Approaches and techniques to avoid development or progression of acute respiratory distress syndrome

Calculated Plasma Volume Status Is Associated With Mortality in Acute Respiratory Distress Syndrome

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The optimal method to assess fluid overload in acute respiratory distress syndrome is not known, and current techniques have limitations. Plasma volume status has emerged as a noninvasive method to assess volume status and is defined as the percentage alteration from ideal plasma volume. We hypothesized that plasma volume status would suggest the presence of significant excess volume and therefore correlate with mortality in acute respiratory distress syndrome.

GTS-21 Reduces Inflammation in Acute Lung Injury by Regulating M1 Polarization and Function of Alveolar Macrophages

BACKGROUND

Acute lung injury (ALI) is a severe outcome of sepsis. Alveolar macrophages (AMs) play key roles in defense, resolution in ALI. The polarization of AMs is dependent on micro environmental stimuli and might influence the progression of ALI. Gainesville Tokushima scientists (GTS)-21, a selective α7 nicotinic acetylcholine receptor agonist of the cholinergic anti-inflammatory pathway (CAP), has recently been established to be promising in the treatment of ALI. However, the molecular mechanism underlying the GTS-21-mediated suppression of inflammatory responses has been explored only partially. In this study, we examined the relation between GTS-21 and AM polarization in ALI.

METHODS

The adoptive transfer of M1 (classically activated) and M2 (alternatively activated)-polarized AMs was performed to AM-depleted ALI mice, along with the administration of GTS-21 in a murine model of lipopolysaccharide (LPS)-induced ALI and in isolated AMs that had been stimulated by LPS in vitro.

RESULTS

The adoptive transfer of M1-polarized AMs aggravated the inflammatory response in the lung in contrast to the adoptive transfer of M2-polarized AMs. GTS-21 protected the lung from the effect of LPS, preventing injury and decreasing the number of AMs, AM-related pro-inflammatory cytokine levels, high mobility group box 1 expression levels in AMs. In addition, GTS-21 significantly diminished the number of M1-polarized AM and increased the number of M2-polarized AM, by flow cytometry, RT-PCR, enzyme-linked immunosorbent assay, and the Arg1 and iNOS activity assays.

CONCLUSION

The GTS-21 substantially ameliorates LPS-induced ALI. This protection is predominantly associated with the inhibition of pulmonary AM M1 polarization and alteration in AM function.

Acute lung injury in patients with COVID-19 infection

During the 2020 Spring Festival in China, the outbreak of a novel coronavirus, named COVID-19 by WHO, brought on a worldwide panic. According to the clinical data of infected patients, radiologic evidence of lung edema is common and deserves clinical attention. Lung edema is a manifestation of acute lung injury (ALI) and may progress to hypoxemia and potentially acute respiratory distress syndrome (ARDS). Patients diagnosed with ARDS have poorer prognosis and potentially higher mortality. Although no effective treatment is formally approved for COVID-19 infection, support of ventilation with oxygen therapy and sometimes mechanical ventilation is often required. Treatment with systemic and/or local glucocorticoids might be helpful to alleviate the pulmonary inflammation and edema, which may decrease the development and/or consequences of ARDS. In this article, we focus on the lung edema and ALI of patients with this widely transmitted COVID-19 infection in order to provide clinical indications and potential therapeutic targets for clinicians and researchers.