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Airway management in the patient who presents with respiratory failure due to COVID-19 is a challenge. The risk of exposing the airway technician and assistants to the virus remains high. This post will outline the most important steps to ensure protection of the airway clinician as well as protection of the patient through the procedure of advanced airway management.

This post starts off at the point where intubation and mechanical ventilation has been identified as the required action, and will not cover the complex clinical process leading up to the decision to intubate (this will be covered in a separate post).

When tracheal intubation of the COVID-19 patient is indicated, the goal is to prioritize provider safety while rapidly and skillfully achieving first attempt success.  

First, some definitions:

Hot Zone

The area immediately surrounding the patient, this space should be able to be isolated by doors, and walls or at least floor to ceiling curtains. Should be a separate area that cannot be entered “by mistake”.

Hot Zone trolley is a trolley that is prepared before the need arises, with all the equipment that will be needed for the first attempt at intubation (see image below in the discussion of equipment set up). This trolley enters the Hot Zone with the staff in full PPE and can thereafter only be handled by staff in full PPE.

This area should be limited to the intrubator and one assistant if possible, with additional assistants available outside the Hot Zone if additional support is required.

Warm Zone

Area where doffing is completed, before the staff are able to move into the Cold Zone, separated from the Hot-Zone by walls/doors (no mixing of air), but marked off to allow the doffing of PPE in a space where the practitioner will not be able to come into contact with those who are not in full PPE (an anteroom to the hot zone can be used if available, otherwise simply a marked off area is acceptable depending on space), there should be hand sanitizer and bins for collection of PPE in this area.

Assistants in this area should wear basic PPE and be available to monitor doffing procedures.

Cold Zone

The area outside the “hot zone” separated by walls and doors, or curtains (there should be no mixing of air between these spaces), separate rooms would be ideal, the back of an ambulance may be used if the space can be closed off from the driver compartment completely.

Cold-zone trolley has all the required rescue and back up equipment which can be handed to the hot-zone if needed.

OK! So we need to intubate this patient… Now what?

Firstly, this is not a decision that should be made late in the process of treating this patient, the closer to the edge the patient is, the more challenging and risky the procedure becomes. It would be ideal to make the decision to intubate this patient EARLY and create a stable and comfortable environment for this difficult procedure to be completed.

The approach to the COVID-19 patient’s airway will be different and difficult enough due to the addition of PPE, plastic visors and sheets or perspex boxes, without having a crashing patient to deal with as well.

EVERY COVID-19 intubation should be considered to be a physiologically, anatomically and psychologically difficult airway from the start.

Concept

The ideas here have been adapted from the SASA Guidelines for management of the COID-19 Airway (linked here: SASA COVID Approach to Airway management

Preparation prior to the management of the airway is vital, equipment in prepacked sets should be ready to be used and kept in an area where they can be safely packed and restocked when needed.

The plan is going to be presented here in five different periods

  1. Decision (indications for intubation confirmed) YELLOW
  2. Before (preparation and PPE) GREEN
  3. Optimize patient (prepare the patient and the “hot room” for airway management) ORANGE
  4. Intubation (perform the skill) RED
  5. After (Doffing and cleaning up equipment) NOT represented on the checklist but see below for more info

On the checklist and flow presented below these are highlighted in the colours noted above: 

Downloaded this as a PDF here.

The tool explained

1. Decision (indications for intubation confirmed)

Don’t use SPO2 or ETCO2 as the only mechanism to make these decisions, assess the patient in their entirety (LOC and work of breathing probably means more than just the numbers in these patients).

2. Before (preparation and PPE) GREEN

This should happen in a separate room to the patient treatment room

Equipment (this should be prepared at all times and be ready for use)

The list below is adapted from the SASA document, and details the different packs that should be available for intubation of the adult patient, these packs should be pre-packed and placed on a mobile trolley for use when needed:

Each of the above should be packed into a separate bag, with the checklist visible inside, this will mean equipment not opened can be reused

The Team (at least):

  • One practitioner who will be performing the airway skills
    • BVM applied to the patient before the intubation (two-handed seal)
    • Performs intubation
    • Managed ventilation post intubation
  • One practitioner to assist with airway skills
    • Squeezes bag for BVM ventilation
    • Secures the ETT
    • Willing and able to perform FONA (front of neck access/cricothyroidotomy) in a CICO situation if needed.
  • One practitioner in the “hot zone” to act as the team manager
    • Reads checklist
    • Keeps team on track with bigger picture
    • Oxygen champion for the patient (watching monitors and trends)
    • Gives medications

All three of these practitioners need to have their roles defined prior to entering the “hot zone”, they should all donn appropriate PPE (an example of DONNING and DOFFING can be found HERE)

  • Plastic apron (according to guidelines) but if available a long sleeve gown
  • Face shield or goggles
  • Consider use of a gown that can also protect the neck area if possible
  • N95 mask well fitted to face
  • Gloves (preferably double gloved)

It would be ideal to have an assistant who remains in the “cool zone” away from the patient room, wearing basic PPE (gloves, simple apron and surgical mask) who can act as an assistant to pass additional equipment to the team in the “hot zone”, and assist with monitoring the donning and doffing of PPE before and after the procedure.

The Plan

Below is a suggestion for the different escalation options:

Medications

The discussion about which medications will be used for the intubation attempt should be had BEFORE entering the room, medications and correct doses should ideally be prepared, drawn up and marked before entering the “Hot Zone”.

The following should be prepared:

  • Pre-intubation medications to be used (pain management/sedation for oxygenation if needed)
  • Intra-intubation
  • Post-intubation
    • Analgesia and sedation
    • Push-dose pressor/dirty Adrenaline as above

It may be a good idea to use the medications that the practitioner is most comfortable with, rather than prescribing what medications to use. 

Ketamine may be the ideal agent for induction in these patients for the following reasons:

  • The risk of haemodynamic compromise is limited (unless the patient is already compromised in which case the risk remains regardless of agent chosen)
  • Ketamine may allow for the control of the more combative patient allowing the mask, nasal cannula and other devices for pre-oxygenation to be used without increased risk of exposure to staff
  • The patient should maintain their own respiratory effort through the pre-oxygenation procedures, limiting the use of BVM ventilation and thus risk of increase aerosol production

See some safe options for airway management for EM below:

Medication Label templates can be found here.

3. Optimize patient (prepare the patient and the “hot room” for airway management)

This step is all about making sure that the “hot zone” airway equipment is ready to be used if needed (using the tool MIDSOLES) to assist as a read-response checklist, as well as making sure the patient is optimized for the intubation attempt. Leave equipment that is not needed for PLAN A in the “cold-zone”, it can be passed in if needed and opened only if required.

Optimizing the patient and the equipment checklist can happen simultaneously if needed

First Attempt should be the best attempt

Optimize the physiology of the patient

Pre-oxygenate

  • Using non-rebreather mask at high flow if patient is breathing spontaneously
  • Or using 2 handed seal on BVM with PEEP set to 10-15cmH20 and oxygen flow into BVM at 15l/min, using small tidal volumes if patient is not spontaneously breathing (set up the BVM as seen in the picture below with an HME filter between mask and device)
  • AVOID active ventilation if possible (increased risk of aerosol creation)
  • Consider placing nasal cannula running at 4-6l/min into nares under the mask, this will allow for APNEIC OXYGENATION once the BVM mask is removed.
  • ETCO2 should be attached to the BVM above the viral filter for this period as it will decrease time to first ventilation once the ETT is in place.

Prepare for Hypotension

  • Consider providing a small fluid bolus prior to medication administration (5-10ml/kg), to prevent a massive drop in BP with the medication admin and sudden change to positive pressure ventilation
  • Have a push dose pressor or dirty Adrenaline mix ready to use if needed (dirty Adrenaline should be “piggy-backed” onto the main line for ease of access if needed).

Expect a difficult airway

As mentioned before, this patient is likely to present challenges from the following perspectives:

Anatomy

  • The addition of protection devices, PPE and other equipment is going to make this a physically challenging airway, anticipate this and prep the station for difficulty
  • Pre-load a bougie and have it ready for use (see some options for this here) and some evidence for why pre-loading might be helpful HERE
  • Have a second ETT (one size up and one size down from the tube you have prepared) ready to go
  • Prep a stylet in case this is needed
  • Prepare and have rescue and surgical kits (packed in their separate bags) handy if needed
  • You have run through the plan for the airway in the “cold-zone”, now is the time to remind each person of their responsibility and ensure the equipment needed is ready for use in the “hot-zone”

 Physiology

  • The patient will likely be hypoxic, with limited physiological reserve, this means the intubation attempt needs to be quick and as efficient as possible
  • Best or most experienced intubator should perform the procedure
  • Patient will likely be acidaemic, this will require a quick intubation to resume good ventilation asap (see the ventilation post for more info about initial ventilation settings)

Psychologically

  • This intubation will be out of your usual comfort zone, with concerns about your own and your team’s safety, awareness of the importance of getting the attempt right the first time
  • This may not be the only or first intubation for the day, you may be tired, strained and mentally exhausted
  • Use some of the techniques linked here to assist you and your team prior to managing the airway (EMCrit: Beat the Stress Fool)

4. Intubation (perform the skill)

Cover the patient to decrease the risk of droplets or aerosol landing on the PPE

  • This can be done using a purpose-made perspex box if your facility or service has one, bear in mind this WILL NOT PREVENT EXPOSURE TO AEROSOL and will only assist with decreasing droplet exposure (you will still need to wear PPE.. and it will likely make you job a LOT harder).
  • This can also be done using some makeshift options (see some options below)
  • It may be better to intubate without any of the hoods or covers over the patient, as it will likely make the already difficult attempt more difficult (see notes below)
  • Place the video-laryngoscope into the patient area, and ensure that you are able to maneuver freely in the space 
  • Medication person should then administer the medications as planned and announce this to the team as they complete the task
  • Use VL to insert the ETT to the appropriate depth
  • Follow plan as discussed if the insertion is not successful
  • Have a low threshold for CICO (if unable to ensure oxygenation consider moving to FONA ASAP)
  • Inflate ETT cuff according to local protocol
  • Confirm ETT using continuous ETCO2 monitoring and waveform, as well as other clinical signs
  • Secure ETT in place
  • Place patient onto pre-set and configured ventilator ASAP (closed circuit ventilator ideal) see ventilation post for basic settings.
  • As soon as intubation has been completed, all additional staff should move to the “warm-zone” for DOFFING procedures.

Some notes about the Intubation Box

There is not really much evidence that the intubation box provides much in the way of protection for aerosol particles. As can be seen in the video below which has been shared on social media, the box really only helps if the droplets are large and not aerosol based. The aerosol still moves past and around the edges of the box, limiting its use.

The risk of using the box may outweigh the benefits of the box (increased difficulty visualising the airway, difficulty as PPE sleeves and cuffs get hooked on the arm holes, challenges with all the equipment required in a small space, and the biggest problem is that NO ONE is used to using such a box in their usual every day practice). The benefit as seen in the video, is very small (possibly even non-existant), for the massive increase in risk to first pass success.

Some more info about the use of a box can be found here: 

Should we use an “aerosol box” for intubation?

5. After: (Doffing and cleaning up equipment)

This should be done in the “warm-zone” with a buddy to monitor the removal of PPE (examples of how to safely DOFF PPE can be found in the second part of this video HERE)

Equipment that has not been placed in the “Hot Zone”

  • This equipment can remain on the “cold-zone” trolley and be reused for the next patient
  • This equipment has not been exposed to any soiled materials and is still housed inside its bags as packing lists suggest above, and so is safe for re-use.

Equipment that entered the “hot-zone”

  • All disposable items opened in the “hot-zone” should immediately be discarded, and not allowed to leave the “hot-zone” unless sealed in waste bags.
  • All reusable equipment that has been used in the “hot-zone” should be bagged and placed on the “hot-zone” trolley for decontamination. This trolley and equipment on it should only be handled by team members in full PPE (as described above).
  • Sealed bags of equipment that entered the “hot-zone” should exit on the trolley and be decontaminated in the “warm zone” before being recycled to the “cold-zone”.

Each facility and service will have specific requirements for the cleaning and decontamination of the equipment that has been used in the “hot-zone”, follow your facility/service’s requirements to ensure that the procedures are completed appropriately.

What if I need to disconnect the vent for some reason?

There is a really good video explaining what to do and how to do it linked here:

If you need to disconnect the INSPIRATORY LIMB of the ventilator see the image below:

Reflections on the system

Some reflections on using the system above from Ulrich Carshagen (who had the fortune of being able to the practice this set-up in a “clean” situation with a patient who required intubation not COVID-19 related and then shortly after had to use the system for a suspected COVID-19 patient)

  1. PPE definitely makes it harder. The glasses fogged up a bit at times. It is hot in the room and everything you are wearing makes it so much worse. Besides that, you are busy doing stressful procedures, so it just adds fuell to the fire. 
  2. It helps so much to work with someone you know and trust.  Decide at the start of each shift who your team is going be and have a discussion with them. Assign roles and talk through how things are going to happen. 
  3. Have everything prepared beforehand, meaning have boxes/bags ready with all your equipment as outlined in the plan. Makes a massive difference!
  4.  ‘The Box’: Using a plastic see-through box really doesn’t affect your ability to do VL or place the tube. If someone is comfortable using VL, intubation will be no problem. 
  5. The holes in our box are relatively small so with the wearing a long sleeve gown, it makes moving your arms around a bit difficult. Most challenging thing was probably to secure the tube after it was in. Also, the space in the box is quite small, so its worthwhile thinking carefully about how to position everything in a logical manner next to patient’s head and on his/her chest. 
  6. Different to what I usually do is once the tube was placed, I connected the vent directly (no BVM first). It is therefore so important to have ETCO2 monitoring available! Listening to the chest is not going to happen soon. 
  7. I can just imagine what a nightmare it will be if a patient vomits during this, so do everything you can to prevent the stomach from inflating (small tidal volumes and ventilations over at least 1 second if you have to use the BVM.

Need CPD points?

Follow the link below to access purchasing options for the activity: 

https://www.aiem.co.za/product/resuscitation-covid-19-patient/

References:

SASA. COVID-19 Update. 2020. SASA Recommendations for Airway Management for COVID-19 Patients. Published by SASA. Available online [https://docs.google.com/document/d/1M1zDXZ8c9ymqn5LlqIu50PU-KFlsG_6W-gVjjg7YeFg]

Salim Rezaie, “COVID-19: The Novel Coronavirus 2019”, REBEL EM blog, March 1, 2020. Available at: https://rebelem.com/covid-19-the-novel-coronavirus-2019/.

Scott Weingart. COVID Airway Management Thoughts. EMCrit Blog. Published on March 27, 2020. Accessed on April 1st 2020. Available at [https://emcrit.org/emcrit/covid-airway-management/ ].

Images presented in this post courtesy of D. Mattison and F. Els. ER Consulting Inc. 2020.

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