Pre- and Apnoeic Oxygenation for RSI in ED
Condition: Intubation; Oxygen Inhalation Therapy
MeSH terms: Respiratory Aspiration
Study type: Interventional

Summary: 
      Critically ill patients may need support for breathing by means of intubation, which is
      placement of a breathing tube into the windpipe. Rapid sequence intubation (RSI) is a method
      commonly used and is performed by administering medications to induce coma and muscle
      paralysis, followed by intubation to allow the ventilator to provide oxygen into the lungs.
      This procedure may be filled with potential complications.

      During RSI, the patient stops spontaneous breathing after medically induced muscle paralysis
      occurs. Adequate oxygenation before and during paralysis is crucial to increase the reserves
      and prolong the time that oxygen levels in the blood remain above 90%, called the safe apnoea
      period. If the oxygen reserves are insufficient, the blood oxygen level will drop and can
      lead to permanent brain damage or even death.

      This study aims to explore if delivering high-flow humidified oxygen at 60L/min via the
      nostrils would be superior to current methods of mask ventilation at 15L/min and nasal
      cannula at 15L/min, before and during paralysis respectively. If successful, this new method
      would allow for a longer safe apnoeic period and increase the chances for doctors to perform
      intubation successfully without the blood oxygen dropping below 90%.
    

Detailed description: 
      Maintaining adequate oxygenation during rapid sequence intubation (RSI) is imperative to
      prevent peri-intubation adverse events that can lead to increased duration of hospital and
      intensive care unit stay, or prolonged vegetative state requiring long-term
      institutionalisation.

      Preliminary data from our emergency department (ED) airway registry revealed that 15% of
      patients experienced desaturation during intubation despite employing current best practices
      during RSI. In this multicentre randomised controlled trial in the ED, we aim to test the
      hypothesis that use of humidified high flow oxygenation via nasal cannula (HFNC) at 60L/min
      maintains higher oxygen saturation compared with current usual care using non-rebreather mask
      for preoxygenation and provides superior apnoeic oxygenation compared to the typical practice
      of 15L/min via standard nasal cannula.

      The main goal of the study would be to improve on the lowest oxygen saturation during
      intubation, and thereby increase the safe apnoeic time during RSI. We plan to enrol adult
      patients who require rapid sequence intubation due to medical, surgical or traumatic
      conditions in the EDs of National University Hospital and Ng Teng Fong General Hospital.

      Eligible patients will undergo block randomisation at equal ratio into 2 possible treatment
      combinations of pre-oxygenation and apnoeic oxygenation. The primary endpoint will be the
      lowest oxygen saturation achieved from time of administration of paralytic agent until
      quantitative end-tidal carbon dioxide is detected for the first intubation attempt.

      Higher failure rates for intubation in unfasted patients in the ED compared to fasted
      patients in elective settings increase the risk of aspiration if re-oxygenation is required
      with bag-valve-mask ventilation. Prolongation of safe apnoea time through maintenance of
      oxygen saturation above 90% using HFNC oxygenation during RSI could potentially change
      current clinical practice, improve standard of care and translate to better outcomes for
      patients.
    

Intervention name(s): High-flow nasal cannulae (HFNC) oxygenation; Non-rebreather mask and standard nasal cannula
Intervention type(s): Device; Device
Intervention description(s): Delivery of 60L/min of supplemental oxygen for pre-oxygenation and apnoeic oxygenation during rapid sequence intubation using the AIRVO™ 2 Humidifier with Integrated Flow Generator (Fisher & Paykel Healthcare, Auckland, New Zealand); Pre-oxygenation using non-rebreather mask and apnoeic oxygenation via nasal cannulae at 15L/min
Other intervention name(s): AIRVO™ 2 Humidifier with Integrated Flow Generator
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: This study consists of 2 arms (intervention and control) of parallel design. The intervention arm will receive high flow nasal cannula (HFNC) oxygenation at 60L/min for pre- and apnoeic oxygenation while the control arm will receive pre-oxygenation via non-rebreather mask and apnoeic oxygenation via nasal cannulae at 15L/min.
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: high flow oxygenation, rapid sequence intubation