This algorithm is a modification of the 2015 ALS Algorithm that is currently taught and used in the UK. The algorithm and supporting materials are available here.
Our answers to this question were compiled from a series of questions we received on this subject.
What are the phases of the algorithm? Can you explain them?
This algorithm aims for the best outcomes for patients and minimise the risks to rescuers when resuscitating patients with COVID-19 or suspected COVID-19.
- Phase 1 emphasises the need for decisions prior to the time of cardiac arrest and that all patients in a healthcare setting should have a prior decision for or not for a CPR attempt. As for the existing non-COVID algorithm prevention of cardiac arrest is not part of the algorithm. The RCUK strongly support use of NEWS2 and treatment planning using the ReSPECT process to minimise the requirement for CPR.
- Phase 2 refers to the assessment and if the rhythm is shockable, defibrillation attempts. Rhythm assessment and defibrillation is not an aerosol generating procedure (AGP) and requires personal protective equipment (PPE) against droplets (Level 2 PPE) as opposed to AGPs (Level 3 PPE).
- Phase 3 refers to starting chest compressions and airway interventions that are AGPs and require PPE for AGPs. Once Phase 3 starts all those involved in the resuscitation attempt must have AGP PPE. Everyone else must be outside the room or distance themselves (the precise safe distance is unknown and likely to be more than 2 metres, and will depend on airflow and other factors).
What happens whilst waiting staff to don PPE for AGPs or the defibrillator to arrive? The initial response is not covered.
The priority is staff safety, and this means that the time taken to don PPE and ensure staff safety is an acceptable part of the resuscitation process. To avoid delays in hospital, patients at risk of cardiac arrest should be cared for in clinical areas where they have appropriate monitoring and availability of equipment and PPE. If staff are wearing PPE for AGPs, they can start chest compressions and airway management whilst awaiting the arrival of a defibrillator.
Why is there an emphasis on defibrillation and repeated shock attempts in the COVID-19 ALS algorithm?
This is for a number of reasons:
a. Patients with a shockable rhythm treated with early defibrillation have the best survival rates and this group has been prioritised in the algorithm. This is the case for both in- and out-of-hospital cardiac arrest. (See supporting information from ICNARC and Warwick)
b. Rhythm assessment and defibrillation is not an aerosol generating procedure (AGP) and requires personal protective equipment (PPE) against droplets (Level 2 PPE) as opposed to AGPs (Level 3 PPE).
c. In an ideal situation there would be a period of chest compression between shock attempts. We have recommended up to 3 shock attempts whilst awaiting colleagues with the correct PPE. If rescuers already have PPE against AGPs (Level 3 PPE), chest compressions can be given between shocks as is usual practice.
The algorithm states give up to three shocks without chest compressions in between. How do we do three shocks with an AED?
The ALS algorithm is specifically for use with a manual defibrillator. If the only defibrillator available is an AED, it will give a first shock if the rhythm is shockable – this first shock will have the highest success rate. As soon as staff with PPE for AGPs are available chest compressions can start.
How do I deliver the up to 3 shocks as described in the COVID-19 ALS algorithm?
Place pads on the patient’s chest and give the first shock with a manual defibrillator as usual. Assess the rhythm after the shock is given. If the rhythm remains shockable give a further shock. If there is a potential perfusing rhythm check for a pulse. If there is a non-shockable rhythm start chest compressions once rescuers with PPE for AGPs are available. All rescuers without PPE for AGPs should distance themselves from the resuscitation attempt when compressions or airway interventions start.
Most COVID-19 patients will be hypoxic and have a non-shockable rhythm. I am concerned that they will not receive optimal management.
Resuscitation Council UK has maintained its long-held position that the safety of rescuers is the first priority. This means that the time taken to ensure the team is safe is an accepted part of the process of resuscitation. To avoid delays in starting CPR, all efforts must be made to avoid the need for CPR (e.g., use of NEWS2 to recognise treat and prevent cardiac arrest, and DNACPR decisions), and if cardiac arrest occurs CPR is performed safely and effectively. This does mean patients at risk of cardiac arrest need to be cared for in an appropriate clinical area that has staff and PPE available.
Hypoxaemic cardiac arrest is not usually a sudden or unexpected event so in many cases there will be an opportunity to intervene prior to cardiac arrest.
Once cardiac arrest occurs survival is poor. For example survival to hospital discharge with good neurological outcome was less than 1% for in-hospital cardiac arrest patients with COVID-19 in a case series from Wuhan China see https://doi.org/10.1016/j.resuscitation.2020.04.005
Why does the COVID algorithm still include extracorporeal CPR as a consideration?
Resuscitation Council UK accepts that this option is not available or feasible in most settings where ALS is carried out. This was the case prior to the COVID-19 pandemic and remains so. It is only available in very specialist settings and the clinicians in these settings will continue to have the expertise as to which patients they use this intervention.
Why does the COVID-19 algorithm section on post cardiac arrest treatment target an oxygen saturation of 94-98% when lower targets are recommended in those with acute lung injury?
The post resuscitation care targets are unchanged from the pre-COVID-19 algorithm. Acute lung injury and aspiration induced lung injury occurs in patients after cardiac arrest and intensive care clinicians already adjust oxygen targets when necessary. This will be the same for patients with an acute lung injury caused by COVID-19. For example, the Surviving Sepsis have suggested an upper oxygen target of 96% in its current COVID-19 Guidelines.
(Published 31 March 2020)