjusted goodness of fit = 0.94). Structural equation modeling showed that the total effect of dysphagia on the prognosis of patients with stroke was 0.694, with a direct effect of 0.599, accounting for 86.31 % of the total effect. The total indirect effect was 0.095, with the mediating effects of serum albumin level and pneumonia accounting for 6.48 % and 7.35 % of the total effect, respectively. The moderating effects of sex on dysphagia and the relationship between activities of daily living, modified Rankin scale score, and length of hospital stay were insignificant (ΔR2 = 0.063, P = 0.145; ΔR2 = 0.002, P = 0.620; ΔR2 = 0.001, P = 0.307).

CONCLUSIONS

Dysphagia can directly affect the prognostic outcomes of patients with stroke and indirectly affect prognosis by triggering pneumonia and lowering albumin levels. Sex was not found to play a moderating role in the relationship between dysphagia and prognosis.

Glucagon-Like Peptide-1 Receptor Agonists Do Not Increase Aspiration During Upper Endoscopy in Patients With Diabetes

BACKGROUND & AIMS

Glucagon-like peptide-1-receptor agonists (GLP1-RAs) have been associated with greater retention of gastric contents, however, there is minimal controlled, population-based data evaluating the potential adverse effects of GLP1-RA in the periprocedural setting. We aimed to determine if there is increased risk of aspiration and aspiration-related complications after upper endoscopy in patients using GLP1-RAs.

METHODS

We used a nationwide commercial administrative claims database to conduct a retrospective cohort study of patients aged 18 to 64 with type 2 diabetes who underwent outpatient upper endoscopy from 2005 to 2021. We identified 6,806,046 unique upper endoscopy procedures. We compared claims for aspiration and associated pulmonary adverse events in the 14 days after upper endoscopy between users of GLP1-RAs, dipeptidyl peptidase 4 inhibitors (DPP4is), and chronic opioids. We adjusted for age, sex, Charlson Comorbidity score, underlying respiratory disease, and gastroparesis.

RESULTS

We found that pulmonary adverse events after upper endoscopy are rare, ranging from 6 to 25 events per 10,000 procedures. When comparing GLP1-RAs with DPP4i, crude relative risks of aspiration (0.67; 95% CI, 0.25-1.75), aspiration pneumonia (0.95; 95% CI, 0.40-2.29), pneumonia (1.07; 95% CI, 0.62-1.86), or respiratory failure (0.75; 95% CI, 0.38-1.48) were not higher in patients prescribed a GLP1-RA. When comparing GLP1-RAs with opioids, crude relative risks were 0.42 (95% CI, 0.15-1.16) for aspiration, 0.60 (95% CI, 0.24-1.52) for aspiration pneumonia, 0.30 (95% CI, 0.19-0.49) for pneumonia, and 0.24 (95% CI, 0.13-0.45) for respiratory failure. These results were consistent across several sensitivity analyses.

CONCLUSIONS

GLP1-RA use is not associated with an increased risk of pulmonary complications after upper endoscopy compared with DPP4i use in patients with type 2 diabetes.

Ionizable lipid nanoparticles enhance lung delivery of gold nanoclusters for improving acute lung injury alleviation

Acute lung injury (ALI) is one of the most common and highly prevailing respiratory system diseases. However, there is still a lack of effective specialized medicines for the treatment of ALI. Biocompatible gold nanoclusters (AuNCs) have shown great potential in alleviating ALI, but their lung-targeted delivery needs to be enhanced. In recent years, lipid nanoparticles (LNPs) have become the most promising delivery system for clinical application and achieved great success in mRNA vaccines during the COVID-19 pandemic. Herein, we constructed a lung-delivery formulation of AuNCs by encapsulating glutathione-coated gold nanoclusters (GA) in lung-delivery ionizable lipid nanoparticles (iLNPs) and termed it as GA@iLNP. Results indicated that GA@iLNP can promote the cellular uptake of GA and enhance the anti-inflammation efficiency in stimulated macrophages in vitro. In addition, iLNP encapsulation significantly increased the lung accumulation of GA in lipopolysaccharide (LPS)-induced ALI mice after intravenous injection and enhanced the alleviations of inflammation and tissue damage in the lungs. These results suggest that organ-selective iLNPs may be an ideal targeted delivery system for AuNCs, providing a powerful tool for translational applications of bioactive AuNCs.

Establishment of rat model for aspiration pneumonia and potential mechanisms

BACKGROUND

Aspiration pneumonia is a severe health concern, particularly for ICU patients with impaired airway defenses. Current animal models fail to fully replicate the condition, focusing solely on chemical lung injury from gastric acid while neglecting pathogen-induced inflammation. This gap hinders research on pathogenesis and treatment, creating an urgent need for a clinically relevant model. This study aimed to develop an improved rat model of aspiration pneumonia by combining hydrochloric acid (HCl) and lipopolysaccharide (LPS) administration.

METHODS

Specific pathogen-free Sprague Dawley rats underwent intratracheal instillation of HCl and LPS. Techniques included rat weight measurement, tracheal intubation, pulmonary function monitoring, lung tissue sampling with HE staining and scoring, bronchoalveolar lavage fluid (BALF) sampling, protein and inflammatory cytokine analysis via BCA and ELISA, BALF pH determination, Evans Blue dye assessment, blood gas analysis, FITC-dextran leakage, Western blotting, electron microscopy, survival analysis, and transcriptome sequencing with bioinformatics. Statistical analysis was performed using GraphPad Prism.

RESULTS

The optimal model involved instillation of 1.5 μL/g.wt HCl (pH = 1) followed by 20 μg/g.wt LPS after 1 h. This model reproduced acute lung injury, including tissue damage, pulmonary microvascular dysfunction, inflammatory responses, hypoxemia, and impaired pulmonary ventilation, with recovery observed at 72 h. PANoptosis was confirmed, characterized by increased markers. Concentration-dependent effects of HCl and LPS on lung damage were identified, alongside cytokine elevation and microvascular dysfunction.

CONCLUSIONS

This optimized model closely mimics clinical aspiration pneumonia, providing a valuable tool for studying pathophysiology and therapeutic strategies.

The efficacy of polymyxin B in treating stroke-associated pneumonia with carbapenem-resistant Gram-negative bacteria infections: a multicenter real-world study using propensity score matching

Objectives

Infection with Carbapenem-resistant Gram-negative bacteria (CR-GNB) poses further challenges in treating stroke-associated pneumonia (SAP) patients. This multicenter retrospective study aimed to evaluate the efficacy of polymyxin B (PMB) in CR-GNB-infected SAP patients and to identify factors that may influence its effectiveness.

Methods

From 1 September 2019, and 30 December 2022, a total of 196 CR-GNB-infected SAP patients from five hospitals in China were included in the study based on specific criteria. Demographics and clinical data were obtained from the electronic medical records. Propensity score matching (PSM) was used to minimize the effect of potential confounding variables. Univariate analysis and multivariate logistic analysis were performed to identify risk factors affecting microbial efficacy.

Results

Among the 196 SAP patients infected with CR-GNB, 24.5% received PMB combined inhalation and 75.5% received non-combined inhalation treatment. The clinical success rate was 68.9%, with 25.5% achieving microbial efficacy within 7 days and 37.8% achieving microbial cure. The 30-day all-cause mortality rate was 14.8%. The incidence of acute kidney injury was 34.7%. After adjustment by propensity score matching, the PMB combined inhalation group exhibited significantly higher microbial efficacy compared to the non-combined inhalation group (46.7% vs. 26.7%, p = 0.049). Multivariate logistic analysis identified multi-site infections and Carbapenem-resistant Pseudomonas aeruginosa infection as independent risk factors for microbial efficacy.

Conclusion

Combined inhalation of PMB demonstrated superior effectiveness in microbial clearance compared to non-combined inhalation in treating CR-GNB-infected SAP patients. We recommend aerosol combined inhalation of PMB and suggest developing personalized PMB-based regimens for individual patients to enhance treatment outcomes.

Predictors of Pneumonia in Patients With Penetration-Aspirations Detected on Fiberoptic Endoscopic Evaluation of Swallowing

Aspiration pneumonia is a serious condition resulting from swallowing dysfunction. However, predicting high risk patients remains challenging. This study aimed to assess the incidence and risk factors for pneumonia in oropharyngeal dysphagia patients exhibiting episodes of penetration or aspiration during fiberoptic endoscopic swallowing evaluation (FEES). A retrospective analysis was performed on patients who visited a dysphagia clinic between 2016 and 2022, and demonstrated at least one episode of penetration or aspiration during the FEES (Penetration Aspiration Scale [PAS] score ≥ 3). Data collected included demographics, comorbidities and FEES findings. Outcomes included mortality, hospital admissions to treat pneumonia events, and incidents of pneumonia managed by primary care providers or outpatient medical facilities. Statistical analyses included descriptive statistics, chi-squared tests, t-tests, logistic regression and Kaplan-Meier survival analysis. Among 73 patients (mean follow-up: 3.87 ± 1.5 years), 33 (45.2%) exhibited penetration, and 40 (54.8%) aspiration. Pneumonia developed in 41 patients (56%), with 33 (45%) hospitalized. A total of 28 patients (38.4%) died during follow-up. A history of prior pneumonia (OR: 1.374, p = 0.02) and Murray Secretion Scale score (OR: 1.121, p = 0.022) were associated with subsequent pneumonia events. Reduced laryngeal sensation showed a near-significant trend toward association with pneumonia-related hospitalizations in the penetration group (58.3% vs. 19%, P = 0.052). No significant association was found between PAS and pneumonia or mortality. Prior pneumonia and secretions accumulation during FEES significantly predict pneumonia in patients presenting with penetration-aspiration during FEES. Reduced laryngeal sensation showed a nearly-significant trend toward pneumonia-related hospitalizations.

Nutrition in the critically ill in resource-limited settings/low- and middle-income countries

PURPOSE OF REVIEW

To share current concepts and provide an overview of the contextual issues and nutrition practices in critically ill patients in resource-limited settings (RLSs)/low- and middle-income countries (LMICs). Most of the world's population reside in these settings which also carries the greatest burden of critical illness.

RECENT FINDINGS

There is a paucity of evidence on nutrition practice in critically ill patients in RLSs and international guidelines are largely based on evidence derived from high-income countries (HICs). While some recommendations are adaptable to RLSs, many are not feasible or directly transferable. Despite the challenges that may prevail, pragmatic solutions can address many of the difficulties to enhance nutrition practice and improve patient outcomes.

SUMMARY

This review provides a contemporary synopsis of nutrition practice in critically ill patients in RLSs covering the relevance of optimal nutrition, gives insights into relevant contextual issues and challenges in RLSs, evaluates recent scientific evidence and available literature pertinent to critically ill patients in RLSs, addresses nutrition guidelines, discusses some pragmatic options and solutions, deals with relevant and important complications that may arise, and offers suggestions and future considerations to enhance nutrition practice in critically ill patients in these settings.

Advantages of short-term antimicrobial treatment for pneumonia and aspiration pneumonia in older patients aged over 65: A nationwide inpatient database study

The duration of antimicrobial therapy required to treat community-acquired pneumonia is often longer than expected, likely because of the high number of such inpatients in developed countries with aging populations. In this study, we evaluated the effects of short-term treatments for both pneumonia and aspiration pneumonia in older Japanese adults using the nation's inpatient database. Inpatients aged ≥ 65 years who were admitted to the hospital for pneumonia or aspiration pneumonia between April 1, 2018, and October 31, 2018, were included. We compared patients treated via intravenous antibiotics for 3-7 days to control patients treated with a similar regimen for 8-28 days, using inverse probability of treatment-weighted Cox regression. The primary outcome was relapse or readmission for pneumonia and death within 30 days after completing antimicrobial therapy. The secondary outcomes were average treatment effect for Clostridioides difficile infection (CDI), chest drainage, and length of hospital stay. The total number of eligible patients was 72,294. The hazard ratio for the primary outcome was 1.04 (95% confidence interval: 0.99-1.10). The mean length of hospital stay was shortened to 9.74 days (range, 9.34-10.1) in the short-term treatment group. The prevalence rates of CDI and chest drainage did not differ significantly between the short- and long-term treatment groups. We observed no statistically significant difference in clinical outcomes between the older adults with pneumonia including aspiration pneumonia who received short- vs long-term antimicrobial therapy.

Improving effective antimicrobial resistance (AMR) prevention in ambulatory care: lessons from secondary appraisal of Belgian anti-infectious treatment care guidelines

The emergence of antimicrobial resistance (AMR) has been designated as a global threat by the World Health Organization. To combat AMR in Belgium, the Belgian Antibiotic Policy Coordination Committee (BAPCOC) has, among others, developed guidelines for the appropriate use of antimicrobials in the ambulatory practice. We aim to assess the current guidelines from an antimicrobial stewardship perspective and procide suggestions for improving the ambulatory antibiotic guidelines for first-line healthcare providers. The 2022 BAPCOC guidelines were independently evaluated by 7 antimicrobial stewardship experts based on the five "Ds" of antimicrobial stewardship. The results were aggregated, summarized, and consensus was sought. Recommendations improving the guidelines were formulated. A total of 52 recommendations were made, covering 16 different (sub)chapters. The most frequently covered topics were urinary tract infections, followed by skin and soft tissue infections. Among the top five recommendations deemed to have the greatest impact on antimicrobial stewardship outcomes, three were related to the diagnosis or treatment duration of urinary tract infections. Tailoring infectious disease and antibiotic treatment guidelines to antimicrobial stewardship principles and the latest literature is essential in combating antimicrobial resistance. Implementing our proposed recommendations in the Belgian ambulatory treatment guidelines could significantly enhance rational and judicious antibiotic use while minimizing the risk of 'antibiotic undertreatment. The proposed 'Choosing Wisely' recommendations have the potential to be applied to a broader (European) context.

Exploring the role of respiratory virus infections in aspiration pneumonia: a comprehensive analysis of cases with lower respiratory tract infections

BACKGROUND

While respiratory virus infection has been implicated in the onset of bacterial pneumonia, no research has investigated the association of respiratory viruses with the onset of aspiration pneumonia (AP). This study aimed to investigate the role of respiratory virus infections in AP.

METHODS

Patients presenting with acute respiratory symptoms and undergoing influenza antigen testing at the emergency department of Okinawa Chubu Hospital from February 2020 to January 2021, and diagnosed with lower respiratory tract infections, were included. Cases were categorized into AP, pneumonia other than AP (non-AP), and acute bronchitis (AB) based on physician diagnoses recorded in medical records. The residual nasal swab specimens were further tested with multiplex PCR tests for respiratory viruses.

RESULTS

A total of 209 subjects were included in the study: 59 in the AP group, 118 in the non-AP group, and 32 in the AB group. The AP group was characterized by older age, higher rates of nursing home residency, a greater prevalence of comorbidities such as cerebrovascular disease and dementia, a lower sputum culture positivity rate, and a different spectrum of causative pathogens compared to the other groups. The virus positivity rate in the AP group was 47%, compared to 50% in the non-AP group and 53% in the AB group, with no significant difference observed. The AP group exhibited the highest rate of only respiratory viruses detected and the lowest rate of both respiratory viruses and bacteria detected among the groups. There was no significant difference in the types of viruses detected between the AP group and the other groups, with rhinovirus being the most frequently detected virus across all groups. In the AP group, virus-negative cases were significantly older on average. No other significant differences in background, symptoms, or clinical data were observed between virus-positive and virus-negative cases within the AP group.

CONCLUSION

In the AP group, the rate of respiratory virus detections was comparable to that of the non-AP and AB groups. This suggests a potential link between respiratory virus infections and the development of AP, emphasizing the need for novel preventive strategies. While distinguishing between AP patients with and without respiratory virus detections based on clinical findings was challenging, recognizing the frequent involvement of respiratory virus infections in AP highlights the importance of enhanced infection control and awareness in its management.

Study on the potential diagnostic value of metabolomics changes in different biological fluids for aspiration pneumonia

BACKGROUND

Aspiration pneumonia (AP) is a type of lung inflammation caused by the aspiration of food, oropharyngeal secretions, or gastric contents. This condition is particularly common in older adults and individuals with impaired swallowing or consciousness. While the diagnosis of AP relies on clinical history, swallowing assessments, and imaging, these methods have significant limitations, often leading to underdiagnosis or misdiagnosis. Reliable biomarkers for AP diagnosis are lacking, making early detection and treatment challenging.

METHODS

Nineteen patients diagnosed with pneumonia were included in this study, divided into two groups: AP (n = 10) and non-AP (n = 9). Biological fluid samples, including bronchoalveolar lavage fluid (BALF), saliva, serum, sputum, and urine, were analyzed using non-targeted liquid chromatography with tandem mass spectrometry (LC-MS/MS). Differential metabolites were identified using fold change analysis, statistical significance, and receiver operating characteristic (ROC) curve analysis to evaluate their diagnostic potential. Spearman correlation was used to examine the relationship between selected metabolites and clinical parameters.

RESULTS

Significant metabolic differences were found between AP and non-AP patients, with many different metabolites identified across biological fluids. Dehydroepiandrosterone sulfate (DHEAS), Androstenediol-3-sulfate (ADIOLS), and beta-muricholic acid were identified as key biomarkers through fold change analysis and ROC curve analysis, showing consistent increasing or decreasing trends in BALF, sputum, and serum samples. DHEAS was found to be negatively correlated with the Acute Physiology and Chronic Health Evaluation II (APACHE II) (r = - 0.619, p = 0.005) in BALF sample. The area under curve (AUC) values showed that these molecules could serve as effective biomarkers for AP.

CONCLUSIONS

This study identifies DHEAS, ADIOLS and beta-muricholic acid as promising biomarkers for AP, with the potential to improve early diagnosis and treatment. These findings underscore the clinical value of metabolomics in developing diagnostic tools for AP, facilitating better clinical management and patient outcomes. Further research is required to validate these biomarkers in larger cohorts and explore their mechanistic roles in AP pathophysiology.

Impact of variations in airborne microbiota on pneumonia infection: An exploratory study

BACKGROUND

Previous studies showed airborne bacteria affect pneumonia incidence, but specific impacts of bacterial communities on Klebsiella pneumoniae infection were unknown.

METHODS

Five different ratios of bacterial community structures were randomly generated. Mice were divided into control, artificial bacterial community exposure, and corresponding Klebsiella pneumoniae challenge groups. Changes in body weight, blood parameters, pulmonary pathology, inflammatory factors, metabolomics, and fecal microbiota were analyzed.

RESULTS

Different bacterial community exposures had varying degrees of influence on body weight, complete blood count, inflammatory factors, alveolar lavage fluid and plasma metabolome, as well as intestinal microbiota at baseline and after infection. Metabolomic analysis showed that microbial exposure affected both bronchoalveolar lavage fluid and plasma metabolomes, suggesting systemic effects of microbial exposure on the organism. Differences in the structure of artificial microbiota had inconsistent effects on both the baseline state and the post-infection state, hinting at crosstalk between microbial exposure and Klebsiella pneumoniae infection. KEGG pathway analysis unveiled possible molecular mechanisms underlying the overall impact of microbial exposure on the lungs and the body as a whole. In the intestinal microbiota, differences were found in composition at the phylum and genus levels. Spearman correlation analysis established potential correlations between intestinal microbiota and differential metabolites, suggesting a potential link within the lung-gut axis.

CONCLUSION

This study demonstrated the significant and systemic impact of air microbiota structure differences on health. Future research should explore the underlying mechanisms to enhance our understanding of the air-environment-health relationship and identify interventions for improving public health strategies.

Signatures of lower respiratory tract microbiome in children with severe community-acquired pneumonia using shotgun metagenomic sequencing

BACKGROUND

Severe community-acquired pneumonia was associated with high morbidity and mortality in children. However, species-level microbiome of lower airway was sparse, and we used shotgun metagenomic next-generation sequencing to explore microbial signatures.

METHODS

We conducted a prospective cohort study to recruit children under 18 who required admission to an intensive care unit for community-acquired pneumonia between December 2019 and February 2022. Lower respiratory specimens were collected on admission for shotgun metagenomic sequencing. The children were divided into two groups. Critical cases were patients with respiratory failure requiring endotracheal ventilator support, and severe cases did not require intubation. Signatures of lower respiratory tract microbiome were compared between groups using an exact k-mer matching metagenomic analysis pipeline (Kraken 2) and a metagenome-assembled genomes pipeline (MetaWRAP).

RESULTS

Totally 66 children were enrolled, and 27 children were critical cases, and the rest were severe cases. There were significant differences in microbial community structure between different severity groups, and microbial abundance was negatively correlated with disease severity. The results showed that Haemophilus influenzae was more prominent in children who were critical, accompanied with increased expression of intracellular transport, secretion, and vesicle transport genes. Rothia mucilaginosa, Dolosigranulum pigrum, and Prevotella melaninogenica tended to be present in less severe community-acquired pneumonia group.

CONCLUSION

This study demonstrated that significantly different microbial community was associated with severity of community-acquired pneumonia requiring intensive care admission. Species-level shotgun metagenomic sequencing facilitates the exploration of potentially pathogenic or protective microbes and shed the light of probiotic development in lower respiratory tract.

Implications for the diagnosis of aspiration and aspergillosis in critically ill patients with detection of galactomannan in broncho-alveolar lavage fluids

Invasive infections with Aspergillus fumigatus in ICU patients are linked to high morbidity and mortality. Diagnosing invasive pulmonary aspergillosis (IPA) in non-immunosuppressed patients is difficult, as Aspergillus antigen (galactomannan [GM]) may have other causes. This retrospective study analyzed 160 ICU surgical patients with positive GM in broncho-alveolar lavage fluid (BALF), classifying them based on AspICU criteria for suspected IPA (pIPA) or aspiration. Patients with pIPA had higher disease severity than those with aspiration, including higher dialysis rates, organ transplantation, corticosteroid use, and Sequential Organ Failure Assessment (SOFA) score. Aspergillus culture was positive in 47.0% of pIPA cases but only 2.6% of aspiration cases (p < 0.001). SOFA score at first positive GM in BALF independently predicted 28-day mortality. In surgical patients with a positive GM in BALF, aspiration is more likely if there's no corticosteroid therapy, negative Aspergillus culture, and a history of aspiration events. Diagnosis of pIPA requires Aspergillus culture or prior corticosteroid therapy in this cohort of critically ill patients.

Effect of one dose of ceftriaxone during endotracheal intubation on the incidence of aspiration pneumonia in cerebral hemorrhage patients: A randomized, controlled, double-blind clinical study protocol

INTRODUCTION

Patients with cerebral hemorrhage often require a tracheal intubation to protect the airway and maintain oxygenation. Due to the use of analgesic and sedative drugs during endotracheal intubation and the opening of the glottis may easily cause aspiration pneumonia. Ceftriaxone is a semi-synthetic third-generation cephalosporin with strong antimicrobial activity against most gram-positive and gram-negative bacteria. It can effectively prevent and treat aspiration pneumonia.

METHODS AND ANALYSIS

This is a prospective, randomized, controlled, double-blind clinical study. Patients with intracerebral hemorrhage (ICH) undergoing endotracheal intubation in Dong E Hospital of Shandong Province from April 2023 to April 2025 will be enrolled and randomly assigned to the intervention group or control group. The intervention group will be treated using 100mL 0.9% sodium chloride with 2g ceftriaxone intravenously over the course of one hour beginning within two hours after endotracheal intubation. The control group will be given 100mL 0.9% sodium chloride injection intravenously of the course of one hour beginning within two hours after endotracheal intubation. The primary outcome is the incidence of aspiration pneumonia within 48 hours after endotracheal intubation. Secondary outcomes include: intensity of antimicrobial use, length of hospital stay, duration without mechanical ventilation, and 28-day mortality.

DISCUSSION

The primary objective of this study is to explore whether a single dose of ceftriaxone administered during endotracheal intubation in patients with ICH reduced the incidence of pneumonia within 48 hours and provide evidence for the prevention of aspiration pneumonia in patients with ICH with endotracheal intubation.

TRIAL REGISTRATION

The trial is registered at the Chinese Clinical Trial Registry: ChiCTR2200066837. Registered on December 19, 2022.

Pulmonary Aspiration Syndromes: An Imaging-based Review

The term "aspiration" describes lung injury that results from unintentional passage of contents other than air into the lungs and bronchial tree, commonly from the gastrointestinal and upper respiratory tracts. Only a small proportion of aspiration-related events are symptomatic, especially in predisposed individuals such as patients with diminished consciousness, impaired swallowing, oesophageal motility disorders, and reflux disease. Aspiration-related syndromes can be classified based on the onset of presentation, composition of the aspirated substance, and anatomic site of injury. When considering the injury site, the aspirated material can either obstruct the airways, thereby presenting with obstructive features (eg, atelectasis on radiographs); it can alternatively affect the lung parenchyma. Lung injury due to aspiration of noxious agents such as acid or lipids is termed chemical aspiration pneumonitis. The aspirated contents can alternatively lead to lung parenchymal infection when the contents are infected, which is termed aspiration pneumonia. We have reviewed the imaging manifestations of various entities related to aspiration and have classified the abnormalities based on the site of injury and the nature of the culprit agent. Differences between "aspiration pneumonitis" and "aspiration pneumonia" are also explored. This is followed by an illustration of a few specific situations related to aspiration in pediatric and adult patients.

Exploration and evaluation of adverse event signals of droxidopa based on the FAERS database

BACKGROUND

This study aims to utilize the FDA's Adverse Event Reporting System (FAERS) for data analysis to explore the potential adverse events associated with Droxidopa in real-world settings, thereby providing reference information for clinical practice.

METHODS

Adverse event reports where Droxidopa was the primary suspected drug were collected from the FAERS database from the third quarter of 2014 to the fourth quarter of 2023. Multiple signal quantification techniques were employed, including ROR, PRR, BCPNN, and MGPS.

RESULTS

A total of 19,295 reports directly related to Droxidopa were screened, encompassing 94 Preferred Terms and involving 27 System Organ Classes. In addition to the adverse events already mentioned in the drug's labeling, this study identified new and valuable adverse event signals, such as Gastrointestinal disorders, Infections and infestations, and Musculoskeletal and connective tissue disorders. Notably, Urinary tract infection, Urinary tract infection pseudomonal, and Pneumonia aspiration were associated with Infections and infestations, indicating the need for heightened vigilance when using Droxidopa in clinical settings. These new signals provide a basis and direction for future research.

CONCLUSION

This study highlights new potential adverse events related to Droxidopa, emphasizing the need for caution, especially concerning Infections and infestations. Further research is warranted to validate these findings.

Effect of pre-hospital living setting on nutritional intake route upon discharge in older adults with aspiration pneumonia: a prospective cohort study

BACKGROUND

Aspiration pneumonia, which often recurs due to dysphagia, worsens as patients move between homes, facilities, and hospitals. The impact of pre-hospital living setting on oral intake at discharge remains unclear. The purpose of this study was to identify the effects of the pre-hospital living setting on the nutritional intake route upon discharge in older patients with aspiration pneumonia.

METHODS

This prospective cohort study included patients aged ≥ 65 years who were admitted to an acute care hospital and diagnosed with aspiration pneumonia. Patients were followed up until discharge or death during hospitalisation. Patient demographic information, pre-hospital living setting (home or nursing facility), functional oral intake scale (FOIS) score, pneumonia severity index, clinical frailty scale score, history of aspiration pneumonia, and pneumonia recurrence during hospitalisation were recorded. Binary logistic regression was used to assess the impact of the pre-hospital living setting on oral intake at discharge as the primary outcome.

RESULTS

Among the 89 included patients (52 males (58.4%); mean age, 84.8 ± 7.9 years), 39.3% (n = 35) had pneumonia recurrence during hospitalisation. The average follow-up period was 44.0 ± 36.6 days. The pre-hospital living setting was independently associated with the nutritional intake route upon discharge (odds ratio = 7.72, 95% confidence interval (95%CI) = 1.70-35.1, p = 0.008).

CONCLUSIONS

The pre-hospital living setting could serve as a good indicator of the nutritional intake route upon discharge. It is essential to optimize care in both nursing facilities and hospital settings when caring for older patients with aspiration pneumonia.

Impact of Multidrug-Resistant Bacterial Colonization on Clinical Characteristics, Antibiotic Treatment, and Clinical Outcomes of Hospital-Acquired Pneumonia

PURPOSE

To determine effects of colonization with multidrug-resistant bacteria (MDRB) in general wards on characteristics, treatment, and prognosis of hospital-acquired pneumonia (HAP).

METHODS

This was a multicenter retrospective cohort study of patients with HAP admitted to 16 tertiary or university hospitals in Korea from July 2019 to December 2019. From the entire cohort, patients who developed pneumonia in general wards with known colonization status before the onset of pneumonia were included in this study. Patients were categorized into a colonization group and a non-colonization group according to MDRB colonization. Patients of the two groups were then compared.

RESULTS

Among a total of 400 patients, 63 were in the MDRB colonization group. HAP caused by MDR-Staphylococcus aureus or MDR-Pseudomonas aeruginosa was more common in the colonization group than in the non-colonization group (24.4% vs. 8.1%, P = 0.006 or 20.0% vs. 5.4%, P = 0.013, respectively). Colonization with certain bacteria was correlated with subsequent infection with the same bacteria. Carbapenem use (36.5% vs. 24.3%, P = 0.044) and appropriateness of initial antibiotics (50.8% vs. 12.8%) were higher in the colonization group than in the non-colonization group. Although in-hospital mortality was similar in the two groups (34.9% vs. 32.9%, P = 0.759), hospital length of stay was longer (38 days vs. 31 days, P = 0.009) and rate of discharge to home was lower (34.1% vs 59.7%, P = 0.002) in the colonization group.

CONCLUSIONS

Colonization with MDRB might influence characteristics and treatment of HAP. However, prognosis of HAP was not associated with MDRB colonization.

Korean Guidelines for the Management and Antibiotic Therapy in Adult Patients with Hospital-Acquired Pneumonia

Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) are correlated with high morbidity and mortality rates. Guidelines that consider local epidemiologic data are fundamental for identifying optimal treatment strategies. However, Korea has no HAP/VAP guidelines. This study was conducted by a committee of nine experts from the Korean Academy of Tuberculosis and Respiratory Diseases Respiratory Infection Study Group using the results of Korean HAP/VAP epidemiologic studies. Eleven key questions for HAP/VAP diagnosis and treatment were addressed. The Convergence of Opinion on Suggestions and Evidence (CORE) process was used to derive suggestions, and evidence levels and recommendation grades were in accordance with the Grading of Recommendations Assessment Development and Evaluation (GRADE) methodology. Suggestions were made for the 11 key questions pertinent to diagnosis, biomarkers, antibiotics, and treatment strategies for adult patients with HAP/VAP. Using the CORE process and GRADE methodology, the committee generated a series of recommendations for HAP/VAP diagnosis and treatment in the Korean context.

Efficacy and Safety of Oral Hydration 1 Hour After Extubation of Patients Undergoing Cardiac Surgery: A Randomized Controlled Trial

BACKGROUND

Thirst is one of the most common and uncomfortable symptoms in patients after cardiac surgery. The postextubation time for early oral hydration (EOH) remains unclear, and there is a lack of studies on its safety and effectiveness.

OBJECTIVE

The aim of this study was to investigate the effects of oral hydration 1 hour after extubation on thirst, salivary pH, salivary flow, oral mucosa, halitosis, gastrointestinal adverse reactions, aspiration pneumonia, and satisfaction in patients undergoing cardiac surgery.

METHODS

Eighty-four patients who underwent cardiac surgery were randomly assigned into 2 groups, for either conventional oral hydration (COH) or EOH. The EOH group drank 30 mL of warm water 1 hour post extubation and thereafter 50 mL hourly for 4 hours. The COH group had nil per os for 4 hours after extubation. If no dysphagia was evident after 4 hours, the patients were instructed to slowly drink water. Thirst intensity was evaluated every hour before the intervention. Nausea and vomiting were recorded after drinking water. The salivary pH, unstimulated salivary flow rate, oral odor, and oral mucosal moisture were evaluated at 1 hour post extubation, immediately before the intervention, and at 4 hour post intervention. Aspiration pneumonia data were collected within 72 hours post intervention. Satisfaction was assessed before leaving the intensive care unit.

RESULTS

The scores for thirst (3.38 ± 1.04; F = 306.21, P < .001), oral mucosa (2.03 ± 0.74; P < .001), and halitosis (2.77 ± 0.63; P < .001) in the EOH group were significantly lower than those in the COH group. The EOH group had significantly higher salivary pH (6.44 ± 1.06; P < .001), unstimulated salivary flow rates (0.18 ± 0.08; P < .001), and patient satisfaction (4.28 ± 0.45; P < .001) than the COH group. Nausea and vomiting did not differ significantly between groups ( P = .60). Aspiration pneumonia was not observed in either group.

CONCLUSIONS

Oral hydration 1 hour after extubation significantly alleviated thirst and stabilized the oral environment without gastrointestinal adverse reactions or aspiration pneumonia, and with increased patient satisfaction.

Oropharyngeal dysphagia impact of pneumonia risk in neurological patients receiving enteral tube feeding: Insights from a gastroenterologist

BACKGROUND

Oropharyngeal dysphagia is prevalent among neurological patients, often necessitating enteral tube feeding with a nasogastric tube (NGT) or percutaneous endoscopic gastrostomy (PEG). These patients are at significant risk of developing aspiration pneumonia. This study aimed to assess the impact of oropharyngeal dysphagia on pneumonia risk requiring hospitalization in neurological patients on long-term enteral tube feeding.

METHODS

This retrospective observational study was conducted between 2015 and 2022. It included neurological patients who underwent upper gastrointestinal endoscopy combined with a Modified Flexible Endoscopic Evaluation of Swallowing (mFEES) for suspect dysphagia, characterized by difficulty or discomfort in swallowing. Participants were either orally fed or had been on long-term enteral tube feeding via NGT or PEG. A 2-year follow-up was conducted to monitor pneumonia cases requiring hospitalization. Multivariate analyses were conducted to identify risk factors for pneumonia requiring hospitalization.

KEY RESULTS

A total of 226 orally fed and 152 enteral tube-fed patients were enrolled. Multivariate analyses showed a significantly increased risk of pneumonia in patients with a history of pneumonia and those receiving enteral tube feeding. Subgroup analysis indicated a significantly lower risk of pneumonia among enteral tube-fed patients with oropharyngeal dysphagia who PEG-fed patients compared to NGT-fed patients (adjusted HR: 0.21, 95% CI: 0.10-0.44, p < 0.001). The cumulative incidence of pneumonia requiring hospitalization was significantly lower in the PEG group than in the NGT group (p < 0.001).

CONCLUSION

mFEES could be a screening tool for oropharyngeal dysphagia. PEG is preferred over NGT for long-term enteral feeding, as it significantly reduces the risk of pneumonia requiring hospitalization, especially in patients with oropharyngeal dysphagia.

[Pneumonia due to silent aspiration: a diagnostic and therapeutic challenge]

Aspiration pneumonia (AP) may present as gross aspiration of large gastric contents or as a consequence of silent aspiration of contaminated oropharyngeal secretions.AP due to silent aspiration is caused by dysphagia and, in some instances, impaired cough reflex. Factors favouring the development of pneumonia include advanced age as well as severe comorbidity and impaired functional status.Therefore, silent aspiration is a frequent etiology of community-acquired pneumonia in aged patients but also of nosocomial pneumonia. Recurrent pneumonia should always prompt the consideration of AP.Treatment of acute AP should include not only the use of antimicrobial agents but also chest physiotherapy and airway clearance techniques. In addition, all patients with silent aspiration and AP should be subject to an investigation of swallowing function and, in the presence of dysphagia, also receive treatment for this condition. This includes methods of restitution, compensation and adaptation of impaired swallowing function.

Association of Low Muscle Strength With Incident Pneumonia in Older Patients With Heart Failure

BACKGROUND

Patients with heart failure (HF) are at an increased risk of developing pneumonia, leading to a high mortality. A decrease in muscle strength due to aging or concomitant disease may contribute to the development of pneumonia in older adults. We sought to investigate the relationship between low muscle strength and pneumonia incidence in older patients hospitalized for worsening HF.

METHODS

We carried out a subanalysis of the FRAGILE-HF, a prospective multicenter observational study, including 1 266 consecutive older (≥65 years) patients hospitalized with HF (mean age 80.2 ± 7.8 years; 57.4% male; left ventricular ejection fraction 46% ± 17%) and information of incident pneumonia observed after discharge. Patients were followed up for 2 years post-discharge.

RESULTS

A total of 88 patients (7.0%) developed pneumonia after discharge, with an incidence of 42.7 per 1 000 person-years. A total of 893 patients with low muscle strength, defined as handgrip strength <28 kg for men and <18 kg for women according to international criteria, were more likely to develop pneumonia than those with normal muscle strength (p < .001; log-rank test). Low muscle strength was a significant predictor of incident pneumonia (adjusted hazard ratio with 95% confidence interval: 2.65 [1.31-5.35], p = .007). Furthermore, the mortality rates were 43.2% in patients who developed pneumonia and 19.3% in those who did not, indicating a heightened risk of death following the onset of pneumonia (adjusted hazard ratio: 4.25 [2.91-6.19], p < .001).

CONCLUSIONS

In older patients hospitalized for HF, low muscle strength was associated with incident pneumonia after discharge.

Risk of aspiration pneumonia and hospital mortality in Parkinson disease: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

This study was undertaken to conduct a meta-analysis on the prevalence of aspiration pneumonia (AP) and hospital mortality in Parkinson disease (PD) as well as the risk of AP in PD patients compared to controls.

METHODS

We searched MEDLINE and Embase from inception to 19 March 2024 to identify cross-sectional, cohort, and case-control studies comparing the frequency of AP and hospital mortality in PD patients. We computed risk ratios (RRs) with accompanying 95% confidence intervals (CIs) for each study and pooled the results using a random-effects meta-analysis.

RESULTS

A total of 781 studies were initially screened, and 13 studies involving 541,785,587 patients were included. Patients with PD had >3 times higher risk of AP compared to controls (RR = 3.30, 95% CI = 1.82-6.00, p < 0.0001). This increased risk was similar in both cohort studies (RR = 3.01, 95% CI = 1.10-8.24, p = 0.03) and case-control studies (RR = 3.86, 95% CI = 3.84-3.87, p < 0.00001). The prevalence of AP in 12 studies was 2.74% (95% CI = 1.69-4.41), and hospital mortality was 10% in six studies (10.0%, 95% CI = 5.32-18.0). Prevalence of AP was higher in studies with smaller sample size (5.26%, 95% CI = 3.08-8.83 vs. 2.06%, 95% CI = 1.19-3.55, p = 0.02).

CONCLUSIONS

Our meta-analysis showed that patients with PD had >3 times higher risk of AP, with an average 2.74% prevalence and 10.0% hospital mortality. Early recognition and treatment of AP in PD patients will help reduce morbidity and mortality. A multidisciplinary holistic approach is needed to address the multifactorial causes of AP.

Therapy of Aspiration: Out-of-Hospital and In-Hospital-Acquired

Therapeutic considerations for aspiration pneumonia prioritize the risk of multidrug-resistant organisms. This involves integrating microbiological insights with each patient's unique risk profile, including the location at the time of aspiration, and whether it occurred in or out of the hospital. Our understanding of the microbiology of aspiration pneumonia has also evolved, leading to a reassessment of anaerobic bacteria as the primary pathogens. Emerging research shows a predominance of aerobic pathogens, in both community and hospital-acquired cases. This shift challenges the routine use of broad-spectrum antibiotics targeting anaerobes, which can contribute to antibiotic resistance and complications such as Clostridium difficile infections-concerns that are especially relevant given the growing issue of antimicrobial resistance. Adopting a comprehensive, patient-specific approach that incorporates these insights can optimize antibiotic selection, improve treatment outcomes, and reduce the risk of resistance and adverse effects.

Bacteriology of Aspiration Pneumonia: The Lung Microbiome and the Changing Microbial Etiology

Aspiration pneumonia refers to the process of alveolar inflammation induced by the inhalation of oropharyngeal secretions into the lower respiratory tract. Predisposing factors comprise swallowing dysfunction, impaired cough reflex, and degenerative neurological diseases. Accumulating evidence projects a fading contribution of anaerobic bacteria in aspiration pneumonia at the expense of Gram-negative bacilli, with Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa, becoming the predominant organisms recovered from respiratory specimens. Aspiration of oropharyngeal secretions colonized with respiratory pathogens induces a profound disequilibrium of the lung microbiota resulting in a state of dysbiosis. Understanding this complex temporal variability between microbiome-host associations was only made possible with the introduction of metagenomic sequencing. In this narrative review, we summarize existing knowledge and elaborate on the evolving microbiology of aspiration pneumonia including the link between oral microbiome and pulmonary aspiration. We also highlight the progress and challenges in instituting microbiome-targeted strategies for preventing and treating the sequelae of aspiration pneumonia.

Medications to Modify Aspiration Risk: Those That Add to Risk and Those That May Reduce Risk

Aspiration pneumonia results from the abnormal entry of fluids into the respiratory tract. We present a review of drugs known to affect the risk of aspiration. Drugs that increase the risk of aspiration pneumonia can be broadly divided into those that affect protective reflexes (like cough and swallowing) due to direct or indirect mechanisms, and drugs that facilitate gastric dysbiosis or affect esophageal and intestinal motility. Chief among the first group are benzodiazepines and antipsychotics, while proton pump inhibitors are the most well-studied in the latter group. Pill esophagitis may also exacerbate swallowing dysfunction. On the other hand, some research has also focused on pharmaceutical modulation of the risk of aspiration pneumonia. Angiotensin-converting enzyme inhibitors have been demonstrated to be associated with a decrease in the hazard of aspiration pneumonia in high-risk patients of Chinese or Japanese origin. Drugs like amantadine, nicergoline, or folic acid have shown some promising results in stroke patients, although the available evidence is thus far not enough to allow for any meaningful conclusions. Importantly, antimicrobial prophylaxis has been proven to be ineffective. Focusing on modifiable risk factors for aspiration pneumonia is relevant since this may help to reduce the incidence of this often severe problem. Among these, several commonly used drug classes have been shown to increase the risk of aspiration pneumonia. These drugs should be withheld in the high-risk population whenever possible, alongside general measures, such as the semirecumbent position during sleep and feeding.

Epidemiology and Pathogenesis of Aspiration Pneumonia

Aspiration pneumonia (AP) remains a critical health issue, especially among older and hospitalized patients. This review focuses on understanding the epidemiology and pathogenesis of AP, exploring key risk factors, and proposing diagnostic strategies. Aspiration pneumonia is commonly associated with hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), where pathogens introduced into the lungs from gastric aspiration cause infection. Several factors, such as oropharyngeal dysphagia, silent aspiration, and poor oral health, contribute to increased risk, especially in frail elderly populations with chronic comorbidities. Diagnostic criteria for AP are not well-defined, complicating accurate diagnosis. Radiographic evidence of pulmonary infiltrates, history of aspiration, and clinical symptoms, such as cough and fever, guide diagnosis, but the absence of specific biomarkers remains a challenge. Furthermore, the microbiome of the lung, which shares characteristics with the oropharyngeal flora, plays a pivotal role in the development of infection. The incidence of AP is likely to increase given the growing elderly population with factors predisposing them to aspiration. It is one of the most common types of pneumonia in older adults, with its prevalence estimated to range from 5% to 24% in cases of CAP admissions. This revision highlights the growing need for comprehensive diagnostic tools and treatment protocols for AP, especially in high-risk populations such as the elderly and those in long-term care. Understanding the underlying mechanisms and the role of silent aspiration can improve prevention strategies and reduce morbidity and mortality in these vulnerable groups.

Imaging of Aspiration: When to Suspect Based on Imaging of Bacterial Aspiration, Chemical Aspiration, and Foreign Body Aspiration

Aspiration-related syndromes comprise a broad spectrum of diseases affecting the airways and lung parenchyma resulting from inadvertent entry of oropharyngeal or gastric contents into the respiratory tract. The diagnosis can be challenging given lack of self-reported symptoms and unwitnessed or silent aspiration events. Aspiration is a common finding in healthy individuals suggesting that host defenses play a critical role in the pathophysiology. In the absence of strict criterion, a high index of suspicion is necessary based on recognition of established risk factors and identification of characteristic imaging findings. Conditions predisposing to altered levels of consciousness and neuromuscular weakness can lead to dysphagia, impaired cough reflux, and subsequent aspiration. The most salient feature on imaging is the anatomic location of the abnormalities, with the superior segments of the lower lobes and posterior segments of upper lobes involved in the recumbent position, and basilar segments of lower lobes in the upright position. Acute syndromes include pneumonia, pneumonitis, and foreign body aspiration. In the more indolent form of aspiration, bronchiectasis, diffuse bronchiolitis, and interstitial lung disease can develop. A detailed understanding of associated radiographic findings for these syndromes can help to implicate aspiration as the cause for imaging abnormalities and ultimately optimize patient management.

Aspiration after Anesthesia: Chemical versus Bacterial, Differential Diagnosis, Management, and Prevention

Aspiration following anesthesia is a major patient issue and a difficulty for anesthesiologists. Aspiration syndromes are more common than anticipated, and the condition is frequently undetected. Clinical signs are often dictated by the characteristics of aspiration, such as the infectivity of the material, its volume, and the severity of the underlying clinical condition. Pulmonary aspiration can cause an acute or persistent inflammatory response in the lungs and upper airways that can be complicated by tracheobronchitis, aspiration pneumonia, aspiration pneumonitis, acute respiratory distress syndrome, and subsequent bacterial infection due to particle, acid, and bacteria-related processes. Aspiration during anesthesia, while relatively rare, poses significant risks for patient morbidity and mortality. Chemical and bacterial aspiration provide distinct diagnostic and management issues. Preventive strategies such as a complete preoperative risk assessment, adherence to fasting rules, proper patient positioning, and the use of protective airway devices are critical in reducing aspiration risk. In addition, drugs such as proton pump inhibitors can help lower stomach acidity and volume. Innovations in monitoring techniques, better training, and awareness activities are critical to enhancing aspiration event management. Given the importance of this entity, this narrative review sought to make an updated overview of the management of aspiration after anesthesia: chemical versus bacterial, differential diagnosis, management, and prevention.

Swallowing and Aspiration: How to Evaluate and Treat Swallowing Disorders Associated with Aspiration Pneumonia in Older Persons

Aspiration pneumonia (AP) is the most severe complication of oropharyngeal dysphagia (OD). It is highly underdiagnosed and undertreated among older patients hospitalized with community-acquired pneumonia (CAP). Our aim is to review the state of the art in the diagnosis and treatment of swallowing disorders associated with AP. We performed a narrative review, including our experience with prior studies at Hospital de Mataró, on the diagnosis and treatment of AP. AP refers to pneumonia occurring in patients with swallowing disorders, frequently coinciding with poor oral health and vulnerability. Its main risk factors include oropharyngeal aspiration, impaired health status, malnutrition, frailty, immune dysfunction, and oral colonization by respiratory pathogens. Incidence is estimated at between 5 and 15% of cases of CAP, but it is highly underdiagnosed. Diagnostic criteria for AP have not been standardized but should include its main pathophysiological element, oropharyngeal aspiration. Recently, a clinical algorithm was proposed, based on the recommendations of the Japanese Respiratory Society, that includes aspiration risk factors and clinical evaluation of OD. To facilitate the task for health care professionals, new artificial intelligence (AI)-based screening tools for OD combined with validated clinical methods such as the volume-viscosity swallowing test (V-VST) for the detection of AP are being validated. Prevention and treatment of AP require multimodal interventions aimed to cover the main risk factors: textural adaptation of fluids and diets to avoid oropharyngeal aspiration; nutritional support to avoid malnutrition; and oral hygiene to reduce oral bacterial load. The diagnosis of AP must be based on standardized criteria providing evidence on the main etiological factor, oropharyngeal aspiration. Clinical algorithms are valid in the diagnosis of AP and the identification of its main risk factors. Combination of AI-based tools with V-VST can lead to massive screening of OD and save resources and improve efficiency in the detection of AP.

Is There a Role for Bronchoscopy in Aspiration Pneumonia?

Aspiration represents the passage of oropharyngeal content to the lower respiratory tract. The interplay between the host and the aspirate proprieties determines the subsequent aspiration syndrome. A low pH, typical of gastric aspirate, favors chemical pneumonitis, whereas an increased bacterial inoculum causes aspiration pneumonia. About a quarter of patients with aspiration pneumonitis will develop a bacterial superinfection during the course of recovery. While antibiotic therapy is indicated for aspiration pneumonia, supportive care remains the cornerstone of treatment in aspiration pneumonitis. However, the overlapping clinical features of these syndromes lead to initiation of antimicrobial therapy in most cases of aspiration. Bronchoscopy can aid in clinical decision-making by direct airway visualization and also by providing access to a series of emerging biomarkers. Invasive microbiological studies increase diagnostic yield and enable a tailored antibiotic treatment. In conjunction with stewardship programs, invasive sampling and novel molecular diagnostics can decrease the amount of inappropriate antibiotic therapy. In the context of foreign body aspiration, bronchoscopy represents both diagnostic and treatment gold standard.

Value of bronchial amylase level for predicting ventilator associated pneumonia in intubated adults: a systematic review and meta-analysis

BACKGROUND

The ability of bronchial amylase level for predicting ventilator associated pneumonia (VAP) has been extensively studied with conflicting results. This meta-analysis aimed to explore the value of bronchial amylase for predicting VAP in intubated adults.

METHODS

PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched up to November 2023. The diagnostic odds ratio (DOR), sensitivity, and specificity were calculated. The summary receiver operating characteristic curve was estimated, and the area under the curve (AUROC) was calculated.

RESULTS

Overall, six studies including 769 patients were included in this review, of whom 273 (36%) were developed VAP. The cutoff values of bronchial amylase level were ranged from 8.1 U/L to 4681.5U/L. Heterogeneity between studies was assessed with an overall Q = 1.99, I2 = 0, and P = 0.185, The pooled sensitivity and specificity for the overall population were 0.78 [95% confidence interval (CI) 0.67-0.86] and 0.75(95% CI 0.56-0.88) respectively. The DOR was 11(95% CI 3.0-40.0). The pooled AUROC was 0.83 (95%CI 0.80-0.86).

CONCLUSIONS

The bronchial amylase is a helpful marker for predicting VAP in intubated adults. However, it cannot be recommended as the single definitive test for VAP, but rather it must be interpreted in context with information from careful medical history, physical examination, and when feasible, microbiological assessment.

Chloramphenicol versus ceftriaxone for the treatment of pneumonia and sepsis in elderly patients with advanced dementia and functional disability. A propensity-weighted retrospective cohort study

BACKGROUND

Sepsis and pneumonia in the elderly comprise a significant portion of medical admissions. Chloramphenicol has been used in Israel for treatment of bacterial infections, without evidence regarding its efficacy and safety.

OBJECTIVES

We aimed to examine whether chloramphenicol was associated with similar outcomes to ceftriaxone, for treatment of sepsis and pneumonia in the elderly with dementia and functional disability.

METHODS

Patients over 75, with dementia and functional disability, admitted to the internal medicine ward at Beilinson Hospital between 2011 and 2021, with community-acquired aspiration pneumonia or sepsis of undetermined source were included. Patients with mild dementia and independent in their activities of daily living were excluded. Primary outcome was 30- and 90-day all-cause mortality. A propensity-weighted multivariable model was constructed using inverse probability of treatment weighting. Results were expressed as OR with 95% CI.

RESULTS

In total, 1558 patients were included: 512 treated with chloramphenicol and 1046 with ceftriaxone. The cohort consisted of elderly patients (mean age 87 ± 6.2 years) with comorbidities; 30- and 90-day all-cause mortality were similar [222/512 (43.3%) versus 439/1046 (41.9%) P = 0.602, and 261/512 (50.9%) versus 556/1046 (53.1%) P = 0.419, respectively]. Propensity-weighted, logistic multivariable analysis for 30- and 90-day all-cause mortality revealed similar mortality rates for chloramphenicol and ceftriaxone (OR 1.049 95% CI 0.217-1.158, OR 0.923 95% CI 0.734-1.112, respectively).

CONCLUSION

In this retrospective cohort of elderly debilitated patients hospitalized with pneumonia and sepsis, we found no difference in 30- and 90-day mortality between those treated with chloramphenicol or ceftriaxone. Further studies should determine the efficacy and safety of chloramphenicol in this population.

Biocatalytic Clusterzyme Patches Restore Lung Function via Immunomodulation and Mitochondria Protection

Currently, pulmonary complications such as lung infections during the perioperative period are still the main cause of prolonged hospitalization and death in patients with lung injury due to the lack of effective drugs. Clusterzyme, a kind of artificial enzyme with a high enzyme-like activity and safety profile, exhibits good effects on reducing oxidative stress and immunomodulation. Here, we present the functionalized patches that is administered on the lung airways and rescues the injured organ via clusterzymes. The long-term antioxidant capacity of the patches significantly ameliorated lipopolysaccharide-induced lung function impairment with a significant reduction in lung goblet cell metaplasia and oxidative stress. The inflammatory factors such as cytokines interleukin-1β, interleukin-6, and tumor necrosis factor-α levels decreased by 50%, while the mtDNA copy number increased by 50% and ATP production increased by 100%. Mice lung function was significantly improved, suggesting that the patches can rescue lung injury by modulating oxidative stress and immune responses as well as protecting the mitochondria, providing an avenue for effective intervention of lung injury.

Interactions between sleep, inflammation, immunity and infections: A narrative review

BACKGROUND

Over the past decades, it has become increasingly evident that sleep disturbance contributes to inflammation-mediated disease, including depression, mainly through activation of the innate immune system and to an increased risk of infections.

METHODS

A comprehensive literature search was performed in PubMed to identify relevant research findings in the field of immunity, inflammation and infections, with a focus on translational research findings from the past 5 years.

RESULTS

Physiological sleep is characterized by a dynamic interplay between the immune system and sleep architecture, marked by increased innate immunity and T helper 1 (Th1) -mediated inflammation in the early phase, transitioning to a T helper 2 (Th2) response dominating in late sleep. Chronic sleep disturbances are associated with enhanced inflammation and an elevated risk of infections, while other inflammatory diseases may also be affected. Conversely, inflammation in response to infection can also disrupt sleep patterns and architecture. This narrative review summarizes current data on the complex relationships between sleep, immunity, inflammation and infections, while highlighting translational aspects. The bidirectional nature of these interactions are addressed within specific conditions such as sleep apnea, HIV, and other infections. Furthermore, technical developments with the potential to accelerate our understanding of these interactions are identified, including advances in wearable devices, artificial intelligence, and omics technology. By integrating these tools, novel biomarkers and therapeutic targets for sleep-related immune dysregulation may be identified.

CONCLUSION

The review underscores the importance of understanding and addressing immune imbalance related to sleep disturbances to improve disease outcomes.

Association between removable prosthesis-wearing and pneumonia: a systematic review and meta-analysis

BACKGROUND

A high burden of respiratory pathogens colonizing removable prosthesis surfaces suggests the potential of association between removable prosthesis-wearing and respiratory infections. Therefore, this systematic review and meta-analysis aimed to evaluate the evidence from clinical studies concerning the association between removable prosthesis-wearing and respiratory infections.

METHODS

Clinical studies that reported respiratory infections associated with adult patients wearing removable prostheses in any centers (hospitals and nursing homes) or communities were included. Literature was searched across five electronic databases (MEDLINE, Cochrane Library, EMBASE, Web of Science, and Scopus) to 28 May 2024. An additional search was performed for unpublished trials and references cited in related studies. The Newcastle-Ottawa Scale was employed for the quality assessment. The certainty assessment was established using GRADE. The results were pooled using a frequentist random-effects meta-analysis and the odds ratios generated.

RESULTS

A total of 1143 articles were identified. Thirteen articles had full-text articles screening and an additional two articles were added through reference linkage. Ultimately, six non-randomized clinical studies reporting various types of pneumonia contributed to this review. Overall odds of having pneumonia among prosthesis wearers were 1.43 (95% CI: 0.76 to 2.69) and 1.27 (95% CI: 1.11 to 1.46) using the random- and fixed-effects models, respectively. The heterogeneity in the meta-analysis was substantial. In subgroup analysis according to the study design, the heterogeneity within prospective studies was much reduced, I2 = 0% (p = 0.355). The certainty of the evidence evaluated using the GRADE approach was low to very low evidence for prosthesis wearers developing pneumonia based on studies.

CONCLUSIONS

There was no conclusive evidence from the non-randomized clinical studies supporting whether prosthesis-wearing is a risk factor for pneumonia based on outcomes from this review.

Prevalence of respiratory signs in dogs with chronic gastroenteropathy in a referral population in the United Kingdom: 42 cases (2020)

OBJECTIVES

To determine the prevalence of respiratory signs in a referral population of dogs with chronic gastroenteropathy in the United Kingdom, and to describe the epidemiology and clinical presentation of the affected dogs.

MATERIALS AND METHODS

Retrospective review of canine patients diagnosed with chronic gastroenteropathy in a referral centre in the United Kingdom. Data included signalment, gastrointestinal and respiratory signs, blood analysis results and, where present, diagnostic imaging techniques, endoscopy, videofluoroscopic swallow study, bronchoalveolar lavage results and treatment response. To be included, a follow-up of a minimum of 3 months was required. Cases were excluded if there was no minimum diagnostic dataset, the aetiology of the respiratory signs was other than gastrointestinal disease or a non-gastrointestinal systemic disease was the cause of the gastrointestinal signs.

RESULTS

One hundred and forty-eight dogs were included and 42 (28.4%) had concurrent respiratory signs. Gagging (69%) and vomiting (52.4%) were the most common gastrointestinal signs, while coughing (50%), tachypnoea (33.3%) and reverse sneezing (30.9%) were the most common respiratory signs. Abdominal ultrasound was performed in 31 (73.8%) while CT scan was the most common modality for thoracic (62.5%) and head (21.9%) imaging. Endoscopic procedures included gastrointestinal (54.8%), bronchoscopy (19%) and rhinoscopy (23.8%). Dietary modification was the most common treatment (66.67%). Eleven dogs (26.2%) had a relapse of the respiratory signs during the follow-up period, of which, nine (81.8%) had a concurrent relapse of the gastrointestinal signs.

CLINICAL SIGNIFICANCE

Concurrent respiratory signs in dogs with chronic gastroenteropathy are frequent. A clinical improvement of these respiratory signs might be achieved during the therapeutic management of gastrointestinal disorders.

Risk of pneumonia-related hospitalization after initiating angiotensin-converting enzyme inhibitors compared with angiotensin II receptor blockers: a retrospective cohort study using LIFE Study data

There is insufficient evidence that angiotensin-converting enzyme inhibitors (ACEIs) can reduce pneumonia by inducing a dry cough that confers a protective effect on the airway. To increase the evidence base on the clinical use of ACEIs for pneumonia prevention, this retrospective cohort study aimed to comparatively examine the risk of pneumonia-related hospitalization between ACEI initiators and angiotensin II receptor blocker (ARB) initiators using claims data from two Japanese municipalities. We identified persons who were newly prescribed any ACEI or ARB as their first antihypertensive agent between April 2016 and March 2020. The Fine-Gray method was applied to a Cox proportional hazards model to estimate the subdistribution hazard ratio (HR) of ACEI use (reference: ARB use) for pneumonia-related hospitalization, with death treated as a competing risk. Sex, age, comorbidities, medications, and pneumococcal immunization were included as covariates. The analysis was conducted on 1421 ACEI initiators and 9040 ARB initiators, and the adjusted subdistribution HR of ACEI use was estimated to be 1.21 (95% confidence interval: 0.89-1.65; P = 0.22). ACEI initiation did not demonstrate any significant preventive effect against pneumonia-related hospitalization relative to ARB initiation. There remains a lack of strong evidence on the protective effects of ACEIs, and further research is needed to ascertain the benefits of their use in preventing pneumonia. We conducted a large-scale retrospective cohort study using real-world healthcare data from a Japanese population. In this study, ACEI initiation did not indicate a significant preventive effect against pneumonia-related hospitalization.