Frequency of Screening and SBT Technique Trial

The requirement for invasive mechanical ventilation is a defining feature of critical illness. Liberation or weaning is the process during which the work of breathing is transferred from the ventilator back to the patient. Approximately 40% of the time spent on mechanical ventilation is dedicated to weaning. Limiting the duration of invasive ventilation has been identified as a key research priority in critical care. Studies support the use of screening protocols (once daily vs. usual care) to identify weaning candidates and the conduct of tests of patient's ability to breathe spontaneously (SBTs). While once daily screening is the current standard of care in national intensive care units (ICUs), it is poorly aligned with the 24/7 ICU care environment wherein a critically ill patients' status can change from hour to hour. Only one large trial has compared alternative SBT techniques \[T-piece vs PS (Pressure Support)\]. No trial has compared a strategy of more frequent screening to once daily screening or alternative SBT techniques. The presence of respiratory therapists (RTs) 24/7 in North American ICUs presents a unique opportunity to screen more frequently, conduct more frequent SBTs, and determine the optimal strategy to liberate critically ill adults from invasive ventilation. The investigators propose to conduct a pilot randomized trial in 100 critically ill adults comparing 'once daily' screening to 'at least twice daily' screening and PS vs. T-piece SBTs in 12 Canadian ICUs. In the proposed trial, the investigators will (i) assess their ability to recruit critically ill adults who can breathe spontaneously or initiate breaths on one of several commonly used modes of ventilation into the trial, (ii) evaluate clinician's ability to implement the trial as designed, (iii) assess current practices in sedation, analgesia and delirium management and timing of patient mobilization prior to conducting screening assessments, (iv) identify barriers (clinician, institut