key: cord-0924567-wm2qibmr
authors: Cook, T. M.; El‐Boghdadly, K.; McGuire, B.; McNarry, A. F.; Patel, A.; Higgs, A.
title: Consensus guidelines for managing the airway in patients with COVID‐19: Guidelines from the Difficult Airway Society, the Association of Anaesthetists the Intensive Care Society, the Faculty of Intensive Care Medicine and the Royal College of Anaesthetists
date: 2020-04-01
journal: Anaesthesia
DOI: 10.1111/anae.15054
sha: efcdacba4277ede02a161c601573b2ec503a7ecf
doc_id: 924567
cord_uid: wm2qibmr

Severe acute respiratory syndrome‐corona virus‐2, which causes coronavirus disease 2019 (COVID‐19), is highly contagious. Airway management of patients with COVID‐19 is high risk to staff and patients. We aimed to develop principles for airway management of patients with COVID‐19 to encourage safe, accurate and swift performance. This consensus statement has been brought together at short notice to advise on airway management for patients with COVID‐19, drawing on published literature and immediately available information from clinicians and experts. Recommendations on the prevention of contamination of healthcare workers, the choice of staff involved in airway management, the training required and the selection of equipment are discussed. The fundamental principles of airway management in these settings are described for: emergency tracheal intubation; predicted or unexpected difficult tracheal intubation; cardiac arrest; anaesthetic care; and tracheal extubation. We provide figures to support clinicians in safe airway management of patients with COVID‐19. The advice in this document is designed to be adapted in line with local workplace policies.

This consensus statement has been brought together at short notice to advise on airway management for patients with coronavirus disease 2019 . 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, Italy and airway experts in the UK. It is probably incomplete but aims to provide an overview of principles. It The one-page summary ( Fig. 1 ) may be useful as a stand-alone resource, and the principles of safe, accurate and swift management must always be considered (Fig. 2) .

The full paper is likely to be of greater value as a reference when planning local services. The advice is based on available evidence and consensus at the time of writing, in what is a fast-moving arena. 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.

Severe acute respiratory syndrome-corona virus-2 (SARS-CoV-2), which causes COVID-19, is a single-stranded ribonucleic acid -encapsulated corona virus and is highly contagious. Transmission is thought to be predominantly by droplet spread (i.e. relatively large particles that settle from the air), and direct contact with the patient or contaminated surfaces (fomites), rather than airborne spread, in which smaller particles remain in the air longer [1, 2] . Procedures during initial airway management and in the intensive care unit (ICU) may generate aerosols which will increase risk of transmission [1] . Healthcare workers (HCW) treating patients with COVID-19 are at increased risk of contracting the illness [3] [4] [5] [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.

The highest viral load of SARS-CoV-2 appears in the 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 appropriate precautions. This is clearly an area of great importance [7] . Whereas 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 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] . and 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] .

There is much debate about the degree to which high-flow nasal oxygen is aerosol-generating and the associated risk 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 high-flow nasal oxygen in a 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, high-flow nasal oxygen is not currently recommended for these patients around the time of tracheal intubation.

Low-flow nasal oxygen (i.e. < 5 l.min À1 via normal nasal cannula) may provide some oxygenation during apnoea and might therefore delay or reduce the extent of hypoxaemia during tracheal 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 high-flow nasal oxygen, 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 who are predicted to be easy to intubate, it is not recommended.

Systems to prevent contamination of healthcare workers, including personal protective equipment Personal protective equipment (PPE) 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 nonabsorbent 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, HCW were at very high risk for infection, but reliable use of PPE significantly reduced this risk [13, 14] . [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 and/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 this standard and, when critical care is expanded to areas outside of ICU, airway management may take place in rooms with positive pressure (e.g. operating theatres) or those with reduced 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] .

This is a high-risk procedure with physiological difficulty: around 10% of patients in this setting develop severe hypoxaemia (S p O 2 < 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 tracheal intubation in the critically ill is often < 80% with up to 20% of tracheal intubations taking > two attempts [19] . 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. Due to 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 case load is sufficient.

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 a 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.

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 [4, 6] . Whereas no clear evidence exists, it is logical to also not include staff who are immunosuppressed or pregnant from airway management of COVID-19 patients.

Due to the uncertainties inherent in the new processes to be adopted, we recommend regular and 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.

Where practical, single-use equipment should be used [24] .

However, where single-use equipment is not of the same quality as re-usable 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 will need appropriate decontamination. It is important to precisely follow manufacturer's instructions for decontamination of reusable equipment.

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

Airway management for patients who are suspected or confirmed to have COVID-19 follows similar principles in both emergency and non-emergency settings (Fig. 1) . 12 Use a tracheal intubation checklist ( Fig. 7 and also see Supporting Information, Appendix S2). 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 (Fig. 8 Anaesthetic and airway technique for emergency tracheal intubation 1 A rapid sequence induction (RSI) approach is likely to be adopted. Use of cricoid force is controversial [28] , so use it where a trained assistant can apply it but promptly remove it if it contributes to tracheal intubation difficulty.

2 Meticulous pre-oxygenation should be with a wellfitting mask for 3-5 min. A closed circuit is optimal (e.g. anaesthetic circle breathing circuit) and a rebreathing circuit (e.g. Mapleson's C ('Waters') circuit is preferable to a bag-mask which expels viruscontaining exhaled gas into the room. 

15 Secure the tracheal tube as normal.

16 Start mechanical ventilation only after cuff inflation.

Ensure there is no leak.

17 Confirm tracheal intubation with continuous waveform capnography.

18 Confirming correct depth of insertion may be difficult.

a Auscultation of the chest is difficult when wearing airborne precaution 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. b Declare difficulty or failure to the team at each stage.

c Mask ventilation may be deferred initially and a secondgeneration SGA used as an alternative between attempts at laryngoscopy. This may reduce aerosol generation due to improved airway seal d If an emergency FONA is required, the simplified DAS 2018 guidance should be followed (Fig. 8b) 

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 proceduressee above. While there are reports from other countries of use of awake tracheal intubation note:

a Topicalisation of the airway will need to be considered carefully to minimise aerosol-generating procedures and coughing. a Undertake appropriate physiotherapy and tracheal and oral suction as normal before extubation.

b Prepare and check all necessary equipment for mask or low flow (< 5 l.min À1 ) nasal cannula oxygen delivery before extubation.

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

d 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.

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

f Likewise, the use of an airway exchange catheter is relatively contra-indicated in a patient with COVID-19 due to potential coughing etc.

The UK Resuscitation Council 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 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." [35] . 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 a cuffed tracheal tube should be the aim. Before this, insertion of an SGA may enable ventilation of the lungs with less aerosol generation than facemask ventilation.

In the absence of a trained airway manager, rescuers should use those airway techniques they are trained in.

Insertion of an SGA should take priority over facemask ventilation to minimise aerosol generation. An SGA with a high seal pressure should be used in preference to one with a low seal. This will usually be a second-generation SGA where available.

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] [37] [38] [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 above. Airway management should be safe, accurate and swift.

There is likely to be a lower threshold for use of an SGA over facemask ventilation and also a lower threshold for tracheal intubation. If using an SGA, 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 than when an SGA is used. opioids (e.g. fentanyl, remifentanil) before extubation.

The management of patients with known or suspected COVID-19 requires specific considerations to safety for staff and patients. Accuracy is critical, and clinicians should avoid unreliable, unfamiliar or repeated techniques during airway management, thus enabling it to be safe, accurate and swift.

Swift care means that it is timely, without rush and similarly without delay. We have highlighted principles that may achieve these goals, but the details of these principles may be subject to change as new evidence emerges.

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