High-Flow Nasal Oxygen for Preoxygenation in Emergency Surgery Patients With Full Stomachs

Official title

Research on Pre-Anesthetic Blood Oxygenation Effect of High-Flow Nasal Oxygen for Emergency Surgery Patients With Full Stomachs

Overview

Patients with full stomachs face a high risk of regurgitation and aspiration under general anesthesia. To minimize the time between the loss of airway protective reflexes and successful tracheal intubation, rapid sequence induction intubation is commonly used. However, these patients are particularly vulnerable to hypoxemia during anesthesia induction, especially in emergency cases. Pre-oxygenation before induction is crucial for ensuring patient safety during apnea. High-flow nasal oxygen (HFNO) therapy, which consists of an air/oxygen blender, an active humidifier, and a single heated circuit, has recently gained widespread use in intensive care units (ICUs) for managing hypoxemic respiratory failure. HFNC can deliver a constant fraction of inspired oxygen (FiO₂) from 0.21 to 1.0 at high flow rates (up to 60 L/min or higher). Its advantages include generating continuous positive airway pressure, reducing anatomical dead space, improving ventilation-perfusion matching, enhancing mucociliary clearance, and decreasing the work of breathing. Given these benefits, HFNO has the potential to improve pre-oxygenation before and during anesthesia induction in emergency surgery patients with full stomachs.

Detailed description

This is a prospective, single-center, randomized controlled trial designed to evaluate the effects of HFNO on preoxygenation before and during anesthesia induction in emergency surgery patients with full stomachs. Adult patients undergoing emergency surgery with general anesthesia will be enrolled in the study.

After obtaining written informed consent, patients will be randomly assigned to one of the study groups:

\- Intervention Group: Patients will undergo HFNO preoxygenation for 3 minutes with a flow rate of 60 L/min of heated and humidified pure oxygen (100% FiO₂, 37°C - Optiflow; Fisher \& Paykel Healthcare, Auckland, New Zealand). To minimize air contamination, large or medium nasal cannulae will be selected based on the patient's nostril size. During the intubation process, HFNO will be maintained to facilitate either: Continuous oxygenation while the patient breathes spontaneously, or Apneic oxygenation during laryngoscopy for rapid sequence intubation (RSI).

\- Control Group: Patients will undergo preoxygenation for 3 minutes using a face mask (sized appropriately to fit the patient and ensure an airtight seal) connected to an Aisys CS2 ventilation system (General Electric, GE Healthcare, Oy, Finland). In this group, the ventilation system will be set with a fresh gas flow of 10 L/min, FiO₂ = 100%, without inspiratory support or expiratory positive pressure. The face mask (Economy, Intersurgical, Fontenay-sous-Bois, France) will be removed after induction to enable intubation.

Rapid sequence induction and intubation were performed using fentanyl (2 mcg/kg), propofol (2 mg/kg), and rocuronium (1 mg/kg). Intubation was performed 90 seconds after rocuronium administration. Cricoid pressure was applied from the moment the patient lost consciousness until intubation was successfully completed.

The current guidelines advise interrupting intubation to focus on oxygenation (ie, face mask ventilation) for oxygen desaturation ≤94%.

Interventions

• Device High-flow nasal cannula therapy application
  Patients will undergo HFNC preoxygenation for 3 minutes with a flow rate of 60 L/min of heated and humidified pure oxygen (100% FiO₂, 37°C - Optiflow; Fisher \& Paykel Healthcare, Auckland, New Zealand). To minimize air contamination, large or medium nasal cannulae will be selected based on the patient's nostril size
• Device Traditional facemask
  Patients will undergo preoxygenation for 3 minutes using a face mask (sized appropriately to fit the patient and ensure an airtight seal) connected to an Aisys CS2 ventilation system (General Electric, GE Healthcare, Oy, Finland). In this group, the ventilation system will be set with a fresh gas flow of 10 L/min, FiO₂ = 100%, without inspiratory support or expiratory positive pressure. The face mask (Economy, Intersurgical, Fontenay-sous-Bois, France) will be removed after induction to enable i

Primary outcome measures

• PaO2 [Time frame: Perioperative]
• Changes SpO2 during 3 minutes of preoxygenation [Time frame: Perioperative]
• Incidence of desaturation during rapid sequence induction anesthesia [Time frame: Periprocedural]
• Number of episode of facemask ventilation during apnea period [Time frame: Periprocedural]

Secondary outcome measures (5)

• Changes TcCO2 [Time frame: Periprocedural]
• Gastric volume [Time frame: Perioperative]
• Incidence of regurgitation and aspiration [Time frame: Periprocedural]
• Nasal congestion [Time frame: 1 hour after extubation]
• Hemodynamic effects [Time frame: During 3 minutes of preoxygenation]

Eligibility criteria

Inclusion criteria

• Emergency surgical patients at risk of gastric fullness requiring endotracheal intubation.
• Patients aged 18 years or older.
• Health status classified as ASA I or II.
• Mallampati classification I or II.

Exclusion criteria

• Patients with a predicted difficult airway, facial deformities, or an inability to achieve a proper mask seal.
• Patients with respiratory diseases.
• Pregnant patients.
• Patients allergic to anesthesia or resuscitation drugs.
• Patients who do not consent to participate in the study.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

Vietnam · 1 center

• Department of Anesthesia, Phu Tho General Hospital — Viet Tri

Publications

• Vargas F, Saint-Leger M, Boyer A, Bui NH, Hilbert G. Physiologic Effects of High-Flow Nasal Cannula Oxygen in Critical Care Subjects. Respir Care. 2015 Oct;60(10):1369-76. doi: 10.4187/respcare.03814. Epub 2015 May 5. PMID 25944940
• Vourc'h M, Asfar P, Volteau C, Bachoumas K, Clavieras N, Egreteau PY, Asehnoune K, Mercat A, Reignier J, Jaber S, Prat G, Roquilly A, Brule N, Villers D, Bretonniere C, Guitton C. High-flow nasal cannula oxygen during endotracheal intubation in hypoxemic patients: a randomized controlled clinical trial. Intensive Care Med. 2015 Sep;41(9):1538-48. doi: 10.1007/s00134-015-3796-z. Epub 2015 Apr 14. PMID 25869405
• Patel A, Nouraei SA. Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE): a physiological method of increasing apnoea time in patients with difficult airways. Anaesthesia. 2015 Mar;70(3):323-9. doi: 10.1111/anae.12923. Epub 2014 Nov 10. PMID 25388828
• Badiger S, John M, Fearnley RA, Ahmad I. Optimizing oxygenation and intubation conditions during awake fibre-optic intubation using a high-flow nasal oxygen-delivery system. Br J Anaesth. 2015 Oct;115(4):629-32. doi: 10.1093/bja/aev262. Epub 2015 Aug 7. PMID 26253608
• Lodenius A, Piehl J, Ostlund A, Ullman J, Jonsson Fagerlund M. Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) vs. facemask breathing pre-oxygenation for rapid sequence induction in adults: a prospective randomised non-blinded clinical trial. Anaesthesia. 2018 May;73(5):564-571. doi: 10.1111/anae.14215. Epub 2018 Jan 13. PMID 29330853
• Lam ND, Son LDT, Phat TM, Thu ND, Nga NT, Son VT, Hong BM. High-flow nasal oxygen versus face-mask ventilation for rapid sequence induction in non-elective surgical patients: a randomized controlled trial. BMC Anesthesiol. 2026 Jan 31;26(1):149. doi: 10.1186/s12871-026-03654-w. PMID 41620676

Identifiers

NCT: NCT06879600 · HongGMHS-No.1185 · NCS42HFNC

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗