Chest wall loading in the ICU: pushes, weights, and positions.

Clinicians monitor mechanical ventilatory support using airway pressures-primarily the plateau and driving pressure, which are considered by many to determine the safety of the applied tidal volume. These airway pressures are influenced not only by the ventilator prescription, but also by the mechanical properties of the respiratory system, which consists of the series-coupled lung and chest wall. Actively limiting chest wall expansion through external compression of the rib cage or abdomen is seldom performed in the ICU.

Successful hemostasis in refractory alveolar hemorrhage using low-dose recombinant activated factor VII.

Diffuse alveolar hemorrhage (DAH) is a life-threatening condition requiring prompt recognition. Conventional therapy, even when initiated early, may not have an immediate effect, and in severe cases, bleeding can persist despite treatment. We report the case of a previously healthy 33-year-old male who developed DAH secondary to granulomatosis with polyangiitis, resulting in respiratory failure and the need for mechanical ventilation.

COVID-19-Related ARDS: Key Mechanistic Features and Treatments.

Acute respiratory distress syndrome (ARDS) is a heterogeneous syndrome historically characterized by the presence of severe hypoxemia, high-permeability pulmonary edema manifesting as diffuse alveolar infiltrate on chest radiograph, and reduced compliance of the integrated respiratory system as a result of widespread compressive atelectasis and fluid-filled alveoli. Coronavirus disease 19 (COVID-19)-associated ARDS (C-ARDS) is a novel etiology caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that may present with distinct clinical features as a result of the viral pathobiology unique to SARS-CoV-2. In particular, severe injury to the pulmonary vascular endothelium, accompanied by the presence of diffuse microthrombi in the pulmonary microcirculation, can lead to a clinical presentation in which the severity of impaired gas exchange becomes uncoupled from lung capacity and respiratory mechanics.

Paradoxical Positioning: Does "Head Up" Always Improve Mechanics and Lung Protection?

Objectives: Head-elevated body positioning, a default clinical practice, predictably increases end-expiratory transpulmonary pressure and aerated lung volume. In acute respiratory distress syndrome (ARDS), however, the net effect of such vertical inclination on tidal mechanics depends upon whether lung recruitment or overdistension predominates. We hypothesized that in moderate to severe ARDS, bed inclination toward vertical unloads the chest wall but adversely affects overall respiratory system compliance (C rs ).

Paradoxical response to chest wall loading predicts a favorable mechanical response to reduction in tidal volume or PEEP.

Background: Chest wall loading has been shown to paradoxically improve respiratory system compliance (C) in patients with moderate to severe acute respiratory distress syndrome (ARDS). The most likely, albeit unconfirmed, mechanism is relief of end-tidal overdistension in 'baby lungs' of low-capacity. The purpose of this study was to define how small changes of tidal volume (V) and positive end-expiratory pressure (PEEP) affect C (and its associated airway pressures) in patients with ARDS who demonstrate a paradoxical response to chest wall loading.

Elastic Power of Mechanical Ventilation in Morbid Obesity and Severe Hypoxemia.

Background: To minimize ventilator-induced lung injury, the primary clinical focus is currently expanding from measuring static indices of the individual tidal cycle (eg, plateau pressure and tidal volume) to more inclusive indicators of energy load, such as total power and its elastic components. Morbid obesity may influence these components. We characterized the relative values of elastic subcomponents of total power (ie, driving power and dynamic power) in subjects with severe hypoxemia, morbid obesity, or their combination.

Performance measure of urinary antigen in patients with Streptococcus pneumoniae bacteremia.

The Streptococcus pneumoniae (SP) urinary antigen (UAg) test is a commonly used assay. The purpose of this study was to evaluate the test's actual performance in the clinical setting and determine the effects of renal function, grade of bacteremia, and severity-of-illness scores on its outcome. Patients with pneumococcal bacteremia were retrospectively identified and stratified on the basis of glomerular filtration rates, number of positive blood cultures, and CURB-65 scores.