Heart Rate VAriability as a MaRker for tItrATing hIgh flOw Nasal Cannula Therapy

NCT07518862 | Recruiting

• 1 other identifier: 25-6168
• Study Type: observational
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

High-flow nasal cannula is a type of non-invasive respiratory support that helps patients breathe more comfortably. Because the flow is high, it can deliver more oxygen to the lungs and make breathing easier by reducing the effort needed to breathe. However, the best strategy to determine the best oxygen flow rate remains uncertain. Reducing flow rates prematurely can increase work of breathing and prolong ICU stay, while unnecessary prolongation can increase costs. Currently, evidence to guide titration is limited. Heart rate variability is the natural variation in the time between each heartbeat. Heart rate variability reflects the level of autonomic nervous system activity in response to stress. The autonomic nervous system is the part of the nervous system that automatically controls how heart rate speeds up and slows down. When heart rate variability is higher, it indicates that the system is able to adjust to changes in the body, including stress. However, when heart rate variability is low, it indicates that the system is constrained and in a state of stress. The VARIATION study is designed to characterize how heart rate variability goal of this observational study is to learn whether heart rate variability can serve as a marker of the appropriateness of high flow nasal cannula flow support during flow titration in patients with respiratory failure. The main question it aims to answer is: Does heart rate variability change before other conventional respiratory signs when there are changes in respiratory function due to inadequate flow rate? Participants already on high flow nasal cannula as part of their regular medical care will:

1. 1.Undergo a stepwise decrease in high flow nasal cannula flow rate.
2. 2.Be recorded continuously with electrocardiogram and electrical impedance tomography.

Conditions

Respiratory Failure; High Flow Nasal Cannula; Heart Rate Variability (HRV)

Keywords

Electrocardiogram (ECG); Electrical Impedance Tomography (EIT)

Outcome Measures

Primary Outcomes (1)

• Change in heart rate variability during flow titration

  During flow titration, maximum of 1 hour and 45 minutes

Secondary Outcomes (2)

• Correlation between heart rate variability and respiratory measures during high flow nasal cannula flow titration

  During flow titration, maximum of 1 hour and 45 minutes

• Agreement between heart rate variability measures derived from pulse oximetry and those derived from ECG

  During flow titration, maximum of 1 hour and 45 minutes

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients on high flow nasal cannula for respiratory failure at Toronto General Hospital (UHN)

You may qualify if:

• Age \> 18
• Currently receiving High-Flow Nasal Cannula Therapy

You may not qualify if:

• FiO2 ≥ 90%
• Pacemaker rhythm or presence of atrial fibrillation
• Post-cardiac surgery patients
• Contra-indications to electrical impedance tomography (EIT) and/or electrocardiogram (ECG) (active implantable medical device, burns, thoracic wounds limiting electrode placement)
• Non-English-speaking

Sponsors & Collaborators

• University Health Network, Toronto: lead

Study Sites (1)

Toronto General Hospital

Toronto, Ontario, M5G 2C4, Canada

RECRUITING

MeSH Terms

Conditions

Respiratory Insufficiency

Condition Hierarchy (Ancestors)

Respiration Disorders; Respiratory Tract Diseases

Central Study Contacts

Rongyu (Cindy) Jin

CONTACT

4163404800 ext 7613; rongyu.jin@uhn.ca

Marcela Amaral

CONTACT

marcela.alvesrendakamaral@uhn.ca

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 1, 2026
• First Posted: April 9, 2026
• Study Start: May 26, 2026
• Primary Completion (Estimated): November 1, 2026
• Study Completion (Estimated): December 1, 2026
• Last Updated: June 18, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)