Technical Innovation in Critical Care in a World of Constraints: Lessons from the COVID-19 Pandemic.

The COVID-19 crisis was characterized by a massive need for respiratory support, which has unfortunately not been met globally. This situation mimicked those which gave rise to critical care in the past. Since the polio epidemic in the 50's, the technological evolution of respiratory support has enabled health professionals to save the lives of critically-ill patients worldwide every year.

Can proportional ventilation modes facilitate exercise in critically ill patients? A physiological cross-over study : Pressure support versus proportional ventilation during lower limb exercise in ventilated critically ill patients.

Background: Early exercise of critically ill patients may have beneficial effects on muscle strength, mass and systemic inflammation. During pressure support ventilation (PSV), a mismatch between demand and assist could increase work of breathing and limit exercise. A better exercise tolerance is possible with a proportional mode of ventilation (Proportional Assist Ventilation, PAV+ and Neurally Adjusted Ventilatory Assist, NAVA).

Oxygenation response to positive end-expiratory pressure predicts mortality in acute respiratory distress syndrome. A secondary analysis of the LOVS and ExPress trials.

Rationale: Previous trials of higher positive end-expiratory pressure (PEEP) for acute respiratory distress syndrome (ARDS) failed to demonstrate mortality benefit, possibly because of differences in lung recruitability among patients with ARDS.

Objectives: To determine whether the physiological response to increased PEEP is associated with mortality.

Methods: In a secondary analysis of the Lung Open Ventilation Study (LOVS, n = 983), we examined the relationship between the initial response to changes in PEEP after randomization and mortality.

[Non-invasive ventilation: indication for acute respiratory failure].

Mask or Non-invasive ventilation (NIV) is used for critically ill patients with acute respiratory failure (ARF): acute exacerbation of chronic obstructive bronchopulmonary disease and severe cardiogenic pulmonary edema are considered as the best indications for NIV since it improves the outcome of these patients. This technique is also proposed for hypoxemic respiratory failure, with more various results. To be effective here, NIV must be established early enough and should not delay intubation if required.

Mechanical ventilation-induced reverse-triggered breaths: a frequently unrecognized form of neuromechanical coupling.

Background: Diaphragmatic muscle contractions triggered by ventilator insuffl ations constitute a form of patient-ventilator interaction referred to as “entrainment,” which is usually unrecognized in critically ill patients. Our objective was to review tracings, which also included muscular activity, obtained in sedated patients who were mechanically ventilated to describe the entrainment events and their characteristics. The term “reverse triggering” was adopted to describe the ventilator-triggered muscular efforts.

Extracorporeal membrane oxygenation for pandemic influenza A(H1N1)-induced acute respiratory distress syndrome: a cohort study and propensity-matched analysis.

Rationale: Many patients with severe acute respiratory distress syndrome (ARDS) caused by influenza A(H1N1) infection receive extracorporeal membrane oxygenation (ECMO) as a rescue therapy.

Objectives: To analyze factors associated with death in ECMO-treated patients and the influence of ECMO on intensive care unit (ICU) mortality.

Methods: Data from patients admitted for H1N1-associated ARDS to French ICUs were prospectively collected from 2009 to 2011 through the national REVA registry.

Interest of a simple on-line screening registry for measuring ICU burden related to an influenza pandemic.

Introduction: The specific burden imposed on Intensive Care Units (ICUs) during the A/H1N1 influenza 2009 pandemic has been poorly explored. An on-line screening registry allowed a daily report of ICU beds occupancy rate by flu infected patients (Flu-OR) admitted in French ICUs.

Methods: We conducted a prospective inception cohort study with results of an on-line screening registry designed for daily assessment of ICU burden.

Clinical review: Update on neurally adjusted ventilatory assist--report of a round-table conference.

Conventional mechanical ventilators rely on pneumatic pressure and flow sensors and controllers to detect breaths. New modes of mechanical ventilation have been developed to better match the assistance delivered by the ventilator to the patient's needs. Among these modes, neurally adjusted ventilatory assist (NAVA) delivers a pressure that is directly proportional to the integral of the electrical activity of the diaphragm recorded continuously through an esophageal probe.