COVID-19 airway management principles

19 March 2020

Airway management: SAS

• Safe – for staff and patient.

• Accurate – avoiding unreliable, unfamiliar or repeated techniques.

• Swift – timely, without rush or delay.

Summary for emergency tracheal intubation of COVID-19 patient

• Tracheal intubation of the patient with COVID-19 is a high-risk procedure for staff, irrespective of the clinical severity of disease.

• In severe COVID-19 it is also a high-risk procedure for the patient.

• Limit staff present at tracheal intubation: one intubator; one assistant; and one to administer drugs and monitor the patient. A runner should be outside the room.

• Create a COVID-19 tracheal intubation trolley that can be used in ICU or elsewhere.

• Wear full Personal protective equipment (PPE) at all times. Consider double gloving. Defog goggles and/or eye wear if possible. Touch as little as possible in the room to avoid fomites.

• Intubate in a negative pressure room with > 12 air changes per hour whenever possible.

• Know and communicate the plan before entering the room; use a checklist to achieve this.

• Take the algorithm or cognitive aid you plan to use into the room or display it there.

• Prepare airway equipment and drugs outside the room as much as possible. Use a kit dump mat if available.

• Plan how to communicate before entering the room.

• The best skilled airway manager present should manage the airway to maximise the first pass success.

• Be safe, accurate and swift. Aim to succeed at the first attempt because multiple attempts increase risk to sick patients and staff. Do not rush but make each attempt the best it can be.

• Use reliable techniques that work, including when difficulty is encountered. The chosen technique may differ according to local practices and equipment. With prior training and availability this is likely to include:

  • Pre-oxygenation with a well-fitting mask and a Mapleson C (‘Waters’) or anaesthetic circuit, for 3–5 minutes.

  • Videolaryngoscopy for tracheal intubation;

  • 2-person, 2-handed mask ventilation with a VE-grip to improve seal;

  • A second generation supraglottic airway device for airway rescue, also to improve seal.

• Place a HME filter between the catheter mount and the circuit at all times. Keep it dry to avoid blocking.

• Avoid aerosol-generating procedures, including high-flow nasal oxygen, non-invasive ventilation, bronchoscopy and tracheal suction without an in-line suction system in place.

• Establish full monitoring: including continuous waveform capnography before, during and after tracheal intubation.

• Use RSI with cricoid force where a trained assistant can apply it. Take it off if it causes difficulty.

• To avoid cardiovascular collapse consider ketamine 1–2 mg.kg-1

• Paralyse with rocuronium 1.2 mg.kg-1 or suxamethonium 1.5 mg.kg-1. Ensure full neuromuscular blockade before attempting tracheal intubation

• Have a vasopressor for bolus or infusion immediately available for managing hypotension.

• Do not face mask ventilate unless needed, and use a 2-person, low flow, low pressure technique if needed.

• Intubate with a 7.0–8.0 mm ID (females) or 8.0–9.0 mm ID (males) tracheal tube with a subglottic suction port.

• Pass the cuff 1–2 cm below the cords to avoid bronchial placement. Confirming position is difficult wearing PPE.

• Inflate the tracheal tube cuff to seal the airway before starting ventilation. Note and record depth.

• Confirm tracheal intubation with continuous waveform capnography – which is present even during cardiac arrest.

• Avoid circuit disconnection - push twist all connections.

• Use a standard failed tracheal intubation algorithm with a cognitive aid if difficulty arises.

• Communicate clearly: simple instructions; closed-loop communication (repeat instructions back); adequate volume without shouting.

• Place a nasogastric tube after tracheal intubation is completed and ventilation established safely.

• If COVID-19 status not already confirmed take a deep tracheal aspirate for virology using closed suction.

• Discard disposable equipment safely after use. Decontaminate reusable equipment fully and according to manufacturer’s instructions.

• After leaving the room ensure doffing of PPE is meticulous.

• Clean the room 20 minutes after tracheal intubation (or last aerosol-generating procedure).

• A visual record of ease of tracheal intubation should be prominently visible in the patient’s room.

• If airway difficulty occurs the subsequent plan should be displayed in the room and communicated between shifts.

Summary

Purpose and context

This document is a consensus document brought together at short notice to advise on airway management for patients with COVID-19. It applies to all those who manage the airway (‘airway managers’). It draws on several sources including relevant literature but more immediately from information from clinicians practicing in China and Italy, and airway experts in the UK. It is likely incomplete but aims to provide an overview of principles. It does not aim to propose or promote individual devices. It is may be complemented or superseded by a more detailed international consensus document in the coming weeks. This will be sign-posted as soon as it is available. The advice in this document is designed to be adapted in line with local workplace policies.

This document does not discuss when to intubate patients, the ethics of complex decision-making around escalation of care or indemnity for staff necessarily working outside their normal areas of expertise. It does not discuss treatment of COVID-19 nor intensive care ventilatory strategies, rather it focuses on airway management.

The summary and Figures 5(a), 6(a), 6(b) and 6(c) may be useful as a stand-alone resource. The full paper is likely to be of greater value as a reference when planning local services. Some references refer to English or UK governmental sites for up to date advice. Those practicing in other countries should be aware that advice in their country may differ and is regularly updated, so they should also refer to their own national guidance.

COVID-19: the need for airway interventions and risks to airway managers

Severe acute respiratory syndrome-corona virus-2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), is a single-stranded ribonucleic acid (RNA) encapsulated corona virus and is highly contagious. Transmission is thought to be predominantly by droplet spread (i.e. relatively large particles that settle in the air), and direct contact with the patient or fomites, rather than ‘airborne spread’ (in which smaller particles remain in the air longer) [1,2]. Procedures during initial airway management and in intensive care unit (ICU) may generate aerosols which will increase risk of transmission [1]. Healthcare workers (HCWs) treating patients with COVID-19 are at increased risk of contracting the illness [3-6].

The predominant COVID-19 illness is a viral pneumonia. Airway interventions are mainly required for tracheal intubation and establishing controlled ventilation. However, as the epidemic increases there will be many patients in the community with COVID-19 who are asymptomatic or have mild disease. These patients may present for emergency surgery for unrelated conditions.

Staff safety

The highest viral load of SARS-CoV-2 appears in sputum and upper airway secretions [1]. Tracheal intubation is a potentially high-risk procedure for the airway manager, particularly as it risks exposure to a high viral load and if transmission occurs to HCWs this may be associated with more severe illness [4]. For this reason, airway managers should take all necessary precautions.

This is clearly an area of great importance [7]. While this article focuses predominantly on management of the airway, staff protection is too important not to include. We discuss in brief, aerosol-generating procedures and personal protective equipment (PPE) are only one part of a system to reduce viral exposure.

There is extensive advice which is updated regularly on infection prevention and control related to COVID-19 [8].

Aerosol-generating procedures

SARS-CoV-2 is spread by inhalation of infected matter containing live virus (which can travel up to 2m) or by exposure from contaminated surfaces (fomites). Aerosol-generating procedures create an increased risk of transmission of infection.

A 2012 systematic review of infection risk to healthcare workers [9], based on limited literature ranked airway procedures in descending order of risk as

1. Tracheal intubation

2. Tracheostomy (and presumed for emergency front-of-neck airway (eFONA))

3. Non-invasive ventilation (NIV)

4. Mask ventilation

 Other potentially aerosol-generating procedures include

• Disconnection of ventilatory circuits during use

• Extubation

• Cardiopulmonary resuscitation (before tracheal intubation)

• Bronchoscopy

• Tracheal suction without a ‘closed in-line system.’

 Transmission of infection is also likely to be possible from faeces and blood although detection of virus in the blood is relatively infrequent [1].

High-flow nasal oxygen and low-flow nasal oxygen

There is much debate about the degree to which HFNO is aerosol-generating and risks of pathogen transmission [10]. Older machines may expose staff to greater risk. The risk of bacterial transmission has been assessed as low [11], but the risk of viral spread has not been studied.

There are other reasons not to use HFNO in an situation of mass illness and mass mechanical ventilation. First, it may simply delay tracheal intubation in those for whom treatment escalation is appropriate [12]. Second, the very high oxygen usage risks depleting oxygen stores, which is a risk as a hospital’s oxygen usage may increase many-fold during an epidemic.

For all these reasons HFNO is not currently recommended for these patients around the time of intubation.

Low flow nasal oxygen (ie <5 L/min via normal ‘nasal cannula’) may provide some oxygenation during apnoea and might therefore delay or reduce the extent of hypoxaemia during intubation. There is no evidence we are aware of regarding its ability to generate viral aerosols, but on balance of likelihood, considering the evidence with HFNO, this appears unlikely. It is neither recommended nor recommended against during emergency tracheal intubation of patients who are likely to have a short safe apnoea time. In patients who are not hypoxaemic, without risk factors for a short safe apnoea time, and predicted to be easy to intubate it is not recommended.

Systems to prevent contamination of healthcare workers, including Personal Protective Equipment

Personal protective equipment forms only one part of a system to prevent contamination and infection of HCWs during patient care. In addition to PPE, procedures such as decontamination of surfaces and equipment, minimising unnecessary patient and surface contact and careful waste management are essential for risk reduction. The virus can remain viable in the air for a prolonged period and on non-absorbent surfaces for many hours or even days [2]: the importance of cleaning, equipment decontamination and correct use of PPE use cannot be overstated. In the SARS epidemic, which was also caused by a corona virus, healthcare workers were at very high risk for infection, but reliable use of PPE significantly reduced this risk [13,14].

Personal protective equipment is not discussed here in detail. General principles are that it should be simple to remove after use without contaminating the user: complex systems should be avoided. It should cover the whole upper body. It should be disposable whenever possible. It should be disposed of appropriately, immediately after removal (doffing). A ‘buddy system’ (observer), including checklists, is recommended to ensure donning and doffing is performed correctly. Personal protective equipment should be used when managing all COVID-19 patients. Full PPE is the minimum appropriate for all airway management of patients with known COVID-19 or those being managed as if they are infected. The Intensive Care Society has made a statement on PPE, describing minimum requirements and noting that PPE needs to be safe, sufficient and use in a manner that ensures supplies are sustainable [15].

It has been suggested that double-gloving for tracheal intubation might provide extra protection and minimise spread by fomite contamination of equipment and surrounds [16]. Fogging of googles or eyewear when using PPE is a practical problem for tracheal intubation in up to 80% of cases (personal communication Huafeng Wei, USA): anti-fog measures, and iodophor or liquid soap may improve this. Training and practising PPE use before patient management is essential for staff and patient safety.

Ideally patients are managed in single, negative pressure rooms with good rates of air exchange (> 12 exchanges per hour) to minimise risk of airborne exposure [17]. In reality, many ICU side rooms do not meet these standard and, when critical care is expanded to areas outside of ICU, airway management may take place in rooms with positive pressure (eg operating theatres) or those with reduce air exchanges. Most operating theatres are positive pressure with high rates of air exchange. These factors may have implications for transmission risk, retention of aerosols and therefore what constitutes appropriate PPE [18].

Guidance on PPE requirements after tracheal intubation is beyond the scope of this document [8].

Tracheal intubation of the critically ill

This is a high-risk procedure with physiological difficulty: around 10% of patients in this setting develop severe hypoxaemia (SpO2 < 80%) and approximately 2% experience cardiac arrest [19,20]. These figures are likely to be higher for patients with severe COVID-19 and drive some of the principles below. The first pass success rate of intubation is often < 80% with up to 20% of tracheal intubations taking > 2 attempts [19]. The increased risk of healthcare worker infection during multiple airway manipulations necessitates use of airway techniques which are reliable and maximise first pass success. This applies equally to rescue techniques if tracheal intubation fails at first attempt.

Delivering care in non-standard environments and by or with staff less trained in critical care

It is likely that management in expanded critical care services will involve working in areas other than standard critical care units. This creates logistical difficulty in airway management.

Monitoring should adhere to Association of Anaesthetists standards and in particular, continuous waveform capnography should be used for every tracheal intubation and in all patients dependent on mechanical ventilation unless this is impossible. Note that even in cardiac arrest during lung ventilation there will be a capnograph trace – a flat trace indicates and should be managed as oesophageal intubation until proven otherwise (‘No trace- wrong place’) [21,22].

Caring for COVID-19 patients may also involve recruitment of staff to the critical care team who do not normally work in that setting and have received emergency training to enable them to deliver care alongside fully-trained staff. In severe escalation even these standards might become difficult to maintain. The Chief Medical Officer has written to all UK doctors to explain regulatory support for this [23]. At its extreme peak, care may also be delivered by retired staff and medical students. Because of the high consequence nature of airway management in these patients, both for the patient and staff, it is recommended that these staff do not routinely take part in airway management of COVID-19 patients.

In some circumstances the development of a specific tracheal intubation team may be an appropriate solution where caseload is sufficient.

The most appropriate airway manager

We recommend that the ‘most appropriate’ clinician manages the airway. This is to enable successful airway management that is safe, accurate and swift. Deciding who is the most appropriate airway manager requires consideration of factors such as the available clinicians’ airway experience and expertise, whether they fall into any of the groups of clinicians who would be wise to avoid tracheal intubation, the predicted difficulty of airway management, its urgency and whether an tracheal intubation team is available. On occasion this may necessitate senior anaesthetists managing airways in lieu of junior anaesthetists or intensivists who do not have an anaesthesia background. However, it is unlikely and unnecessary that tracheal intubation will be the exclusive preserve of one specialty. Judgement will be required.

Staff who should avoid involvement in airway management

This is a problematic area and there is no national guidance. In some locations, healthcare providers are excluding staff who are themselves considered high risk. Current evidence would include in this group, older staff (the mortality curve rises significantly > 60 years of age), cardiac disease, chronic respiratory disease, diabetes, recent cancer and perhaps hypertension and obesity [4,6]. While no clear evidence exists, it is logical to also exclude staff who are immunosuppressed or pregnant from airway management of known or suspected COVID-19 patients.

Simulation

Due to the uncertainties inherent in the new processes to be adopted, we recommend a regular, full in situ simulation of planned processes, to facilitate familiarity and identification of otherwise unidentified problems, before these processes are used in urgent and emergent patient care situations.

Single vs reusable equipment

Where practical single-use equipment should be used [24]. However, where single-use equipment is not of the same quality as reusable equipment this creates a conflict. It is also possible that supplies of single-use equipment may run short. The balance of risk to patients and staff (frontline and those involved in transport and decontamination of equipment) should be considered if a decision is made to use reusable airway equipment. We recommend use of the equipment most likely to be successful, while balancing the above factors. Reusable equipment but will need appropriate decontamination. It is important to precisely follow manufacturer’s instructions for decontamination of reusable equipment 

When to intubate the critically ill COVID-19 patient

This document does not consider when patients should be intubated. However, in order to avoid aerosol-generating procedures it is likely that patients may be intubated earlier in the course of their illness than in other settings. 

Fundamentals of airway management for a suspected or confirmed COVID-19 patient.

This section includes significant repetition of the one-page summary but is expanded and relates both to emergency and non-emergency airway management.

1 Prepare. This involves

a.     Institutional preparation (equipment for routine management and for managing difficulty, adequate numbers of appropriately trained staff, availability of tracheal intubation checklists, PPE etc) should be in place well before airway management occurs. If this does not already exist it is strongly recommended it is put in place urgently. Resources from this guideline may form part of that preparation.

b.     Team and individual preparation require knowledge of the institutional preparation, the skills required, how to use PPE correctly and assessment of the patient’s airway to predict difficulty and prepare the airway strategy (Table 1). It is accepted that MACOCHA is not widely used but it is validated and recommended.

Table 1 MACOCHA score calculation worksheet (originally from 25). Score 0 to 12: Cut-off indicating difficult tracheal intubation is ≥ 3.

2.     Create a COVID-19 tracheal intubation trolley. Critically ill patients may need to be intubated in a location other than ICU. On ICU tracheal intubation will likely take place in single rooms. Prepare a tracheal intubation trolley that can be taken to the patient and decontaminated after use. Figure 1 illustrates how simple this may be. Appendix 1 provides some guidance on its contents.

3.     Have a strategy. The airway strategy (the primary plan and the rescue plans, and when they are transitioned to) should be in place and the airway team briefed, before any part of airway management take place.

4.     Involve the smallest number of staff necessary. This is not an argument for solo operators but staff who have no direct role in the airway procedure should not unnecessarily be in the room where airway management is taking pace. Three individuals are likely required: and intubator, an assistant and a third person to give drugs and watch monitors. A runner should be watching from outside and able to summon help rapidly if needed (Figure 2).

5.     Wear appropriate, checked PPE. Even in an emergency and including cardiac arrest, PPE should be in worn and checked before all airway management and staff should not expose themselves to risk in any circumstance.

6.     Avoid aerosol-generating procedures wherever possible. If a suitable alternative is available, use it. If aerosol generation takes place the room is considered contaminated, full PPE should be used and the room should be deep cleaned after 20 minutes [24].

7.     Focus on promptness and reliability. The aim is to achieve airway management successfully at the first attempt. Do not rush but make each attempt the best it can be. Multiple attempts are likely to increase risk to multiple staff and to patients.

8.     Use techniques that are known to work reliably across a range of patients, including when difficulty is encountered. The actual technique may differ according to local practices and equipment. Where training and availability is in place this is likely to include:

• use of a kit dump mat (Figure 3);

• videolaryngoscopy for tracheal intubation;

• a 2-person 2-handed mask ventilation with a VE grip (Figure 4);

• a second-generation SAD for airway rescue (eg i-gel, Ambu aura gain, LMA ProSeal, LMA Protector)

9.     The most appropriate airway manager should manage the airway.

10.    Do not use techniques you have not used before or are not trained in. Again, for the reasons stated above, this is not a time to test new techniques.

11.  Ensure all necessary airway kit is present in the room before tracheal intubation takes place. This includes the airway trolley and a cognitive aid consistent with the rescue strategy.

a.     Monitoring including working continuous waveform capnography
b.     Working suction
c.      Ventilator set up
d.     Working, checked IV access

12.  Use an tracheal intubation checklist – see Figure 5. This is designed to aid preparedness and should be checked before entering the patient’s room as part of preparation.

13.  Use a cognitive aid if difficulty arises – see Figure 6. Airway difficulty leads to cognitive overload and failure to perform optimally. A cognitive aid will help focus the team and enhance transitioning through the algorithm. Two algorithms are provided: that derived from the DAS 2018 guidelines for tracheal intubation of the critically ill [20] has intentionally been reduced in scope and choices removed to accommodate the current setting and encourage reliable and prompt decision making and actions

14. Use clear language and closed loop communication. It may be hard to communicate when wearing PPE and staff may be working outside normal areas of practice. Give simple instructions. Speak clearly and loudly, without shouting. When receiving instructions repeat what you have understood to the person speaking. If team members do not know each other well, a sticker with the individual’s name can be placed on the top of the visor to aid communication with other staff.

Anaesthetic and airway technique for emergency tracheal intubation

• An RSI approach is likely to be adopted. Use of cricoid force is controversial [28], use it where a trained assistant can apply it but promptly remove it if it contributes to tracheal intubation difficulty.

• Meticulous preoxygenation should be with a well-fitting mask for 3-5 minutes. A closed circuit is optimal (e.g. anaesthetic circle) and a re-breathing circuit (e.g. Mapleson’s C (‘Waters’) circuit is preferable to a bag- mask which expels virus-containing exhaled gas into the environment.

• Place a heat ad moisture exchanger (HME) between the catheter mount and the circuit. Non-invasive ventilation(NIV) should be avoided. High-flow nasal oxygen (HFNO) is not recommended.

• Patient positioning including ramping in the obese and reverse Trendelenburg positioning should be adopted to maximise safe apnoea time.

• In agitated patients a delayed sequence tracheal intubation technique may be appropriate

• In view of the high-risk cardiovascular instability, ketamine 1-2 mg.kg— is recommended for induction of anaesthesia and rocuronium 1.2mg.kg-1 for neuromuscular blockade, which should be given as early as practical. These.  measures minimise apnoea time and risk of patient coughing. If suxamethonium is used the dose should be 1.5 mg/kg.

• Ensure full neuromuscular blockade before tracheal intubation is attempted. A nerve stimulator maybe used or wait 1 minute.

• Ensure a vasopressor for bolus or infusion is immediately available for managing hypotension.

• If there is a good seal on the face mask, gentle continuous positive airway pressure (CPAP) may be applied only after reliable loss of consciousness (to avoid coughing) to minimise the need for mask ventilation. Bag-mask ventilation may be used to assist ventilation and prevent hypoxia if indicated. Use a Guedel airway to maintain airway patency. Use the 2-handed, 2-person technique with a VE-grip to improve seal [29]. When bag-mask ventilation is applied, minimal oxygen flows and airway pressures consistent with achieving this goal should be used.

• Alternatively, a second-generation SAD may be inserted, after loss of consciousness and before tracheal intubation, to replace the role of bag-mask ventilation  or if this is difficult[7,30].

• Laryngoscopy should be undertaken with the device most likely to achieve prompt first pass successful tracheal intubation in all circumstances in that operator’s hands – in most fully trained airway mangers this is likely to be a videolaryngoscope.

a.     Stay as distant from the airway as it practical to enable optimal technique (whatever device is used)
b.     Using a videolaryngoscope with a separate screen enables the operator to stay further from the airway and this technique is recommended for those trained
in their use.
c.     If using a videolaryngoscope with a Macintosh blade a bougie may be used.
d.     If using a videolaryngoscope with a hyperangulated blade a stylet is required.
e.     Where a videolaryngoscope is not used a standard MacIntosh blade and a bougie (either pre-loaded within the tracheal tube or immediately available)
is likely the best option
f.      If using a bougie or stylet, be careful when removing it so as not to spray secretions on the intubating team

• Intubate with a 7.0-8.0 mm ID (females) or 8.0-9.0 mm ID (males) tracheal tube, in line with local practice. Use a tracheal tube with a subglottic suction port where possible.

• During tracheal intubation place the tracheal tube without losing sight of it on the screen and pass the cuff 1-2 cm below the cords, to avoid bronchial intubation.

• Inflate the cuff with air to a measured cuff pressure of 20-30 cmH2O immediately after tracheal intubation.

• Secure the tracheal tube, as normal.

• Start mechanical ventilation only after cuff inflation. Ensure there is no leak.

• Confirm tracheal intubation with continuous waveform capnography.

• Confirming correct depth of insertion may be difficult.

a.     Auscultation of the chest is difficult when wearing enhanced PPE and is likely to risk contamination of the stethoscope and staff, so is not recommended.
b.     Watching for equal bilateral chest wall expansion with ventilation is recommended.
c.      Lung ultrasound or CXR may be needed if there is doubt about bilateral lung ventilation.

• Once correct position is established record depth of tracheal tube insertion prominently.

• Pass an nasogastric tube after successful tracheal intubation is complete and ventilation established to minimise the need for later interventions.

• If the patient has not yet been confirmed as COVID-19 positive collect a deep tracheal sample using closed suction for COVID-19 testing. Some upper airway samples are false negatives.

• A visual record of tracheal intubation should be prominently visible on the patient’s room (an example is shown in Figure 7).

Unexpected difficulty

• The basic algorithm for tracheal intubation can usefully adhere to the simplified Difficult Airway Society (DAS) 2018 guideline for tracheal intubation of the critically ill patient (Figure 6a and 6b) or the Vortex approach (Figure 6c). If there is difficulty with tracheal intubation this should be managed according to standard rescue algorithms with attention to the following:

a.  Transition through the algorithm promptly, consider minimising number of attempts at each technique.
b.  Declare difficulty or failure to the team at each stage.
c.   Face mask ventilation may be deferred initially and a 2nd generation SAD used as an alternative between attempts at laryngoscopy. This may reduce aerosol generation because of improved airway seal
d.  If an emergency front of neck airway (eFONA) is required, the simplified DAS 2018 guidance should be followed (Figure 6c). The scalpel-bougie-tube technique is particularly preferred in COVID-19 patients because of the risk of aerosolisation with the oxygen insufflation associated with cannula techniques. To improve simplicity, we have only provided the option of the scalpel-bougie -tube technique. If a different technique is specifically adopted and trained for in your department this may also be appropriate.

Where there is difficulty a difficult airway plan should be recorded, prominently displayed and communicated to staff at shift change overs (an example of an ICU airway alert form is shown in Figure 8).

Predicted difficult airway

• The choice of airway technique in a predicted difficult airway will be specific to the patient’s needs and is therefore beyond the scope of this guideline.

• Many techniques for managing the difficult airway will include potentially aerosol-generating procedures – see above. While there are reports from other countries of use of awake tracheal intubation.

  • Topicalisation of the airway will need to be considered carefully to minimise aerosol-generating procedures and coughing.

  • Flexible bronchoscopy techniques (whether alone, via a SAD conduit or with a videolaryngoscope, so called video-assisted flexible intubation (VAFI) are likely to be aerosol-generating and therefore unlikely to be first choice.

  • Alternative difficult tracheal intubation techniques include tracheal intubation via a SAD including an intubating LMA (blind or flexible bronchoscope-assisted), or via another SAD with (video guidance and an Aintree catheter).

 Airway management after tracheal intubation and trouble shooting

• Use an HME filter close to the patient, instead of a heated humidified circuit (wet circuit), but take care this does not become wet and blocked.

• Monitor airway cuff pressure carefully to avoid airway leak. If using high airway pressures, ensure cuff pressure at least 5 cm H2O above peak inspiratory pressure. Cuff pressure may need to be increased before any recruitment manoeuvres to ensure there is no cuff leak.

• Monitor and record tracheal tube depth at every shift to minimise risk of displacement.

• Managing risk of tracheal tube displacement. This is a risk during patient repositioning including proning, de-proning nasogastric tube aspiration or positioning, tracheal suction and oral toilet. Cuff pressure and tracheal tube depth should be checked and corrected both before and after these procedures. There is a risk of tracheal tube displacement during sedation holds and this should be considered in when planning these (eg timing, nursing presence etc).

• Suction. Closed tracheal suction is mandatory wherever available.

• Cuff leak - If a cuff leak develops to avoid aerosol-generation pack the pharynx while administering 100% oxygen and setting up for reintubation. Immediately before reintubation, pause the ventilator.

• Airway interventions. Physiotherapy and bagging, transfers, proning, de-proning, tune repositioning. If the intervention requires a disconnection of the ventilator from the tracheal tube – before the airway intervention

  • Consider administering neuromuscular blockade.

  • Pause the ventilator so that both ventilation and gas flow stops

  • Clamp the tracheal tube

  • Separate the circuit with the HME still attached to the patient

  • Reverse this procedure after reconnection.

• Accidental disconnection. Pause the ventilator. Clamp the tracheal tube. Reconnect promptly and unclamp the tracheal tube.

• Accidental extubation. This should be managed as usual, but management should be preceded by full careful donning of PPE before attending to the patient, irrespective of clinical urgency.

• Tracheostomy is a high-risk procedure because of aerosol-generation and this should be taken into account if it is considered. It may be prudent to delay tracheostomy until active COVID-19 disease is passed.

Risk of blockage of an HME filters

Actively heated and humidified ‘wet circuits’ may be avoided after tracheal intubation to avoid viral load being present in the ventilator circuit. This will theoretically reduce risks of contamination of the room if there is an unexpected circuit disconnection. There is a risk of the filter becoming blocked if it becomes wet. This will cause blockage of the filter and may be mistaken for patient deterioration, which it also may then cause: consider whether the HME is wet and blocked if there is patient deterioration or difficulty in ventilation. If the HME filter is below the tracheal tube/catheter mount condensed liquid may saturate the HME; this is particularly likely to occur if both an HME and a wet circuit are used simultaneously [31].

Extubation

• Many ICUs routinely extubate patients directly onto HFNO for up to 24 hours. This is unlikely to be desirable or feasible in patients with COVID-19, consequently, extubation may be delayed, unless pressure of beds demands otherwise.

• Efforts should be made to minimise coughing and exposure to infected secretions at this time.

  • Undertake appropriate physiotherapy and tracheal and oral suction as normal before extubation.

  • Prepare and check all necessary equipment for mask or low flow (< 5 l.min-1) nasal cannula oxygen delivery before extubation.

  • During anaesthesia drugs to minimise coughing at emergence include dexmedetomidine, lidocaine and opioids [32]. The value of these is unproven in critical care and needs to be balanced against adverse impact on respiratory drive, neuromuscular function and blood pressure. For these reasons, routine use is currently unlikely.

  • While a SAD may be considered as a bridge to extubation to minimise coughing this involves a second procedure and the possibility of airway difficulty after SAD placement so is unlikely to be a first-line procedure [33,34].

  • Likewise, the use of an airway exchange catheter is relatively contra-indicated in a patient with COVID19 due to potential coughing.

  • After extubation ensure the patient immediately wears a facemask as well as their oxygen mask or nasal cannulae where this is practical.

 Airway management during cardiac arrest

• The UK resuscitation council (RC(UK)) has published statements on the management of cardiac arrest in patients with COVID-19 [35].

• Airway procedures undertaken during management of cardiac arrest are likely to expose the rescuer to a risk of viral transmission. The RC(UK) guidance states that “The minimum PPE requirements to assess a patient, start chest compressions and establish monitoring of the cardiac arrest rhythm are an FFP3 facemask, eye protection, plastic apron, and gloves.”

• Avoid listening or feeling for breathing by placing your ear and cheek close to the patient’s mouth.

• In the presence of a trained airway manager early tracheal intubation with cuffed tracheal tube should be the aim.

• Before this, insertion of an SAD may enable ventilation of the lungs with less aerosol generation than face mask ventilation.

• In the absence of a trained airway manager, rescuers should use those airway techniques they are trained in. Insertion of a SAD should take priority over face mask ventilation to minimise aerosol generation.

• A SAD with a high seal pressure should be used in preference to one with a low seal. This will usually be a 2nd generation SAD when available.

 Airway management for anaesthesia

• While it is beyond the scope of this document to define which patients need precautions, it is worth noting that patients may be asymptomatic with COVID-19 but infective [36-39], though symptomatic patients are more likely to pose a risk of transmission. During an epidemic there should be a very low threshold for considering a patient at risk of being infective and it may become necessary to treat all airway interventions as ‘high risk’.

• Decisions around airway management should be undertaken using the fundamental principles described on above.

• Airway management should be Safe, Accurate and Swift.

• There is likely to be a lower threshold for use of a SAD over mask ventilation and also a lower threshold for tracheal intubation (see below).

• If using a SAD spontaneous ventilation may be preferred to controlled ventilation, to avoid airway leak.

• Drug choices may differ from when intubating a patient with critical illness and, in particular if the patient is not systemically unwell, ketamine may not be chosen as the induction agent.

• Note that tracheal intubation is associated with more coughing at extubation then when a SAD is used. Avoiding this may be by

  • Use of a SAD instead of tracheal intubation

  • Changing a tracheal tube to a SAD prior to emergence

  • Use of I.V. or intacuff lidocaine or I.V. dexmetomidine, or opioids (eg fentanyl, remifentanil) prior to extubation.

Authors: Profesor T Cook, Dr K El-Boghdadly, Dr A Higgs.

Review and comment: Nicholas Chrimes, Laura Duggan, Jerry Nolan, Barry McGuire, Al McNarry, Fiona Kelly, Anil Patel, and members of the 4-bodies core COVID-19 group

Appendix 1
Exemplar contents of COVID-19 airway trolley

• PPE x 4

• Drugs

• CMAC trolley with screen

• CMAC blades (one each of size 3,4 and D)

• Disposable Mapleson C circuit

• Subglottic drainage tracheal tube (size 7.0 and 8.0)

• Standard tracheal tube (all other sizes except size 7 and 8)        

• Parker flex tip size 6.0: for nasal intubations and awake fibreoptic intubations

• Capnography monitoring line

• Guedel airways

• Adult McGill forceps

• Blue Portex swivel connector 15mm     

• Gum elastic bougie

• CMAC tracheal intubation stylet

• igel size 3,4,5 

• ProSeal LMA size 3,4,5 (1 of each)

• ProSeal LMA introducer

• Sachets of water-soluble gel lubricant   

• Aintree intubating catheter 19 Fr 56 cm (blue)

• eFONA set (Size 10 scalpel, size 6 cuffed tracheal tube, tracheal dilator) 

• Ascope3 bronchoscope trolley with screen

• Just one bronchoscope screen, next to airway/resus trolley nearest ABG machine          

• Grey “slim” (size 3.8) disposable bronchoscope 

• Size 4.0 mm and size 5.0 (blue)                                     

• Sheet on back of CMAC blade packets – for tracking

  • Place one copy in patient’s notes

  • Put a second copy in file on top of airway trolley to allow traceability

  • Place red sticker in patient’s notes.

References

1. Wang W, Xu Y, Gao R, et al. Detection of SARS-CoV-2 in Different Types of Clinical Specimens. JAMA. Published online March 11, 2020. doi:10.1001/jama.2020.3786

2. van Doremalen N, Bushmaker T, Morris DH et al. Aerosol and surface stability of HCoV-19 (SARS-CoV-2) compared to SARS-CoV-1. NEJM in press doi: https://doi.org/10.1101/2020.03.09.20033217. The https://www.medrxiv.org/content/10.1101/2020.03.09.20033217v1.full.pdf  (Accessed 13 March 2020)

3. Wang D, Hu B, Hu C, et al. Clinical Characteristics of 138 Hospitalized Patients With 2019 Novel Coronavirus–Infected Pneumonia in Wuhan, China. JAMA. Published online February 07, 2020. doi:10.1001/jama.2020.1585 https://jamanetwork.com/journals/jama/fullarticle/2761044 (Accessed 13 March 2020) 

4. Wu Z, McGoogan JM. Characteristics of and Important Lessons From the Coronavirus Disease 2019 (COVID-19) Outbreak in China. Summary of a Report of 72 314 Cases From the Chinese Center for Disease Control and Prevention JAMA. Published online February 24, 2020. doi:10.1001/jama.2020.2648

5. The COVID-19 Task force of the Department of Infectious Diseases and the IT Service Istituto Superiore di Sanità. Integrated surveillance of COVID-19 in Italy.  https://www.epicentro.iss.it/coronavirus/bollettino/covid-19-infografica_eng.pdf (Accessed 13 March 2020)

6. Guan W, Ni Z, Hu Y et al. Clinical Characteristics of Coronavirus Disease 2019 in China. NEJM February 28, 2020, at NEJM.org. DOI: 10.1056/NEJMoa2002032 https://www.nejm.org/doi/full/10.1056/NEJMoa2002032 (Accessed 13 March 2020)

7. Cheung JCH, Ho LT, Cheng JV, Cham EYK, Lam KN. Staff safety during emergency airway management for COVID-19 in Hong Kong. Lancet respiratory Medicine. Published: February 24, 2020DOI: https://doi.org/10.1016/S2213-2600(20)30084-9  (Accessed 13 March 2020)

8. Public Health England. COVID-19: infection prevention and control guidance. https://www.gov.uk/government/publications/wuhan-novel-coronavirus-infection-prevention-and-control/wuhan-novel-coronavirus-wn-cov-infection-prevention-and-control-guidance#mobile-healthcare-equipment (Accessed 13 March 2020)

9. Tran K, Cimon K, Severn M, Pessoa-Silva CL, Conly J. Aerosol generating procedures and risk of transmission of acute respiratory infections to healthcare workers: a systematic review. PLoS One 2012; 7: e35797.

10. Respiratory Therapy Group, Chinese Medical Association Respiratory Branch. Expert Consensus on Respiratory Therapy Related to New Coronavirus Infection in Severe and Critical Patients.  Chinese Journal of Tuberculosis and Respiratory Medicine, 2020, 17: Pre-published online . DOI: 10.3760 / cma.j.issn.1001-0939.2020.002

11. Leung CCH, Joynt GM, Gomersall CD, et al. Comparison of high-flow nasal cannula versus oxygen face mask for environmental bacterial contamination in critically ill pneumonia patients: a randomized controlled crossover trial. Hosp Infect. 2019; 101: 84-87. doi: 10.1016/j.jhin.2018.10.007.

12. Renda T, Corrado A, Iskandar G, Pelaia G, Abdalla K, Navalesi P. High-flow nasal oxygen therapy in intensive care and anaesthesia. Br J Anaesth. 2018; 120: 18-27.

13. Nicolle L. SARS safety and science. Can J Anesth 2003; 50: 983-8

14. Loeb M, McGeer A, Henry B, et al. SARS among critical care nurses, Toronto. Emerg Infect Dis 2004; 10: 251-5

15. https://www.ics.ac.uk/COVID19.aspx?hkey=d176e2cf-d3ba-4bc7-8435-49bc618c345a&WebsiteKey=10967510-ae0c-4d85-8143-a62bf0ca5f3c (Accessed 13 March 2020).

16. Casanova LM, Rutala WA, Weber DJ, Sobsey MD. Effect of single- versus double gloving on virus transfer to health care workers’ skin and clothing during removal of personal protective equipment. Am J Infect Control 2012; 40: 369–74.

17. Wax RS, Chrisitan MD. Practical recommendations for critical care and anesthesiology teams caring for novel coronavirus (2019-nCoV) patients. Canadian Journal of Anesthesia (2020) https://doi.org/10.1007/s12630-020-01591-x (Accessed 13 March 2020).

18. Li Y, Huang X, Yu IT, Wong TW, Qian H. Role of air distribution in SARS transmission during the largest nosocomial outbreak in Hong Kong. Indoor Air 2005; 15: 83-95.

19. Nolan JP, Kelly FE. Airway challenges in critical care. Anaesthesia. 2011 Dec;66 Suppl 2:81-92

20. Higgs A, McGrath BA, Goddard C, et al. Guidelines for the management of tracheal intubation in critically ill adults. Br J Anaesth 2018; 120: 323-352.

21. RCoA. Capnography: No Trace = Wrong Place. July 2018.  https://www.youtube.com/watch?v=t97G65bignQ (Accessed 13 March 2020).

22. Cook TM, Harrop- Griffiths WHG. Capnography prevents avoidable deaths. BMJ 2019;364:l439 doi: https://doi.org/10.1136/bmj.l439

23. Joint statement: Supporting doctors in the event of a Covid-19 epidemic in the UK  https://www.gmc-uk.org/news/news-archive/supporting-doctors-in-the-event-of-a-covid19-epidemic-in-the-uk  (Accessed 13 March 2020).

24. Public Health England. Environmental decontamination, in COVID-19: infection prevention and control guidance  https://www.gov.uk/government/publications/wuhan-novel-coronavirus-infection-prevention-and-control/wuhan-novel-coronavirus-wn-cov-infection-prevention-and-control-guidance#decon (Accessed 13 March 2020).

25. De Jong, A., N. Molinari, N. Terzi, et al. Early identification of patients at risk for difficult intubation in the intensive care unit: development and validation of the MACOCHA score in a multicenter cohort study. Am J Respir Crit Care Med 2013; 187: 832-839

26. Chan A. Department of anaesthesia and Intensive Care, Chinese University Hong Kong. https://www.aic.cuhk.edu.hk/covid19/ February 2020 (Accessed 13 March 2020).

27. The Vortex approach. http://vortexapproach.org/ (Accessed 13 March 2020).

28. Cook TM. The cricoid debate - balancing risks and benefits. Anaesthesia. 2016; 71: 721-2.

29. Fei M, Blair JL, Rice MJ et al. Comparison of effectiveness of two commonly used two-hand mask ventilation techniques on unconscious apnoeic obese adults. British Journal of Anaesthesia 2017; 118, 618-24

30. Keller C, Brimacombe J, Kleinsasser A, Brimacombe L. The Laryngeal Mask Airway ProSeal(TM) as a temporary ventilatory device in grossly and morbidly obese patients before laryngoscope-guided tracheal intubation. Anesth Analg. 2002; 94: 737-40

31. Medicines and Healthcare Regulatory authority. Risk of using different airway humidification devices simultaneously.  NHS/PSA/W/2015/012 December 2015. https://www.england.nhs.uk/patientsafety/wp-content/uploads/sites/32/2015/12/psa-humidification-devices.pdf (Accessed 13 March 2020)

32. Tung A, Fergusson NA, Ng N, Hu V, Dormuth C, Griesdale DEG. Medications to reduce emergence coughing after general anaesthesia with tracheal intubation: a systematic review and network meta-analysis. Br J Anaesth. 2020 Feb 22. pii: S0007-0912(20)30012-X. doi: 10.1016/j.bja.2019.12.041. [Epub ahead of print]

33. Glaisyer HR, Parry M, Lee J, Bailey PM. The laryngeal mask airway as an adjunct to extubation on the intensive care unit. Anaesthesia. 1996; 51: 1187-8

34. Laver S, McKinstry C, Craft TM, Cook TM.  European DAS extubation guidelines Use of the ProSeal LMA in the ICU to facilitate weaning from controlled ventilation in two patients with severe episodic bronchospasm. Journal of Anaesthesiology 2006; 23: 977-8

35. Resuscitation Council. Resuscitation Council UK Statement on COVID-19 in relation to CPR and resuscitation in healthcare settings. March 2020.  https://www.resus.org.uk/media/statements/resuscitation-council-uk-statements-on-covid-19-coronavirus-cpr-and-resuscitation/covid-healthcare/ (Accessed 13 March 2020).

36. Bai Y, Yao L, Wei T, Tian F, Jin DY, Chen L, Wang M. Presumed Asymptomatic Carrier Transmission of COVID-19. JAMA. 2020 Feb 21. https://jamanetwork.com/journals/jama/fullarticle/2762028  (Accessed 13 March 2019)

37. Rothe C, Schunk M, Sothmann P. Transmission of 2019-nCoV Infection from an Asymptomatic Contact in Germany. N Engl J Med 2020; 382:970-971 DOI: 10.1056/NEJMc2001468

38. Tong ZD, Tang A, Li KF. Potential Presymptomatic Transmission of SARS-CoV-2, Zhejiang Province, China, 2020. Emerg Infect Dis. 2020;26(5). http://journal.yiigle.com/LinkIn.do?linkin_type=pubmed&DOI=10.3760/cma.j.cn112338-20200228-00207 (Accessed 13 March 2019)

39. Nishiura H, Linton NM, Akhmetzhanov AR. Serial interval of novel coronavirus (2019-nCoV) infections [J]. MedRxiv preprint 2020. https://www.medrxiv.org/content/10.1101/2020.02.03.20019497v2.full.pdf  (Accessed 13 March 2019)

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