Estimated reading time: 6 minutes
The International Liaison Committee on Resuscitation (ILCOR) is the umbrella organisation for national resuscitation councils and federations around the world (including the American Heart Association. Australian and New Zealand Committee on Resuscitation, the European Resuscitation Council and groups in Canada, India, Asia, and Southern Africa).
Every year they publish a summary of their task force updates that have occurred throughout the year and in this post, I will attempt to summarise these even further (the 99-page document is rather unwieldy for the Emergency Clinician with a short attention span). If you would like to read the whole document this has been simultaneously published (open access) in both Resuscitation and Circulation.
Methodology
This review includes work from six Task Forces (hence the extraordinary number of authors), covering 90 different topics. They include systematic reviews (Sysrev), scoping reviews (ScopREvs) and evidence updates (EvIp) all leading to Cardiovascular Care Science With Treatment Recommendations (CoSTR) publications. ILCOR love an abbrev…
The evidence is graded by expert systematic reviewers and task force members, into high, moderate, low and very low levels of certainty of evidence, all based on a PICO (population, intervention, comparator and outcome) question. It will surprise none of you to learn that many of the recommendations reach only low or very low certainty of evidence. However, sometimes it is important to understand what we don’t know – all too often it seems to me that we present many of our actions during resuscitation as definitive when they are quite the opposite.
Recommendations
It would be impossible to give you all of the details so I have picked out some of the highlights. We will do a future post summarising the recommendations for paediatric resuscitation.
1, ECPR in Cardiac Arrest
Recommendation
We suggest that ECPR may be considered as a rescue therapy for selected patients with OHCA when conventional CPR is failing to restore spontaneous circulation in settings in which this can be implemented (weak recommendation, low-certainty evidence)
ILCOR. 2023
This is a topic we have covered at St Emlyn’s before, not least in our recent podcast with Andy Curry and I am pleased to say that ILCOR come to many of the same conclusions he has.
A systematic review looked at three new RCTs since its last guidance, the ARREST trial, the EROCA trial and the INCEPTION trial. They rated the overall level of evidence as low, because of “inconsistency and imprecision and was considered very low for in-hospital cardiac arrest (IHCA) because there were no trials for IHCA”. Thus their recommendation is graded as ‘weak’
Being in refractory cardiac arrest is bad. Like really bad. So any potential treatment is potentially beneficial, hence why there is this curious situation where there is little evidence of benefit, yet we are still using it occasionally, particularly in enthusiastic and specialist centres. ILCOR recognises large knowledge gaps
- Few, and no large, randomized trials of ECPR compared with standard care
- The optimal patient population who may benefit from ECPR
- Whether subgroups of patients such as those with cardiac arrest related to pregnancy or pulmonary embolism benefit from ECPR
- The optimal time to initiate ECPR in cases of refractory cardiac arrest
- Whether ECPR should be initiated in the prehospital or in-hospital setting
- The optimal techniques for providing safe and timely ECPR
- The optimal techniques for providing safe and timely ECPR
The final statement perhaps sums the situation up perfectly – “We acknowledge that ECPR is a complex intervention that requires considerable resources and training that are not universally available but also acknowledge the value of an intervention that may be successful in individuals for whom usual CPR techniques have failed”.
2, Double Sequence Defibrillation
Recommendation –
We suggest that a DSED strategy (weak recommendation, low-certainty evidence) or a VC defibrillation strategy (weak recommendation, very low–certainty evidence) may be considered for adults with cardiac arrest who re-main in VF or pulseless ventricular tachycardia after ≥3 consecutive shocks
ILCOR. 2023
There has been one RCT since the last guideline, which we have reviewed previously at St Emlyn’s – The DOSE-VF trial. For more details please see our blog posts, but in essence, this trial looked at different defibrillation strategies for patients in refractory (already had more than three shocks) ventricular fibrillation. This included a vector change – changing the pad position, and the use of two defibrillators to deliver two shocks in quick succession.
Although the trial showed some benefit, just what is ‘refractory VF’ isn’t always easy to decide. Is it patients who never get out of VF, or does it include those with rhythm changes who go back into VF. There is a hint of ‘see-through CPR’ algorithms that may help with this decision making in the future. There is also a concern that this may damage defibrillators and perhaps even void the warranty, so think hard (and check with manufacturers) before you start = considering adopting this.
3, Calcium in Cardiac Arrest
Recommendation –
We recommend against routine administration of calcium for the treatment of OHCA in adults (strong recommendation, moderate-certainty evidence)
ILCOR. 2023
It may come as a surprise to you that this was even considered (what’s next – procainamide?), but apparently, it continues to be given ‘frequently’. This is outside its recognised use in hyperkalemia, wide QRS interval on ECG, hypocalcemia, hypermagnesemia, calcium channel blocker overdose, or haemorrhage (although all these are listed as ‘knowledge gaps’).
This review was prompted by the publication of a trial in JAMA in 2021, looking at the use of calcium in out-of-hospital cardiac arrest. Two other trials were included in the review (both from the 1980s).
Let’s waste no more time on this – don’t give calcium in undifferentiated cardiac arrest. There. Said it.
4, Drowning
There were clearly some interested experts on the ILCOR task force when it came to drowning, where they looked at seven different questions. I must admit that as a prehospital physician, many of these simply made sense, but the guideline is also looking to help non-specialists in the management of these patients..
Recommendations
- On boat CPR – do it if you are trained and it is safe to do so
- In water resuscitation – ventilations only may be delivered if rescuers are trained in this technique
- You should start CPR until an AED is available.
- Ventilation equipment – mouth to mouth, mouth to nose or pocket-mask ventilation should be used by bystanders
- Ventilation equipment – bag-valve-mask ventilation can be used by lifeguards or others trained in BLS, who have a duty to respond.
- Recommendations for CPR in drowned patient who have been removed from teh water are the same as for all patients in cardiac arrest
All of the recommendations center on effective resuscitation, focusing on treating hypoxemia, the leading cause of cardiac arrest in drowning. There is also detail for those organisations most likely to encounter these situations, suggesting they take into account local conditions, types of vessels, availability of equipment and training and the number of available rescuers.
4, Prediction of outcome following cardiac arrest
This is a topic that vexes those of us involved in resuscitation on an almost daily basis and I know I would love there to be more objective measures that could be used. This document considers a range of options, many of which are much more likely to take place in a critical care/intensive care environment.
Recommendations
We suggest…
- A Glasgow Coma Score of >3 in the first four days after cardiac arrest may indicate an increased likelihood of survival (weak recommendation, very low-certainty evidence)
- We suggest using the ‘absence of diffusion restriction’ on MRI between 72 hours and 7 days after ROSC, in combination with other tests for predicting good neurological outcome of adults who are comatose (weak recommendation, very low-certainty evidence)
- We suggest using normal neuron specific enolase (<17 μg/L) within 72 hours after ROSC, in combination with other tests, for predicting favorable neurological outcome in adults who are comatose after cardiac arrest (weak recommendation, very low–certainty evidence).
- We suggest using a continuous or nearly continuous normal-voltage EEG background without periodic discharges or seizures within 72 hours from ROSC in combination with other indices to predict good outcome in patients who are comatose after cardiac arrest (weak recommendation, very low–certainty evidence).
We suggest against…
ILCOR 2023
- We suggest against using gray-white matter ratio (GWR), quantitative regional abnormality, and Alberta Stroke Program Early CT Score on brain CT to predict good neurological outcome in patients who are comatose after cardiac arrest (weak recommendation, very low–certainty evidence).
- We suggest against using apparent diffusion coefficient on brain MRI to predict good neurological outcome in patients who are comatose after cardiac arrest (weak recommendation, very low–certainty evidence)
- We suggest against using gradient-recalled echo on brain MRI to predict good neurological outcome in patients who are comatose after cardiac arrest (weak recommendation, very low–certainty evidence).
- We suggest against using serum levels of glial fibrillary acidic protein, serum tau protein, or NfL in clinical practice for predicting favorable neurological outcome in adults who are comatose after cardiac arrest (weak recommendation, very low–certainty evidence)
- We suggest using a continuous or nearly continuous normal-voltage EEG background without periodic discharges or seizures within 72 hours from ROSC in combination with other indices to predict good outcome in patients who are comatose after cardiac arrest (weak recommendation, very low–certainty evidence).
- There is insufficient evidence to recommend for or against using a low-voltage or a discontinuous EEG background on days 0 to 5 from ROSC to predict good neurological outcome after cardiac arrest (weak recommendation, very low–-certainty evidence)
- We suggest against using heterogeneous, non–ACNS-defined favorable EEG patterns to predict good neurological outcome after cardiac arrest (weak recommendation, very low–certainty evidence).
- We suggest against the use of other EEG metrics, including reduced montage or amplitude-integrated EEG, BIS, or EEG-derived indices, to predict good out-come in patients who are comatose after cardiac arrest (weak recommendation, very low–certainty evidence)
You will notice, disappointingly, the favourite statement weak recommendation, very low–certainty evidence, for all of these suggestions (whether for or against).
Neuron-specific enolase seems to be the only novel, potentially useful biomarker for prognostication.
Summary
There is lots more to read in this consensus document, not least the ‘evidence updates’ (which are a helpful reminder if not practice changing).
Life support continues to be a relatively evidence light area and my one take home is that continuing to do the basics well is vital – there isn’t a a new revolutionary treatment on the way any time soon. At St Emlyn’s we’ll continue to try to keep you up to date with all the new evidence as it comes out.
