An observational study in Ventilatory Failure, Hypoxemic Respiratory Failure and Weaning Failure, sponsored by Unity Health Toronto. Active, not recruiting at 1 site in Canada. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-10.
Sponsored by Unity Health Toronto · Observational
The goal of this observational study is to assess the potential non-invasive tools (e.g. regional ventilation, respiratory muscle response, lung mechanic's parameters) to identify the risk of failure when using high flow nasal cannula (HFNC) or non-invasive ventilation (NIV).
The main question, it aims to answer is:
Does abnormal regional ventilation could predict HFNC or NIV failure?
This is a single-center, prospective, physiological study.
The study will enroll patient who has used either HFNC or NIV for the indications of 1. to prevent worsening acute hypoxemic respiratory failure or 2. to prevent reintubation. Once being confirmed to meet the inclusion criteria, the research team will apply the electrical impedance tomography (EIT) on the patient and start recording for 5-10 minutes as well as perform diaphragm and parasternal intercostal muscle ultrasound when the patient is using HFNC or NIV. The current HFNC or NIV setting, some lung mechanic's parameters (e.g. rapid shallow breathing trial (RSBI), negative airway pressure generated during the first 100 milisecond (P0.1), end-expiratory occlusion pressure(ΔPocc) derived from NIV machine), patient's characteristic, dyspnea scores (intensive care respiratory distress observation scale, IC-RDOS; work of breathing scale; self-report of dyspnea visual analog scale, D-VAS), ICU and hospital length of stay will be also collected.
The investigator will use EIT to visualize where air goes in the patient's lung and inspiratory muscle ultrasonography (diaphragm and parasternal intercostal muscle) to visualize the muscle activities when using HFNC or NIV. EIT is a measurement often used in the ICU since it allows easy visualization and is a non-invasive technique. The sensors measure electrical current changes during inspiration and expiration and will not cause any pain or radiation concerns. The EIT belt (3-cm diameter) will be placed around the chest without causing adverse event/discomfort/pain.
The duration of study will be approximately 30 minutes. The study will be conducted one time for one enrolled patient.
HFNC or NIV (device) failure is considered as either intubation/reintubation or death, whatever has come first. It will be followed up to 7 days.
The investigators will proceed with the measurements only with agreement from the clinical team. The investigators will analyze the data collected offline with a dedicated software afterwards.
After these study procedures are completed, data will also be collected from the participant's chart and combined with relevant information from the HFNC or NIV settings and vital functions. Confidentiality will be maintained throughout the entire study.
96 studies on the registry are indexed under Hypoventilation; 21 are open to participants now.
This study's planned enrollment of 80 is close to the median of 74 across 28 observational studies indexed under Hypoventilation.
Browse Hypoventilation studies →Unity Health Toronto is the lead sponsor of 447 studies on the registry; 82 are open to participants now.
Of its 5 completed or terminated interventional studies of FDA-regulated products, 1 (20%) have results posted.
Counted across the registry records on this site, refreshed daily.
Patient who is using high flow nasal cannula (HFNC) or non-invasive ventilation (NIV) to either prevent 1. intubation in the context of acute hypoxemic respiratory failure or 2. reintubation in the context of high risk group of extubation.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Difference in regional ventilation distribution (%)
The primary endpoint is to assess regional ventilation distribution (%) when using HFNC or NIV to predict a device failure.
Time frame: The parameter is measured at the time of enrolment. Failure of HFNC or NIV is adjudicated at 7 days.
Diaphragm or parasternal intercostal muscle thickening fraction
To assess ultrasound measurement of inspiratory muscle activity when using HFNC or NIV to predict a device failure.
Time frame: The parameter is measured at the time of enrolment. Failure of HFNC or NIV is adjudicated at 7 days.
Rapid shallow breathing index (RSBI) in mL/breaths/min
To assess non-invasive respiratory - rapid shallow breathing index (RSBI) derived from NIV to predict a device failure.
Time frame: The parameter is measured at the time of enrolment. Failure of HFNC or NIV is adjudicated at 7 days.
Respiratory drive using negative airway pressure generated during the first 100 millisecond (P0.1)
To assess respiratory drive - using negative airway pressure generated during the first 100 millisecond (P0.1) in cmH2O to predict device failure.
Time frame: The parameter is measured at the time of enrolment. Failure of HFNC or NIV is adjudicated at 7 days.
Respiratory effort using end-expiratory airway occlusion pressure (ΔPocc)
To assess respiratory effort using end-expiratory airway occlusion pressure (ΔPocc) in cmH2O to predict device failure
Time frame: The parameter is measured at the time of enrolment. Failure of HFNC or NIV is adjudicated at 7 days.
The intensive care respiratory distress observation scale (IC-RDOS)
To assess the level of dyspnea using intensive care respiratory distress observation scale (IC-RDOS) to predict a device failure. There is no minimum or maximum range depending on patient's heart rate, the higher score means worse outcome. When the score ≥ 2.4, it likely indicates clinically important dyspnea requiring clinical management.
Time frame: The parameter is measured at the time of enrolment. Failure of HFNC or NIV is adjudicated at 7 days.
The work of breathing scale
To assess the work of breathing scale to predict a device failure. Minimum is 3 and maximum is 12, the higher score means worse outcome. When the score \> 4, it likely indicates severe respiratory distress.
Time frame: The parameter is measured at the time of enrolment. Failure of HFNC or NIV is adjudicated at 7 days.
Self-report of dyspnea visual analog scale (D-VAS)
To assess self-report of dyspnea visual analog scale (D-VAS) to predict a device failure. Minimum is 0 and maximum is 10, the higher score means worse outcome. When the score \> 3, it likely indicates dyspnea and being used for quality of palliative care unit
Time frame: The parameter is measured at the time of enrolment. Failure of HFNC or NIV is adjudicated at 7 days.
Plan to share: No
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From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is active, not recruiting, as verified in Nov 2026. You cannot join it, but the record below documents what was studied.
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