Does the Intensity of Therapy Correspond to the Severity of Acute Respiratory Distress Syndrome (ARDS)?

The intensity of respiratory treatment in acute respiratory distress syndrome (ARDS) is traditionally adjusted based on oxygenation severity, as defined by the mild, moderate, and severe Berlin classifications. However, ventilator-induced lung injury (VILI) is primarily determined by ventilator settings, namely tidal volume, respiratory rate, and positive end-expiratory pressure (PEEP). All these variables, along with respiratory elastance, are included in the concept of mechanical power.

Predictors of VILI risk: driving pressure, 4DPRR and mechanical power ratio-an experimental study.

Background: Ventilator-induced lung injury (VILI) is one of the side effects of mechanical ventilation during ARDS; a prerequisite for averting it is the quantification of its risk factors associated with a given ventilatory setting. Many clinical variables have been proposed as predictors of VILI, of which driving pressure is the most widely used. In this study, we compared the performance of driving pressure, four times the driving pressure added to respiratory rate (4DPRR) and mechanical power ratio.

Rethinking ARDS classification: oxygenation impairment fails to predict VILI risk.

Purpose: The selection and intensity of respiratory support for ARDS are guided by PaO/FiO. However, ventilator-induced lung injury (VILI) is linked to respiratory mechanics and ventilator settings. We explored whether the VILI risk is related to ARDS severity based on oxygenation.

Impact of Fluid Balance on the Development of Lung Injury.

Rationale: The pathophysiological relationship between fluid administration, fluid balance, and mechanical ventilation in the development of lung injury is unclear.

Objectives: To quantify the relative contribution of mechanical power and fluid balance in the development of lung injury.

Methods: Thirty-nine healthy female pigs, divided into four groups, were ventilated for 48 hours with high (~18J/min) or low (~6J/min) mechanical power; and high (~4L) or low (~1L) targeted fluid balance.

Acute renal response to changes in carbon dioxide in mechanically ventilated female pigs.

Kidney response to acute and mechanically induced variation in ventilation associated with different levels of PEEP has not been investigated. We aimed to quantify the effect of ventilatory settings on renal acid-base compensation. Forty-one pigs undergoing hypo- (<0.

Non-invasive respiratory support in elderly hospitalized patients.

Introduction: The proportion of elderly people among hospitalized patients is rapidly growing. Between 7% to 25% of ICU patients are aged 85 and over and noninvasive respiratory support is often offered to avoid the risks of invasive mechanical ventilation or in patients with a 'do-not-intubate' order. However, while noninvasive respiratory support has been extensively studied in the general population, there is limited data available on its efficacy in elderly patients with ARF.

Mechanical power ratio threshold for ventilator-induced lung injury.

Rationale: Mechanical power (MP) is a summary variable incorporating all causes of ventilator-induced-lung-injury (VILI). We expressed MP as the ratio between observed and normal expected values (MP).

Objective: To define a threshold value of MP leading to the development of VILI.

Mechanical power during robotic-assisted laparoscopic prostatectomy: an observational study.

Background: Robotic-assisted laparoscopic radical prostatectomy (RALP) requires pneumoperitoneum and steep Trendelenburg position. Our aim was to investigate the influence of the combination of pneumoperitoneum and Trendelenburg position on mechanical power and its components during RALP.

Methods: Sixty-one prospectively enrolled patients scheduled for RALP were studied in supine position before surgery, during pneumoperitoneum and Trendelenburg position and in supine position after surgery at constant ventilatory setting.

Short-term effects of small volume saline infusion on acid base equilibrium in critically ill patients.

Background: Short-term acid-base effects of 0.9% saline solution infusion are not well described. Aim of this study was to assess the effects of a fluid challenge with 0.

The evaluation of a non-invasive respiratory monitor in ards patients in supine and prone position.

Purpose: The Prone positioning in addition to non invasive respiratory support is commonly used in patients with acute respiratory failure. The aim of this study was to assess the accuracy of an impedance-based non-invasive respiratory volume monitor (RVM) in supine and in prone position.

Methods: In sedated, paralyzed and mechanically ventilated patients in volume-controlled mode with acute respiratory distress syndrome scheduled for prone positioning it was measured and compared non-invasively tidal volume and respiratory rate provided by the RVM in supine and, subsequently, in prone position, by maintaining unchanged the ventilatory setting.

Determinants of acute kidney injury during high-power mechanical ventilation: secondary analysis from experimental data.

Background: The individual components of mechanical ventilation may have distinct effects on kidney perfusion and on the risk of developing acute kidney injury; we aimed to explore ventilatory predictors of acute kidney failure and the hemodynamic changes consequent to experimental high-power mechanical ventilation.

Methods: Secondary analysis of two animal studies focused on the outcomes of different mechanical power settings, including 78 pigs mechanically ventilated with high mechanical power for 48 h. The animals were categorized in four groups in accordance with the RIFLE criteria for acute kidney injury (AKI), using the end-experimental creatinine: (1) NO AKI: no increase in creatinine; (2) RIFLE 1-Risk: increase of creatinine of > 50%; (3) RIFLE 2-Injury: two-fold increase of creatinine; (4) RIFLE 3-Failure: three-fold increase of creatinine; RESULTS: The main ventilatory parameter associated with AKI was the positive end-expiratory pressure (PEEP) component of mechanical power.

Impact of mechanical power and positive end expiratory pressure on central vs. mixed oxygen and carbon dioxide related variables in a population of female piglets.

Introduction: The use of the pulmonary artery catheter has decreased overtime; central venous blood gases are generally used in place of mixed venous samples. We want to evaluate the accuracy of oxygen and carbon dioxide related parameters from a central versus a mixed venous sample, and whether this difference is influenced by mechanical ventilation.

Materials And Methods: We analyzed 78 healthy female piglets ventilated with different mechanical power.

Estimation of normal lung weight index in healthy female domestic pigs.

Introduction: Lung weight is an important study endpoint to assess lung edema in porcine experiments on acute respiratory distress syndrome and ventilatory induced lung injury. Evidence on the relationship between lung-body weight relationship is lacking in the literature. The aim of this work is to provide a reference equation between normal lung and body weight in female domestic piglets.

Early time-course of respiratory mechanics, mechanical power and gas exchange in ARDS patients.

Purpose: To describe the clinical course of ARDS during the first three days of mechanical ventilation, to compare ventilatory setting, respiratory mechanics and gas exchange variables collected during the first three days of mechanical ventilation between patients who survived and died during intensive care unit (ICU) stay and to investigate the variables associated with mortality at ICU admission and throughout the first three days of mechanical ventilation.

Materials And Methods: Prospective observational study. Mechanically ventilated ARDS patients were studied at ICU admission and for the following three days.

Machine learning predicts lung recruitment in acute respiratory distress syndrome using single lung CT scan.

Background: To develop and validate classifier models that could be used to identify patients with a high percentage of potentially recruitable lung from readily available clinical data and from single CT scan quantitative analysis at intensive care unit admission. 221 retrospectively enrolled mechanically ventilated, sedated and paralyzed patients with acute respiratory distress syndrome (ARDS) underwent a PEEP trial at 5 and 15 cmHO of PEEP and two lung CT scans performed at 5 and 45 cmHO of airway pressure. Lung recruitability was defined at first as percent change in not aerated tissue between 5 and 45 cmHO (radiologically defined; recruiters: Δnon-aerated tissue  > 15%) and secondly as change in PaO between 5 and 15 cmHO (gas exchange-defined; recruiters: ΔPaO2  > 24 mmHg).

Differences in clinical characteristics and quantitative lung CT features between vaccinated and not vaccinated hospitalized COVID-19 patients in Italy.

Background: To evaluate the differences in the clinical characteristics and severity of lung impairment, assessed by quantitative lung CT scan, between vaccinated and non-vaccinated hospitalized patients with COVID-19; and to identify the variables with best prognostic prediction according to SARS-CoV-2 vaccination status. We recorded clinical, laboratory and quantitative lung CT scan data in 684 consecutive patients [580 (84.8%) vaccinated, and 104 (15.

High- versus Low-Flow Extracorporeal Respiratory Support in Experimental Hypoxemic Acute Lung Injury.

In the EOLIA (ECMO to Rescue Lung Injury in Severe ARDS) trial, oxygenation was similar between intervention and conventional groups, whereas [Formula: see text]e was reduced in the intervention group. Comparable reductions in ventilation intensity are theoretically possible with low-flow extracorporeal CO removal (ECCOR), provided oxygenation remains acceptable. To compare the effects of ECCOR and extracorporeal membrane oxygenation (ECMO) on gas exchange, respiratory mechanics, and hemodynamics in animal models of pulmonary (intratracheal hydrochloric acid) and extrapulmonary (intravenous oleic acid) lung injury.

Mechanical Power Ratio and Respiratory Treatment Escalation in COVID-19 Pneumonia: A Secondary Analysis of a Prospectively Enrolled Cohort.

Background: Under the hypothesis that mechanical power ratio could identify the spontaneously breathing patients with a higher risk of respiratory failure, this study assessed lung mechanics in nonintubated patients with COVID-19 pneumonia, aiming to (1) describe their characteristics; (2) compare lung mechanics between patients who received respiratory treatment escalation and those who did not; and (3) identify variables associated with the need for respiratory treatment escalation.

Methods: Secondary analysis of prospectively enrolled cohort involving 111 consecutive spontaneously breathing adults receiving continuous positive airway pressure, enrolled from September 2020 to December 2021. Lung mechanics and other previously reported predictive indices were calculated, as well as a novel variable: the mechanical power ratio (the ratio between the actual and the expected baseline mechanical power).

Left Ventricular Diastolic Dysfunction in ARDS Patients.

Background: The aim of this study was to evaluate the possible presence of diastolic dysfunction and its possible effects in terms of respiratory mechanics, gas exchange and lung recruitability in mechanically ventilated ARDS.

Methods: Consecutive patients admitted in intensive care unit (ICU) with ARDS were enrolled. Echocardiographic evaluation was acquired at clinical PEEP level.