Impact of Positive End-Expiratory Pressure and FiO on Lung Mechanics and Intrapulmonary Shunt in Mechanically Ventilated Patients with ARDS Due to COVID-19 Pneumonia.

This study aimed to investigate the effects of inspired oxygen fraction (FiO) and positive end-expiratory pressure (PEEP) on gas exchange in mechanically ventilated patients with COVID-19. Two FiO (100%, 40%) were tested at 3 decreasing levels of PEEP (15, 10, and 5 cmHO). At each FiO and PEEP, gas exchange, respiratory mechanics, hemodynamics, and the distribution of ventilation and perfusion were assessed with electrical impedance tomography.

Incidence of asymptomatic catheter-related thrombosis in intensive care unit patients: a prospective cohort study.

Background: Catheter-related thrombosis (CRT) incidence, rate, and risk factors vary in literature due to differences in populations, catheters, diagnostic methods, and statistical approaches. The aim of this single-center, prospective, observational study was to assess incidence, incidence rate (IR), cumulative incidence, and risk factors by means of IR ratio (IRR) of asymptomatic CRT in a non-oncologic Intensive Care Unit (ICU) population. CRT development was assessed daily by means of ultrasound screening.

Mechanical Ventilation for COVID-19 Patients.

Non-invasive ventilation (NIV) or invasive mechanical ventilation (MV) is frequently needed in patients with acute hypoxemic respiratory failure due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. While NIV can be delivered in hospital wards and nonintensive care environments, intubated patients require intensive care unit (ICU) admission and support. Thus, the lack of ICU beds generated by the pandemic has often forced the use of NIV in severely hypoxemic patients treated outside the ICU.

Individualized positive end-expiratory pressure guided by end-expiratory lung volume in early acute respiratory distress syndrome: study protocol for the multicenter, randomized IPERPEEP trial.

Background: In acute respiratory distress syndrome (ARDS), response to positive end-expiratory pressure (PEEP) is variable according to different degrees of lung recruitability. The search for a tool to individualize PEEP based on patients' individual response is warranted. End-expiratory lung volume (EELV) assessment by nitrogen washing-washout aids bedside estimation of PEEP-induced alveolar recruitment and may therefore help titrate PEEP on patient's individual recruitability.

Prone position in intubated, mechanically ventilated patients with COVID-19: a multi-centric study of more than 1000 patients.

Background: Limited data are available on the use of prone position in intubated, invasively ventilated patients with Coronavirus disease-19 (COVID-19). Aim of this study is to investigate the use and effect of prone position in this population during the first 2020 pandemic wave.

Methods: Retrospective, multicentre, national cohort study conducted between February 24 and June 14, 2020, in 24 Italian Intensive Care Units (ICU) on adult patients needing invasive mechanical ventilation for respiratory failure caused by COVID-19.

Viscoelastic Coagulation Monitor as a Novel Device to Assess Coagulation at the Bedside. A Single-Center Experience During the COVID-19 Pandemic.

Viscoelastic coagulation monitor (VCM) is a portable device developed to evaluate the viscoelastic properties of whole blood activated by contact with glass. In this study, VCM was employed to analyze the viscoelastic profiles of 36 COVID-19 intensive care patients. Full anticoagulant dose heparin (unfractionated [UFH]; low molecular weight [LMWH]) was administrated to all patients.

The Medical Emergency Team in Italy: an overview of in-hospital emergencies response.

Background And Aim: Medical Emergency Team (MET), implemented in many hospitals worldwide, aims to improve the safety of in-hospital patients whose condition is deteriorating. This study describes MET presence and organization in the Italian National Healthcare System Hospitals.

Methods: A national survey with an online questionnaire was performed.

Monitoring respiratory mechanics during assisted ventilation.

Purpose Of Review: Accurate monitoring of the mechanical properties of the respiratory system is crucial to understand the pathophysiological mechanisms of respiratory failure in mechanically ventilated patients, to optimize mechanical ventilation settings and to reduce ventilator-induced lung injury. However, although the assessment of respiratory mechanics is simple in patients undergoing fully controlled ventilation, it becomes quite challenging in the presence of spontaneous breathing activity. Aim of the present review is to describe how the different components of respiratory mechanics [resistance, static compliance, and intrinsic positive end-expiratory pressure (PEEP)] can be measured at the bedside during assisted modes of ventilation.

Respiratory Mechanics, Lung Recruitability, and Gas Exchange in Pulmonary and Extrapulmonary Acute Respiratory Distress Syndrome.

Objectives: Acute respiratory distress syndrome is a clinical syndrome characterized by a refractory hypoxemia due to an inflammatory and high permeability pulmonary edema secondary to direct or indirect lung insult (pulmonary and extrapulmonary form). Aim of this study was to evaluate in a large database of acute respiratory distress syndrome patients, the pulmonary versus extrapulmonary form in terms of respiratory mechanics, lung recruitment, gas exchange, and positive end-expiratory pressure response.

Design: A secondary analysis of previously published data.

Inflammation and primary graft dysfunction after lung transplantation: CT-PET findings.

Background: The leading cause of early mortality after lung transplantation is Primary graft dysfunction (PGD). We assessed the lung inflammation, inflation status and inhomogeneities after lung transplantation. Our purpose was to investigate the possible differences between patients who did or did not develop PGD.

Thromboelastography-based anticoagulation management during extracorporeal membrane oxygenation: a safety and feasibility pilot study.

Background: There is no consensus on the management of anticoagulation during extracorporeal membrane oxygenation (ECMO). ECMO is currently burdened by a high rate of hemostatic complications, possibly associated with inadequate monitoring of heparin anticoagulation. This study aims to assess the safety and feasibility of an anticoagulation protocol for patients undergoing ECMO based on thromboelastography (TEG) as opposed to an activated partial thromboplastin time (aPTT)-based protocol.

Opening pressures and atelectrauma in acute respiratory distress syndrome.

Purpose: Open lung strategy during ARDS aims to decrease the ventilator-induced lung injury by minimizing the atelectrauma and stress/strain maldistribution. We aim to assess how much of the lung is opened and kept open within the limits of mechanical ventilation considered safe (i.e.

Airway driving pressure and lung stress in ARDS patients.

Background: Lung-protective ventilation strategy suggests the use of low tidal volume, depending on ideal body weight, and adequate levels of PEEP. However, reducing tidal volume according to ideal body weight does not always prevent overstress and overstrain. On the contrary, titrating mechanical ventilation on airway driving pressure, computed as airway pressure changes from PEEP to end-inspiratory plateau pressure, equivalent to the ratio between the tidal volume and compliance of respiratory system, should better reflect lung injury.

Severe hypoxemia: which strategy to choose.

Background: Acute respiratory distress syndrome (ARDS) is characterized by a noncardiogenic pulmonary edema with bilateral chest X-ray opacities and reduction in lung compliance, and the hallmark of the syndrome is hypoxemia refractory to oxygen therapy. Severe hypoxemia (PaO2/FiO2 < 100 mmHg), which defines severe ARDS, can be found in 20-30 % of the patients and is associated with the highest mortality rate. Although the standard supportive treatment remains mechanical ventilation (noninvasive and invasive), possible adjuvant therapies can be considered.

Mechanical Power and Development of Ventilator-induced Lung Injury.

Background: The ventilator works mechanically on the lung parenchyma. The authors set out to obtain the proof of concept that ventilator-induced lung injury (VILI) depends on the mechanical power applied to the lung.

Methods: Mechanical power was defined as the function of transpulmonary pressure, tidal volume (TV), and respiratory rate.

Respiratory mechanics and lung stress/strain in children with acute respiratory distress syndrome.

Background: In sedated and paralyzed children with acute respiratory failure, the compliance of respiratory system and functional residual capacity were significantly reduced compared with healthy subjects. However, no major studies in children with ARDS have investigated the role of different levels of PEEP and tidal volume on the partitioned respiratory mechanic (lung and chest wall), stress (transpulmonary pressure) and strain (inflated volume above the functional residual capacity).

Methods: The end-expiratory lung volume was measured using a simplified closed circuit helium dilution method.

Lung Recruitment Assessed by Respiratory Mechanics and Computed Tomography in Patients with Acute Respiratory Distress Syndrome. What Is the Relationship?

Rationale: The assessment of lung recruitability in patients with acute respiratory distress syndrome (ARDS) may be important for planning recruitment maneuvers and setting positive end-expiratory pressure (PEEP).

Objectives: To determine whether lung recruitment measured by respiratory mechanics is comparable with lung recruitment measured by computed tomography (CT).

Methods: In 22 patients with ARDS, lung recruitment was assessed at 5 and 15 cm H2O PEEP by using respiratory mechanics-based methods: (1) increase in gas volume between two pressure-volume curves (P-Vrs curve); (2) increase in gas volume measured and predicted on the basis of expected end-expiratory lung volume and static compliance of the respiratory system (EELV-Cst,rs); as well as by CT scan: (3) decrease in noninflated lung tissue (CT [not inflated]); and (4) decrease in noninflated and poorly inflated tissue (CT [not + poorly inflated]).

Lung inhomogeneities, inflation and [18F]2-fluoro-2-deoxy-D-glucose uptake rate in acute respiratory distress syndrome.

The aim of the study was to determine the size and location of homogeneous inflamed/noninflamed and inhomogeneous inflamed/noninflamed lung compartments and their association with acute respiratory distress syndrome (ARDS) severity.In total, 20 ARDS patients underwent 5 and 45 cmH2O computed tomography (CT) scans to measure lung recruitability. [(18)F]2-fluoro-2-deoxy-d-glucose ([(18)F]FDG) uptake and lung inhomogeneities were quantified with a positron emission tomography-CT scan at 10 cmH2O.

Lung inhomogeneities and time course of ventilator-induced mechanical injuries.

Background: During mechanical ventilation, stress and strain may be locally multiplied in an inhomogeneous lung. The authors investigated whether, in healthy lungs, during high pressure/volume ventilation, injury begins at the interface of naturally inhomogeneous structures as visceral pleura, bronchi, vessels, and alveoli. The authors wished also to characterize the nature of the lesions (collapse vs.

Lung recruitability is better estimated according to the Berlin definition of acute respiratory distress syndrome at standard 5 cm H2O rather than higher positive end-expiratory pressure: a retrospective cohort study.

Objectives: The Berlin definition of acute respiratory distress syndrome has introduced three classes of severity according to PaO2/FIO2 thresholds. The level of positive end-expiratory pressure applied may greatly affect PaO2/FIO2, thereby masking acute respiratory distress syndrome severity, which should reflect the underlying lung injury (lung edema and recruitability). We hypothesized that the assessment of acute respiratory distress syndrome severity at standardized low positive end-expiratory pressure may improve the association between the underlying lung injury, as detected by CT, and PaO2/FIO2-derived severity.

The assessment of transpulmonary pressure in mechanically ventilated ARDS patients.

Purpose: The optimal method for estimating transpulmonary pressure (i.e. the fraction of the airway pressure transmitted to the lung) has not yet been established.

Compressive forces and computed tomography-derived positive end-expiratory pressure in acute respiratory distress syndrome.

Background: It has been suggested that higher positive end-expiratory pressure (PEEP) should be used only in patients with higher lung recruitability. In this study, the authors investigated the relationship between the recruitability and the PEEP necessary to counteract the compressive forces leading to lung collapse.

Methods: Fifty-one patients with acute respiratory distress syndrome (7 mild, 33 moderate, and 11 severe) were enrolled.

Low-dose chest computed tomography for quantitative and visual anatomical analysis in patients with acute respiratory distress syndrome.

Purpose: Chest computed tomography (CT) is a fundamental tool for the characterization of acute respiratory distress syndrome (ARDS). Its frequent use is, however, hindered by the associated radiation exposure. The aim of the present study was to evaluate, in patients with ARDS, the accuracy of quantitative and visual anatomical lung analysis performed on low-dose CT.