Proportional Assist Ventilation for Minimizing the Duration of Mechanical Ventilation: The PROMIZING Study

A staged enrolment process will be used to identify patients eligible to be enrolled and randomized in the study. At each stage of the enrolment process, a patient must meet inclusion criteria and not meet exclusion criteria in order to pass. To progress to the next stage, patients must continue to pass criteria from the prior stages. After enrolment, there are also specific tests to perform (with pass/fail criteria) to determine eligibility to be randomized. A. SCREENING INCLUSION CRITERIA: * A1. Age 18 years or older * A2. Intubated and receiving any mode of invasive mechanical ventilation ≥ 24 hours A. SCREENING EXCLUSION CRITERIA: * A3. Anticipating withdrawal of life support and/or shift to palliation as the goal of care * A4. Severe central neurologic disorder (eg. Hemorrhage, stroke, tumour) causing elevated intracranial pressure, or impaired control of breathing, or requiring specific ventilator adjustments (i.e. To attain specific CO2 target) or requiring neurosurgical intervention * A5. Known or suspected severe or progressive neuromuscular disorder likely to result in prolonged or chronic ventilator dependence (eg. Guillain-Barré syndrome, Myasthenia Gravis, ALS, MS, high spinal cord injury, kyphoscoliosis or other restrictive disorder) (Note that obesity hypoventilation syndrome that may be managed with nocturnal non-invasive ventilation is NOT an exclusion under A5) * A6. Severe COPD: Baseline daytime hypercapnia (pCO2\> 50 mmHg) OR GOLD 4 airflow limitation …