Update in acute lung injury and mechanical ventilation 2013

HIF1A-dependent induction of alveolar epithelial PFKFB3 dampens acute lung injury

Acute lung injury (ALI) is a severe form of lung inflammation causing acute respiratory distress syndrome in patients. ALI pathogenesis is closely linked to uncontrolled alveolar inflammation. We hypothesize that specific enzymes of the glycolytic pathway could function as key regulators of alveolar inflammation. Therefore, we screened isolated alveolar epithelia from mice exposed to ALI induced by injurious ventilation to assess their metabolic responses. These studies pointed us toward a selective role for isoform 3 of the 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB3). Pharmacologic inhibition or genetic deletion of Pfkfb3 in alveolar epithelia (Pfkfb3loxP/loxP SPC-ER-Cre+ mice) was associated with profound increases in ALI during injurious mechanical ventilation or acid instillation. Studies in genetic models linked Pfkfb3 expression and function to Hif1a. Not only did intratracheal pyruvate instillation reconstitute Pfkfb3loxP/loxP or Hif1aloxP/loxP SPC-ER-Cre+ mice, but pyruvate was also effective in ALI treatment of wild-type mice. Finally, proof-of-principle studies in human lung biopsies demonstrated increased PFKFB3 staining in injured lungs and colocalized PFKFB3 to alveolar epithelia. These studies reveal a specific role for PFKFB3 in counterbalancing alveolar inflammation and lay the groundwork for novel metabolic therapeutic approaches during ALI.

Comparison of three fixation methods for orotracheal intubation in 95 adults

BACKGROUND

The present study aimed to compare three fixation methods for orotracheal intubation.

METHODS

Through literature retrieval, the effects of the adhesive/twill tape method, fixator method, and adhesive/twill tape-fixator alternation method on patients with tracheal intubation in the intensive care unit (ICU) were compared.

RESULTS

The fixator and alternation methods were more effective in protecting the tongue mucosa and teeth. The alternation method was superior to the other two methods in maintaining the position of the endotracheal intubation. However, the difference in facial and lip injuries between the three methods was not statistically significant.

CONCLUSION

The fixator method can significantly reduce intraoral injury and is more suitable for older people with weak tongue mucosa and loose teeth. These are worth popularizing among a wider group.

Protocol for two-arm pragmatic cluster randomized hybrid implementation-effectiveness trial comparing two education strategies for improving the uptake of noninvasive ventilation in patients with severe COPD exacerbation

Background

COPD is the fourth leading cause of death in the US, and COPD exacerbations result in approximately 700,000 hospitalizations annually. Patients with acute respiratory failure due to severe COPD exacerbation are treated with invasive (IMV) or noninvasive mechanical ventilation (NIV). Although IMV reverses hypercapnia/hypoxia, it causes significant morbidity and mortality. There is strong evidence that patients treated with NIV have better outcomes, and NIV is recommended as first line therapy in these patients. Yet, several studies have demonstrated substantial variation in the use of NIV across hospitals, leading to preventable morbidity and mortality. Through a series of mixed-methods studies, we have found that successful implementation of NIV requires physicians, respiratory therapists (RTs), and nurses to communicate and collaborate effectively, suggesting that efforts to increase the use of NIV in COPD need to account for the complex and interdisciplinary nature of NIV delivery and the need for team coordination. Therefore, we propose to compare two educational strategies: online education (OLE) and interprofessional education (IPE) which targets complex team-based care in NIV delivery.

Methods and design

Twenty hospitals with low baseline rates of NIV use will be randomized to either the OLE or IPE study arm. The primary outcome of the trial is change in the hospital rate of NIV use among patients with COPD requiring ventilatory support. In aim 1, we will compare the uptake change over time of NIV use among patients with COPD in hospitals enrolled in the two arms. In aim 2, we will explore mediators’ role (respiratory therapist autonomy and team functionality) on the relationship between the implementation strategies and implementation effectiveness. Finally, in aim 3, through interviews with providers, we will assess acceptability and feasibility of the educational training.

Discussions

This study will be among the first to carefully test the impact of IPE in the inpatient setting. This work promises to change practice by offering approaches to facilitate greater uptake of NIV and may generalize to other interventions directed to seriously-ill patients.

Trial registration

Name of registry: ClinicalTrials.gov

Trial registration number: NCT04206735

Date of Registration: December 20, 2019

DNA repair and genomic stability in lungs affected by acute injury

Acute pulmonary injury, or acute respiratory distress syndrome, has a high incidence in elderly individuals and high mortality in its most severe degree, becoming a challenge to public health due to pathophysiological complications and increased economic burden. Acute pulmonary injury can develop from sepsis, septic shock, and pancreatitis causing reduction of alveolar airspace due to hyperinflammatory response. Oxidative stress acts directly on the maintenance of inflammation, resulting in tissue injury, as well as inducing DNA damages. Once the DNA is damaged, enzymatic DNA repair mechanisms act on lesions in order to maintain genomic stability and, consequently, contribute to cell viability and homeostasis. Although palliative treatment based on mechanical ventilation and antibiotic using have a kind of efficacy, therapies based on modulation of DNA repair and genomic stability could be effective for improving repair and recovery of lung tissue in patients with acute pulmonary injury.

Risk Trajectories of Readmission and Death in the First Year after Hospitalization for Chronic Obstructive Pulmonary Disease

RATIONALE

Characterization of the dynamic nature of posthospital risk in chronic obstructive pulmonary disease (COPD) is needed to provide counseling and plan clinical services.

OBJECTIVES

To analyze risk of readmission and death after discharge for COPD among Medicare beneficiaries aged 65 years and older and to determine the association between ventilator support and risk trajectory.

METHODS

We computed daily absolute risks of hospital readmission and death for 1 year after discharge for COPD, stratified by ventilator support. We determined the time required for risks to decline by 50% from maximum daily values after discharge and for daily risks to plateau. We compared risks with those found in the general elderly population.

MEASUREMENTS AND MAIN RESULTS

Among 2,340,637 hospitalizations, the readmission rate at 1 year was 64.2%, including 63.5%, 66.0%, and 64.1% among those receiving invasive, noninvasive, and no ventilation, respectively. Among 1,283,069 hospitalizations, mortality at 1 year was 26.2%, including 45.7%, 41.8%, and 24.4% among those same respective groups. Daily risk of readmission declined by 50% within 28, 39, and 43 days and plateaued at 46, 54, and 61 days among those receiving invasive, noninvasive, and no ventilation, respectively. Risk of death declined by 50% by 3, 4, and 17 days and plateaued by 21, 18, and 24 days in the same respective groups. Risks of hospitalization and death were significantly higher after discharge for COPD than among the general Medicare population.

CONCLUSIONS

Discharge from the hospital is associated with prolonged risks of readmission and death that vary with need for ventilator support. Interventions limited to the first month after discharge may be insufficient to improve longitudinal outcomes.

Molecular and Immune Biomarkers in Acute Respiratory Distress Syndrome: A Perspective From Members of the Pulmonary Pathology Society

Acute respiratory distress syndrome (ARDS) is a multifactorial syndrome with high morbidity and mortality rates, characterized by deficiency in gas exchange and lung mechanics that lead to hypoxemia, dyspnea, and respiratory failure. Histologically, ARDS is characterized by an acute, exudative phase, combining diffuse alveolar damage and noncardiogenic edema, followed by a later fibroproliferative phase. Despite an enhanced understanding of ARDS pathogenesis, the capacity to predict the development of ARDS and to risk-stratify patients with the disease remains limited. Biomarkers may help to identify patients at the greatest risk of developing ARDS, to evaluate response to therapy, to predict outcome, and to improve clinical trials. The ARDS pathogenesis is presented in this article, as well as concepts and information on biomarkers that are currently used clinically or are available for laboratory use by academic and practicing pathologists and the developing and validating of new assays, focusing on the assays' major biologic roles in lung injury and/or repair and to ultimately suggest innovative, therapeutic approaches.

Metabolomics and Its Application to Acute Lung Diseases

Metabolomics is a rapidly expanding field of systems biology that is gaining significant attention in many areas of biomedical research. Also known as metabonomics, it comprises the analysis of all small molecules or metabolites that are present within an organism or a specific compartment of the body. Metabolite detection and quantification provide a valuable addition to genomics and proteomics and give unique insights into metabolic changes that occur in tangent to alterations in gene and protein activity that are associated with disease. As a novel approach to understanding disease, metabolomics provides a "snapshot" in time of all metabolites present in a biological sample such as whole blood, plasma, serum, urine, and many other specimens that may be obtained from either patients or experimental models. In this article, we review the burgeoning field of metabolomics in its application to acute lung diseases, specifically pneumonia and acute respiratory disease syndrome (ARDS). We also discuss the potential applications of metabolomics for monitoring exposure to aerosolized environmental toxins. Recent reports have suggested that metabolomics analysis using nuclear magnetic resonance (NMR) and mass spectrometry (MS) approaches may provide clinicians with the opportunity to identify new biomarkers that may predict progression to more severe disease, such as sepsis, which kills many patients each year. In addition, metabolomics may provide more detailed phenotyping of patient heterogeneity, which is needed to achieve the goal of precision medicine. However, although several experimental and clinical metabolomics studies have been conducted assessing the application of the science to acute lung diseases, only incremental progress has been made. Specifically, little is known about the metabolic phenotypes of these illnesses. These data are needed to substantiate metabolomics biomarker credentials so that clinicians can employ them for clinical decision-making and investigators can use them to design clinical trials.

Hypoxia signaling during acute lung injury

Acute lung injury (ALI) is an inflammatory lung disease that manifests itself in patients as acute respiratory distress syndrome and thereby contributes significantly to the morbidity and mortality of patients experiencing critical illness. Even though it may seem counterintuitive, as the lungs are typically well-oxygenated organs, hypoxia signaling pathways have recently been implicated in the resolution of ALI. For example, functional studies suggest that transcriptional responses under the control of the hypoxia-inducible factor (HIF) are critical in optimizing alveolar epithelial carbohydrate metabolism, and thereby dampen lung inflammation during ALI. In the present review we discuss functional roles of oxygenation, hypoxia and HIFs during ALI, mechanisms of how HIFs are stabilized during lung inflammation, and how HIFs can mediate lung protection during ALI.