Pre-oxygenation With Facemask Oxygen vs High-flow Nasal Oxygen vs High-flow Nasal Oxygen Plus Mouthpiece Oxygen (PREOX)

University College Hospital Galway

Status: Completed

Conditions: Apnea; Respiration; Arrest; Anesthesia

Treatments: Other: Pre-oxygenation

Study type: Interventional

Funder types: Other

Identifiers

NCT04767867

Preox-HFNO

Details and patient eligibility

About

Pre-oxygenation increases oxygen reserves in the body to reduce the likelihood of oxygen desaturation on induction of general anaesthesia. Pre-oxygenation with facemask is the commonest method method of pre-oxygenation. High-flow nasal oxygen is a newer alternative. This study randomises participants to receive pre-oxygenation by one of three methods: facemask, high-flow nasal oxygen, high-flow nasal oxygen plus mouthpiece.

Full description

The administration of supplemental oxygen prior to induction of anaesthesia is known as pre-oxygenation. Pre-oxygenation increases oxygen reserves in the body with the purpose of delaying the time until oxygen desaturation after breathing stops (apnoea) following the administration of an anaesthetic. In the last decade, clinicians have begun utilising high-flow nasal oxygen for pre-oxygenation. However, the rationale for this is based largely on its ability to achieve ongoing oxygenation after the onset of apnoea (apnoeic oxygenation). This study isolates oxygen administration with high-flow nasal oxygen to the period when the person is breathing, without ongoing oxygen administration during the apnoea period, to quantify its effects during the pre-oxygenation period only. A third group of participants breathes oxygen through a mouthpiece in addition to receiving oxygen via high-flow nasal cannulae. The effect of these pre-oxygenation methods will be measured by the time taken until oxygen saturation levels decline to the lower end of the normal range (92%), along with other parameters such as blood oxygen levels.

Enrollment: 84 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• 18 years of age or older
• ASA 1 or 2
• Receiving a general anaesthetic for non-emergent surgery

Exclusion criteria

• ASA score ≥3
• BMI ≥ 30 kg/m2
• Nasal obstruction
• Baseline SpO2 ≤95% on room air
• Anticipated difficult airway management
• Requirement for awake intubation
• Pregnancy
• Positive PCR test for coronavirus.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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84 participants in 3 patient groups

Facemask oxygen (FM)

Experimental group

Description:

100% oxygen administered via facemask through circle system with adjustable pressure-limiting valve at 0 cmH20. Participant instructed to 'breathe normally'

Treatment:

Other: Pre-oxygenation

High-flow nasal oxygen (HFNO)

Active Comparator group

Description:

100% oxygen administered via high-flow nasal cannulae at 50 L/min. Participant instructed to 'keep the mouth closed and breathe normally'

Treatment:

Other: Pre-oxygenation

High-flow nasal oxygen plus mouthpiece oxygen (HFNO+MP)

Active Comparator group

Description:

100% oxygen administered via high-flow nasal cannulae at 50 L/min. Additionally, 100% oxygen administered via mouthpice through circle system with adjustable pressure-limiting valve at 0 cmH20. Participant instructed to 'keep the mouth closed and breathe normally'.

Treatment:

Other: Pre-oxygenation