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

Not Applicable

Completed

• Conditions: Anesthesia; Apnea; Respiration; Arrest
• Interventions: Other: Pre-oxygenation

• Registration Number: NCT04767867
• Lead Sponsor: University College Hospital Galway

Brief Summary

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.

Detailed 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.

Study Timeline

• Study Start: 2020-08-01
• Primary Completion: 2021-01-13
• Study Completion: 2021-01-13
• Study First Submitted: 2021-01-31
• Status Verified: 2021-02
• Study First Submitted QC: 2021-02-22
• Last Update Submitted: 2021-02-22
• Study First Posted: 2021-02-23
• Last Update Posted: 2021-02-23

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 84

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.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
High-flow nasal oxygen (HFNO)	Pre-oxygenation	100% oxygen administered via high-flow nasal cannulae at 50 L/min. Participant instructed to 'keep the mouth closed and breathe normally'
Facemask oxygen (FM)	Pre-oxygenation	100% oxygen administered via facemask through circle system with adjustable pressure-limiting valve at 0 cmH20. Participant instructed to 'breathe normally'
High-flow nasal oxygen plus mouthpiece oxygen (HFNO+MP)	Pre-oxygenation	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'.

Primary Outcome Measures

Name	Time	Method
Time to oxygen desaturation	Immediately after the intervention	The time period from the onset of apnoea (determined by visual inspection) until an oxygen saturation of 92% is measured by pulse oximetry.

Secondary Outcome Measures

Name	Time	Method
Correlation between end-tidal carbon dioxide measurement and arterial partial pressure of carbon dioxide	Etco2 obtained at the time of resumption of ventilation. Paco2 obtained from the preceding blood gas measurement.	The EtCO2 value used for comparison is the highest value recorded during the first five respiratory cycles by manual ventilation with the adjustable pressure-limiting valve set at 20cmH20.
Change in acid-base status during apnoea	At 0, 1, 2 minutes and each 2 minutes thereafter	As measured by blood gas analysis
Arterial partial pressure of oxygen after pre-oxygenation.	At 3 minutes of pre-oxygenation	As measured by blood gas analysis
Arterial partial pressure of carbon dioxide change during pre-oxygenation	At 0 and 3 minutes	As measured by blood gas analysis
Change in arterial partial pressure of carbon dioxide during apnoea	At 0, 1, 2 minutes and each 2 minutes thereafter	As measured by blood gas analysis

Trial Locations

Locations (1)

University Hospital Galway; 🇮🇪 Galway, Ireland