Seattle, Washington is primarily known for three things: being the hometown of Starbucks coffee; being the birthplace of grunge; and having an impressive rate of survival from out-of-hospital cardiac arrest (OHCA). It was therefore appropriate that the Cardiac Arrest Survival Summit took place in downtown Seattle at the Hyatt Regency Hotel between 9–13th December 2019. Delegates representing 21 countries from around the world converged on the Pacific Northwest to hear from internationally recognised clinicians, leaders and patients who sought to inform and motivate delegates to improve survival from sudden cardiac arrest in their own community. This conference review seeks to disseminate key messages from the Cardiac Arrest Survival Summit to a wider audience and is supplemented by the author's own experience of meeting the leadership team at King County Medic One and undertaking clinical observation shifts with an ambulance crew in South Seattle.
History of King County Medic One
Survival from OHCA is measured using internationally agreed criteria, referred to as the Utstein Reference Standard (Cummins et al, 1991), and such a standardised reporting system allows comparisons between systems. In 2018–19, the London Ambulance Service reported survival to hospital discharge rates for patients with an initial presenting rhythm of ventricular fibrillation or ventricular tachycardia (VF/VT) of 36.6% (London Ambulance Service, 2019) and while this is above the national average for England, it is below the 56% figure reported by King County Seattle (Seattle and King County Emergency Medical Services (EMS), 2019). While this article seeks, in part, to shed some light on how Seattle has achieved such impressive rates of survival from OHCA, it is also worth considering the contextual background.
Throughout the 1960s, increased attention was focused on what would now be referred to as ‘resuscitation science’. It was during this period that Bernard Lown and colleagues at Harvard Medical School first applied the principles of electrophysiology to aberrant cardiac arrhythmias, which led to the development of the first defibrillators (Rapport, 2019) (Figure 1). Around the same time, James Jude, William Kouwenhoven and Guy Knickerbocker came to the conclusion (while undertaking electrophysiology research and applying defibrillation paddles to dogs) that when force was applied across the chest wall, this could produce waveforms on an electrocardiogram (ECG) (Kouwenhoven et al, 1960) (Figure 2). Their description of closed chest compressions coupled with the research undertaken by Dr Lown et al (1962), now form the foundation for what has come to be referred to as Basic Life Support (Figure 2). While resuscitation medicine has undoubtedly advanced considerably, the concepts of chest compressions and early defibrillation are the cornerstone of good resuscitation practice.
This was understood by Dr Frank Pantridge, a consultant cardiologist at the Royal Victoria Hospital in Belfast, who sought to take coronary care to the streets of Northern Ireland and developed a primitive EMS in which over 300 people were treated for cardiac emergencies (Pantridge and Geddes, 1967). Alongside his colleague, John Geddes, the data collected from this initial foray into prehospital care for communities at risk of sudden cardiac arrest were published in the Lancet (Pantridge and Geddes, 1967) and, on the other side of the world in the Pacific Northwest, a United States cardiology resident, Dr Leonard Cobb, was following the results carefully.
Dr Cobb had come to two conclusions. First, that many lives could be saved if patients had access to early defibrillation and good quality basic life support, and, perhaps more controversially, that it might be possible to train firefighters with only a high school diploma to undertake the kind of medical interventions that were previously firmly within the domain of the medical profession. Like many good ideas challenging the accepted wisdom of the time, there was resistance, both from the City of Seattle, who expressed concerns regarding the funding of the system, and from firefighter unions and the medical profession itself.
However, Dr Cobb was an astute operator and recruited Seattle Fire Chief Gordon Vickery and the formidable Dr Michael Copass. Less than a decade after external cardiac massage was described by Kouwenhoven et al (1960), the King County Medic One programme hit the streets of Seattle with 10 highly trained Seattle firefighters responding to cardiac emergencies. While this might not seem particularly innovative in the context of 21st century prehospital care, the idea of individuals with only high school diplomas performing advanced life support without direct medical supervision challenged the paradigm of emergency care and demonstrated the need for innovation (Rapport, 2019).
This approach and willingness to develop novel strategies continued, and, in 1971, funding was acquired to train members of the public to perform CPR. In 1973, 18 000 Seattleites were trained in CPR and over the next two years a further 100 000 people within the Greater Seattle area were trained (Young, 1973). It was these early leaders with a clear vision for how prehospital care might improve survival from OHCA who laid the foundations for the success story of Seattle's cardiac arrest survival rates. However, good systems are more than the sum of their parts and it is testament to the leadership of Leonard Cobb, Gordon Vickery and Michael Copass that their vision has continued (Baskett and Baskett, 2007). The baton has been firmly passed to Drs Mickey Eisenberg, Tom Rea, Peter Kudenchuk and Michael Sayre, and, while the King County Medic One programme has evolved, the founding principles remain as relevant today as they did in 1968.
Those early concepts of public engagement, access to early defibrillation, robust data collection processes and a culture which fosters excellence and strives for continual quality improvement through transparency, accountability and ongoing learning processes have meant that Seattle's King County Medic One Programme continues to be the benchmark by which other systems are measured. It was therefore appropriate that the Cardiac Arrest Survival Summit was opened by Dr Mickey Eisenberg.
Public engagement
Dr Eisenberg's keynote speech provided an overview of the EMS system in Seattle and discussed some of the factors that had led to such impressive rates of survival from OHCA. Dr Eisenberg referred to what he termed the ‘slope of death’ and discussed the importance of front-loading cardiac arrest care to ensure that the downward trajectory of this slope could be delayed by early identification of cardiac arrest, early initiation of bystander CPR and, crucially, early defibrillation through the use of publicly accessible defibrillators (Eisenberg, 2013). Data suggest that 80% of King County Seattle are trained in basic life support (many received training during high school) and this has led to high rates of bystander CPR, currently at 67% (Seattle and King County EMS, 2019). Furthermore, Seattle has one of the highest concentrations of publicly accessible automated external defibrillators (AEDs) anywhere in the world with 13 AEDs/km² (Comparison data for Seattle/London is given in Table 1) (London Ambulance Service, 2019) and all police and fire service vehicles carry AEDs and are trained in high-performance CPR (HP-CPR) (Figure 3). But, of course, more can still be done and by adopting the mantra that ‘everyone in VF/VT survives,’ such deaths from OHCA are viewed as preventable deaths, which drives a process of continual quality improvement. Seattle are currently debating whether to make basic life support training mandatory in order to obtain a Washington state driving license. Initiatives such as this in Denmark have led to a dramatic increase in the number of people trained in CPR/AED use (Wissenberg et al, 2013).
| Seattle | London | |
|---|---|---|
| High % of residents trained in CPR. There is a focus on re-certifying CPR training which may improve the quality of bystander CPR | 75% CPR trained, including re-certification | Unknown CPR training rate - will improve on curriculum |
| High levels of bystander CPR | 70% | 65% |
| High-quality CPR guidance to the bystander from call taker | CPR coaching routinely reviewed | CPR coaching not routinely reviewed |
| Quick time from 911 pick up to start of compressions | 2 mins 58 secs | 4 mins 22 secs |
| High defibrillator availability | c. 3200 (13 per km2) | c. 5300 (3 per km2) |
| Quick face to face initial response, including from EMTs, firefighters or clinically trained volunteer responders | 5.2 mins average | 10 mins average |
| High-quality learning from experience | Every arrest reviewed with EMT | Most arrest reviewed with CTM or APP |
| Effectiveness of chest compression measured through defibrillator data download | c. 100% defib downloads | c. 20% (March ‘19) |
Similarly, dispatcher-assisted or telecommunicator-CPR (T-CPR) is viewed as a key component of the system and, while many EMS systems around the world use T-CPR, the role of dispatchers is often incorrectly viewed as secondary to their clinical counterparts (Rea et al, 2001). Within King County, all dispatchers receive significant and ongoing training in T-CPR and every 911 call for cardiac arrest (including those that were not identified) is reviewed, allowing call takers to listen back, review and discuss what could have been improved (Eisenberg, 2017). This is not punitive, but part of an ongoing process of quality improvement in which all levels of the organisation are encouraged to engage, participate in and share in the success of the organisation. A key feature of high performing systems is the ability to adapt to a changing landscape. With advances in smartphone technology, King County are now investigating how the use of video calls can be used to enhance the identification of cardiac arrest and encourage the initiation of bystander CPR/AED use to lower the trajectory of the slope of death.
Two-tiered system
During my time in Seattle, I had the opportunity to meet with the Assistant Director of Operations at King County Medic One and undertake a 24-hour ‘ride along’ with a medic unit from South Seattle. During both of these encounters, I asked what the single biggest contributory factor to survival in Seattle had been. While almost everyone I spoke to repeated the mantra that ‘it takes a system to save a life’ and there is no single cause, many alluded to the nature of their two-tiered system. In this system, emergency medical technicians (EMTs) respond to lower acuity 911 calls and provide treatment for the majority of patients who present to the ambulance service. While not as skilled as paramedics in terms of scope of practice, these EMTs respond regularly to 911 calls, are able to obtain a patient history, and initiate treatment, including the administration of drugs such as adrenaline, glucagon and naloxone. Due to the exposure these EMTs get, they are skilled at determining when further support is required and, when these situations arise, a medic unit is dispatched (Seattle and King County EMS, 2019).
Paramedics in King County Seattle respond only to the most serious 911 calls and for a population of 750 000 in the city of Seattle, there are only six medic units staffed by paramedics. The proportion of acutely unwell patients seen by individual paramedics is therefore higher and this provides them with significantly more clinical experience of managing acutely unwell patients than paramedics in the UK. Their scope of practice is broadened and is comparable to UK critical care practitioners. In addition to drugs commonly seen in the Joint Royal Colleges Ambulance Liaison Committee (JRCALC) guideline (Association of Ambulance Chief Executives (AACE), 2019), their formulary of drugs also includes adenosine, calcium chloride, diltiazem, magnesium sulphate, metoprolol, and norepinephrine, alongside drugs used to autonomously initiate prehospital emergency anaesthesia, including etomidate, suxemethonium and midazolam (Seattle and King County EMS, 2017). It would seem that while the number of 911 calls attended by the paramedics of King County Medic One are somewhat reduced in comparison to the UK system, they are targeted to where they are most likely to add value. This enables them to both impact significantly upon patient care and ensure that their own clinical practice and the skills within their armoury are slick and regularly practised.
High-performance cardiopulmonary resuscitation
On the first day of the conference, delegates had the opportunity to attend a workshop on HP-CPR, led by the Resuscitation Academy. Having attended numerous Basic Life Support courses, both as a learner and as an instructor, I was somewhat sceptical as to how I might benefit from this session. The key takeaway message for me, however, was that while most systems will claim to be advocating good quality basic life support, the reality is that this critical step in the chain of survival is often performed suboptimally (Abella et al, 2005; Zapletal et al, 2014; Soar et al, 2015).
The International Liaison Committee on Resuscitation (ILCOR) follows all international guidelines and advise that chest compressions should be undertaken in the centre of the patient's chest, at a rate of 100–120 compressions/minute, with adequate depth, full chest wall recoil and minimal interruptions in compressions, thus ensuring a high frequency of chest compression fraction (Soar et al, 2015). ILCOR also emphasises the importance of controlled ventilations of 350–500 mls, interventions such as airway management and vascular access being undertaken with no interruptions in chest compressions, and the rescuer performing chest compressions alternating every 2 minutes (Soar et al, 2015). While none of these skills individually are particularly challenging with robust educational programmes, research demonstrates that each of the components outlined above are often performed suboptimally (Zapletal et al, 2014). This is reflected in the first of the Resuscitation Academy mantras; ‘It's not complicated, but it's not easy’ (Resuscitation Academy, 2020). To optimally engage in HP-CPR, the use of CPR feedback devices and a metronome is mandated in all cases to reduce cognitive load and ensure optimal performance by every rescuer.
None of the factors in HP-CPR should come as a surprise, even to student paramedics at the very start of their career. But can we really say that our systems are performing these essential skills optimally and we have fully adopted HP-CPR? The reality for many of us is that we simply don't have the data to provide a sufficient answer and thus, ‘Measure, Improve’ is another of the key mantras espoused by the Resuscitation Academy. But what does this mean in practice?
To quantitatively measure the quality of care provided to patients in cardiac arrest, all monitors/defibrillators are set to record audio at the scene of a cardiac arrest and these audio recordings are matched to electronic patient records and their ECGs. Therefore, a complete picture of patient management can be formulated. The medical director at King County Medic One reviews the management of every single cardiac arrest and provides feedback and advice to the attending clinicians regarding their clinical performance. This is not punitive, and the leadership team were keen to acknowledge that, of course, the management of cardiac arrest can be challenging, and mistakes do occur. However, this feedback was welcomed by all of the clinicians that I met and therefore, an open and transparent culture is fostered. This is summarised in 2 of the 10 steps that advocate systems that ‘work towards accountability’ and ‘work towards a culture of excellence.’
On the final day of the conference, several crews from King County Medic One were unexpectedly stood down and asked to undertake HP-CPR on a QCPR mannequin on stage in front of an audience of over 1000 delegates. The simulation was not faultless, but all metrics measured by the QCPR mannequin were in excess of 90% and this was not merely ‘good quality CPR,’ this was ‘HP-CPR’ and was one of the highlights of the conference.
Ambulance clinicians must now shine a spotlight upon our own clinical practice and ask ourselves if we would welcome the addition of CPR feedback devices, metronomes, audio/CCTV recording, reviews and feedback on every cardiac arrest case we attend? If the question makes you somewhat uncomfortable, as it does me, your service is likely not engaged in HP-CPR.
High-frequency, low-dose CPR and advanced airway interventions
While HP-CPR is the cornerstone of basic life support, multiple studies have demonstrated that skill retention deteriorates significantly over time (Mancini and Kaye, 1985; Kaye and Mancini, 1986; Hamilton, 2005; Madden 2006; Semeraro et al, 2006). Several studies, however, have now demonstrated that HP-CPR training that adopts a ‘little and often’ approach results in a higher degree of skill retention (Oermann et al, 2011; Sutton et al, 2011), and this has become known as high-frequency, low-dose CPR. Indeed, a 2020 study (Panchal et al, 2020) demonstrated retention of simulated CPR skills during each quarter exceeding high quality guideline thresholds. There is a paucity of data relating to the frequency with which UK paramedics receive basic life support refresher training, but anecdotal evidence suggests operational demands inhibit protected refresher training in this critical skill. Nevertheless, Panchal et al (2020) report programme compliance of 97%, suggesting that it is possible to adopt high-frequency, low-dose CPR training while meeting ongoing clinical demand. As clinical medicine increasingly adopts an evidence-informed approach to the development of clinical guidelines, perhaps it is time for UK higher education institutions and ambulance services to adopt an evidence-informed approach to the teaching of HP-CPR?
While the two-tiered system advocated by King County Seattle places an emphasis on HP-CPR, for those patients who fail to respond to initial basic life support and defibrillation, advanced life support is initiated. This typically involves advanced airway management and, although controversy has existed for many years, in the UK, endotracheal intubation has historically been seen as the gold standard intervention. However, several studies have demonstrated an unacceptably high incidence of oesophageal intubation (Strote et al, 2009) and although endotracheal intubation still sits within the UK's paramedics scope of practice (JRCALC, 2019), several ambulance services have now withdrawn this skill from clinical practice. The reasons for this are complex and multifactorial, but are due to studies suggesting a high incidence of oesophageal intubation, local reporting of serious and adverse incidents and recent studies suggesting that cardiac arrest outcomes using new generation supraglottic airway devices are comparable to endotracheal intubation (Benger et al, 2018).
Once again, a wealth of evidence suggests that to maintain competence, regular training and exposure to this skill is necessary (Deakin et al, 2010). A 1998 study suggests that 57 intubations were required in order to achieve a first pass success rate of 90% (Konrad et al, 1998). Comparatively, most UK paramedics working outside of a helicopter emergency medical services/critical care environment, typically encounter less than five cardiac arrests each year and it is clear that opportunities for exposure to this skill are limited (Benger et al, 2018).
The King County Medic One paramedics that I encountered during my observational shifts in Seattle discussed the need for ongoing continuous professional development and stated that they are required to perform a minimum of 12 intubations per year to maintain competence, although many clinicians far exceed this requirement. While many UK ambulance services have now withdrawn endotracheal intubation from local guidelines, it would seem that the debate surrounding this skill will continue. UK ambulance services must learn that while an evidence-informed approach is increasingly being adopted to shape clinical guidelines, the same scientific and robust approach should be used to develop and shape educational policies.
The importance of incremental change
At 56%, King County Seattle has one of the highest survival rates from OHCA in the world (Seattle and King County EMS, 2019). In attending the Cardiac Arrest Survival Summit and meeting both the leadership team and clinicians at King County Medic One, I had hoped to find the secret ingredient in their recipe for success. The reality is that almost everyone I encountered was either unable to identify the single most significant factor to the impressive survival rates or repeated the mantra that ‘it takes a system to save a victim.’ It became apparent that perhaps the key to improving survival was ‘the aggregation of marginal gains.’ This phrase was coined by Dave Brailsford who had been appointed Performance Director of British Cycling in 2003, and whose philosophy was based around the concept that a 1% improvement in performance in multiple areas, could result in significant overall performance. This philosophy has been adopted by King County Medic One, and the service has adopted a holistic approach to improving all aspects of prehospital cardiac arrest care.
Cardiac arrest remains a serious medical emergency, however, data from Seattle, and a growing number of cities throughout the world (Wissenberg et al, 2013; London Ambulance Service, 2019), have demonstrated that management is not futile and many more individuals are surviving with good neurological outcomes. However, there is significant geographic variation in survival rates and this degree of disparity is inequitable. While survival from OHCA in the UK is improving, there is much that can be learned from the Pacific Northwest and, if we are willing to shine a spotlight upon all areas of our practice, there are likely to be many more opportunities for marginal gains. As Mickey Eisenberg would say, ‘It's not complicated, but it's not easy’—will the UK accept the challenge?