Comparison of Different Oxygen Flow Rates During Preoxygenation Using High-Flow Nasal Oxygen

NCT06736132 | Active Not Recruiting

• 2 other identifiers: DNR: 2024-04565-01SLS-1000363 & SLS-999871
• Study Type: interventional
• Target: 75
• Locations: 1 country
• Sites: 1

Brief Summary

High-flow nasal oxygen (HFNO) has been used for many years to help people with breathing difficulties in the intensive care and after surgery. More recently, it has become a helpful tool during induction of anaesthesia to prevent oxygen levels from dropping when managing the airway. HFNO is particularly effective at delivering oxygen even when a patient is not breathing (apnoea), making it useful during surgeries on the voice box (larynx) because it eliminates the need for a breathing tube, giving surgeons a clear view. HFNO is now also being used to prepare patients for anaesthesia (preoxygenation). Research shows that it works just as well as traditional tight-fitting oxygen masks while offering added benefits like better comfort for patients, easier handling for anaesthetists, and a smooth transition to oxygen delivery during apnoea. One reason HFNO is effective is that it creates a mild pressure in the lungs, called positive end-expiratory pressure (PEEP), which improves oxygen storage in the lungs. This pressure depends on the flow rate of oxygen and is higher when the patient keeps their mouth closed. For every increase of 10 liters per minute in flow rate, HFNO generates 1 cmH2O of PEEP. This pressure helps increase the lung's capacity to hold oxygen, making the process of preoxygenation more efficient. Most studies on HFNO for preoxygenation have used flow rates of up to 60 liters per minute. However, we don't yet know if higher flow rates could further improve preoxygenation or extend the time patients can safely go without breathing.

Conditions

Airway Anesthesia; Preoxygenation; High Flow Nasal Canula

Keywords

Preoxygenation; High-flow nasal oxygen; Anaesthesia induction

Outcome Measures

Primary Outcomes (1)

• Safe apnoea time

  Comparison of the time from start of apnoea until reaching a SpO2 = 93% between the different flow rates

  From start of apnoea after anaesthesia induction until peripheral oxygen saturation drops to 93%. This time fram will probably be between 5 and 15 minutes.

Secondary Outcomes (4)

• Tolerance of 360 seconds of apnoea

  From apnoea start until 5 minutes of apnoea

• Arterial oxygen levels during preoxygenation

  From start of preoxygenation until end of preoxygenation (approximately 3 to 4 minutes)

• Discomfort assessment

  From start of preoxygenation until the end of preoxygenation, this time fram will be three minutes.

• Lung impedance changes

  From start of preoxygenation until end of apnoea (approximately 5 to 15 minutes)

Other Outcomes (2)

• Differences in end-tidal and arterial carbon dioxide levels

  From start of apnoea until end of apnoea (approximately 5 to 10 minutes)

• Rate of arterial carbon dioxide increase during apnoea

  From start of apnoea until end of apnoea (approximately 5 to 10 minutes)

Study Arms (3)

High-flow nasal oxygen, flow rate 45 l/min

ACTIVE COMPARATOR

Preoxygenation using high-flow nasal oxygen with a flow rate of 45 l/min

Device: High-flow nasal oxygen

High-flow nasal oxygen, flow rate 70 l/min

EXPERIMENTAL

Preoxygenation using high-flow nasal oxygen with a flow rate of 70 l/min

Device: High-flow nasal oxygen

High-flow nasal oxygen, flow rate 95 l/min

EXPERIMENTAL

Preoxygenation using high-flow nasal oxygen with a flow rate of 95 l/min

Device: High-flow nasal oxygen

Interventions

High-flow nasal oxygen DEVICE

In this study, we will use high-flow nasal oxygen for preoxygenation in patients undergoing elective anaesthesia. Preoxygenation with high-flow nasal oxygen is most often performed at flow rates of \<50 l/min. In this study, patients will be randomised to preoxygenation using high-flow nasal oxygen and flow rates of 45 l/min, 70 l/min or 95 /min.

High-flow nasal oxygen, flow rate 45 l/min; High-flow nasal oxygen, flow rate 70 l/min; High-flow nasal oxygen, flow rate 95 l/min

Eligibility Criteria

• Age: 18 Years - 84 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adult, 18-84 years old
• ASA 1-3
• BMI \< 35
• Planned for elective surgery

You may not qualify if:

• Cardiac disease (ischemic heart disease, heart failure (NYHA ≥2), ongoing arrhythmias, pulmonary hypertension)
• Severe asthma, moderate to severe COPD
• Pregnancy
• Baseline oxygen saturation \< 95%
• Nasal obstruction
• Known or anticipated difficult airway
• Patients with electrical active implants where lung impedance analysis is contraindicated
• Not capable of understanding study information and signing a written consent

Sponsors & Collaborators

• Region Stockholm: lead
• Karolinska Institutet: collaborator

Study Sites (1)

Karolinska University Hospital

Solna, 17176, Sweden

Location

Related Publications (1)

• Sjoblom A, Hoffman F, Hedberg M, Forsberg IM, Jonsson Fagerlund M. Preoxygenation with high-flow nasal oxygen at various flow rates in elective surgical patients: a prospective, randomised, single-blind clinical trial. Br J Anaesth. 2025 Dec 18:S0007-0912(25)00816-5. doi: 10.1016/j.bja.2025.11.017. Online ahead of print.

  PMID: 41419379 DERIVED

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, CARE PROVIDER
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: Randomised controlled trial

Study Record Dates

• First Submitted: December 9, 2024
• First Posted: December 16, 2024
• Study Start: January 13, 2025
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): December 1, 2026
• Last Updated: June 27, 2025

Record last verified: 2024-12

Data Sharing

• IPD Sharing: Will not share

Locations

SE (1)