Intrinsic Respiratory Rate Assessment During Mechanical Ventilation to Accelerate Spontaneous Breathing and Extubation

The objective of this study is to investigate the impact of assessing intrinsic respiratory rate in mechanically ventilated patients with reverse triggering on the facilitation of transition to spontaneous breathing and successful extubation.

Patients will be excluded if under current use of continuous neuromuscular blocking agent or severe metabolic acidosis (Ph<7.25 at the time of study procedure.

Patients will be screened every morning from 8:00 am to 9:00 am all the patients under controlled ventilation to detect the presence of reverse triggering by looking at the screen on the ventilator (2-5 min observation). The research team (research MDs, physiotherapists and respiratory therapists) is very well trained at detecting reverse triggering. Patients will then be randomized to standard of care or intervention using a deferred consent model.

• Control group: standard care.
• Intervention group: The intervention is a simple brief test as follows: With the ventilator set with the patient clinical settings, it will be performed an up to 30sec-long or two inspiratory effort and expiratory occlusion maneuver on the ventilator and/or switch the patient to pressure support for up to 30sec-long to assess the presence of intrinsic respiratory rate.

If an intrinsic respiratory rate ≥8 breaths per minute is present and P/F ratio is ≥150 it will be performed a 5-minute "test" in pressure support ventilation with the pressure support level to match the clinical setting of the patient. If the patient tolerates well 5 minutes in pressure support (see criteria below) the clinical team will be informed:

• It will be indicated that the patient tolerated 5 min of pressure support ventilation and suggest to the clinicians and physician in charge to transition the patient to pressure support ventilation plus suggest reducing sedation.

Inclusion criteria

• Adult patients (aimed at equal number of men and woman) sedated and under controlled ventilation having reverse triggering.

Exclusion criteria

• under current use of continuous neuromuscular blocking agent or severe metabolic acidosis (Ph<7.25) at the time of study procedure.