All patients with suspected or confirmed COVID-19 who are at increased risk of acute deterioration or cardiac arrest should be appropriately flagged to the local rapid response team (RRT) or whichever other team has been designated to provide code response.^{3 - 5} The use of severity scores and tracking systems, as well as the use of a “code yellow” system for identification of patients who are periarrest, allow early detection of critically ill patients and can optimize the care of cardiac arrest when it does occur;^{2 , 5}

Assessment of the potential difficulty of laryngoscopy/intubation must be performed on admission to the hospital and/or Intensive Care Unit (ICU) and recorded appropriately in the patient’s medical record. Scores such as MACOCHA ( Mallampati, obstructive Apnea syndrome, reduced Cervical mobility, limited mouth Opening, Coma, severe Hypoxemia, and non-Anesthesiologist operator ) or mnemonics such as LEMON ( Look, Evaluate, Mallampati, Obstruction, Neck ) can assist in determination of the difficult airway, activation of appropriate support, and prompt a request for a difficult airway trolley or cart;^{6 , 7}

Considering that two therapies currently under evaluation as potential treatments for COVID-19, chloroquine and hydroxychloroquine, may prolong the QT interval in up to 17% of patients, it is essential to consider the risk of severe polymorphic ventricular arrhythmias – especially torsades de pointes – and consequent occurrence of cardiac arrest with shockable rhythms;^{4 , 8 - 10}

The patients most at risk of polymorphic tachycardias in this context are older adults; women; and those with COVID-related myocarditis, heart failure, liver or kidney dysfunction, electrolyte disturbances (particularly hypokalemia and hypomagnesemia), and bradycardia. Identification of patients who already have a prolonged (> 500 ms) corrected QT interval (QTc) at baseline is paramount, and ECG monitoring should be performed daily as long as QT-prolonging drugs are used.^{4 , 8 - 10}

The decision of whether or not to initiate CPR must continue to be made on an individualized basis, be it during prehospital care, in the emergency department, or in the ICU. The potential benefits for the patient, the safety and exposure hazards of the code team, and the potential for futility of resuscitation maneuvers must be taken into account. Nevertheless, CPR should always be performed unless advance directives clearly state otherwise;^{1 , 2}

“Do not attempt CPR” (DNACPR) or “not for CPR” decisions/directives must be properly documented and communicated to the team. Palliative and end-of-life care should follow local and institutional policy.^{1 , 2}

Standard + aerosol precautions are recommended for all members of the code team in order to ensure adequate personal protection. Prompt availability of Personal Protective Equipment (PPE), e.g., by keeping PPE kits ready in every crash cart or trolley, minimizes the delay in initiating chest compressions and helps maintain continuity of care.^{3 , 4 , 11 - 14} Each PPE kit must include an N95 filtering facepiece respirator, face shield, waterproof gown, cap, long-cuff disposable gloves, and goggles;

The safety of the code team should be the utmost priority even if this means delaying chest compressions, and all those who respond to the code must first don appropriate PPE. In particular, CPR should not be started on any patient with suspected or confirmed COVID-19 until the code team is fully attired with appropriate PPE;^{3 , 4 , 11 - 14}

The number of team members at the site of the code (if it is an enclosed space such as a private room or cubicle) should be restricted;^{2 , 4 , 15 , 16}

Hand hygiene plays an important role in reducing the transmission of COVID-19. All team members must wash their hands with soap and water (only when visibly soiled) or use an alcohol-based hand sanitizer;^{3 , 15}

Adherence to all applicable federal (Ministry of Health) and local government guidelines is mandatory.

Recognition of cardiac arrest should follow ILCOR/AHA and Brazilian Society of Cardiology guidelines. Assessment should start by checking for responsiveness, breathing (chest rise and fall), and presence of a central pulse;^{1 , 2}

In adults, CPR should begin with continuous chest compressions. If the patient does not already have an invasive or advanced airway (orotracheal tube or extraglottic airway device) in place, a mask delivering low-flow oxygen or a towel should be placed over the patient’s mouth and nose before initiating compressions and kept in place until an invasive airway is secured,⁸ as chest compressions can generate aerosols;

In children, CPR should preferably consist of compressions and ventilation with a bag-valve-mask (BVM) coupled to a high-efficiency particulate arrestance (HEPA) filter until a definitive airway is established, since pediatric arrest is most commonly of respiratory etiology, and compression-only CPR is known to be less effective in this population.³ If a BVM with HEPA filter is not available, compression-only CPR with a standard oxygen mask or towel covering the patient’s mouth is a reasonable alternative;¹⁷

Despite the guidance of some emergency medical services that prehospital care of cardiac arrest in the absence of a medical professional (lay rescuer CPR) should be limited to hands-only CPR, the recommendation that the patient’s oral cavity be sealed to prevent aerosol generation as described above still stands;^{4 , 8 , 9 , 14}

Cardiac monitoring should be placed as soon as possible to ascertain whether there is a shockable rhythm, so as not to delay defibrillation if appropriate and provide guidance as to the optimal resuscitation algorithm to follow;^{1 , 2}

Defibrillation of a shockable rhythm should never be delayed to secure the airway or for other procedures;^{1 , 2}

If the patient already had a face mask in place to deliver supplemental oxygen before cardiac arrest occurred, it should be kept on until intubation, but delivering low-flow oxygen only (6–10 L/min at most); higher flow rates may be aerosol-generating;

If the patient does not have any airway device in place, the rescuer should place a cloth or towel over the patient’s mouth and nose and begin continuous compressions;

Before considering termination of CPR, any reversible causes should be identified and addressed, with particular emphasis on hypoxia, acidemia, and coronary thrombosis – all cited as common causes of death in recent publications on COVID-19.³ Additionally, polymorphic torsades de pointes -type ventricular tachycardia (associated with QT prolongation, which is known to be caused by drugs under investigation as potential COVID-19 treatments) and cardiac tamponade (associated with myocarditis), as well as ventilation-induced pneumothorax, have all been described as causes of cardiac arrest.

BVM or bag-valve-tube (BVT) ventilation should be avoided, due to the high risk of aerosol generation and staff contamination.^{3 , 15 , 18 , 19} If BVM ventilation is absolutely necessary, two rescuers should always be present to allow a two-handed mask seal, and an oropharyngeal (Guedel) cannula should be placed. In this case, 30 compressions and two breaths should be performed in adults and 15 compressions and two breaths in children until an invasive airway has been established, at which point the ratio should switch to continuous compressions and one breath every 6 seconds for adults and children alike. Placement of a HEPA filter between the mask and the bag is recommended ( Figures 1 to 3 );

Figure 1

Considering that hypoxia is one of the main causes of cardiac arrest in patients with COVID-19, invasive airway access should be prioritized for isolation purposes, due to the lower likelihood of aerosol generation and, consequently, staff contamination, as well as the possibility of achieving better ventilation and oxygenation patterns.^{15 , 16 , 19 - 21} During airway instrumentation, chest compressions should be halted to protect the code team. It is suggested that airway instrumentation be performed or attempted during pulse checks, to reduce hands-off time. It is recommended that orotracheal intubation always be performed by the most experienced operator present;

Videolaryngoscopy with a blade capable of providing a wide-angle view should be the first-line method of choice for quick, safe, and definitive airway management, ideally on first attempt, and always performed by the most experienced physician. In the event of intubation failure, the assistance of a second operator must be requested immediately. Videolaryngoscopy should again be prioritized for the second attempt;^{16 , 20 , 21}

For children, videolaryngoscopy with a blade suitable for the size of the patient is recommended; there is no particular need for a wider view angle;²⁰

If intubation fails again or is deemed impossible, an extraglottic device (laryngeal tube or laryngeal mask) should be placed. This will allow closed-circuit mechanical ventilation and capnography until conditions are present for establishment of a definitive (surgical) airway via tracheostomy or cricothyrotomy.^{20 , 22} In children, a laryngeal mask suitable for the patient’s weight and size is the extraglottic device of choice.²³ In Brazil, placement of extraglottic airway devices is within the scope of practice of both physicians and nurses, and can thus be an alternative for airway management in prehospital intermediate life support or limited advanced life support, as well as in nurse-led codes.^{1 , 2} Nevertheless, endotracheal intubation is still recommended whenever possible, largely with the aim of reducing aerosol generation;

When more than one extraglottic device is available, priority should be given whenever possible to that providing the best airway seal and the possibility of sequential placement of an orotracheal tube through the device lumen (Fastrach™ or other intubating laryngeal mask airway);

Even after a patient has been intubated or has an extraglottic device in place, occlusion and sealing of the oral cavity is still important to reduce aerosolization; this can be done with towels, gauze packs, or a standard surgical mask;

When cardiac arrest occurs in a patient already on mechanical ventilation, the patient should be connected to the ventilator through a closed ventilation circuit and the ventilator parameters set as follows ( Chart 1 ):

Volume assist-control ventilation mode; VT = 6 mL/kg PBW Respiratory rate = 10 bpm FiO2 = 100% Flow trigger = disabled or sensitivity threshold -15 to -20 PEEP = 0 VT alarms = maximum and minimum allowed by device Pressure alarms = 60 cmH2O maximum, 1 or 0 cmH2O minimum High and low minute volume alarms = maximum and minimum allowed by device Apnea time = 60 seconds

FiO₂: fraction of inspired oxygen; PBW: predicted body weight; PEEP: positive end-expiratory pressure; VT: tidal volume.

The exact same parameters apply in children;

Some ventilators provide a “CPR mode” function, which automatically adjusts the alarm limits and ventilator parameters as described above. For mechanically ventilated patients, it is recommended that a HEPA filter be placed in the ventilation circuit after the orotracheal tube and a second filter at the expiratory circuit;^{16 , 20 , 21}

To minimize aerosol generation, the tube should be clamped with a strong straight hemostat whenever there is a need to switch ventilator circuits (BVM to mechanical ventilator circuit, for instance);

For the safety of the team and the patient, adhesive pads (which do not require disconnection from the ventilator) should always be preferred for defibrillation. If manual (paddle) defibrillation is needed, the ventilator should be placed in standby mode and the orotracheal tube disconnected from the ventilator, keeping the HEPA filter attached to the tube, only after the shock has been delivered.

High-quality chest compressions should be performed, ensuring:

Allow full recoil of chest after each compression; do not lean on the patient’s chest;

Minimize interruptions in chest compressions; pauses should be limited to 10 seconds at most (for two breaths). Consider performing CPR with the goal of the highest possible chest compression fraction, aiming at a minimum of 60% to 80%;

Rotate out with another team member every 2 minutes to avoid rescuer fatigue, which can lead to poor compressions;

If the patient is in the supine position, compressions should be performed in the center of the chest, on the lower half of the breastbone (sternum);

Considering the need for PPE use to limit the risk of aerosol generation, the strenuous nature of resuscitation maneuvers, the potential for rescuer fatigue and exhaustion, and the need to minimize the number of team members present during resuscitation, use of a mechanical chest compression device is advised for adults whenever one is available.

If the patient is in prone position with no invasive airway in place, he or she should be quickly repositioned supine, CPR should be initiated, and an invasive airway device should be placed as soon as possible, preferably by orotracheal intubation;

If the patient is already intubated and ventilated, it is recommended that CPR maneuvers be initiated with the patient still in prone position. The surface landmark for hand placement is the exact posterior projection of the site for chest compressions, i.e., in the interscapular region, at the T7-T10 level ( Figure 4 ). Attempts to de-prone (i.e., return the patient to the supine position) should be performed with maximum care to avoid ventilator disconnection and minimize the risk of aerosolization. If adhesive defibrillator pads are available, they should be placed in an anteroposterior arrangement;^{10 , 22 , 23}

Figure 4

If no adhesive pads are available, manual defibrillation can be attempted by placing the sternal paddle on the dorsal region and the apical paddle on the patient’s flank ( Figure 5 ). It is recommended that the effectiveness of CPR be assessed by end-tidal CO₂monitoring (partial pressure of carbon dioxide > 10 mmHg) and invasive blood pressure monitoring (diastolic blood pressure > 20 mmHg). It bears stressing that evidence for this maneuver is still unclear and, whenever possible, the patient should be de-proned, as the supine position is best suited for high-quality CPR and adequate ventilation.

Figure 5

If the patient is not already in intensive care, an ICU bed with respiratory isolation should be requested even before return of spontaneous circulation (ROSC) is achieved;^{3 , 15 , 16}

All equipment used during CPR should be disposed of or sanitized following manufacturer recommendations and institutional or local guidelines;³

All surfaces onto which airway/resuscitation equipment was placed must also be cleaned as per local guidelines. Check that no airway management devices (including laryngoscopes and face masks) have been left on the bed. All equipment should be left on the intubation tray if possible;³

After the code, team members should doff all PPE safely, avoiding self-contamination.^{3 , 15} Particular attention is required during this step, which is when contamination of health care workers is most likely to occur (through contact with patient secretions and respiratory droplets).

In the prehospital environment, CPR should never be attempted in patients with suspected or confirmed COVID-19 who present with obvious signs of death;³

Prehospital care providers should follow standard + aerosol precautions when caring for patients with suspected or confirmed COVID-19;

The population should be instructed to notify the dispatcher if the victim is suspected to have COVID-19 when calling an ambulance. This allows prehospital care providers to don appropriate PPE before arrival at the scene. Emergency medical service dispatchers and physician regulators/medical directors are strongly advised to conduct active case-finding of COVID-19 by inquiring about flu-like symptoms, fever, and dyspnea during calls;

CPR should be limited to continuous chest compressions. Mouth-to-mouth ventilation, even with use of a pocket CPR mask, should never be performed for patients with suspected or confirmed COVID-19;³

Considering that most out-of-hospital cardiac arrests occur at home, in pediatric out-of-hospital arrests, the lay rescuer will most likely be a parent, family member, or caregiver who will already be in close contact with the child and thus exposed to respiratory secretions. In this case, the lay rescuer should be instructed to perform compressions and consider mouth-to-mouth ventilation if he or she is able and willing to do so, since most pediatric arrests are secondary to respiratory causes;²³

Hands-only CPR is a reasonable alternative if the rescuer is unable or unwilling to provide mouth-to-mouth resuscitation or has not had close contact with the child before;¹⁷

The rescuer should cover the victim’s mouth and nose with a cloth or towel (or, if available, place a mask delivering low-flow oxygen) to prevent suspension of aerosols generated during CPR;

Do not delay defibrillation. Early use of an automated external defibrillator (AED) significantly increases the odds of survival and does not increase the risk of COVID-19 transmission;

Positive-pressure BVM ventilation should be avoided at all cost. If absolutely necessary, it must always be performed by two providers, one of whom will be exclusively responsible for sealing the mask to the patient’s face, using the most suitable grip technique to avoid air leak. A BVM may only be used if a HEPA filter is available and has been placed at the bag-valve interface.

In children, CPR should preferably consist of chest compressions and BVM ventilation (always with a HEPA filter);

Otherwise, prehospital airway management should follow the aforementioned recommendations for in-hospital care – namely, ensuring that a BVM and any other ventilation devices are equipped with HEPA filters and that an advanced airway device (tracheal tube or extraglottic airway) is placed as early as possible;

Open the rear doors of the transport vehicle and activate the heating, ventilation, and air conditioning (HVAC) system during any aerosol-generating procedures (do this away from pedestrian traffic);

Family members or chaperones may not ride along in the ambulance in the same compartment as the patient. According to Ministry of Health recommendations, patients with suspected or confirmed COVID-19 are not allowed any chaperones who may be at risk of contamination. It is suggested that companions or chaperones be instructed to make their own way to the health facility;

If the transport vehicle lacks an isolated driver compartment, the outside air vents in the driver’s area should be opened and the rear exhaust fans turned on at the highest setting.

Perform debriefing at the end of each code to support team growth and improvement;^{1 , 2}

All health care workers involved in the care of patients with suspected or confirmed COVID-19 should undergo skills training in donning and, especially, doffing PPE as soon as possible, as well as participate in simulated code blue response;^{15 , 16 , 20 , 21}

Skills training and continuing medical education are paramount to protecting staff and improving safety in patient care. The use of moulages/vignettes, realistic simulation resources, and distance education resources is strongly recommended.