Intubation approach for suspected COVID-19 infection

This is a suggested approach to intubation for patients with suspected COVID-19, from pre-oxygenation to ventilator connection, with the goal of limiting virus escape during those steps. The approach will vary based on available equipment.

When a patient with suspected COVID-19 requires emergency endotracheal intubation, the team is presented with the challenge of containing the virus as much as possible. Transitioning from pre-oxygenation to ventilator connection involves steps in which the virus may be aerosolized. Clinicians experienced in COVID-19 intubation in China recommend methods that minimize aerosolization.¹ Below we describe and demonstrate one approach.

A non-rebreather mask set to high flow rates is commonly used for preoxygenation prior to intubation in typical patients.² In suspected COVID-19 infection, it is unclear what effect high oxygen flow rates through a non-rebreather mask may have on aerosolization of the patient’s exhalations. The non-rebreather presents several potential issues: respiratory aerosols may escape around an inadequate seal, and it is not possible to filter the patient’s exhalation.

A bag-valve-mask (BVM) may also be used for pre-oxygenation.^3–5 When done properly, it achieves higher fractions of expired oxygen (FeO₂) than a non-rebreather mask.⁶ This requires a one-way valve on the expiratory port of the bag to separate the inhalation and exhalation routes. Without a one-way valve, room air is pulled in through the exhalation port during inhalation.

Some bag-valve-masks have a built-in one-way valve on the exhalation outlet. When a bag is being used that does not, a positive end-expiratory (PEEP) valve can be connected and set to zero. This effectively creates a one-way expiratory valve. If PEEP is desired, a nasal cannula can be applied to the patient under the mask to pressurize the mask, and the PEEP valve can be adjusted to a set PEEP level.^3,7 This is an optional step only required when PEEP is desired. In order to limit aerosolization, it should be done before the mask is applied. Alternatively, PEEP can be provided by pressurizing an end-tidal CO2 adapter on the bag side of the viral filter with oxygen tubing.⁸

This video demonstrates the setup of the bag-valve-mask that includes a viral filter and end-tidal CO2 sampler. The filter should be high-efficiency and is connected directly to the mask.

If the viral filter is not part of your department’s typical stock, it can be added to your intubation kit so it is immediately available and in the room when needed.

The video below demonstrates the intubation steps. Intubation may be done with either a video or non-video laryngoscope. When video is available, it offers the benefit of a video screen view that will enlarge the view of the vocal cords without the intubator close to the patient’s face. When it is unavailable and standard non-video laryngoscope must be used (for example, due to cleaning time between multiple intubations in rapid succession), proper height of the patient’s gurney (with the patient’s forehead horizontally aligned with the intubator’s xiphoid process) also allows the intubator to remain further from the patient and offers a better view.⁹ The photo below demonstrates proper bed height. Note that this photo was taken for demonstration purposes during task training and DOES NOT demonstrate appropriate personal protective equipment (PPE).

1. Apply the bag-valve-mask to the spontaneously breathing patient for pre-oxygenation. Set the oxygen flow rate to 15 L/min or higher, ensuring that the reservoir bag remains inflated. The bag is not squeezed. With inhalation, the patient draws oxygen from the bag and reservoir. The one-way PEEP valve prevents room air from entering the expiratory outlet. Exhaled breaths close the duck-bill valve and exhalation goes through the respiratory port and out the one-way PEEP valve.
2. Induce and paralyze the patient with chosen medications for rapid sequence intubation (RSI).
3. Remove the mask and pass the endotracheal tube.
4. Inflate the endotracheal tube cuff. This is done prior to any ventilation to prevent aerosolization around the tube seal.
5. Disconnect the mask from the BVM and connect the endotracheal tube to the BVM at the viral filter.
6. Bag the patient.
7. When a ventilator is available, disconnect the bag from the patient at the end-tidal CO₂, while keeping the viral filter connected to the patient’s endotracheal tube.
8. Connect the endotracheal tube to the ventilator.

References

1. Cheung JC-H, Ho LT, Cheng JV, Cham EYK, Lam KN. Staff safety during emergency airway management for COVID-19 in Hong Kong. The Lancet Respiratory Medicine. 2020.
2. A Non-Rebreather Mask for Oxygenation of a Spontaneously-Breathing Unstable Patient with Hypoxia. https://www.instagram.com/p/B79H4sWBFc3/. Accessed March 16, 2020.
3. COVID19 (Corona Virus) Intubation Packs and Preoxygenation. https://youtu.be/C78VTEAHhWU. Accessed March 16, 2020.
4. Oxygenation -Understanding Your BVM Device 2. https://youtu.be/PJiRABugTfg. Accessed March 16, 2020.
5. Can This Pediatric BVM Be Used for Preoxygenation? https://youtu.be/YHrd10qDscA. Accessed March 16, 2020.
6. Groombridge C, Chin CW, Hanrahan B, Holdgate A. Assessment of Common Preoxygenation Strategies Outside of the Operating Room Environment. Acad Emerg Med. 2016;23(3):342-346.
7. CPAP from Bags with and without Supplemental Oxygen for COVID19 Intubations. https://youtu.be/HT9DTisAN8A. Accessed March 17, 2020.
8. COVID19 CPAP Set Up without Nasal Cannula. https://youtu.be/QEMBJXfEd2M. Accessed March 18, 2020.
9. Lee H-C, Yun M-J, Hwang J-W, Na H-S, Kim D-H, Park J-Y. Higher operating tables provide better laryngeal views for tracheal intubation. Br J Anaesth. 2014;112(4):749-755.