Safe Airway Management in COVID-19 Adult Patients

The Aerosol-Danger of SARS-Cov-2

​The outbreak of the SARS Coronavirus-2 (SARS-CoV-2) in China 2019 has within a short time spread around the globe and is just about to hit central Europe. Although about 80% of all confirmed cases develop a mild febrile illness, around 17% develop severe Corona viral disease (COVID-19) with findings of acute respiratory distress syndrome (ARDS), of which about 4% will require mechanical ventilation. 

Since this virus, which was previously unknown to humans, spread rapidly around the globe, a large number of patients requiring intensive medical care now arise within a very short time.
​
The lungs are the organs most affected by COVID-19 because the virus accesses host cells via the enzyme ACE2, which is most abundant in type II alveolar cells of the lungs. This results in mainly type 1 respiratory failure, which often requires urgent tracheal intubation and mechanical ventilation.

Due to viral shedding in the patient's lungs, COVID-19 spread mainly via droplets. Events like coughing, high flow nasal oxygen (High-Flow), intubation and more can cause aerosol generation, allowing these airborne particles to travel even further distances.

Performing endotracheal intubation in these patients is, therefore, a high-risk procedure, and it is required to adhere to certain principles to avoid infection of health care providers. 

The Safe Airway Societies of Australia and New Zealand have published a consensus statement that describes the problem very well and provides practical tips based on the currently available evidence.
​

1. Non Invasive Ventilation (NIV) and High Flow Nasal Oxygen (High-Flow)

​Current evidence suggests that the failure rate of NIV in COVID-19 patients seems to be similarly high as observed among Influenza A patients. Failure in these patients resulted in higher mortality.

In general, NIV is recommended to be avoided or at least used very cautiously!

The utility of High-Flow in viral pandemics in unknown. There is some evidence suggesting a decreased need for tracheal intubation compared to conventional oxygen therapy.

High Flow Nasal Oxygen is worth a try, although it has to be assumed, that this is aerosol-generating.

High-Flow should only be used in (negative pressure) airborne isolation rooms, and staff should wear full personal protective equipment (PPE) including N95/P2 masks.

 NIV and High-Flow are NOT recommended for patients with severe respiratory failure or when it seems clear that invasive ventilation is inevitable! 

Full Personal Protective Equipment PPE

​
2. Environment for Airway Management

Negative pressure ventilation rooms with an antechamber are ideal. If not available, normal pressure rooms with closed doors are recommended. Positive pressure ventilation areas like in theatre should be avoided!

​

3. Intubation-Specific Recommendations

Use disposable equipment if possible

Prior to intubation oxygen can be delivered via nasal cannulas (standard or High-Flow), simple face-mask or non-rebreather mask.

NIV should be used very cautiously or be avoided due to its unproven utility in ARDS and the risk of aerozolisation.

​Pre-oxygenation should be performed using a well fitting occlusive face-mask

A viral filter, if available (or at least a HME), must be inserted between the face-mask and manual ventilation device!

Non-rebreather masks are NOT recommended as they provide suboptimal pre-oxygenation and promote aerosolization. 

Nasal oxygen should NOT be used during pre-oxygenation or for apnoeic oxygenation for the same reason.

Mechanical ICU ventilators and anaesthetic machines can be used to oxygenate and ventilate COVID-Patients. The choice will depend on their availability.


Prepare for Difficult Intubation in Advance!

​
Consider initial video laryngoscopy if available. Have a 'difficult airway set' ready to use if required. Keep the cardiac arrest trolley nearby. 

If a supraglottic device is indicated, second-generation devices (e.g. iGel) are recommended due to their higher seal pressure.

Intubated patients should be immediately equipped with closed suction systems.

A cuff manometer should be used to measure tracheal tube cuff pressure and allow the best possible sealing. 
​

Team Setup

​
Limit the number of team members in the room. 

Use the most experienced clinician for airway management. Consider calling for help (e.g. senior anaesthetist).

Be sure to get 'Runners' available in the antechamber for additional help.

Personal Protective Equipment PPE

​
​
Clinician managing the airway (intubation, bronchoscopy, tube repositioning, percutaneous dilatational tracheostomy) and his direct assistants: 
​

•     Impervious gown
•     N95/FFP2 mask
•     Face shield or goggle for eye protection
•     Surgical cap
•     Consider double gloves (outer gloves can be removed after airway management)

In general: all procedures that carry the risk of aerosolization should be performed wearing a N95/FFP2 face-mask. Otherwise, surgical masks are considered safe.

Follow hospital and/or WHO guidelines for both donning and doffing of PPE.
​

---

4. Extubation-Specific Recommendations

​Ideally, patients should be non-infective when extubated, but this is unfeasible as resources might be drained. If there remains a risk of viral transmission, consider the following:​

• Patients should be ready for extubation onto face-mask
• NIV and High-Flow should be avoided
• Use the same level of PPE as is worn during intubation
• The patient should NOT be encouraged to cough
• A simple oxygen mask should be placed on the patient immediately post-extubation

Brewster DJ at al. Med J Aust; 16 March 2020