COVID-19 Emergency Department Assessment & Management Guideline

Purpose

As an emergency response, this guideline was produced to assist Emergency Department (ED) clinicians during the early phase of the COVID-19 pandemic with the assessment and management of suspected COVID-19 patients (adults). It is written for an Australian context but may be useful within EDs worldwide and some aspects may also be useful within:

  • Pre-hospital environments: such as Urgent Care, General Practice and Retrieval
  • Other in-hospital critical care environments such as Intensive Care and Anaesthetics.

Updates:

  • The last major update occurred in May and a major update is due shortly. Some recent advances such as the use of dexamethasone in the management of certain COVID-19 patients are not included. Please see our Record of Guideline Updates to easily review any recent changes.

Other Guidelines

For Australian clinicians we also recommend the following guidelines:

Please note the disclaimer detailing information about the references for his guideline.

Feedback and recommendations for additional resources are welcomed via our Contact Page or via our recently enabled “Comments” at the bottom of this page.

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Triage

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Summary

  • Patients considered to be “at risk of transmitting COVID-19 infection” to staff and other patients should be identified in a formalised process and provided a surgical mask to wear.
  • The definition of “at risk” patients will vary between jurisdiction and with time so consult local guidelines.
  • The “at risk” patient definition is different to the local “COVID testing criteria” – the latter is not relevant to triage.
  • Well patients should be directed to another service if available (e.g. purpose designed “COVID Clinic”) or directed home by the triage staff member, as appropriate, according to a locally agreed protocol.
  • Patients requiring ED assessment should be provided the highest level of isolation that balances the patient’s clinical risk of infectivity and the available methods of isolation – a methodology for ranking isolation effectiveness of ED spaces and prioritising patient’s access to these spaces is provided below.
  • Critically unwell patients will need to be managed in repurposed non-traditional resuscitation areas (e.g. negative pressure areas/single rooms) or traditional resuscitation areas may require temporary installation of barriers to improve infection control properties.
  • Triage staff should wear PPE appropriate for the routine care of patients.

Initial Triage

Patients considered to be “at risk of transmitting COVID-19 infection” to staff and other patients should be identified at, or ideally before, Emergency Department (ED) triage in a formalised process and provided a surgical mask to wear.  Note that it is not relevant whether these “at risk” patients meet formal criteria for diagnostic testing, as the latter criteria are based on a balance between population risks and availability of testing resources as opposed to risk to staff and other ED patients of contracting infection from patients.
The definition of a patient “at risk”of transmitting COVID-19 infection” and  the definition of patients who meet “formal criteria for testing” will vary between jurisdictions and may change frequently so consult local guidelines.

While waiting for triage, at risk patients should be separated from the general waiting room in an appropriate clinical or non-clinical area, inside or outside of the department, with sufficient distancing between patients.

Post triage disposition and cohorting:

Well patients should be directed to another service if available (e.g. purpose designed “COVID Clinic”) or directed home by the staff member (nurse and/or doctor) as appropriate according to a locally agreed protocol that balances the small additional risks incurred by well looking patients from this accelerated brief assessment and the risks to the community of disease spread that are minimised by directing these patients away from the ED. Triage staff should wear PPE appropriate for the routine care of patients.

Patients requiring an ED assessment should be provided the highest level of isolation that balances the patient’s clinical risk of infectivity and the available methods of isolation. The available methods of isolation in ED ranked by degree of effectiveness are demonstrated in this figure from ACEM:

Where lower levels of isolation are used, suspected COVID-19 patients should be grouped within the same geographical area. In regions where COVID-19 has become endemic with high levels of community disease, availability of higher level isolation spaces will be overwhelmed by demand and large sections of a department may need to be used to cohort “at risk” patients.

In order of priority, preference for treatment spaces with the highest levels of isolation should be given to (ACEM):

1. Patients with suspected or confirmed COVID-19 who are undergoing, or are likely to undergo, an aerosol generating procedure or event (AGP)

2. Patients with suspected COVID-19 receiving supplemental oxygen.

3. Other patients with confirmed COVID-19.

4. Other patients with suspected COVID-19.

Critically unwell patients need to be managed in an appropriate clinical area for their needs while maintaining safe protection of staff. Non-traditional resuscitation areas (negative pressure rooms, single rooms), may require repurposing for the care of the critically ill if they have better infection control properties than the traditional resuscitation area which is usually an open plan design without airflow control. Where that is not possible, temporary barriers will require installation to separate clinical areas within traditional resuscitation areas such as lightweight temporary walls and plastic sheeting.

Assessment

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Clinical Presentation

Summary:

  • COVID-19 can present with a wide range of symptoms, but fever and/or dry cough are most common.
  • Approximately half of COVID-19 patients may be afebrile on presentation so the presence of fever should not be relied upon when determining if patients are “at risk” of COVID-19.
  • In regions where COVID-19 has high endemic prevalence, the typical presentation will be less useful to clinicians and COVID-19 may need to be considered in a wide range of clinical presentations either as a triggering/exacerbating factor or as an incidental finding.

Fever (88%), dry cough (67%) are most common. Other less common symptoms include fatigue (38%), sputum production (33%), shortness of breath (19%), headache 13%), myalgia or arthralgia (15%), chills (11%), nausea or vomiting (5%), diarrhoea (4%). (WHO China 2020) Fever is commonly absent on arrival to ED – in one cohort fever was present in only 44% of patients at presentation but developed in 89% after hospitalisation. (Guan et al, NEJM 2020). Consequently screening for fever or respiratory infections symptoms will be required in order to be sufficiently sensitive to detect potential cases as the presence of fever can not be relied upon at presentation.

Rhinitis/nasal congestion alone is uncommon with COVID-19 (about 5%) and is more likely in keeping with influenza/common cold viruses. However COVID-19 is not ruled out and whether you consider COVID-19 in such patients will depend on the current overall prevalence of disease in your population and local public health advice.

Mean incubation period is 5-6 days, with a very wide range from 1-14 days (WHO China 2020).

Disease is generally slow onset in terms of severity (unlike influenza) with a 1 week prodrome of myalgias, cough, low grade fevers gradually leading to more severe trouble breathing in the second week of illness.

80% have mild-moderate disease, 14% have severe disease and 6% have critical disease. Individuals at highest risk for severe disease and death include people aged over 60 years and those with underlying conditions such as hypertension, diabetes, cardiovascular disease, chronic respiratory disease and cancer.(WHO China 2020).

Examination, aside from vital signs, is generally non-specific and unlikely to enhance diagnostic accuracy substantially. Given their marginal additional value, the role of previously routine examinations such as chest auscultation and throat inspection that expose staff to risk of infection, within the context of a pandemic is unclear.

It has been noted that patients can present hypoxic without significant tachypnoea and that lung auscultation can be unremarkable despite significant chest xray findings.

In regions where COVID-19 has high endemic prevalence, the typical presentation will be less useful to clinicians and COVID-19 may need to be considered in a wide range of clinical presentations either as a triggering/exacerbating factor or as an incidental finding.

Investigations

For unwell patients being assessed in ED, investigations are aimed at

  • Risk stratifying for COVID-19 versus alternate aetiology
  • Determining severity

Bloods:

Summary: Leukopaenia, lymphopaenia, raised CRP and a low procalcitonin (if available) may be suggestive of COVID-19

  • Full Blood Count
    • Usually normal WBC with leukopaenia in about 1/3
    • Lymphopaenia common in ⅓-⅔
  • CRP
    • >10 in 61% on admission (Guan et al, NEJM 2020) and appears to track disease severity and prognosis.  In patients suffering with severe respiratory failure with a normal CRP level an alternative diagnosis should always be sought. (IPCC19)
  • Procalcitonin
    • In the same large cohort, 95% of patients measured <0.5 (Guan et al, NEJM 2020). Increased procalcitonin may therefore indicate alternate diagnosis (e.g. bacterial pneumonia) or in admitted patients, an increase from baseline may indicate bacterial superinfection.
  • Other tests may be indicated as required for assessment of the patient’s clinical state and signs of organ failure – e.g Urea & Electrolytes, Liver Function Tests (LFTs). Liver enzymes are frequently elevated in the presence of COVID-19 infection.

Micro

Imaging:

Chest Xray

Consider chest xray (CXR) in most patients, particularly those being considered for admission. Well patients, fit for discharge, are unlikely to benefit from CXR.

If CXR is performed, it is recommended to perform portable CXR in ED to minimise risk of disease spread. (ACEM – Imaging)

CT

CT is the most sensitive test (though relatively non-specific). (Fang 2020, Ai 2019), so consider:

  • If CXR negative, and high degree of suspicion of COVID-19 and there is clinical need to determine diagnosis urgently that will change management

However transport to CT can increase disease spread so should be used sparingly in selected cases. Patients transported to radiology will need all providers to wear PPE appropriate for routine patient care and the CT area will need appropriate cleaning post scan which could result in significant CT downtime.

COVID-19 suggestive changes on xray include include lobar/ multi-lobar / bilateral lung infiltrates/consolidation. (IPCC19) On CT changes include ground glass opacity and peripheral distribution of changes. However unilateral findings on CXR or CT occur in approximately 14-25% especially if mild or early disease.

Ultrasound

There are promising reports of the utility of point of care ultrasound (POCUS) as a diagnostic modality of COVID-19 though widespread uniform guidelines for its use or evaluations of accuracy  in this area are currently lacking. Disadvantages of POCUS include:

  • Lack of uniform skills training in lung ultrasound across ED providers
  • The length of time required in close proximity to the patient
  • The extensive cleaning regime required of all ultrasound related parts post use in a suspect COVID-19 patient.

ACEM has stated they do not recommend CXR, CT or lung ultrasound to diagnose COVID-19 but do recommend its use for exclusion of other pathology from the differential diagnosis or to identify the cause of sudden deterioration in a patient. (ACEM – Imaging)

Management

General

Management is primarily supportive care and treatment of complications.

The primary cause of mortality in COVID-19 patients is type 1 respiratory failure from several hypothesised causes including  V/Q mismatching due to pulmonary vasoplegia (causing  loss of hypoxic pulmonary vasoconstriction) and pulmonary vascular microthrombi, alveolar derecruitment and ARDS. Consequently the Treatment of Hypoxia & Respiratory Failure will be the primary management focus of this document.

Other management considerations in COVID-19:

  • There are no proven pharmaceutical treatments for COVID-19 other than supportive care. (ASID) Various candidates with low level or no human evidence of efficacy are currently being trialled around the world.
  • Prophylactic anticoagulation should be considered in all patients immobilised for extended periods such as intubated patients. However evidence of microthrombi contributing to hypoxia has lead a few centres to trial therapeutic anticoagulation – results from this approach are not yet known.
  • All unproven drug therapies (including therapeutic anticoagulation) are generally only recommended within the context of properly approved randomised controlled trials. [National COVID-19 Clinical Evidence Taskforce]
  • Where bronchodilators are required avoid nebulisers to reduce aerosolisation of virus (ANZICS) and use metered dose inhaler (MDI) and spacer.
  • Shock is uncommon (particularly pre-intubation) but if occurs, early vasopressors and inotropes should be initiated to enable a conservative fluid resuscitation/hydration strategy in order to reduce the risk of ARDS with the intermediate term goal of a negative fluid balance. (SSC, ANZICS) Early vasopressors/inotropes are most rapidly commenced by a good quality peripheral venous line (with regular monitoring of the intravenous line site) which can be converted to central venous access, if and when appropriate.
    • More recently it has been suggested however that the patients with the type L phenotype (see Oxygenation Overview section) may be able to tolerate more fluid than type H patients, particularly if given relatively low volumes at a slower rehydration pace (rather than resuscitation pace).

Treatment of Hypoxia and Respiratory Failure

Summary of Treatment of Hypoxia & Respiratory Failure Section

  • Traditional recommendations for oxygenation are to target saturations above 90-92%, up to 96%. However, there are a subset of COVID-19  patients,  the so called“happy hypoxics” or “silent hypoxics”, who are mentally alert despite sometimes profoundly low oxygen saturations who may warrant a different approach. [See Oxygenation Overview section]  
  • Prone positioning and repositioning of awake patients in lateral recumbent and sitting positions has anecdotally been found to improve saturations and reduce work of breathing in some COVID-19 patients.  [See Oxygenation Overview section]  
  • Initial oxygen therapy usually involves a graded escalation from low flow nasal prongs to hudson mask to non-rebreather mask (NRM) with all patients wearing a surgical mask on top of these therapies to reduce viral droplet dispersal. To reduce viral dispersal, some sources recommend transitioning from nasal prongs directly to NRM, skipping the Hudson masks.  [See Initial Oxygen Therapy section]
  • For patients hypoxic on 15L of oxygen via a NRM, the management options are High Flow Nasal Cannula (HFNC), Non-invasive Ventilation (NIV), intubation and palliation.
  • Early in the pandemic an “early intubation approach” was the predominant advocated practice due to belief that HFNC and NIV may expose staff to greater risk of infection and be less effective. However the early intubation strategy is no longer recommended as it has seen patients intubated for very prolonged periods, with high failed extubation rates and high mortality. Instead a graded respiratory support approach escalating through non-invasive strategies is recommended. [see Oxygenation Overview section]
  • 2 alternative phenotypes of COVID-19 patients have been described, L (Low) & H (High). Type L patients predominate early in severe disease and appear sensitive to both Patient-Self Inflicted Lung Injury (P-SILI) (from excessive work of breathing) and high positive pressure injury (from high PEEP CPAP, BiPAP and ARDSnet mechanical ventilation). There have been resultant recommendations for changes in management. [see Oxygenation Overview section] This includes:
    • High FiO2, low-intermediate PEEP non-invasive strategies (HFNC and CPAP) titrated more to reducing excessive work of breathing than oxygen saturations per se.
    • Where this is unsuccessful, early intubation is advised over prolonged, ineffective non-invasive strategies.
    • Upon intubation, a marked deviation from the previously recommended high PEEP, low tidal volume ARDSnet, “lung protective” ventilator protocols towards a high FiO2, low-intermediate PEEP, modest tidal volume strategy in type L patients. [see Post Intubation Care section]
  • Where intubation is indicated, there are numerous modifications required to the peri-intubation process for suspected COVID-19 patients to maximise staff safety. [See Intubation section]

Oxygenation Overview

Rapid evolution of recommended COVID-19 management is emerging from the epicentres of the pandemic (Gattinoni 2020, EMRAP live 31/3/20 & 7/4/20, EMCRIT Wee 30/3/20, REBELCast 5/4/20 EM Cases COVID Update 5/4/20). This section incorporates these new advances into the management paradigm.

Standard recommendations generally suggest hypoxic patients should be provided oxygen therapy by the lowest Fi02 method capable of providing saturations that are greater than 90-92% and no higher than 96%. (SSC, IPCC19, ASID)

However, some surprising peculiarities in the presentation of COVID-19 patients and the management of their hypoxia have been described:

  • Permissive Hypoxaemia: A unique syndrome of COVID-19 patients has been described (the so called “the happy hypoxics” or “silent hypoxics”) who are mentally alert and lack significant respiratory distress despite hypoxaemia that would usually prompt treatment, sometimes with profoundly low oxygen saturations.
    • It has also been theorised that given the lack of distress in some profoundly hypoxaemic patients, that COVID-19 may interfere with oxygen saturation measurements possibly through affects on haemoglobin however while this may play a role, there are anecdotal reports that blood gas arterial oxygen measurements still roughly correlate with oxygen saturations.
    • Altered triggers for escalation of oxygenation therapies: It has been suggested that a less aggressive escalation of care through progressive non-invasive and invasive therapies may be uniquely warranted in these patients. Decisions to escalate oxygenation therapies may need to be based less rigidly on measured oxygen saturations and respiratory rate per se and instead more closely based on reduced mental alertness and excessive work of breathing. 
  • Awake Proning: While proning has been suggested for intubated patients, recent anecdotal reports suggest symptomatic improvement from encouraging self-proning as well as repositioning in other positions (e.g. lateral recumbent, seated) in cooperative, awake patients. A CARP (COVID Awake Repositioning/Proning Protocol) has been suggested by emcrit

Awake proning in the “happy hypoxic” on her smartphone. Source: @EricLeeMD

Titrated oxygen therapy is usually provided in a graduated fashion via low flow nasal prongs (0.5-4L/min) → Hudson mask (4-8L/min)  → non rebreather mask (10-15L/min). To reduce viral dispersal, some sources recommend transitioning from nasal prongs directly to NRM, skipping the Hudson masks. [See Initial Oxygen Therapy section]

For patients hypoxic on 15L of oxygen via a NRM, the management options are:

    • High Flow Nasal Cannula (HFNC)
    • Non-invasive Ventilation
    • Intubation
    • Palliation

The Early Intubation Strategy is Dead … or Modified

“Early intubation” had been the predominant paradigm early in the pandemic due to a belief that non-invasive strategies resulted in high infection risks to staff and were relatively futile in avoiding intubation (see NIV & HFNC section for full discussion).  However there is no evidence that choosing early intubation instead of NIV or HFNC improves outcome. In fact, early reports from the epicentres of the pandemic suggest intubated patients remain on ventilators for extended periods, often fail extubation requiring re-intubation and mortality rates appear to be high. There were initial sporadic reports suggesting mortality of intubated patients to be between 50-90% and more recently a large published cohort of 2634 hospitalised patients in New York, found a very high mortality of 88% in intubated patients (76% under 65y.o and 97% over 65y.o).  The cohort represents patients admitted from 1st March and the mortality data was from those who had completed care by 4th April (death or discharge) so it is likely (though not definite) that the majority of those were managed during a period when the “early intubation” approach was prevailing. (Richardson JAMA 22/4/2020)

Suggested graded respiratory support progression from EM Cases COVID-19 Updates 5/4/20

For discussion regarding how to maximise staff safety see NIV & HFNC section

Intubated patients are thought to pose lower risk of viral dispersion to staff as they are ventilated via a closed circuit without leak. However both the process of intubating and extubating are high risk to staff and there are reports of accidental ventilator circuit disconnection when intubated, particularly when patients are transported out of ED. There is some uncertainty regarding the comparative risks to staff of NIV & HFNC – both can be minimised depending on equipment available and set up (see NIV & HFNC section). 

Consequently, and combined with the knowledge yielded from revelation of distinct L & H patient phenotypes (see below) practice in the pandemic epicentres has moved towards the carefully measured use of HFNC and/or CPAP (titrated more to work of breathing rather than oxygen saturations per se), and alternate ventilator settings when intubated (see Post Intubation Care section). 

While the evidence from the pandemic epicentres is also of low quality (consisting primarily of ancedotes, case series, expert opinion and almost exclusively retrospective data), given the early intubation approach was the deviation from standard of care for hypoxaemic paitents, the higher burden of evidence  falls to this approach. As this burden has not been met and there is similar low level evidence disputing it, reversion to our standard of care approach is warranted and consequently the recommendations against NIV and HFNC have been generally withdrawn. Notably guideline recommendations have recently been updated to endorse non-invasive strategies: UK NHS guideline 6/4/20 recommends CPAP,  and both the Australian National COVID-19 Clinical Evidence Taskforce 30/4/30 and the US National Institute of Health (NIH) guideline 21/4/20 now recommend a trial of HFNC and NIV.  Measures of trial success and when to convert to intubation are discussed below.

 

While the early intubation approach is largely rescinded, a “modified” early intubation approach may still be indicated in the following scenarios:

  • Patients with abnormal mentation
  • The uncommon patients with hypercapnoea, except perhaps acute on chronic COPD patients who could trial BiPAP (see NIV & HFNC section).
  • In patients not responding effectively to a limited trial of non-invasive strategies to:
    • Prevent P-SILI (Patient Self Induced Lung Injury – see below)
    • Avoid precipitous deterioration.
      • While “intubating early in the disease process” is no longer advised, “making early decisions regarding intubation” when evaluating trials of NIV and HFNC is subtly different and definitely advisable. The COVID-19 intubation process takes significant time to prepare and execute (see Intubation section) and given patients can deteriorate quickly, failure to decide to intubate early could result in patient demise. This reinforces the above recommendation to not persist with prolonged trials of non-invasive therapy that are ineffective at achieving clinical targets, such as reduced work of breathing with normal mentation.

L & H Phenotypes

Luciano Gattinoni, a world expert in ARDS, has released a series of landmarks papers (ICM 2020, Critical Care 2020, JAMA 2020), detailing how the Italian experience has revealed 2 very different phenotypes of COVID-19 patients with severe hypoxia, described as the L (Low) and  H (High) phenotypes. The H phenotype is typical of usual ARDS patients with high lung weight from oedema and resultant alveolar derecruitment and may benefit from the recommended high PEEP ARDSnet ventilator protocols to aid recruitment. However it appears that most patients start as the L type (and may transition to the H type) and while severe hypoxia is also a feature, this is thought to be caused by several alternative factors including V/Q mismatching due to pulmonary vasoplegia (causing  loss of hypoxic pulmonary vasoconstriction) and pulmonary vascular microthrombi as well as relatively low levels of interstitial oedema & alveolar derecruitment.

Excessive work of breathing causes lung injury

It has been previously described (Brochard, 2017) that in the awake spontaneously breathing patient where their increased work of breathing is excessive, accompanying the high tidal volumes is high negative intra-thoracic pressure swings . When this is combined with increased lung permeability due to inflammation, it results in interstitial lung oedema. This process is known as Patient Self-Inflicted-Lung Injury (P-SILI).

It is currently theorised that in the type L patients with low resistance-high compliance lungs, prolonged periods of excessive work of breathing may be causing P-SILI. Combined with innate disease progression in COVID-19, this results in type L patients transitioning (gradually or sometimes precipitously) to the H phenotype as lung oedema increases to a critical mass causing derecruitment of alveoli.

It is also thought that type L patients are sensitive to high positive pressure lung injury from strategies including high PEEP CPAP, BiPAP and mechanical ventilation with ARDSnet strategy.


Consequently, balancing the risks of P-SILI and high positive pressure lung injury has resulted in a suggested middle ground, where the strategy of oxygenation therapy in COVID-19 patients with severe hypoxia should be to:

  • First trial “high FiO2/intermediate PEEP”, non-invasive strategies such as HFNC and/or CPAP with the primary aim of reducing excessive work of breathing and consequently avoid P-SILI.
    • Implicit in this strategy is a “Permissive Hypoxaemia” approach where “reasonable saturations” are accepted (where usual sats targets are not achieved) as long as the work of breathing goal is achieved and mentation is intact. However specific alternative minimum saturation targets have not been determined, partly it seems due to high variation between patients.
  • If this is not successfully achieved, intubation should then occur.

It is thought that executing this “modified early intubation strategyin these patients who have failed non-invasive strategies by this measure may consequently reduce lung injury and transition to the H phenotype with attendant higher mortalities. Furthermore, upon intubation of said patents, an alternative high Fio2/intermediate PEEP/ moderate tidal volume strategy has been advocated (see Post Intubation Care section). 

Where the decision is made to intubate, there are numerous modifications required to the peri-intubation process to maximise staff safety. [See Intubation section]

Avoiding the vortex of lung injury from excessive work of breathing using NIV and then early intubation only if this fails to curb respiratory effort.

Source: Marini & Gattinoni, JAMA 2020 PMID 32329799

Initial Oxygen Therapy

Titrated oxygen therapy is usually provided in a graduated fashion via low flow nasal prongs (0.5-4L/min) → Hudson (simple) mask (4-8L/min)  → non rebreather mask (10-15L/min).

Where nasal prongs are used alone, always place a surgical mask on the patient. The placement of a surgical mask over the top of Hudson and non-rebreather masks (NRM) are likely to enhance staff safety as well.

There is evidence that viral dispersion risk is substantially reduced with NRM (10 cm dispersion) compared with both nasal prongs and standard oxygen masks (40cm dispersion) (Hui 2014). This has lead some sources to recommend that patients who are hypoxic on low flow nasal prongs should be transitioned directly to NRM, skipping Hudson masks entirely. (ACEM – Treatment) However if surgical masks are placed over all masks, it is unknown  if any difference in viral dispersion would remain.

These oxygen therapies do not qualify as AGPs and consequently PPE appropriate for routine care is appropriate. (ANZICS, SAS, WHO, ACEM, Aus DOH PPE)

Non Invasive Ventilation (NIV) and High Flow Nasal Cannula (HFNC)

Summary:

  • There is controversy and uncertainty regarding both the safety and efficacy of NIV and HFNC in COVID-19 patients and a paucity of quality evidence to guide decision making. Early in the pandemic, guidelines and opinion favoured an early intubation strategy but expert opinion from pandemic epicentres and guidelines now recommends NIV and HFNC therapies for severe hypoxaemia. [see Oxygenation Overview section].
  • For both NIV and HFNC, staff should wear Tier 2 PPE for AGPs, and the procedure should ideally occur in a negative pressure room. If not available,  see Triage section for the recommended hierarchy of alternative clinical spaces.
  • NIV
    • Efficacy
      • There were concerns that NIV may fail to prevent intubation in most patients based on very limited data from influenza and MERS cohorts. However experience from the pandemic epicentres has found NIV to be effective at avoiding intubation.
    • Infection risk:
      • NIV is an Aerosol Generating Procedure (AGP), Initial concerns re staff safety based primarily on older evidence from SARS has been ameliorated by the use of modern ventilators that can provided closed-circuit NIV with viral filters that reduce risk of viral spread only to mask leak or removal.
    • CPAP is the preferred modality over BiPAP as it is the preferred therapy for type 1 respiratory failure and the lower alveolar pressures are less likely to attend the same level of risk of lung injury [see Oxygenation Overview section] and disease aerosolisation.
    • Respiratory fatigue and hypercapnoea is uncommon. Where this occurs, early intubation is still often advocated over BiPAP except in patients with co-existent presentations known to be responsive to BiPAP i.e. acute on chronic exacerbations of COPD.
  • HFNC
    • Infection risk:
      • Infectious risk to staff remains unknown. There is some evidence hinting that using newer well fitting HFNC, with the patient wearing a surgical mask may not be much higher risk to staff than oxygen face mask therapy. However while evidence is limited and uncertainty remains, it should be considered an AGP.
      • A surgical mask should be placed on the patient and there is low level evidence backing up scientific plausibility that this may substantially reduces infective risk to staff.
    • There remain legitimate concerns that HFNC could deplete oxygen stores in smaller centres, or even in larger centres if health systems are overwhelmed in a pandemic and this must be considered, prepared for and managed on a regional basis.
    • HFNC with attendant surgical mask has several potential benefits over NIV (discussed below) and is consequently more commonly recommend as preferred initial therapy prior to a trial of NIV

There is controversy and uncertainty regarding both the safety and efficacy of NIV and HFNC in COVID-19 patients and a paucity of quality evidence to guide decision making. Early in the pandemic, guidelines and opinion favoured an early intubation strategy but experience from epicentres of the pandemic questioned this approach and practice moved back to a graded escalation through non-invasive strategies before intubation. More recently, Australian and international guidelines have been updated to match this evolving experience and now generally recommend NIV and HFNC as therapeutic options for severe hypoxaemia in COVID-19. [see Oxygenation Overview section].

Both NIV and HFNC, are considered Aerosol Generating Procedures (AGPs) so staff should wear Tier 2 PPE for AGPs, and the procedure should ideally occur in a negative pressure room. If not available, see Triage section for the recommended hierarchy of alternative clinical spaces.

NIV

NIV had questionable utility in limited studies of viral pneumonia before COVID-19. Studies with NIV used for Influenza A (H1N1) found that NIV failed in 57-85% of patients (Kumar 2009, Rodriguez 2017). Additionally a study of MERS coronavirus outbreak found 92% of patients initially managed with NIV required intubation (Alraddadi 2019). However early in the pandemic, in one small case series of patients with COVID-19 in Wuhan, only 48% of patients started on NIV required intubation  (Yang 2020) which was somewhat more promising, albeit based on very limited numbers. Since then reported experience in the pandemic epicentres has found NIV, specifically CPAP to be effective as a therapy in avoiding intubation and supporting patients to recovery.

Unfortunately most evidence and discussion regarding NIV, groups CPAP in together with BiPAP despite much of the concerning prior data being in reference to BiPAP. There are strong theoretical grounds that CPAP may be a preferable treatment as it is the preferred NIV mode for type 1 respiratory failure generally and attends reduced mean airway pressures and therefore reduced risk of lung injury and viral aerosolisation. While guidelines generally now endorse a trial of NIV, experience from the pandemic epicentres generally recommends CPAP, and CPAP is specifically advocated over BiPAP for the care of COVID-19 patients in the UK (NHS guideline 6/4/20). The helmet-mask interface theoretically has lower risk of air leak and potentially improved comfort, has been used extensively in Italy and has been recommended by some sources (IPCC19) but this is currently not widely available in Australian healthcare.

There remains some concern that prolonged periods of NIV may cause P-SILI (Patient Self Induced Lung Injury), where the patient’s work of breathing remains excessive, and may convert Type L patients into Type H resulting in increased mortality. Strategies to minimise this risk have been advocated such as using CPAP over BiPAP and using high FiO2 and low to intermediate PEEP (5-10cm H20). [see Oxygenation Overview section].

Respiratory fatigue and hypercapnoea is uncommonly seen in hypoxaemic COVID-19 patients. Where this occurs, early intubation is still often advocated over BiPAP except in patients with co-existent presentations known to be responsive to BiPAP i.e. acute on chronic exacerbations of COPD.(NHS guideline 6/4/20)

NIV is an Aerosol Generating Procedure (AGP) and evidence primarily from SARS suggested that NIV provided a high risk of infection to attending staff, however this was based on the use of older circuit set ups that vented the patient’s aerosolised expirations directly to room air. However modern NIV systems can minimise this risk by using closed-circuit NIV which involves:

  • The use of a non-vented mask
  • The expiratory limb tubing feeding back into the machine (typically achieved by using a ventilator rather than a stand alone NIV machine)
  • Connecting a high efficiency viral filter between mask and the expiratory limb

Where closed-circuit NIV is used the infectivity risk is reduced to the mask leak (which should be actively minimised as much as possible) and unplanned removal of the mask by the patient. Both of these risks should be actively minimised – the mask leak should be evaluated and the mask repositioned or replaced to minimise leak while patient compliance should be optimised with adequate education and reassurance +/- careful and judicious pharmacotherapy.

Where mask removal is planned the ventilation should be ceased (with NIV pressures  reduced to zero and the oxygen flow terminated) just prior to removal.

HFNC

Some sources recommend against HFNC because of concerns that it may increase viral aerosolisation, fail to prevent intubation and consume oxygen supplies (NHS Guideline 6/4/20, IPCC19), while other sources recommend it as a therapy since newer, well fitted HFNC systems are thought to have a relatively low risk of aerosolisation with potential to avoid intubation (NC19CET 30/4/20, NIH 21/4/20, ANZICS, SSC, WHO). There is little high quality evidence to resolve this debate but opinion and the most recently updated guidelines now recommend HFNC.

Regarding efficacy, in one small cohort study of 25 patients with severe influenza A/H1N1 infection, HFNC was successful in 45%, with severe patients eventually requiring intubation. (Rello, 2012) For COVID-19, a small cohort from Chongqing, China recently demonstrated that of 17 patients treated with HFNC for severe disease, 7 (41%) experienced treatment failure and were transferred onto NIV. Of these 7, 2 (29%) required eventual intubation which reveals a very low 12% rate of overall treatment failure from a sequential HFNC/NIV approach. (Wang, 2020). Notably though, selection bias may exaggerate any benefit of HFNC in these small non-randomised trials.

Regarding infection risk, one small study found no difference in bacterial aerosolisation between HFNC at 60L/min and oxygen face mask therapy. (Leung, 2019). However while evidence is limited and uncertainty remains, it should be considered an AGP.

A surgical mask should be placed on the patient using HFNC as it is scientifically very plausible that this should reduce viral dispersal, and there is some evidence in support this though the source is an industry sponsored analysis of a slightly different technology which lacks peer review (Vapotherm Report).

There remain legitimate concerns that HFNC could deplete oxygen stores in smaller centres, or even in larger centres if health systems are overwhelmed in a pandemic and this must be considered, prepared for and managed on a regional basis.

HFNC with attendant surgical mask has several potential benefits over NIV via an NIV mask:

  • Improved patient comfort
  • Easier ability for patient to eat and drink and to enact other strategies such as patient self-proning.
  • Possible reduced infection risk to staff due to:
    • Reduced inherent aerosolisation from the therapy
    • Reduced attendances required by staff to the patient to deal with mask comfort issues or requests to remove the mask.
    • Reduced risk of patient suddenly removing the mask

Consequently several sources recommend HFNC be trialled first before NIV as part of graded respiratory support for hypoxaemic COVID-19 patients.

Introduction

There are a number of alterations to the usual peri-intubation process that need to be made in order to minimise the risk of infection to attending staff. While there remains some resistance to the routine use of intubation checklists in EDs, as COVID-19 intubations represent a significant deviation from routine practice with high risks to staff, the use of a purpose designed COVID-19 intubation checklist should be considered mandatory in every department. Additionally, frequent and repeated simulation is recommended for staff training for what is a complex, unfamiliar and high stress clinical scenario.

Given the added complexity of the peri-intubation process and the need for the intubation team to carefully don PPE, the pre-intubation preparation period can take significant time. Consequently decisions regarding intubation need to be made early, as the team will not be able to safely intervene to intubate a crashing patient.

The peri-intubation process is high risk for aerosol generation. PPE appropriate for AGPs is required by all staff in the room and some centres use additional precautions (see PPE for “highest risk” AGPs), especially for the intubator at the highest risk. If practical and available use a single room, ideally a negative pressure room. Limit staff present at tracheal intubation to one intubator, one airway assistant and one to team lead/administer drugs/monitor patient (COVID-19 AMP) together with 1-2 “runners” positioned immediately outside the room, to provide additional assistance if and when required. Where an “ante room” exists connected to a negative pressure room used for intubation, ideally 1 “door” runner” (“dirty runner”) should be stationed within this also wearing PPE appropriate for AGPs, while an “outside room” runner  (“clean runner”) stands outside of the ante room to source equipment and drugs that are unexpectedly needed and pass them to the “door runner”.

There is a balance between bringing into the room as much equipment that is most likely required for intubation safety and needing to minimise the amount of equipment that is contaminated by entering the room that will need to be either cleaned or discarded post intubation. Consequently backup safety equipment that has a low chance of being used, like a hyper-angulated video laryngoscope blade or cricothyrotomy equipment, may be best left outside the room in the “clean” area but still readily available if called for.

It is critical that departments ensure that all viral filters used for NIV or the peri-intubation period are rated as high efficiency viral/bacterial filters with >99.9% filtration. Viral filters can be stand alone filters or can be HME (Heat Moisture Exchange) filters with high efficiency viral filtration properties. However some HME filters do not have these required properties so this must be confirmed before stocking in critical care areas.

Introduction

Airway Assessment

A standard ED airway assessment should be performed as permitted by patient clinical state and performed from as distant a position from the patient as possible. However awake intubation for predicted difficult intubation is not advisable due to high risk of disease spread. If difficult intubation is predicted, consider alternatives such as “priming” for CICO Rescue (Can’t Intubate, Can’t Oxygenate) prior to delivering pre-intubation sedation/paralysis i.e position person at the patient’s neck fully prepared as per the Vortex CICO status “SET”.

Epicentre anecdotes report a high number of patients with pharyngeal oedema above the cords on intubation with some difficulty passing a flexible bougie and the use of a less flexible stylet type introducer being suggested as an alternative. (EMRAP live 31/3/20)

Maximise 1st pass success
  • All standard of care aspects of optimal intubation management should be employed to maximise first pass success.
  • Specifically, this should include using the most capable intubator who is readily available to intubate (COVID-19, AMP, ANZICS, SAS) and using video laryngoscopy (VL) (ANZICS, SAS). Additionally VL can allow the intubator to maintain a greater distance from the patient’s mouth to reduce disease spread. (SAS)
Drugs

Give a high dose paralytic to ensure adequate and rapid paralysis to minimise the length of the apnoeic period and to reduce risk of coughing in the peri-intubation period for staff safety.

There is no consensus on dosing but Suxamethonium 1.5mg-2mg/kg or Rocuronium 1.5mg/kg have been suggested. The standard 1.2mg/kg dose of rocuronium is arguably most appropriate for the rapid sequence intubation of well patients – in unwell patients higher doses have been suggested to absolutely minimise the risk of coughing and ensure rapid paralysis.

Some advocate rocuronium as the preferred choice over suxamethonium as for the former, the lack of muscular fasciculations (with attendant reduced muscular oxygen consumption) may prolong time to desaturations while the longer period of paralysis further reduces the risk of coughing in the peri-intubation period.

In haemodynamically unstable patients ketamine is the sedation drug of choice. However even in the stable patients, ketamine could still be argued to be the preferred agent, for if the patient does not cooperate with preoxygenation, ketamine can be administered prior to intubation as part of a DSI (Delayed Sequence Intubation) approach – dissociative procedural sedation to enable preoxygenation. Even if ketamine is not chosen as the preferred intubating agent, it should be taken into the room to enable DSI if required.

Preoxygenation:

Summary:

  • Most suitable preoxygenation options within ED’s are the Bag Valve Mask (BVM) with PEEP valve or the Mapleson C circuits.
  • For most EDs, using a BVM with a PEEP valve is likely to be the most practical and familiar option for the ED provider.
  • Regardless of device choice, modifications are required to maximise safety including holding the mask with a 2 handed approach, attaching a viral filter between the mask and the rest of the equipment and avoiding positive pressure ventilations where possible.
  • VAPOX protocol (Ventilator Assisted Preoxygenation) has strong theoretical benefits for the intubation of patients who remain hypoxic on NRM but it is not recommended for preoxygenation of COVID-19 patients. For more information click here.
  • Minimise the interval between removal of patient’s protective mask and the application of the BVM (or Mapleson) connected face mask with viral filter attached. (SAS)
  • A minimum of 5 minutes of preoxygenation is recommended to fully pre-oxygenate the patient.
  • Some sources suggest to depressurise the circuit (remove PEEP) during the apnoeic period, prior to removal of the face mask from the patient and before the intubation attempt to reduce the risk of viral dispersal from chest deflation.

Patients who are hypoxic on face mask oxygen are at higher risk of mortality on intubation if they are not optimised prior to intubation. Consequently a preoxygenation device with a low risk of viral dispersal to staff and that can provide PEEP will be required. Additionally for simplicity the same device should generally be used for re-oxygenation (see below) between intubation attempts.

The most suitable options for preoxygenation within ED’s are the Bag Valve Mask (BVM) or Mapleson C circuits. (SAS) For both options, key requirements include:

  • Placing a viral filter between the mask and the rest of the equipment
    • The viral filter should be applied directly to the face mask as an increased number of connections between the face mask and filter increase the opportunity for disconnection on the patient side. (SAS)
  • Monitoring continuous waveform capnography (SAS) by placing a CO2 monitor between viral filter and the rest of the device or (ideally) attaching a CO2 sampling line to the viral filter (if such equipment is available). A triangular rather than a square CO2 trace or a low numerical value can indicate mask leak (SAS) and being pre-attached can remove a task required post intubation before connecting to the ventilator.
  • Using a 2 hand grip on the mask to minimise face mask air leak. (SAS)
  • Generally avoiding positive pressure manual ventilation during preoxygenation. During the post-paralysis apnoeic period, patients with severe disease may require manual ventilation to prevent profound desaturation. To minimise the risk of aerosolisation of airway secretions, this should be performed as a two person technique, with the airway assistant gently squeezing the bag and adjusting the level of PEEP as required. (SAS)

For most departments, the simplest and most familiar option would be to use the Bag Valve Mask (BVM) as the preoxygenation device with a PEEP valve attached to provide PEEP.

The Mapleson C circuit  is an alternative that can deliver PEEP and has the advantage of bag deflation providing an indication of mask leak. However it is generally not widely available or commonly utilised in EDs.

VAPOX protocol (Ventilator Assisted Preoxygenation) has strong theoretical benefits for the intubation of patients who remain hypoxic on NRM. However for COVID-19 there are a number of modifications that need to be made to ensure staff safety that both increase cognitive load in a high stress situation and reduce some of the usual benefits of VAPOX protocol. Consequently it is not recommended for COVID-19 preoxygenation. For more information see the addendum at the end of this post.

Minimise the interval between removal of patient’s protective mask and the application of the BVM or Mapleson connected face mask with viral filter attached. (SAS)

A minimum of 5 minutes of preoxygenation is recommended to fully pre-oxygenate the patient.

At the end of the post-paralysis apnoeic period, when the preoxygenation device is removed from the patient, the deflation of the lungs (that were splinted under the pressure of PEEP) exposes staff to additional risk of viral dispersal. The level of risk this affords is unclear, though some sources recommended to depressurise the circuit during the apnoeic period prior to removal of the preoxygenation device. Examples of how this can be achieved are:

  • BVM: Dial PEEP valve to zero or disconnect the PEEP valve
  • Mapleson C: Open the APL (adjustable pressure limiting) valve to zero

Disconnecting the BVM bag or the Mapleson C circuit from their connection to the viral filter is another option to depressurise the circuit, but this is not recommended due to the attendant risk of accidental disconnection of the viral filter from the face mask at that time.

Re-oxygenation between failed intubation attempts

Re-oxygenation will be most practically achieved using the same device chosen for the preoxygenation of the patient e.g. if a BVM was chosen for preoxygenation it should be used for re-oxygenation. This should be performed as a 2 person technique with a 2 handed mask grip as described above

Some sources suggest using a Supra-Glottic Airway (SGA) instead of a face mask  (i.e. remove the mask from the BVM) for more effective delivery of re-oxygenation with potentially less air leak.(Alfred Guideline) However removal of the SGA for successive attempts at intubation may result in dispersal of viral droplets. Where an SGA is used, use of a second-generation device is recommended as its higher seal pressure during positive pressure ventilation decreases the risk of aerosolisation of virus containing fluid particles. (SAS)

Apnoeic Oxygenation

Summary: the balance of risks and benefits favours avoiding the use of nasal cannula for apnoeic oxygenation.

Nasal cannula with oxygen flow at 10-15L/min are generally considered routine peri-intubation care during contemporary ED intubation to extend the safe apnoea period. There is concern regarding potential viral aerosolisation to intubating staff (SAS) though it is unclear how substantial viral aerosolisation would be at these flow rates, particularly given there is dispute about the same for HFNC at far higher flow rates, albeit with staff typically located further away than intubators are.

A further consideration is that in critically ill patients with respiratory failure and shunt physiology requiring PEEP, apnoeic oxygenation may not add additional benefit as suggested by the FELLOW trial (Semler 2016). Consequently balancing possible risks and limited benefits in this population, suggests avoiding the use of apnoeic oxygenation nasal cannula.

Post Intubation Care

Summary:

  • The ETT cuff should be immediately inflated, prior to any attempts at ventilation post intubation to minimise expired air leak to staff.
  • Consider immediate connection to the ventilator post intubation to avoid serial connections/disconnections of equipment as each poses a risk of accidental disconnection and viral dispersal.
  • Do not use auscultation of the chest to confirm ETT placement and depth as this increases proximity of the intubator to the patient’s expired air without yet confirmed ETT placement.
  • The ETT should always be clamped prior to any planned disconnection.
  • Accidental circuit disconnection, particularly during patient transport is a high risk to staff. Consequently special care should be taken to secure points at risk of disconnection post intubation with dressing such a “tegaderm” or tape.
  • In-line suction is recommended to be used within the ventilator circuit and this has significant implications for the set up of your viral filters, CO2 monitoring and timing of disconnections of the circuit.
  • PPE appropriate for AGPs should be worn by any staff attending an intubated patient at all times.
  • Ventilator settings:
    • ARDSnet based, high PEEP “lung protective” ventilation was the prevailing recommendation early the pandemic although the recognition of the L & H patient phenotypes (see Oxygenation Overview section) has resulted in unresolved debate.
    • Tidal Volume (TV):
      • 6mL/kg based on predicted/ideal body weight has been shown to be lung protective and improve outcomes in heterogenous ARDS patients and in some patients with relatively normal lungs. In general this should be the target TV – a case for consideration of slightly higher volumes (7-8mL/kg is discussed below in select patients.
    • PEEP:
      • There is considerable debate and concern about high PEEP strategies and their potential to increase mortality in type L patients. Consequently a high FiO2,  low to intermediate PEEP (5-10cm H20) strategy should be considered in type L patients.

The ETT cuff should be immediately inflated, prior to any attempts at ventilation post intubation to minimise expired air leak to staff. (ANZICS, SAS)

For post intubation ventilation, some sources recommend immediate connection of the ventilator to the ETT (via CO2 monitor and viral filter) instead of ventilating with the BVM or Mapleson C in order to reduce the number of connections and disconnections, as each poses a risk of accidental disconnection and viral dispersal.

Confirmation of ETT placement and depth should occur through:

  • Visualising passage through the cords
  • Alignment of the ETT black vocal cord marker with the vocal cords.
  • ETT misting
  • End tidal CO2 trace
  • Post intubation CXR when appropriate

Specifically, this should not include auscultation of  the chest as this increases proximity of the intubator to the patient’s expired air without yet confirmed ETT placement.

The ETT should always be clamped prior to any planned disconnection.

Reports from regions experiencing high volumes of COVID-19 patients, suggest that there is a significant risk of viral dispersal to staff from the accidental disconnection of the ventilator circuit and this risk is highest during transport of the patient out of the ED. Accidental disconnections can occur at any point of the ventilator circuit between:

  • Patient and ETT (extubation)
  • ETT and viral filter
  • Viral filter and in line CO2 monitor (if separate devices)
  • In line CO2 monitor and the ventilator tubing
  • Ventilator tubing and the ventilator.

Consequently special care should be taken to secure points at risk of disconnection post intubation with dressing such a “tegaderm” or tape.

In-line suction is recommended to be placed in the ventilator circuit. As this can not be provided through the viral filter, the in-line suction device will need to be placed distal to the viral filter. This can be achieved in 1 of 2 ways:

  • Planned disconnection of the circuit post intubation (with attendant ETT clamping) between ETT and viral filter post intubation
  • The use of a 2nd viral filter that is pre-connected (before intubation) just distal to the ventilator tubing with the in-line suction pre-connected just distal to this. Immediately post intubation, the 1st viral filter will need to be removed before connection of the ETT to the circuit. This approach has implications for the CO2 monitoring device.
    • If the CO2 monitoring is provided by attachment of a sampling line to the viral filter side port, this line will simply need to be removed from 1st filter and rapidly attached to 2nd filter post intubation.
    • If the CO2 monitoring is provided by an in-line monitoring device:
      • This can be left in place and connected directly to the in-line suction on its distal side. The disadvantage of this set up is that the CO2 monitoring device is now distal to the 2nd viral filter which can result in clogging of the sensor with secretions (not removed through suctioning) resulting in further planned disconnections of the circuit. To avoid this, the CO2 monitor would need to be moved proximal to the 2nd viral filter immediately post intubation at the same time as the 1st viral filter is being removed.
      • Alternatively the CO2 in line monitor can be pre-connected before intubation proximal to the 2nd filter but this attends a large disadvantage of not being able to use this during preoxygenation and re-oxygenation.

Due to the ever present risk of accidental disconnection of the ventilator circuit, PPE appropriate for AGPs is recommended at all times for staff attending an intubated patient.

Ventilator settings:

  • The ARDSnet high PEEP “lung protective” ventilation was the prevailing recommendation early in the pandemic with low tidal volumes (starting at 6ml/kg based on predicted/ideal body weight) with high PEEP (using a PEEP-FiO2 table). However since the release of the Gattinoni paper revealing the L and H phenotypes (See Oxygenation Overview section) it is thought that while an appropriate strategy for the H phenotype with high resistance (low compliance, high lung weight and high recruitability), this strategy may have been contributing to alveolar pressure injury and increased mortality in the L phenotype.
  • PEEP:
    • For the L phenotype, a high FiO2, intermediate PEEP (8-10cmH20) strategy has been advocated.
  • TV:
    • Gattinoni recommends that “once intubated and deeply sedated, the Type L patients, if hypercapnic, can be ventilated with volumes greater than 6 ml/kg as the high compliance results in tolerable strain without the risk of VILI (Gattinoni 14/4/20) and the “higher TV [7-8ml/kg)] could help avoid reabsorption atelectasis and hypercapnia due to hypoventilation with lower tidal volumes” (Marini & Gattinoni 24/4/20)
    • However low TV (6mL/kg) has been shown to be lung protective and improve outcomes in heterogenous ARDS patients and in some patients with relatively normal lungs and consequently other sources recommend to use this traditional target and only consider higher TV where other strategies to deal with concerning levels of hypercapnia have been exhausted such as increasing RR and review of dead space from HME filters. (Fan 1/8/20)
  • Distinguishing between Type L and H ventilated patients:
    • While CT scan is the recommended as the best tool to distinguish between Type L and Type H patients (by Gattinoni), if not available/practical, surrogate markers can be used such as respiratory system compliance and recruitability.
  • The use of a tape measure to determine a patient’s height and calculate ideal body weight to avoid common overestimation of the patient’s weight and resultant excessive tidal volumes, is advocated in the (non-COVID-19 related) LOV-ED protocol.

Appendices

PPE

There is variation in PPE advice between different countries. The common Australian recommendations are summarised and explained below which have been based primarily around the Australian Department of Health interim PPE recommendations for inpatients & non-inpatients,  AHPPC statements on PPE (7/4/20, 24/4/20), ACEM and the AMA PPE guidelines. Conflicts between guidelines are addressed specifically in the section on Australian PPE guideline differences.

Doffing of PPE is a high risk time for staff contamination. It is recommended that both donning and doffing occur within a buddy-system to carefully observe and guide the process in an area with instruction posters also provided as a visual and memory guide. Formal, repeated staff training in PPE donning and doffing should be considered mandatory.

PPE requirements are useful to conceptualise using a 3 tiered approach. The first 2 tiers are represented in essentially all official guidelines and should be considered mandatory. The 3rd tier (suggested only for the “highest risk” AGPs) from an “official standpoint” is effectively optional as it is not specifically recommended in most official guidelines but is being utilised with a high degree of variability and heterogeneity at many health services and hospitals within Australia. Notably some overseas countries and institutions have been applying this 3rd tier more rigorously than Australia.  An evidence based discussion of the 3 tier approach has now been published by Lockhart 23/4/2020.

In addition to staff PPE below, the patient should also wear a surgical mask if at all possible.

Tier 1 – For routine patient care use:

  • contact precautionslong sleeved gown and gloves plus
  • droplet precautions – surgical mask and eye protection (face shield or goggles)

These recommendations appear based on previously known droplet spread of coronaviruses, limited evidence of COVID-19 disease spread and is supported by a recent large trial in influenza care in outpatient settings demonstrating no benefit of P2/N95 masks over standard masks in preventing infection of health care workers (Radonovich, 2019)

There is conflict between different Australian PPE guidelines regarding Tier 1 Routine Care PPE. Different guidelines recommend different exceptions to this Tier 1 Routine Care PPE. They either directly recommend, or suggest consideration of, upgrading to Tier 2 AGP PPE for routine care (i.e replacing surgical mask with N92/P2 mask) in the following situations:

  • When taking swabs from a patient with fever and shortness of breath and/or severe cough (i.e as opposed to relatively well patients without severe cough) (Aus DOH recommendation)
  • When providing routine care to a patient with severe acute respiratory disease/critically unwell (e.g. such as in an intensive care or high dependency unit) (ACEM PPE & AMA PPE Guidelines).
    • There is evidence that such patients may produce greater viral loads with higher amounts of viral contamination detected in intensive care environments. There is no logical  reason to suspect that this would not similarly apply to the same critically unwell patients being managed within ED environments.
  • Staff in a COVID Assessment Clinic (based on a risk assessment)(ACEM PPE)
  • Staff with prolonged direct clinical care in higher risk patient environments such as clinical areas with cohorted severe acute respiratory infection (ACEM PPE)

Tier 2 – For aerosol generating procedures (AGP) use:

  • contact precautions – long sleeved gown and gloves plus
  • airborne precautions – P2/N95 mask (with fit check) and eye protection (face shield or goggles)

i.e the only change when transitioning from Tier 1 to Tier 2 is that the surgical mask is replaced with the P2/N95 mask. No other additional precautions are recommended.

Tier 3 – For “highest risk” aerosol generating procedures (AGP) consider:

  • contact precautions – long sleeved gown and gloves plus
  • airborne precautions – P2/N95 mask (with fit check) and eye protection (face shield or goggles)
  • Plus additional precautions to achieve one or all of the following 3 purposes (with examples listed):
    • Maximise body coverage to better protect the neck, face, hair and wrists.
      • Changes in gloves
        • Use of elongated gloves to prevent gap between wrists & gown sleeve
        • Use of double gloving
      • Change in Eye Protection:
        • Specific use of face shield instead, or in addition to goggles
        • Fully enclosed goggles instead of open design goggles.
      • Changes in Head/Neck protection
        • Caps, or hoods
        • Full body suits with hoods
    • Improve air filtration efficacy to a higher level than that provided by “fit checked” (but not “fit tested”) N95 masks.
      • “Fit tested” N95 masks
      • N99/P3 or N100 respirators; includes
        • Elastomeric reusable half/full facepiece respirators
        • Powered Air Purifying Respirators (PAPR)
          • These can also provide better face +/- head covering depending on design.
    • Reduce body contamination post procedure
      • e.g changing scrubs, taking showers

Note that:

  • The “highest risk” AGPs within the ED environment generally refers to intubation.
  • This 3rd tier is currently not formally advocated in most Australian guidelines as discussed above.
  • There is currently high variation in Tier 3 precaution use between institutions with no accepted standard of what should constitute Tier 3 precautions  –  Lockhart 23/4/2020 provides one standard definition.

Arguments for and against the 3rd tier

  • For:
    • There is no evidence that Tier 2 precautions provide adequate protection for staff performing the highest risk AGPs. In contrast there are reports of staff being infected despite Tier 2 precautions and a plausible scientific basis that would dispute the effectiveness of Tier 2 precautions for these procedures. Given this, prioritising staff safety should result in an upgrade to some form of Tier 3 precautions. This is supported by the precautionary principle which applies when there are risks of morally unacceptable harm (staff death) based on scientifically tenable concerns despite a lack of robust data to accurately quantify the risk.
    • Staff stress and anxiety produced by the perception of inadequate protection when performing highly complex procedures (such as COVID-19 intubation) could lead to poor patient outcomes as well as ongoing risk to staff mental health.
  • Against
    • The use of 3rd tier precautions introduces complexity and some additional infection risks, which without proper planning and training may not reduce overall infection risk (or even increase risk):
      • Additional pieces of equipment can sometimes add significant time to donning and doffing
      • There can be significant risk of contamination with doffing and disposing/decontaminating some equipment, particularly without proper training.
      • There can also be significant complexity regarding the disinfection of reusable items.
    • Known Tier 2 PPE failures can be explained by staff error as opposed to equipment failure (although equipment failure is not ruled out and staff error may be an unavoidable systemic issue that may not be eliminated by training).
    • There may be significant cost implications of implementing Tier 3 precautions.
    • There may be difficulties accessing consistent supply of Tier 3 precaution related equipment.

Differences between Australian PPE Guidelines

ACEM

The ACEM PPE guidelines, while broadly similar to the Australian Government and AHPPC PPE advice, includes some key differences. Notably it contains a table that provides practical guidance regarding “PPE in specific clinical situations”.

Some differences based on this table include:

  • ACEM recommends consideration of  lower level precautions of surgical mask + gloves for:
    • For staff not directly in contact with patients (>1.5m distance from patients at all times) who enter a cohorted isolation area (i.e: low risk encounter in a moderate risk area)
    • For clinical staff in direct contact with patients screened negative or minimal for COVID risk and no respiratory symptoms (i.e moderate risk encounter with a low risk patient)
  • ACEM recommends consideration of upgrading to tier 2 (PPE recommended for AGPs) in certain non-AGP “routine care” situations that are otherwise high risk encounters (based on type of contact and/or type of patient) such as:
    • Staff in a COVID Assessment Clinic (based on a risk assessment)
    • Staff in direct contact with patients with “severe acute respiratory infection”
    • Staff with prolonged direct clinical care in higher risk patient environments such as clinical areas with cohorted severe acute respiratory infection.

For more detailed information see ACEM-PPE Guideline.

 

AMA

Of note, the federal Australian Medical Association (AMA) PPE Guidelines also largely conformed to federal government recommendations above but shared with ACEM the exception to the recommendation for PPE required for routine patient care, that droplet precautions should be upgraded to airborne precautions when caring for patients with severe respiratory disease (such as in an intensive care or high dependency unit).

Aerosol Generating Procedures & Events

(Adapated from SAS Consensus Statement)
Aerosol generating events
  • Coughing/sneezing
  • NIV without closed-circuit or with closed-circuit but inadequate seal
  • Positive pressure ventilation with inadequate seal*
  • High flow nasal oxygen (HFNO)
  • Delivery of nebulised/atomised medications via simple face mask
  • Cardiopulmonary resuscitation (prior to intubation)
  • Tracheal extubation
  • Tracheal suctioning (without closed system).
Procedures vulnerable to aerosol generation
  • Laryngosopy
  • Tracheal intubation
  • Bronchoscopy/Gastroscopy
  • Front-of-neck airway (FONA) procedures (including trachestomy, cricothyroidotomy)

* The reliability of seal is greatest with tracheal tube > supraglottic airway > face mask

References

Record of Guideline Updates

This guideline is periodically updated as new information becomes available to our team (i.e is a “living guideline”). This section provides a record of updates so that people who have read earlier versions of the guideline can quickly get up to speed with any changes.

Disclaimer

This COVID-19 Disclaimer is provided in conjunction with our general website disclaimer.
Due to the emergent nature of the threat to our patients and health system, the information provided is based on a review of a wide range of resources without as thorough a vetting process regarding their accuracy as would be possible in non-emergent circumstances. Additionally some information sources include collegiate conversations via a wide range of clinical and social media forums as well as expert opinion rather than established evidence (which is lacking). EDGuidelines.com does not warrant that the information is free from error or omission.

Clinicians must exercise their own judgement regarding these matters and whether to utilise this information in their clinical care of patients. In particular, it is recommended you consult updated local guidelines and consider patient specific factors in applying any of this information.

EDguidelines.com disclaims all liability for outcomes related to the use of information on this page.

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