High-Flow Nasal Oxygen vs Noninvasive Ventilation in Patients With Acute Respiratory Failure: The RENOVATE Randomized Clinical Trial.

Importance: High-flow nasal oxygen (HFNO) and noninvasive ventilation (NIV) are commonly used respiratory support therapies for patients with acute respiratory failure (ARF).

Objective: To assess whether HFNO is noninferior to NIV on the rates of endotracheal intubation or death at 7 days in 5 patient groups with ARF.

Design, Setting, And Participants: This noninferiority, randomized clinical trial enrolled hospitalized adults (aged ≥18 years; classified as 5 patient groups with ARF: nonimmunocompromised with hypoxemia, immunocompromised with hypoxemia, chronic obstructive pulmonary disease [COPD] exacerbation with respiratory acidosis, acute cardiogenic pulmonary edema [ACPE], or hypoxemic COVID-19, which was added as a separate group on June 26, 2023) at 33 hospitals in Brazil between November 2019 and November 2023 (final follow-up: April 26, 2024).

An International Factorial Vignette-Based Survey of Intubation Decisions in Acute Hypoxemic Respiratory Failure.

Objectives: Intubation is a common procedure in acute hypoxemic respiratory failure (AHRF), with minimal evidence to guide decision-making. We conducted a survey of when to intubate patients with AHRF to measure the influence of clinical variables on intubation decision-making and quantify variability.

Design: Factorial vignette-based survey asking "Would you recommend intubation?" Respondents selected an ordinal recommendation from a 5-point scale ranging from "Definite no" to "Definite yes" for up to ten randomly allocated vignettes.

Pressure support, patient effort and tidal volume: a conceptual model for a non linear interaction.

Pressure support ventilation (PSV) is a form of assisted ventilation which has become frequently used, with the aim of partially unloading the patient's inspiratory muscles. Both under- and over-assistance should be avoided to target a lung- and diaphragm- protective ventilation. Herein, we propose a conceptual model, supported by actual data, to describe how patient and ventilator share the generation of tidal volume (Vt) in PSV and how respiratory system compliance (Crs) affects this interaction.

Does patient-ventilator asynchrony really matter?

Purpose Of Review: Past observational studies have reported the association between patient-ventilator asynchronies and poor clinical outcomes, namely longer duration of mechanical ventilation and higher mortality. But causality has remained undetermined. During the era of lung and diaphragm protective ventilation, should we revolutionize our clinical practice to detect and treat dyssynchrony?

Recent Findings: Clinicians' ability to recognize asynchronies is typically low.

A short duration of mechanical ventilation alters redox status in the diaphragm and aggravates inflammation in septic mice.

Background: Mechanical ventilation (MV) is a life support method used to treat patients with respiratory failure. High tidal volumes during MV can cause ventilator-induced lung injury (VILI), but also affect other organs, such as the diaphragm (Dia) causing ventilator-induced diaphragmatic dysfunction (VIDD). VIDD is often associated with a complicated course on MV.

Clinical implementation of advanced respiratory monitoring with esophageal pressure and electrical impedance tomography: results from an international survey and focus group discussion.

Background: Popularity of electrical impedance tomography (EIT) and esophageal pressure (Pes) monitoring in the ICU is increasing, but there is uncertainty regarding their bedside use within a personalized ventilation strategy. We aimed to gather insights about the current experiences and perceived role of these physiological monitoring techniques, and to identify barriers and facilitators/solutions for EIT and Pes implementation.

Methods: Qualitative study involving (1) a survey targeted at ICU clinicians with interest in advanced respiratory monitoring and (2) an expert focus group discussion.

Heterogeneous impact of Sighs on mortality in patients with acute hypoxemic respiratory failure: insights from the PROTECTION study.

Background: Sigh breaths may impact outcomes in acute hypoxemic respiratory failure (AHRF) during assisted mechanical ventilation. We investigated whether sigh breaths may impact mortality in predefined subgroups of patients enrolled in the PROTECTION multicenter clinical trial according to: 1.the physiological response in oxygenation to Sigh (responders versus non-responders) and 2.

Impact of airway closure and lung collapse on inhaled nitric oxide effect in acute lung injury: an experimental study.

Background: Efficacy of inhaled therapy such as Nitric Oxide (iNO) during mechanical ventilation may depend on airway patency. We hypothesized that airway closure and lung collapse, countered by positive end-expiratory pressure (PEEP), influence iNO efficacy. This could support the role of an adequate PEEP titration for inhalation therapy.

Pressure control plus spontaneous ventilation versus volume assist-control ventilation in acute respiratory distress syndrome. A randomised clinical trial.

Purpose: The aim of this study was to compare the effect of a pressure-controlled strategy allowing non-synchronised unassisted spontaneous ventilation (PC-SV) to a conventional volume assist-control strategy (ACV) on the outcome of patients with acute respiratory distress syndrome (ARDS).

Methods: Open-label randomised clinical trial in 22 intensive care units (ICU) in France. Seven hundred adults with moderate or severe ARDS (PaO/FiO < 200 mmHg) were enrolled from February 2013 to October 2018.

Continuous measurements of respiratory muscle blood flow and oxygen consumption using noninvasive frequency-domain near-infrared spectroscopy and diffuse correlation spectroscopy.

Prior studies of muscle blood flow and muscle-specific oxygen consumption have required invasive injection of dye and magnetic resonance imaging, respectively. Such measures have limited utility for continuous monitoring of the respiratory muscles. Frequency-domain near-infrared spectroscopy and diffuse correlation spectroscopy (FD-NIRS & DCS) can provide continuous surrogate measures of blood flow index (BF) and metabolic rate of oxygen consumption (MRO).

Reverse triggering ? a novel or previously missed phenomenon?

Background: Reverse triggering (RT) was described in 2013 as a form of patient-ventilator asynchrony, where patient's respiratory effort follows mechanical insufflation. Diagnosis requires esophageal pressure (P) or diaphragmatic electrical activity (EA), but RT can also be diagnosed using standard ventilator waveforms.

Hypothesis: We wondered (1) how frequently RT would be present but undetected in the figures from literature, especially before 2013; (2) whether it would be more prevalent in the era of small tidal volumes after 2000.

Expiratory flow limitation during mechanical ventilation: real-time detection and physiological subtypes.

Background: Tidal expiratory flow limitation (EFL) complicates the delivery of mechanical ventilation but is only diagnosed by performing specific manoeuvres. Instantaneous analysis of expiratory resistance (Rex) can be an alternative way to detect EFL without changing ventilatory settings. This study aimed to determine the agreement of EFL detection by Rex analysis and the PEEP reduction manoeuvre using contingency table and agreement coefficient.

Dyssynchronous diaphragm contractions impair diaphragm function in mechanically ventilated patients.

Background: Pre-clinical studies suggest that dyssynchronous diaphragm contractions during mechanical ventilation may cause acute diaphragm dysfunction. We aimed to describe the variability in diaphragm contractile loading conditions during mechanical ventilation and to establish whether dyssynchronous diaphragm contractions are associated with the development of impaired diaphragm dysfunction.

Methods: In patients receiving invasive mechanical ventilation for pneumonia, septic shock, acute respiratory distress syndrome, or acute brain injury, airway flow and pressure and diaphragm electrical activity (Edi) were recorded hourly around the clock for up to 7 days.