Partial Neuromuscular Blockade for Lung Protective Mechanical Ventilation

Partial Neuromuscular Blockade to Facilitate Lung and Diaphragm Protective Mechanical Ventilation in Intensive Care Unit Patients: a Randomized Controlled Pilot Study

Controlled mechanical ventilation may lead to the development of diaphragm muscle atrophy, which is associated with weakness and adverse clinical outcome. Therefore, it seems reasonable to switch to partially supported ventilator modes as soon as possible. However, in patients with high respiratory drive, the application of partially supported modes may result in high lung distending pressures and diaphragm injury.

Recently, the investigators published a study that demonstrated that a low dose of neuromuscular blocking agents (NMBA) facilitates lung-protective ventilation and maintains diaphragm activity in intensive care unit (ICU) patients. That study was conducted in a small (N=10), selected group of patients and partial neuromuscular blockade was applied for only 2 hours (proof-of-concept study). Therefore, further research has to be done before this strategy can be applied in clinical practice.

The primary goal is to investigate the feasibility and safety of prolonged (24 hours) partial neuromuscular blockade in patients with high respiratory drive in partially supported mode. The secondary goals are to evaluate the effect of this strategy diaphragm function, lung injury, hemodynamics and systemic inflammation.

Inclusion Criteria:

• high respiratory drive, defined as tidal volume > 8ml/kg PBW on inspiratory support of 12 cmH2O.
• sedation level: richmond agitation-sedation scale (RASS) ≤ -3
• ventilated in pressure support mode

Exclusion Criteria:

• recent use of NMBA (< 2 hrs)
• arterial pH < 7.25
• hemodynamic instability, i.e. high dose vasopressors (>0.5 μg/kg/min) or inotropes (dobutamine >15 μg/kg/min or enoximone >25 μg/kg/min)
• intracranial pressure > 20 cmH2O
• past medical history of neuromuscular disorders
• known pregnancy
• known previous anaphylactic reaction to NMBA's.