Screening Elderly PatieNts For InclusiOn in a Weaning Trial: The SENIOR Trial

The aim of the trial was to assess metrics that reflected our ability to consent, enroll and recruit elderly and older invasively ventilated patients and evaluate adherence to the study protocols in preparation for conducting a large weaning trial.

Research Results

Project findings and information will be updated on a continual basis.

About the Project

Weaning is the process of transferring the work of breathing from the ventilator back to the patient. Approximately 40% of the total time spent on mechanical ventilation is dedicated to weaning. Research supports that the use of specific strategies to wean patients including the use of daily screening (to identify patients who can breathe spontaneously) and the conduct of tests of patient’s ability to breathe spontaneously to limit the time spent on ventilators and improve outcomes. No randomized trial has evaluated the optimal screening frequency to identify patients to undergo a spontaneous breathing trial (SBT) and no weaning trial has ever been conducted in older patients.

The SENIOR Trial was the first weaning trial conducted with older persons living with frailty. This trial was also novel in (1) evaluating our ability to recruit older critically ill patients into a mechanical ventilation trial, (2) assessing whether protocols can be adhered to similarily in both study arms and (3) obtaining preliminary estimates of differences in important clinical outcomes between older and much older participants. This trial provided valuable information to better inform discussions with older persons, critically ill patients and their SDMs regarding weaning outcomes.

Project Team

Principal Investigator:

Karen Burns, MD, MSc, FRCPC — St. Michael’s Hospital/University of Toronto


Laurent Brochard, MD — St. Michael’s Hospital

Deborah Cook, MD, MSc — St. Joseph’s Hospital, Hamilton

Peter Dodek, MD, MHSc — St. Paul’s Hospital, Vancouver

Eddy Fan, MD, MPH, BSc — Toronto General Hospital

Jan Friedrich, MD, MSc, D.Phil, BSc — St. Michael’s Hospital

Lori Hand, RRT — Hamilton General Hospital

Michelle Kho, PhD, PT — St. Joseph’s Hospital

François Lamontagne, MD, MSc — Université de Sherbrooke

Maureen Meade, MD, MSc — McMaster University

Sangeeta Mehta, MD, BSc — Mount Sinai Hospital, Toronto

Andrew Seely, MD, PhD — Ottawa General Hospital

Project Contact: Leena Rizvi —

CAT 2013-45

Key words: weaning; spontaneous breathing; mechanical ventilation; randomized trial; outcomes

Rationale, Objectives & Research Plan

Rationale: The elderly are increasingly represented in our ICUs. Relevant to mechanical ventilation trials, the frail elderly may have comorbid illnesses, malnutrition, and thus reduced tolerance and greater potential to fatigue during weaning. Collectively, these factors may influence the process of weaning and impact upon clinically important weaning outcomes.

Objectives: (1) Demonstrate the ability to recruit invasively ventilated elderly (age > 65 years) critically ill adults into a weaning trial comparing alternative screening strategies, (2) demonstrate that clinicians can adhere to the assigned screening protocols in both study arms and (3) describe the (i) proportion of enrolled elderly and very elderly trial participants, (ii) proportion of consents obtained and declined for trial participation similar between eligible elderly and very elderly trial participants and (iii) rates and reasons for trial exclusion based between eligible elderly and very elderly patients

Research plan: In the context of a multicentre, pilot trial involving 100 elderly (> 65 years) critically ill adults comparing two strategies to identify weaning candidates (‘once daily’ vs. ‘at least twice daily’ screening) in 11 ICUs across Canada, we aim to assess metrics that reflect our ability to consent, enroll, and recruit elderly and very elderly invasively ventilated patients and evaluate adherence to the study protocols in preparation for conducting a large weaning trial.

Communication to Researchers

Key Findings:

Compared to a trial involving patients younger than 65 years (RELEASE Trial involving critically ill adults), we demonstrated that:

  • Patients aged 65 years and older have similar consent and enrollment rates.
  • There were fewer adverse events in older patients; however, they occurred at a similar frequency.
  • More frequent screening (at least twice daily) to identify patients who are ready to undergo a test of spontaneous breathing [or spontaneous breathing trial (SBT)] had similar effects on important clinical outcomes.

Why was this study needed?

While elderly critically ill patients are increasingly represented in our intensive care units (ICUs), little data exist regarding their recruitment and consent rates in mechanical ventilation trials. Moreover, no trials have been conducted in older adults to examine the effect of different weaning strategies. Consequently, we do not know whether older adult patients who are often living with frailty, malnutrition and comorbidities, should be included in weaning trials with patients younger than 65 years.

Brief overview of the methodology:

We conducted two contemporaneous, multicenter, pilot randomized controlled trials (RCTs) [RELEASE (< 65 years) and SENIOR (> 65 years)] comparing ‘once daily’ to ‘at least twice daily’ screening in critically ill adults who were invasively ventilated for at least 24 hours. In both trials, we evaluated recruitment rates, reasons for exclusion, consent rates, protocol adherence (target: ≥ 80%) and crossovers (aim: < 10%). Within and between trials, we assessed the effect of the alternative screening frequencies on adverse events and clinical outcomes.

Potential impact of findings on clinical practice/patient care and how this impact might be measured:

  • Both trials had similar recruitment and consent rates, protocol adherence, and outcomes with no increase in adverse events.
  • Our findings justify the inclusion of adult patients aged younger and older than 65 years in one large weaning trial in the future.

Remaining knowledge/research gaps:

  • Successful completion of the RELEASE and SENIOR trials informed the design and conduct of another pilot trial, the Frequency of screening And SBT Technique trial (FAST Trial) comparing both screening frequency (once vs. at least twice daily) and SBT technique (T-piece vs. Pressure Support + Positive End-Expiratory Pressure).
  • After successfully completing the FAST pilot trial, we will conduct a large multi-centre North American trial to evaluate the effects of how often clinicians screen patients (screening frequency) and the test used to assess spontaneous breathing (SBT technique) on important clinical outcomes. The primary outcome of this trial will be the time to successful extubation.