Acute respiratory distress syndrome (ARDS) is characterized by acute bilateral pulmonary
infiltrates and impairment of oxygen uptake. For example, pneumonia can cause the development
of ARDS. Despite modern intensive care treatment, mortality in ARDS patients remains high
(40%). Invasive mechanical ventilation (MV) is the mainstay of ARDS treatment. Controlled MV
is the conventional ventilation strategy to ensure lung protective ventilation (low tidal
volumes) and recovery of the lungs. However, among disadvantages of controlled MV are the
development of respiratory muscle atrophy (due to disuse) and the need for high dose
sedatives to prevent patient-ventilator asynchrony. The use of high doses of sedatives and
respiratory muscle weakness are associated with increased morbidity, worse clinical outcomes
and prolonged MV.
Besides controlled MV, a patient can be ventilated with supported ventilation. Supported MV
decreases the likelihood to develop muscle atrophy, improves oxygenation and hemodynamics,
and lowers consumption of sedatives. However potential disadvantages of supported ventilation
include generation of too high tidal volumes, especially in patients with high respiratory
drive. A previous study in healthy subjects has shown that titration of neuromuscular
blocking agent (NMBA) can decrease activity of inspiratory muscles, while maintaining
adequate ventilation. It is hypothesized that low dose NMBA may enable supported MV with
adequate tidal volumes, in patients with high respiratory drive.