Mucins and Asthma : Are We Headed to the Revolutionary Road?

Mucus represents the first line of defense of our respiratory tract and mucociliary clearance is essential for maintaining the homeostasis of airway epithelium. The latter mechanisms are altered in asthma and mucus plugging of proximal and distal airways is the main cause of death in cases of fatal asthma. Starting from the influential review performed by Luke R. Bonser and David J. Erle in 2017, we discuss the latest evidence in terms of mucins regulation and potential treatment of mucus hypersecretion and tissue remodeling in severe asthma

Recruitment maneuvers in acute respiratory distress syndrome and during general anesthesia

The use of low tidal volume ventilation and low to moderate positive end-expiratory pressure (PEEP) levels is a widespread strategy to ventilate patients with non-injured lungs during general anesthesia and in intensive care as well with mild to moderate acute respiratory distress syndrome (ARDS). Higher PEEP levels have been recommended in severe ARDS. Due to the presence of alveolar collapse, recruitment maneuvers (RMs) by causing a transient elevation in airway pressure (i.e. transpulmonary pressure) have been suggested to improve lung inflation in non-inflated and poorly-inflated lung regions. Various types of RMs such as sustained inflation at high pressure, intermittent sighs and stepwise increases of PEEP and/or airway plateau inspiratory pressure have been proposed. The use of RMs has been associated with mixed results in terms of physiological and clinical outcomes. The optimal method for RMs has not yet been identified. The use of RMs is not standardized and left to the individual physician based on his/her experience. Based on the same grounds, RMs have been proposed to improve lung aeration during general anesthesia. The aim of this review was to present the clinical evidence supporting the use of RMs in patients with ARDS and during general anesthesia and as well their potential biological effects in experimental models of acute lung injury

Helmet CPAP to Treat Acute Hypoxemic Respiratory Failure in Patients with COVID-19 : a Management Strategy Proposal

Since the beginning of March 2020, the coronavirus disease 2019 (COVID-19) pandemic has caused more than 13,000 deaths in Europe, almost 54% of which has occurred in Italy. The Italian healthcare system is experiencing a stressful burden, especially in terms of intensive care assistance. In fact, the main clinical manifestation of COVID-19 patients is represented by an acute hypoxic respiratory failure secondary to bilateral pulmonary infiltrates, that in many cases, results in an acute respiratory distress syndrome and requires an invasive ventilator support. A precocious respiratory support with non-invasive ventilation or high flow oxygen should be avoided to limit the droplets' air-dispersion and the healthcare workers' contamination. The application of a continuous positive airway pressure (CPAP) by means of a helmet can represent an effective alternative to recruit diseased alveolar units and improve hypoxemia. It can also limit the room contamination, improve comfort for the patients, and allow for better clinical assistance with long-term tolerability. However, the initiation of a CPAP is not free from pitfalls. It requires a careful titration and monitoring to avoid a delayed intubation. Here, we discuss the rationale and some important considerations about timing, criteria, and monitoring requirements for patients with COVID-19 respiratory failure requiring a CPAP treatment

The Extracellular Matrix of the Lung: The Forgotten Friend!

The extracellular matrix represents the three-dimensional scaffold of the alveolar wall, which is composed of a layer of epithelial and endothelial cells, their basement membrane, and a thin layer of interstitial space lying between the capillary endothelium and the alveolar epithelium [1]. In the segment where the epithelial and endothelial basement membranes are not fused, the interstitium is composed of cells, a macromolecular fibrous component, and the fluid phase of the extracellular matrix, functioning as a three dimensional mechanical scaffold characterized by a fibrous mesh consisting mainly of collagen types I and III, which provides tensile strength, and elastin conveying an elastic recoil [2, 3]. The three-dimensional fiber mesh is filled with other macromolecules, mainly glycosaminoglycans (GAGs), which are the major components of the non-fibrillar compartment of the interstitium [4]. In the lung, the extracellular matrix plays several roles, providing: a) mechanical ten sile and compressive strength and elasticity; b) a low mechanical tissue compliance, thus contributing to the maintenance of normal interstitial fluid dynamics [5]; c) low resistive pathway for effective gas exchange [2]; d) control of cell behavior by binding of growth factors, chemokines, cytokines, and interaction with cell-surface receptors [6]