Pulmonary stretch and lung mechanotransduction: implications for progression in the fibrotic lung.

Lung fibrosis results from the synergic interplay between regenerative deficits of the alveolar epithelium and dysregulated mechanisms of repair in response to alveolar and vascular damage, followed by progressive fibroblast and myofibroblast proliferation and excessive deposition of extracellular matrix. The increased parenchymal stiffness of fibrotic lungs significantly affects respiratory mechanics, making the lung more fragile and prone to non-physiological stress during spontaneous breathing and mechanical ventilation. Given their parenchymal inhomogeneity, fibrotic lungs may display an anisotropic response to mechanical stresses with different regional deformations (micro-strain). This behavior is not described by the standard stress-strain curve but follows the mechano-elastic models of “squishy balls”, where the elastic limit can be reached due to the excessive deformation of parenchymal areas with normal elasticity, surrounded by inelastic fibrous tissue or collapsed induration areas, which tend to protrude outside the fibrous ring. Increasing evidence has shown that non-physiological mechanical forces applied to fibrotic lungs with as34 sociated abnormal mechanotransduction could favor the progression of pulmonary fibrosis. With this review we aim at summarizing the state of the art on the relation between mechanical forces acting on the lung and biological response in pulmonary fibrosis, with a focus on the progression of damage in the fibrotic lung during spontaneous breathing and assisted ventilatory support

Ventilatory support and mechanical properties of the fibrotic lung acting as a "squishy ball"

Protective ventilation is the cornerstone of treatment of patients with the acute respiratory distress syndrome (ARDS); however, no studies have yet established the best ventilatory strategy to adopt when patients with acute exacerbation of interstitial lung disease (AE-ILD) are admitted to the intensive care unit. Due to the severe impairment of the respiratory mechanics, the fibrotic lung is at high risk of developing ventilator-induced lung injury, regardless of the lung fibrosis etiology. The purpose of this review is to analyze the effects of mechanical ventilation in AE-ILD and to increase the knowledge on the characteristics of fibrotic lung during artificial ventilation, introducing the concept of "squishy ball lung". The role of positive end-expiratory pressure is discussed, proposing a "lung resting strategy" as opposed to the "open lung approach". The review also discusses the practical management of AE-ILD patients discussing illustrative clinical cases

Integrated intErventional bronchoscopy in the treatment of locally adVanced non-small lung cancER with central Malignant airway Obstructions: a multicentric REtrospective study (EVERMORE).

Objectives- Despite new therapeutic perspectives, the presence of central airways occlusion (CAO) in patients with locally advanced non-small cell lung cancer (NSCLC) is associated with poor survival. There is no clear evidence on the clinical impact of interventional bronchoscopy as a part of an integrated treatment to cure these patients. Materials and methods- This retrospective cohort study was conducted in two teaching hospitals over a 10 years period (January 2010-January 2020) comparing patients with NSCLC at stage IIIB and CAO at disease onset treated with chemotherapy/radiotherapy (standard therapy-ST) with those receiving interventional bronchoscopy plus ST (integrated treatment-IT). Primary outcome was 1-year survival. The onset of respiratory events, symptoms-free interval, hospitalization, need for palliation, and overall mortality served as secondary outcomes. Results- A total of 100 patients were included, 60 in the IT and 40 in the ST group. Unadjusted Kaplan-Meier estimates showed greater effect of IT compared to ST on 1-year survival (HR=2.1 95%CI[1.1-4.8], p=0.003). IT showed a significantly higher survival gain over ST in those patients showing KRAS mutation (7.6 VS 0.8 months,<0.0001), a lumen occlusion >65% (6.6 VS 2.9 months,<0.001), and lacking the involvement of left bronchus (7 VS 2.3 months,<0.0001). Compared to ST, IT also showed a favorable difference in terms of new hospitalizations (p=0.03), symptom-free interval (p=0.02), and onset of atelectasis (p=0.01). Conclusions- In patients with NSCLC stage IIIB and CAO, additional interventional bronchoscopy might impact on 1-year survival. Genetic and anatomic phenotyping might allow identifying those patients who may gain life expectancy from the endoscopic intervention

Effects of cytokine blocking agents on hospital mortality in patients admitted to ICU with acute respiratory distress syndrome by SARS-CoV-2 infection: Retrospective cohort study

Background: The use of cytokine-blocking agents has been proposed to modulate the inflammatory response in patients with COVID-19. Tocilizumab and anakinra were included in the local protocol as an optional treatment in critically ill patients with acute respiratory distress syndrome (ARDS) by SARS-CoV-2 infection. This cohort study evaluated the effects of therapy with cytokine blocking agents on in-hospital mortality in COVID-19 patients requiring mechanical ventilation and admitted to intensive care unit. Methods: The association between therapy with tocilizumab or anakinra and in-hospital mortality was assessed in consecutive adult COVID-19 patients admitted to our ICU with moderate to severe ARDS. The association was evaluated by comparing patients who received to those who did not receive tocilizumab or anakinra and by using different multivariable Cox models adjusted for variables related to poor outcome, for the propensity to be treated with tocilizumab or anakinra and after patient matching. Results: Sixty-six patients who received immunotherapy (49 tocilizumab, 17 anakinra) and 28 patients who did not receive immunotherapy were included. The in-hospital crude mortality was 30,3% in treated patients and 50% in non-treated (OR 0.77, 95% CI 0.56-1.05, p=0.069). The adjusted Cox model showed an association between therapy with immunotherapy and in-hospital mortality (HR 0.40, 95% CI 0.19-0.83, p=0.015). This protective effect was further confirmed in the analysis adjusted for propensity score, in the propensity-matched cohort and in the cohort of patients with invasive mechanical ventilation within 2 hours after ICU admission. Conclusions: Although important limitations, our study showed that cytokine-blocking agents seem to be safe and to improve survival in COVID-19 patients admitted to ICU with ARDS and the need for mechanical ventilation

Response letter to Spinelli E, et al. and Jha

Not availabl

Spontaneous breathing and evolving phenotypes of lung damage in patients with COVID-19.

The mechanisms of acute respiratory failure other than inflammation and complicating the SARS-CoV-2 infection are still far from being fully understood, thus challenging the management of COVID-19 patients in the critical care setting. In this unforeseen scenario, the role of an individual’s excessive spontaneous breathing may acquire critical importance, being one potential and important driver of lung injury and disease progression. The consequences of this acute lung damage may impair lung structure forecasting the model of a fragile respiratory system. This perspective article aims to analyze the progression of injured lung phenotypes across the SARS-CoV-2 induced respiratory failure, pointing out the role of spontaneous breathing and also tackling the specific respiratory/ventilatory strategy required by the fragile lung type

Synthetic Models for Biological Trinuclear Copper Clusters. Trinuclear and Binuclear Complexes Derived from an Octadentate Tetraamine-Tetrabenzimidazole Ligand

Synthetic Models for Biological Trinuclear Copper Clusters. Trinuclear and Binuclear Complexes Derived from an Octadentate Tetraamine-Tetrabenzimidazole Ligan

Response Letter to Tuffet S, et al. and to Michard F, et al.

Not availabl

Early awake proning in critical and severe COVID-19 patients undergoing noninvasive respiratory support: a retrospective multicenter cohort study.

Introduction- In non-intubated patients with COVID-19 pneumonia, awake prone position associated with non-invasive respiratory support (NRS) demonstrated only physiological benefits. Nonetheless, it might be arguable that at least a selected subset of these patients is going to obtain significant clinical gains. Methods- This retrospective cohort study was conducted in two teaching hospitals comparing effects of awake prone position in addition to usual care (PP) with standard care alone (SC)in severe and critical COVID-19 patients undergoing NRS. Primary outcome was endotracheal intubation (ETI) rate. In-hospital mortality, time to ETI, tracheostomy, length of RICU and hospital stay served as secondary outcomes. Risk factors associated with ETI were also investigated in PP group. Results- A cohort of 114 patients (38 and 76 in PP and SC group, respectively) was analyzed. Greater ETI risk reduction rate was observed in PP as compared with SC both at unadjusted estimates (HR=0.45 95%CI [0.2-0.9], p=0.02), and even after adjustment for confounders (HR=0.59 95%CI[0.3-0.94], p=0.03). Compared with SC, PP group also showed a favorable difference in terms of days free from respiratory support, length of RICU and hospital stay, but not in mortality or tracheostomy rate. Conclusion- Early awake proning in spontaneously breathing Covid-19 patients is associated with a risk reduction of intubation rate.Findings prompt further randomized controlled trials to answer the pending questions on the real efficacy of PP in this setting