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Hi Everyone! In light of the ongoing COVID-19 pandemic and with the ERC 2020 Virtual Congress fast approaching, we thought that this was the perfect time to provide some virtual education to our Young ERC followers!
In the run up to the ERC Congress we are going to post a thread once a week on #ResusciTuesdays which explores a key topic in cardiac arrest and the evidence surrounding it. We will initially focus on the chain of survival in out of hospital cardiac arrest.
This week in #ResusciTuesdays we are looking at recognition of OHCA. Many think it is; head-tilt chin-lift, look, listen and feel for breath, and feel for pulse. BUT is a pulse check reliable? Can a non-HCP be expected to identify agonal breathing? Let’s Explore!
A physical examination to identify cardiac arrest should be considered the same way as any other diagnostic test we perform, we need to know the sensitivity and specificity. In OHCA it is vital that we maximise our sensitivity, as if cardiac arrests are missed then CPR is delayed
Although CPR carries some risks due to the physical injuries caused to the patient, some decrease in specificity is acceptable if it allows us to minimise the number of arrests we miss.
Current ERC BLS guidelines recommend a head-tilt chin-lift and then look, listen and feel for breathing for 10 seconds. Why no pulse check I hear you ask? Well this paper https://www.resuscitationjournal.com/article/S0300-9572(96)01016-7/fulltext showed only 2% were able to confidently identify pulselessness within 10 seconds.
Increasingly training programmes have discussed the identification of ‘normal breathing’ to increase the sensitivity of the look, listen, and feel process by trying to ensure patients in cardiac arrest with agonal breathing are recognised.
A project was run by the Resus Council UK to produce an effective animation which helps with the recognition of cardiac arrest. These videos can help learners understand agonal breathing and are a great adjunct for those delivering BLS courses. https://www.resus.org.uk/research/research-funded-by-rc-uk/recognising-cardiac-arrest-animation-project/
Another chance to recognise a cardiac arrest is during the call to the emergency services and it has been shown that identifying cardiac arrest at this stage improves outcomes! https://www.resuscitationjournal.com/article/S0300-9572(17)30157-0/abstract
Typically, the dispatcher will prompt the caller with the questions ‘is the patient breathing?’ and ‘is the patient responding?’. If the answer to both is no, the caller will be prompted to begin CPR (and may be talked through the process, as we will explore next week!).
But what do you do if the caller says that they are not sure if they are breathing? Do you encourage them to start CPR to maximise that all important sensitivity? Is there a role for more senior clinicians to be involved in the identification of these patients during the call?
A recent ILCOR investigation showed that there is significant heterogeneity in current practice and in the way that diagnostic capability is tracked. Therefore they were unable to draw any significant conclusions. https://costr.ilcor.org/document/dispatch-diagnosis-of-cardiac-arrest-systematic-review
One group investigated the use of machine learning in dispatch. A system which involved analysis of the wording used and the sounds in the background increased OHCA identification but also gave more false alarms. Once again increasing sensitivity at the expensive of specificity!
While there may not be definitive answers – this work paves the way for further exciting research which may allow us to improve OHCA outcomes in the future!
So that’s the end of the first #ResusciTuesdays – feel free to comment or share to open the dialogue about recognition of cardiac arrest! Next week we will be talking about bystander CPR. Feel free to share below resources which may be a good addition to that discussion! Thanks!
