The following is a summary of “Physiological effects and safety of bed verticalization in patients with acute respiratory distress syndrome,” published in the August 2024 issue of Critical Care by Bouchant et al.

Trunk inclination in supine patients with Acute Respiratory Distress Syndrome (ARDS) affects respiratory mechanics, oxygenation, and efficiency, with semi-recumbent positions worsening ventilatory efficiency and gas exchange, especially in COVID-19-related ARDS.

Researchers conducted a retrospective study evaluating how trunk inclination affects respiratory mechanics, oxygenation, and gas exchange in patients with ARDS, especially with COVID-19-related ARDS.

They conducted a physiological study on patients with early ARDS across 2 ICUs at CHU Clermont-Ferrand, France. The protocol entailed a 30-minute gradual verticalization process, transitioning from a 30^° semi-seated position (baseline) to various inclinations (0^°, 30^°, 60^°, and 90^°), and then returning to the baseline. Measurements included were tidal volume, positive end-expiratory pressure (PEEP), esophageal pressures, and data from pulmonary artery catheters. The main objective was to assess changes in transpulmonary driving pressure throughout the verticalization procedure.

The result showed 30 patients (May 2020 to January 2021)in the study with a modest increase in transpulmonary driving pressure from the baseline (median [IQR], 9 [5–11] cmH²O) to the 90^° position (10 [7–14] cmH²O, P<0–2 for the overall positional effect in the mixed model). Verticalization led to an increase in end-expiratory lung volume, accompanied by reductions in alveolar strain and improvements in arterial oxygenation. However, verticalization was also linked to decreased cardiac output and stroke volume, along with higher doses of norepinephrine and elevated serum lactate levels, leading to the interruption of the procedure in two patients. No other AEs, such as falls or accidental removal of equipment, were reported.

Investigators concluded that verticalizing ARDS patients to 90^° is feasible and improves end-expiratory lung volume and oxygenation up to 30^°, though risks of overdistension and hemodynamic instability increase beyond this angle, requiring tailored bed positioning based on clinical needs.

Source: ccforum.biomedcentral.com/articles/10.1186/s13054-024-05013-y