title: Optimizing oxygenation and intubation conditions during awake fibre-optic intubation using a high-flow nasal oxygen-delivery system.
abstract: BACKGROUND
  Awake fibre-optic intubation is a widely practised technique for anticipated difficult airway management. Despite the administration of supplemental oxygen during the procedure, patients are still at risk of hypoxia because of the effects of sedation, local anaesthesia, procedural complications, and the presence of co-morbidities. Traditionally used oxygen-delivery devices are low flow, and most do not have a sufficient reservoir or allow adequate fresh gas flow to meet the patient's peak inspiratory flow rate, nor provide an adequate fractional inspired oxygen concentration to prevent desaturation should complications arise.
  
  
  METHODS
  A prospective observational study was conducted using a high-flow humidified transnasal oxygen-delivery system during awake fibre-optic intubation in 50 patients with anticipated difficult airways.
  
  
  RESULTS
  There were no episodes of desaturation or hypercapnia using the high-flow system, and in all patients the oxygen saturation improved above baseline values, despite one instance of apnoea resulting from over-sedation. All patients reported a comfortable experience using the device.
  
  
  CONCLUSIONS
  The high-flow nasal oxygen-delivery system improves oxygenation saturation, decreases the risk of desaturation during the procedure, and potentially, optimizes conditions for awake fibre-optic intubation. The soft nasal cannulae uniquely allow continuous oxygenation and simultaneous passage of the fibrescope and tracheal tube. The safety of the procedure may be increased, because any obstruction, hypoventilation, or periods of apnoea that may arise may be tolerated for longer, allowing more time to achieve ventilation in an optimally oxygenated patient.
authors.affiliation: Department of Anaesthesia, Guy's and St Thomas' NHS Foundation Trust, Great Maze Pond, London SE9 3RT, UK.
authors.forename: S
authors.initials: S
authors.lastname: Badiger
authors.affiliation: Department of Anaesthesia, Guy's and St Thomas' NHS Foundation Trust, Great Maze Pond, London SE9 3RT, UK.
authors.forename: M
authors.initials: M
authors.lastname: John
authors.affiliation: Department of Anaesthesia, Guy's and St Thomas' NHS Foundation Trust, Great Maze Pond, London SE9 3RT, UK.
authors.forename: R A
authors.initials: RA
authors.lastname: Fearnley
authors.affiliation: Department of Anaesthesia, Guy's and St Thomas' NHS Foundation Trust, Great Maze Pond, London SE9 3RT, UK drimranahmad1@gmail.com.
authors.forename: I
authors.initials: I
authors.lastname: Ahmad
mesh_terms: D000281:Administration, Intranasal / Q000379:methods*; D005260:Female; D005336:Fiber Optic Technology; D006801:Humans; D000860:Hypoxia / Q000517:prevention & control; D007442:Intubation, Intratracheal / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000008:administration & dosage*; D011446:Prospective Studies; D014851:Wakefulness
chemical_list: D010100:Oxygen
keywords: anaesthetic techniques, fibre-optic; intubation, tracheal tube; oxygen, delivery systems