Continuous On-Demand Diaphragm Neurostimulation to Prevent Diaphragm Inactivity During Mechanical Ventilation: A Phase 1 Clinical Trial (STIMULUS).

Rationale: Diaphragm inactivity during invasive mechanical ventilation may predispose the lung and diaphragm to injury, and is associated with adverse clinical outcomes.

Objectives: Assess the feasibility of continuous on-demand diaphragm neurostimulation-assisted mechanical ventilation to maintain diaphragm activity in the absence of respiratory drive for at least 24 hours of mechanical ventilation.

Methods: In a single center phase 1 clinical trial, patients receiving invasive mechanical ventilation for acute hypoxemic respiratory failure or after thoracic surgery underwent transvenous diaphragm neurostimulation delivered in synchrony with mechanical ventilation.

Association of Standardized Liberation Trials and Duration of V-V ECMO in Patients with Acute Respiratory Failure.

Rationale: There is a paucity of evidence around strategies to liberate patients from veno-venous extracorporeal membrane oxygenation (V-V ECMO) for acute respiratory failure.

Objectives: The primary aim of this study was to determine if adopting standardized liberation trials (SLTs) for V-V ECMO is associated with duration of ECMO. The secondary aim was to identify factors associated with unsafe liberation, and the effects of unsafe liberation on mortality to ICU discharge.

Effect of Higher or Lower PEEP on Pendelluft During Spontaneous Breathing Efforts in Acute Hypoxemic Respiratory Failure.

In acute hypoxemic respiratory failure (AHRF), spontaneous breathing effort can generate excessive regional lung stress and strain manifesting as pendelluft. Higher PEEP may reduce pendelluft and reduce regional lung stress and strain during spontaneous breathing. This study aimed to establish whether higher or lower PEEP ameliorates pendelluft and to characterize factors determining the presence and magnitude of pendelluft during spontaneous breathing efforts.

Long-Term Mental Health Morbidity in Adult Survivors of COVID-19 Critical Illness: A Population-Based Cohort Study.

Background: Surviving COVID-19 critical illness may be associated with important long-term sequelae, but little is known regarding mental health outcomes.

Research Question: What is the association between COVID-19 critical illness and new mental health diagnoses after discharge?

Study Design And Methods: We conducted a population-based cohort study in Ontario, Canada (January 1, 2020-March 31, 2022). We included consecutive adult survivors (age ≥ 18 years) of COVID-19 critical illness and compared them with consecutive adult survivors of critical illness from non-COVID-19 pneumonia.

Heterogeneous Treatment Effects of High-Frequency Oscillatory Ventilation for Acute Respiratory Distress Syndrome: A Post Hoc Analysis of the Oscillation for Acute Respiratory Distress Syndrome Treated Early (OSCILLATE) Trial.

Objectives: We sought to evaluate whether different subgroups of adults with acute respiratory distress syndrome (ARDS) respond differently to high-frequency oscillatory ventilation (HFOV).

Design: The Oscillation for ARDS Treated Early (OSCILLATE) trial was a randomized controlled trial of HFOV vs. conventional ventilation that found an increased risk of in-hospital mortality (primary outcome) with HFOV.

Designing a Bayesian adaptive clinical trial to evaluate novel mechanical ventilation strategies in acute respiratory failure using integrated nested Laplace approximations.

Background: Adaptive trials usually require simulations to determine values for design parameters, demonstrate error rates, and establish the sample size. We designed a Bayesian adaptive trial comparing ventilation strategies for patients with acute hypoxemic respiratory failure using simulations. The complexity of the analysis would usually require computationally expensive Markov Chain Monte Carlo methods but this barrier to simulation was overcome using the Integrated Nested Laplace Approximations (INLA) algorithm to provide fast, approximate Bayesian inference.

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.

Determinants of Effect of Extracorporeal CO Removal in Hypoxemic Respiratory Failure.

BACKGROUND: Dead space and respiratory system elastance (Ers) may influence the clinical benefit of a ventilation strategy combining very low tidal volume (VT) with extracorporeal carbon dioxide removal (ECCO2R) in patients with acute hypoxemic respiratory failure. We sought to evaluate whether the effect of ECCO2R on mortality varies according to ventilatory ratio (VR; a composite variable reflective of dead space and shunt) and Ers. METHODS: Secondary analysis of a trial of a strategy combining very low VT and low-flow ECCO2R planned before the availability of trial results.

Mortality in Patients with Obesity and Acute Respiratory Distress Syndrome Receiving Extracorporeal Membrane Oxygenation: The Multicenter ECMObesity Study.

Patients with obesity are at increased risk for developing acute respiratory distress syndrome (ARDS). Some centers consider obesity a relative contraindication to receiving extracorporeal membrane oxygenation (ECMO) support, despite growing implementation of ECMO for ARDS in the general population. To investigate the association between obesity and mortality in patients with ARDS receiving ECMO.

A New Global Definition of Acute Respiratory Distress Syndrome.

Since publication of the 2012 Berlin definition of acute respiratory distress syndrome (ARDS), several developments have supported the need for an expansion of the definition, including the use of high-flow nasal oxygen, the expansion of the use of pulse oximetry in place of arterial blood gases, the use of ultrasound for chest imaging, and the need for applicability in resource-limited settings. A consensus conference of 32 critical care ARDS experts was convened, had six virtual meetings (June 2021 to March 2022), and subsequently obtained input from members of several critical care societies. The goal was to develop a definition that would ) identify patients with the currently accepted conceptual framework for ARDS, ) facilitate rapid ARDS diagnosis for clinical care and research, ) be applicable in resource-limited settings, ) be useful for testing specific therapies, and ) be practical for communication to patients and caregivers.

Limiting Dynamic Driving Pressure in Patients Requiring Mechanical Ventilation.

Objectives: Previous studies reported an association between higher driving pressure (∆P) and increased mortality for different groups of mechanically ventilated patients. However, it remained unclear if sustained intervention on ∆P, in addition to traditional lung-protective ventilation, improves outcomes. We investigated if ventilation strategies limiting daily static or dynamic ∆P reduce mortality compared with usual care in adult patients requiring greater than or equal to 24 hours of mechanical ventilation.