Weaning From Prolonged Mechanical Ventilation

Patients requiring prolonged mechanical ventilation (defined as more than 21 days) account for more than 37% of all ICU costs. As such, these patients are now transferred to centers that specialize in weaning from mechanical ventilation, so called long-term acute care (LTAC) facilities. Despite the proliferation of LTAC facilities, research on methods for expediting weaning is lacking. In addition, little information is available regarding long-term survival and patient's perception of quality of life after a prolonged course of mechanical ventilation.

In patients receiving mechanical ventilation in an ICU, randomized trials have revealed that ventilator duration was significantly influenced by weaning methods. The two most common weaning methods are pressure support and spontaneous breathing trials. Unlike the ICU, the relative efficacy of these two techniques in weaning patients requiring prolonged ventilation at a LTAC facility is largely unknown. The aim of this proposal is to determine whether the length of time required for weaning from prolonged ventilation differs with pressure support versus spontaneous breathing trials. The second aim is to determine the long-term impact of prolonged ventilation on survival, functional status and quality of life.

Inclusion criteria

• Mechanical Ventilation for at least 21 days

Exclusion criteria

• Hypoxemia (oxygen saturation < 90% with fractional inspired O2 concentration > 0.40, and positive end-expiratory pressure > 5 cm H2O
• Hemodynamic instability (requiring intravenous vasoactive agents, such as dopamine > 5 mg/kg/min)
• Profound neurological deficits (large stroke)
• Documented bilateral phrenic nerve injury
• Previous admission to RML Hospital
• Life expectancy less than 3 months