Recent advances in mechanical ventilation in patients with acute respiratory distress syndrome

Abstract

Acute respiratory distress syndrome (ARDS) is characterised by different degrees of severity and different stages. Understanding these differences can help to better adapt the ventilatory settings to protect the lung from ventilator-induced lung injury by reducing hyperinflation or keeping the lung open when it is possible. The same therapies may be useful and beneficial in certain forms of ARDS, and risky or harmful at other stages: this includes high positive end-expiratory pressure, allowance of spontaneous breathing activity or use of noninvasive ventilation. The severity of the disease is the primary indicator to individualise treatment. Monitoring tools such as oesophageal pressure or lung volume measurements may also help to set the ventilator. At an earlier stage, an adequate lung protective strategy may also help to prevent the development of ARDS.

FIGURE 1

Change in transpulmonary pressure (P_L) from passive to active breathing during a) volume control ventilation (VCV) and b) pressure control ventilation (PCV). By contrast to VCV, with PCV an increasing effort will increase the flow and volume delivered. P_aw: airway pressure; P_mus: muscular pressure.

FIGURE 2

Effect of increasing inspiratory effort on delivered tidal volume during pressure-targeted ventilation. P_aw: airway pressure; P_oes: oesophageal pressure.