Preoxygenation With a High-flow Nasal Cannula or a Simple Mask Before General Anesthesia in Head and Neck Surgery
Condition: Head and Neck Neoplasm
MeSH terms: Head and Neck Neoplasms
Study type: Interventional

Summary: 
      Objectives: To assess arterial oxygen partial pressure (PaO2) at defined time points during
      the preoxygenation and to compare between high ﬂow heated humidified nasal oxygen versus
      standard preoxygenation with oxygen insufflation via face mask over at least 5 minutes
      Methods: This randomized, single-blinded, prospective study was conducted at Asan Medical
      Center in Seoul, Republic of Korea.

      Populations: Patients undergoing head and neck surgery Expected outcomes: The course of PaO2
      levels is superior to those of the face mask during the whole preoxygenation procedure and
      after the intubation.
    

Detailed description: 
      Rationale & background information:

      Pre-oxygenation before general anesthesia is usually achieved using oxygen delivered via a
      facemask before induction of anesthesia; this potentially extends the time available for
      securing the airway before hypoxemia to 6 min. The lungs are commonly ventilated with a
      bag/facemask technique after induction, and this can be repeated if attempts at intubating
      the trachea are prolonged. However, facemask ventilation has traditionally been avoided in
      the circumstance which has the risk of gastric insufflation of gas, leading to increased
      intragastric pressure and raised risk of pulmonary aspiration of stomach contents. In
      addition, if difficult ventilation is anticipated, facemask ventilation may not be possible
      at all, and 6 minutes with hypoxemia may be insufficient for intubation.

      An ideal preoxygenation to extend apnea tolerance during anesthesia induction is essential to
      avoid live threatening airway incidents. The high-flow nasal cannula, the OptiFlow System
      (Thrive, Fisher & Paykel®, Aukland New Zealand), has the ability to deliver warmed and
      humidified oxygen through specially designed nasal cannula and enable oxygen to be
      comfortably delivered at rates of > 70 liter/min. Several study showed that nasal delivery of
      humidified oxygen to paralyzed and anesthetized patients at these rates maintains oxygenation
      and achieves acceptable carbon dioxide concentration. The investigators hypothesized that an
      extended apneic period without facemask ventilation could be particularly beneficial to
      patients undergoing general anaesthesia.

      Study goals and objectives:

      To assess arterial oxygen partial pressure (PaO2) at defined time points during the
      preoxygenation and to compare between high ﬂow heated humidified nasal oxygen versus standard
      preoxygenation with oxygen insufflation via face mask over at least 5 minutes
    

Intervention name(s): High-flow nasal cannula; simple mask
Intervention type(s): Device; Device
Intervention description(s): Apply high ﬂow heated (34 °C) and humidified nasal oxygen with the OptiFlow System (Thrive, Fisher & Paykel®, Aukland New Zealand) using a ﬂow of 30 liter/minute and an inspiratory oxygen fraction (FiO2) of 1.0. Increase the oxygen flow to 60 liter/minute over the course of the first minute. Ask the patients not to speak during anesthesia induction and keep the mouth closed.; Perform standard preoxygenation by oxygen insufflation via a face mask using the standard anesthesia ventilators (semicircular system) with 100% oxygen ﬂow of 12 liter/minute. The patients breathe with tidal volume.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: preoxygenation; high-flow nasal cannula