Respiratory Management of COVID 19

Original Editor - Naomi O'Reilly

Top Contributors - Naomi O'Reilly, Kim Jackson, Rachael Lowe, Laura Ritchie, Lucinda hampton, Admin, Vidya Acharya, Tarina van der Stockt, Khloud Shreif, Leana Louw, Nicole Hills, Tony Lowe, Wendy Walker, Simisola Ajeyalemi and Wanda van Niekerk  

Introduction

Coronavirus Disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome-Corona Virus-2 (SARS-CoV-2), 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, rather than ‘airborne spread’ (in which smaller particles remain in the air longer). There is still no specific antiviral treatment for COVID-19 infection, only supportive therapies including respiratory care for affected patients, especially in more severe cases.

Approximately 15% of individuals with COVID-19 develop moderate to severe disease and require hospitalisation and oxygen support, with a further 5% who require admission to an Intensive Care Unit and supportive therapies including intubation and ventilation. The most common complication in severe COVID-19 patients is severe pneumonia, but other complications may include Acute Respiratory Distress Syndrome (ARDS), Sepsis and Septic Shock, Multiple Organ Failure, including Acute Kidney Injury and Cardiac Injury, which are more prevalent in at-risk groups including Older Age (> 70 years) and those with Co-morbid Disease such as Cardiovascular Disease, Lung Disease, Diabetes and those who are Immunosuppressed. In a small proportion of these, the illness may be severe enough to lead to death. Data currently suggests that illness is less common and usually less severe in younger adults.

Clinical Syndromes

The World Health Organisation outlines the following Clinical Syndromes associated with COVID-19:

Mild Illness	Patients present with uncomplicated upper respiratory tract viral infection and may have non-specific symptoms such as fever, fatigue, cough (with or without sputum production), anorexia, malaise, muscle pain, sore throat, dyspnea, nasal congestion, or headache. Rarely. patients may also present with diarrhoea, nausea, and vomiting. The elderly and immunosuppressed may present with atypical symptoms. Symptoms due to physiologic adaptations of pregnancy or adverse pregnancy events, such as dyspnea, fever, GI-symptoms or fatigue, may overlap with COVID- 19 Symptoms.
Pneumonia	Adult: with pneumonia but no signs of severe pneumonia and no need for supplemental oxygen. Child: with non-severe pneumonia who has a cough or difficulty breathing + fast breathing: Fast Breathing (in breaths/min) .< 2 months old ≥ 60; 2-11 months old ≥ 50; and 1-5 years old ≥ 40, and no signs of severe pneumonia. Patients may be productive, with an increased sputum load but this is a less common presentation in viral pneumonia.
Severe Pneumonia	Adolescent or Adult: Fever or suspected respiratory infection, plus one of the following: High Respiratory Rate > 30 breaths/min; Severe Respiratory Distress; or SpO2 ≤ 93% on Room Air. Child: with a cough or difficulty in breathing, plus at least one of the following: Central Cyanosis or SpO2 < 90%; Severe Respiratory Distress (e.g. Grunting, Very Severe Chest Indrawing); Signs of Pneumonia with a general danger sign: Inability to breastfeed or drink, Lethargy or Unconsciousness, or Convulsions. Other signs of pneumonia may be present: Chest Indrawing; Fast Breathing (in breaths/min): < 2 months: ≥ 60; 2 - 11 months: ≥ 50;1 - 5 years: ≥ 40. While the diagnosis is made on clinical grounds; chest imaging may identify or exclude some pulmonary complications.
Acute Respiratory Distress Syndrome (ARDS)	Onset: Within 5 - 7 days from the onset of initial respiratory symptoms Diagnostic Tools (Radiograph, CT Scan, or Lung Ultrasound): Bilateral Opacities, not fully explained by volume overload, lobar or lung collapse, or nodules; Origin of Pulmonary Infiltrates: Respiratory failure not fully explained by cardiac failure or fluid overload; Need Objective Assessment (e.g. Echocardiography) to exclude Hydrostatic cause of infiltrates/oedema if no risk factor present. Oxygenation Impairment in Adults: Based on PF Ratio, which is the ratio of arterial oxygen partial pressure to fractional inspired oxygen Mild ARDS: 200 mmHg < PaO2/FiO2a ≤ 300 mmHg (with PEEP or CPAP ≥ 5 cmH2O, Ornon-ventilated) Moderate ARDS: 100 mmHg < PaO2/FiO2 ≤ 200 mmHg (with PEEP ≥ 5 cmH2O, or Non-ventilated) Severe ARDS: PaO2/FiO2 ≤ 100 mmHg (with PEEP ≥ 5 cmH2O, or Non-ventilated) When PaO2 is not available, SpO2/FiO2 ≤ 315 suggests ARDS (including in Non-ventilated patients). Oxygenation Impairment in Children: Note OI = Oxygenation Index and OSI = Oxygenation Index using SpO2. Use PaO2-based metric when available. If PaO2 not available, wean FiO2 to maintain SpO2 ≤ 97% to calculate OSI or SpO2/FiO2 ratio: Bilevel (NIV or CPAP) ≥ 5 cmH2O via full face mask: PaO2/FiO2 ≤ 300 mmHg or SpO2/FiO2 ≤ 264 Mild ARDS (Invasively Ventilated): 4 ≤ OI < 8 or 5 ≤ OSI < 7.5 Moderate ARDS (Invasively Ventilated): 8 ≤ OI < 16 or 7.5 ≤ OSI < 12.3 Severe ARDS (Invasively Ventilated): OI ≥ 16 or OSI ≥ 12.3.
Sepsis	Adults: Life-threatening organ dysfunction caused by a dysregulated host response to suspected or proven infection. Signs of organ dysfunction include: Altered Mental Status; Difficult or Fast Breathing; Low Oxygen Saturation; Reduced Urine Output; Fast Heart Rate; Weak Pulse; Cold Extremities; Low blood Pressure; Skin Mottling; Laboratory Evidence of Coagulopathy, Thrombocytopenia, Acidosis, High Lactate, or Hyperbilirubinemia. Children: Suspected or proven infection and ≥ 2 age-based systemic inflammatory response syndrome criteria, of which one must be abnormal temperature or white blood cell count.
Septic Shock	Adults: Persisting hypotension despite volume resuscitation, requiring vasopressors to maintain MAP MAP ≥ 65 mmHg and serum lactate level > 2 mmol/L. Children: Any hypotension (SBP < 5th centile or > 2 SD below normal for age) or two or three of the following: Altered Mental State; Tachycardia or Bradycardia - HR < 90 bpm or > 160 bpm in Infants or HR < 70 bpm or > 150 bpm in Children; Prolonged Capillary Refill (> 2 sec) or Feeble Pulse; Tachypnoea; Mottled or Cool Skin or Petechial or Purpuric Rash; Increased Lactate; Oliguria; Hyperthermia or Hypothermia

Patients with severe disease often need oxygenation support. High-flow oxygen and noninvasive positive pressure ventilation have been used, but the safety of these measures is uncertain, and they should be considered aerosol-generating procedures that warrant specific isolation precautions and PPE considerations. Some patients may develop acute respiratory distress syndrome and warrant intubation with mechanical ventilation; extracorporeal membrane oxygenation may be indicated in patients with refractory hypoxia.

Procedures at Risk of Contamination

COVID-19 is spread by inhalation of infected matter containing live virus, which can travel up to 2m or by exposure from contaminated surfaces. Aerosol-generating procedures create an increased risk of transmission of infection. Rachael Moses, a Consultant Physiotherapist at Lancashire Teaching Hospital, suggests that particular attention should be given during those interventions that place the health care staff at greater risk of contamination for aerial dispersion of droplets.

Aerosol Generating Procedures (AGP)

Aerosols generated by medical procedures are one route for the transmission of the COVID-19 virus. For patients with suspected/confirmed COVID-19, any of these potentially infectious AGPs should only be carried out when essential and minimised as much as possible. Where these procedures are indicated, they should be carried out in a single room with the doors shut but preferably should be completed in a Negative Pressure Side Room. Only those healthcare staff who are needed to undertake the procedure should be present. Full PPE Equipment including a disposable, Fluid Repellent Surgical Gown, Gloves, Eye Protection and an FFP3 Respirator Mask should be worn by those undertaking the procedure and those in the room and good hand hygiene following the procedure. Hair cover should also be considered. The following procedures are considered to be potentially infectious AGPs:

• Intubation, Extubation and Related Procedures;
• Tracheotomy/Tracheostomy Procedures;
• Manual Ventilation;
• Open Suctioning;
• Bronchoscopy;
• Non-Invasive Ventilation (NIV) e.g. Bi-level Positive Airway Pressure (BiPAP)and Continuous Positive Airway Pressure Ventilation (CPAP);
• Surgery and Post-Mortem Procedures in which high-speed devices are used;
• High-Frequency Oscillating Ventilation (HFOV);
• High-flow Nasal Oxygen (HFNO)
• Induction of Sputum; Note: Induction of sputum typically involves administration of nebulised saline to moisten and loosen respiratory secretions (this may be accompanied by chest physiotherapy such as percussion and vibration to induce forceful coughing). This may be required if lower respiratory tract samples are needed

Certain other procedures/equipment may generate an aerosol from material other than patient secretions but are not considered to represent a significant infectious risk. Procedures in this category include:

• Administration of Pressurised Humidified Oxygen;
• Administration of Medication via Nebulisation; Note: During nebulisation, the aerosol derives from a non-patient source (the fluid in the nebuliser chamber) and does not carry patient-derived viral particles. If a particle in the aerosol coalesces (combines) with a contaminated mucous membrane, it will cease to be airborne and therefore will not be part of an aerosol. Staff should use appropriate hand hygiene when helping patients to remove nebulisers and oxygen masks.

Physiotherapy Specific Aerosol Generating Techniques

• Manual Techniques (e.g. Percussion/Manual Assisted Cough) that may lead to coughing and expectoration of sputum
• Use of Positive Pressure Breathing Devices (e.g. IPPB), Mechanical Insufflation-Exsufflation (Cough Assist) Devices, Intra/Extra Pulmonary High Frequency Oscillation Devices (e.g. the Vest / MetaNeb / Percussionaire etc.)
• Any Mobilisation or Therapy that may result in Coughing and Expectoration of Mucus
• Any Diagnostic Interventions that involve use of Video Laryngoscopy that can result in Airway Irritation and Coughing (e.g. Direct Visualisation during airway clearance techniques or when assisting Speech and Language Therapists perform Fibreoptic Endoscopic Evaluation of Swallow)

Decontamination

Reusable (communal) non-invasive equipment must be decontaminated:

• between each patient and after patient use;
• after blood and body fluid contamination; and
• at regular intervals as part of equipment cleaning.

An increased frequency of decontamination should be considered for reusable non-invasive care equipment when used in isolation/cohort areas.

Equipment

• Reusable equipment should be avoided if possible; if used, it should be decontaminated according to the manufacturer’s instructions before removal from the room. If it is not possible to leave equipment inside a room then follow IPC Guidelines on Decontamination. This usually involves cleaning with neutral detergent, then a chlorine-based disinfectant, in the form of a solution at a minimum strength of 1,000ppm available chlorine (e.g. “Haz-Tab” or other brands).
• If possible use dedicated equipment in the isolation room. Avoid storing any extraneous equipment in the patient’s room
• Dispose of single-use equipment as per clinical waste policy inside a room
• Point of care tests, including blood gas analysis, should be avoided unless a local risk assessment has been completed and shows it can be undertaken safely
• Ventilators and mechanical devices (e.g. Cough Assist Machines) should be protected with a high-efficiency viral-bacterial filter such as BS EN 13328-1.
• When using mechanical airway clearance filters should be placed at the machine end and the mask end before any expiratory or exhalation ports. Filters should be changed when visibly soiled or dependent on the filter used either after each use or every 24 hours and complete circuit changes should be undertaken every 72 hours (please follow trust guidance on this)
• Closed system suction should be used if patients are intubated or have tracheostomies
• Disconnecting a patient from mechanical ventilation should be avoided at all costs but if required the ventilator should be placed on standby
• Manual hyperinflation (bagging) should be avoided if possible and attempt ventilator recruitment manoeuvres where possible and required
• Water humidification should be avoided, and a heat and moisture exchanger should be used in ventilator circuits
• Disposable crockery and cutlery may be used in the patient’s room as far as possible to minimise the numbers of items which need to be decontaminated
• Any additional items such as Stethoscopes, Pulse Oximeters, Ultrasound Probes that are taken into a room will also need to be disinfected, regardless of whether there has been direct contact with the patient or not. This is due to the risk of environmental contamination of the equipment within the isolation room.

Patients Rooms

• If AGPs are undertaken in the patient’s own room, the room should be decontaminated 20 minutes after the procedure has ended (please follow trust IPC guidance on this also).
• If a different room is used for a procedure it should be left for 20 minutes, then cleaned and disinfected before being put back into use.
• Clearance of any aerosols is dependent on the ventilation of the room. In hospitals, rooms commonly have 12 to 15 air changes per hour, and so after about 20 minutes, there would be less than 1 per cent of the starting level (assuming cessation of aerosol generation).
• If it is known locally that the design or construction of a room may not be typical for a clinical space, or that there are fewer air changes per hour, then the local IPCT would advise on how long to leave a room before decontamination.

Oxygen Support

WHO recommends supplemental oxygen therapy immediately for patients with respiratory distress, hypoxaemia or shock with a target SpO2 > 94%. Patients may continue to have increased work of breathing or hypoxemia even when oxygen is delivered via a face mask with reservoir bag (flow rates of 10 - 15 L/min, which is typically the minimum flow required to maintain bag inflation; FiO2 0.60 - 0.95).

Early recognition and referral of patients with worsening respiratory function while on conventional oxygen therapies, such as simple face masks or masks with reservoir bags, are important to ensure the timely and safe escalation of respiratory support. Early optimisation of care and involvement of Intensive Care Unit is recommended.

High Flow Nasal Oxygen (HFNO)

There has been some differing opinions on the use of HFNO due as an aerosol generating procedure but based on the Italian experience, HFNO has been found to be beneficial at the early stage, with a select cohort of patients who present with hypoxemic respiratory failure with no evidence of hypercapnia and can prevent intubation in some patients. Given that HFNO is an aerosol generating procedure negative pressure rooms are preferable for patients receiving HFNO therapy and all staff entering the room should wear full PPE Equipment including a disposable, fluid repellent surgical gown, gloves, eye protection and an FFP3 respirator mask. Flow rates of up to 60% and 100% oxygen are possible with HFNO.

Early recognition and referral of patients with worsening respiratory function (hypercapnia, acidaemia, respiratory fatigue), haemodynamic instability or those with altered mental status are important to ensure the timely and safe escalation of respiratory support, with consideration for early invasive mechanical ventilation if appropriate.

Ventilatory Support

Acute or chronic hypoxaemia is a common reason for admission to intensive care and for provision of mechanical ventilation. Various refinements of mechanical ventilation or adjuncts are employed to improve patient outcomes.

Non-Invasive Ventilation (CPAP/NIV)

Routine use of non-invasive ventilation is not recommended.

Non-invasive ventilation, an aerosol generating procedure, is when oxygen is given as breathing support by using a face mask or nasal mask under positive pressure, and is a recognised evidence based intervention utilised for the treatment of hypercapnic respiratory failure. The amount of pressure generally alternates depending on inhalation or exhalation. Although non-invasive ventilation may temporarily improve oxygenation and reduce the work of breathing in patients with viral infections complicated by pneumonia this method does not necessarily change the natural disease course and as such non-invasive ventilation is not routinely recommended, and has no role in severe hypoxemic respiratory failure. Where non-invasive ventilation is utilised a clear plan for treatment failure and escalation of care should be in place. 

Current experience suggests that non-invasive ventilation for COVID-19 can be associated with a high failure rate, delayed intubation, and possibly increased risk of aerosolisation with poor mask fit It seems clear from the available evidence that non-invasive ventilation should not be routinely used when the patient has severe respiratory failure or a trajectory that suggests that invasive ventilation is inevitable. In such circumstances, deteriorating patients should be considered for early endotracheal intubation and transitioned from oxygen therapy via a simple facemask to invasive ventilation without delay. Negative prognostic factors for non-invasive ventilation success are: overall severity, renal failure, hemodynamic instability.

Non-invasive ventilation has been considered an effective strategy with a specific cohort of patients in the early presentation of COVID-19, in particular with presentations of COVID-19 with hypercapnic respiratory failure, such as those with concomitant respiratory conditions e.g. COPD. In Italy, where non-invasive ventilation has been utilised with this cohort group, they recommend to perform a single attempt of up to 1 hour.  If you don't see substantial improvements, alert the medical team, as the patient should be considered for early endotracheal intubation and invasive ventilation within a controlled environment with adequate infection prevention and control measures taken.

In order for non-invasive ventilation to be delivered in a safe manner and minimise the risk of aerosolisation, negative pressure single rooms should be used, using a dual link system with separate expiatory port or use of a double port filter system with a viral filter placed between the mask and the respiratory port.

Recommendations in terms of non-invasive ventilation preferences are;

1. First Choice: CPAP without humidification and with Hood / Helmet PEEP between 10 - 12 cmH20 and up to 15-20 cmH2O according to patient’s needs, tolerance and any side-effects.
2. Second Choice: CPAP with mask
3. Third Choice: NIV with face mask (total full face mask / oronasal face mask with filter between mask respiratory port)

Non-invasive ventilation can be used effectively to bridge extubation and can be used to support extubation in the intensive care unit.

Invasive Ventilation

Lung protective mechanical ventilation (MV) is the recommended strategy for the management of acute respiratory failure, which aims to protect the lung. This is when mechanical ventilation is employed with the use of a low tidal volume strategy (4-8ml/kg predicted body weight) and limiting plateau pressures to less than 30 cmH2O. Permissive hypercapnia is usually well-tolerated and may reduce volutrauma, local over distention of normal alveoli as achievement of adequate oxygenation is key. Higher levels of PEEP, greater than 15 cmH2O, are recommended.

Alternate modes of ventilation such as APRV may be considered based on clinician preference and local experience. Viral, rather than HME filters, should be utilised, and circuits should be maintained for as long as allowable, as opposed to routine changes.

Generally patients are sedated to allow adequate control of ventilation. While good practice to perform daily sedation holds patients with COVID-19 may be kept under deeper sedation until adequate oxygenation levels are achieved to reduce the risk of ventilator dysynchrony and control respiratory drive, which is important to achieve adequate target tidal volumes.Use of neuromuscular blockade agents are not recommended, unless the patient has significant ventilator dysynchrony and lung de-recruitment.

Use of recruitment measures are not recommended in severe ARDS, but may be considered during the weaning phase but in the case of COVID-19 patients, manual recruitment methods such as manual hyperinflation with involve a break in the circuit is not recommended due to increased risk of droplet spread.

In the majority of patients with COVID-19, endotrachael tubes are used, with very few requiring tracheostomy. It is vital that cuffs are inflated at all times, and never deflated during any treatments. If tracheostomy is indicated subglotic tracheotomy should be utilised so above cuff vocalisation can be achieved without needing to deflate the cuff to improve communication and swallow.

Positioning

Positioning is a vital component of management for the mechanically ventilated COVID-19 patient, with regular turning recommended to prevent atelectasis, optimise ventilation and prevent pressure sores. Positioning can included lateral side lying positioning but may also include prone positioning, which is well recognised to treat hypoxemic respiratory failure. Prone ventilation is ventilation that is delivered with the patient lying in the prone position. Prone ventilation may improve lung mechanics and gas exchange, thus improving oxygenation in the majority of patients with ARDS, and could improve outcomes. Current reports suggest prone ventilation is effective in improving hypoxia associated with COVID-19 and should be completed in the context of a hospital guideline that includes appropriate PPE for staff, and that minimise the risk of any adverse events, e.g. accidental extubation and breaking of the circuit. In adult patients you want to maintain prone positioning for at least 16 hours of longer.

Suctioning

Closed inline suction catheters are recommended and imperative. Any disconnection of the patient from the ventilator should be avoided to prevent lung decruitment and aerosolisation. If necessary, the endotracheal tube should be clamped and the ventilator disabled (to prevent aerosolisation). Suctioning is not required routinely but should be used as required.

Nebulisation

Use of nebulisers is not recommended and use of metered-dose inhalers are preferred where possible.

Humidification

Use of humidification, both cold and warm water, is not recommended and HME Filters should be used.

Weaning and Liberation from Mechanical Ventilation

Standard weaning protocols should be followed. HFNO and/or NIV with well-fitted facemask with separate inspiratory and expiratory can be considered as bridging therapy post-extubation but must be provided with strict use of staff PPE.

Specific Respiratory Techniques

Acute Phase

Where the Patient is awake, cooperative and in weaning stage then we can consider use of the Active Cycle of Breathing Technique, Lung Volume Recruitment procedures including Breath Stacking combined with positioning to ensure patient involvement in their treatment.

Ventilator Disconnection

Anything in relation to Ventilator Disconnection should not be utilised e.g. Manual Hyper Inflation / Bagging.

Mechanical Insufflation-Exsufflation (Cough Assist) Devices

Generally not indicated or required in Viral Pneumonia, as they do not tend to have productive chests, retained secretions or problems with sectretion retenion or mucus plugging. not recommended for use as they do not have, If you felt it was indicated you would need to discuss use of same with the Medical Team considering the physiological impact of Insufflation-Exsufflation in someone who may already have an acute lung injury, which may be counterproductive to the Lung Protection Strategy utilised. This may be considered for use in those patients with co-morbid conditions where these techniques were part of their normal airway clearance strategies, but benefit versus risk would need to be discussed with the team. This is not recommended and would not be considered first line intervention. As it is an Aerosol Generating Procedure full PPE would need to be in place and in order to protect the Machine and Patient a double viral filter systems should be in place at the mask and device expiratory port.

Lung Ultrasound

Diagnostic Lung Ultrasound has been identified as a potential diagnostic tool in the assessment and management of COVID-19. It shows similar findings to radiological cases, and has a higher degree of accuracy than the bedside chest radiograph and approaches levels of accuracy seen with computed tomography (CT) for many pathologies that reach the pleura, Lung Ultrasound can be used throughout the course of the treatment process to track the evolution of the disease, to monitor lung recruitment maneuvers, to provide feedback in relation to success of interventions and to assist decision making in relation to weaning and liberation from mechanical ventilation.

Manual Techniques

Controversy over effectiveness of manual techniques. Minimal evidence for Percussion. Some evidence for Expiatory Vibs and Manual Assisted Cough

Prevention of Complications

Physiotherapists can play a key role in the prevention of a range of complications including ventilator associated pneumonia's, secondary infections, contractures, or pressure areas.

Reduced Days of Mechanical Ventilation:

•  Use weaning protocols or development of individual weaning plans
•  Assessment of spontaneous breathing capacity and readiness for extubation, including involvement in daily sedation holds and spontaneous breathing trials.

Reduce the Incidence of Ventilator-Associated Pneumonia

Really important to reduce the risks of this, as with any secondary infection it will increase the number of days intubated and ventilated and time in the Intensive Care Unit, taking up a bed space for longer than should be required and reduce flow through the hospital.

• Keep the patient in a semi-sitting position (30 - 45 Degrees);
• Regular 2 Hourly Turning to minimise risk of Atelectasis and Consolidation;
• Prone Ventilation where Indicated and Appropriate; In China & Italy they often had multiple patients proned within the ICU.
• Use a Closed Suction System; Periodically Drain and Discard Condensate In Tubing;
• Use a new ventilation circuit for each patient, once the patient is ventilated change the circuit only if it is damaged or soiled, not routinely;
• Change Heat Moisture Exchanger when it malfunctions, when soiled, or every 5-7 days;
• Assist in the Extubuatiuon Phase, and weaning potential from Invasive Ventilation.

Reduce the Incidence of Pressure Ulcers

• Turn the patient every 2 hours

Reduce the Incidence of Intensive Care-Related Myopathy

• Mobilise the patient as soon as their condition allows and when safe to do so.

Resources

1. World Health Organisation This document is intended for clinicians taking care of hospitalised adult and paediatric patients with a severe acute respiratory infection (SARI) when a nCoV infection is suspected. It is not meant to replace clinical judgment or specialist consultation but rather to strengthen clinical management of these patients and provide up-to-date guidance. Best practices for severe acute respiratory infection including Infection Prevention and Control and optimized supportive care for severely ill patients are essential. Clinical management of Severe Acute Respiratory Infection when Novel Coronavirus (nCoV) Infection is suspected
2. Italian Thoracic Society (AIPO - ITS) and Italian Respiratory Society (SIP/IRS) This document is intended for clinicians taking care of hospitilised patients with COVID-19, and outlines the management of patients from first contact and triage through respiratory management . Managing the Respiratory Care of patients with COVID-19.

References