In the event of study inclusion before 10:00 am, both study arms will be initiated on the day of randomization. For patients randomized after 10:00 am, only one assessment will be required in both study arms on day one. Similarly, if patients can breathe spontaneously on PS or trigger spontaneous breaths on volume or pressure AC, volume or pressure SIMV ± PS, PRVC, PAV, VS, or APRV before 10:00 am, then the allocated screening protocol can resume. However if, patients can not be returned to a mode that permits spontaneous breaths (PS) or supports triggered breaths (volume or pressure AC, volume or pressure SIMV ± PS, PRVC, PAV, VS, or APRV) until after 10:00 am, screening will be conducted only once daily in both treatment arms on the day of the return and will resume as per treatment allocation thereafter.