Each year in the UK, around 60 000 people suffer an out-of-hospital cardiac arrest (OHCA), with resuscitation attempted by paramedics in less than 50% of cases (London Ambulance Service, 2016; McClelland et al, 2016). Of these resuscitation attempts, only an average of 8–10% of patients survive to hospital discharge (Pell et al, 2003; Perkins and Brace-McDonnell, 2015; Resuscitation Council UK, 2015).
These are alarmingly low rates, even though the average response time for UK ambulance trusts was below 8 minutes in 2015 (London Ambulance Service, 2016). However, the overall survival-to-discharge rates increase when a paramedic OHCA specialist resource is involved in the resuscitation (Clarke et al, 2013; London Ambulance Service, 2016; McClelland et al, 2016). This demonstrates the utmost importance of immediate and skilled intervention for OHCAs.
The current article will identify the evidence base for a dedicated paramedic OHCA resource, and will look at some of the impacts such resources have had on patient outcomes within UK ambulance trusts to date. Trials assessing the efficacy of such a specialist resource have demonstrated positive results, and identified further areas for consideration (Clarke et al, 2013; Perkins and Brace-McDonnell, 2015; London Ambulance Service, 2016; McClelland et al, 2016).
The chain of survival
Survival from OHCA depends on a system of time-critical interventions known as the ‘chain of survival’ (Nolan et al, 2006). Improved outcomes from OHCA have been reported by centres that have optimised these interventions in their area (Sunde et al, 2007). Pre-hospital resuscitation is a vital part of the ‘chain of survival’ and high-quality resuscitation requires both good technical and non-technical skills (Hunziker et al, 2010; Norris and Lockey, 2012). Ambulance services can start delivering all four of the elements within the chain. These include:
It is imperative that each element is managed as effectively and efficiently as possible to ensure the best possible outcomes.
The survival rates from OHCAs in the UK are poor and need improvement. The overall survival rate for OHCAs in other developed countries is generally higher, with 21% in North Holland (Grasner et al, 2011) and 25% in Norway (Lindner et al, 2011)— more than double the rates in the UK. Although these figures are based on data that were collected using varying methods in each country, they highlight the need for improvement in the UK and also demonstrate the possibility of better outcomes of OHCAs. Countries with a high percentage of bystander cardiopulmonary resuscitation (CPR) and defibrillator administration have demonstrated that this is a very effective intervention. However, it is a long intervention process which requires the training of a greater proportion of the population, beginning at school age (Lorem et al, 2008; Lindner et al, 2011). However, improving the technical and non-technical skills of paramedics, and focusing on the management of OHCA, could improve the overall outcome for patients, and within a short time frame (Hunziker et al, 2010; Norris and Lockey, 2012; Bossaert et al, 2015).
Guidelines and policy
The European Resuscitation Guidelines (Bossaert et al, 2015) recommend that ambulance services should evaluate their processes to deliver care that ensures the best possible outcomes. The guidelines also acknowledge that training in non-technical skills (e.g. communication, leadership and role delegation) are as important as technical skills in resuscitation (Norris and Lockey, 2012; Bossaert et al, 2015). In addition, the National Institute for Health and Care Excellence (NICE) (2013) guidelines set the national standards for health management in England and Wales, but these focus more on the importance of CPR and defibrillator use as well as post-resuscitation management. Although the NHS, UK Ambulance Services, the UK government and the wider community have recognised the need to improve the management of OHCAs (British Heart Foundation (BHF), 2017), there is no UK government policy directly targeting this issue.
Assessment of OHCA patient management by England and Welsh ambulance services depends on two national Ambulance Quality Indicators (AQIs):
There are many internal and external factors that influence both AQIs, and some of these vary based on geographical and demographical areas. For instance, a rural ambulance service may struggle to reach a patient in time to attempt resuscitation according to the AQI (7 minutes). Rural community projects, such as community-first responders, and public-access defibrillators may be sufficient to improve this (Weir, 2015).
Evidence base
The evidence base for a specialist paramedic OHCA resource is quite clear. Evidence suggests that the more a small group of clinicians is exposed to OHCA patients, the more effective the advanced skills and resuscitation will be (Dyson et al, 2016; McClelland et al, 2016). In turn, increased paramedic exposure to OHCA resuscitation is associated with increased patient survival (Dyson et al, 2016). Trials within the UK have shown a significant increase in ROSC and hospital-to-discharge rates with the use of varying forms of this concept in practice (Clarke et al, 2014; London Ambulance Service, 2015; 2016; McClelland et al, 2016). Furthermore, the concept has been shown to be feasible, with no negative impact on overall ambulance response times or performance targets (Clarke et al, 2014).
Good teamwork, clear communication and effective leadership are described as vital non-technical skills during resuscitation attempts. Recent studies have shown that good non-technical skills are associated with better overall team performance during simulated OHCA management, specifically demonstrating vast improvements in effective CPR (Hunziker et al, 2010).
OHCA enhanced scope of practice
Currently the scope of practice for paramedics within the UK varies greatly depending on area of practice and specialisation, and this includes those skills relevant to management of OHCA and ROSC. Paramedics who are preferentially tasked to OHCAs have enhanced skills relevant to those patients to promote best outcomes (McClelland et al, 2016; Hammell, 2017).
The author acknowledges that across the UK there are varied adaptations to the core principle of targeting OHCA patients with a specialist resource. These adaptations bring a wide array of extra skills and equipment, some of these extended skills include but are not limited to:
To gain a better understanding of the variations seen, the author has randomly picked three ‘Paramedic OHCA Specialist Resource’ concepts to show the variations that can currently be seen across the UK with regards to deployment, skills, training and to compare patient outcomes. These concepts will be analysed and their impact on patient outcomes identified.
Concept in practice
Scottish Ambulance Service
The Scottish Ambulance Service (SAS) have a paramedic dedicated OHCA resource called 3RU primarily based in Edinburgh. The paramedics who staff this resource have undergone additional training in OHCA leadership and use of a mechanical CPR device, both with no additional cost to the trust, as well as undergoing fortnightly debriefs and simulation training (Hammell, 2017).
The impact this resource had on patient outcome was obtained using a Freedom of Information request (FOI). The survival to hospital discharge rates were not recorded by the SAS for any OHCA patients they attend, so this outcome is unfortunately not available. However, they could provide their ROSC rates.
Table 1 shows the positive impact that the 3RU resource had on OHCA patient ROSC rates. Between 2013 and 2017 patients were up to 11% more likely to obtain a ROSC if the dedicated OHCA resource was present at the resuscitation attempt (Hammell, 2017).
| 2013–14 | 2014–15 | 2015–16 | 2016–17 | |
|---|---|---|---|---|
| Number attempted resuscitation | 3030 | 3272 | 3140 | 3454 |
| Number ROSC |
512 |
659 |
664 |
735 |
| Number 3RU in attendance | 63 | 104 | 133 | 139 |
| Number ROSC 3RU |
18 |
31 |
37 |
43 |
North East Ambulance Service
The North East Ambulance Service (NEAS) has a similar dedicated OHCA resource called Cardiac Arrest Response Unit (CARU). NEAS deployed its CARU unit to any Red 1 (immediately life-threatening requiring a blue-light response) call, which appears to be an OHCA within a 19-minute radius of its current location. A 19-minute radius was selected based on the resource responding as a secondary response, able to get to the scene before the initial responders either left the scene with the patient or stopped resuscitative attempts. The 19-minute radius also covered most of the densely populated local urban area (McClelland et al, 2016).
Selected paramedics each had experience working within pre-hospital care of over 10 years, and were put through a specialist pre-hospital emergency resuscitation course and the pre-hospital anaesthetics (PHA) course run by the Great North Air Ambulance Service (GNAAS). In addition to these external courses, CARU team members make a commitment to ongoing training and practice (McClelland et al, 2016). In terms of extended scope of practice, CARU paramedics have been trained to use external cardiac pacing and to cardiovert patients, primarily for stabilising post-ROSC patients. CARU also uses adrenaline as an inotrope for post-ROSC cardiovascular support, and has training in the use of pre-hospital ultrasound, emergency surgical airway, and mechanical CPR equipment.
NEAS was unable to provide a yearly breakdown for CARU ROSC and survival rates in an FOI request. However, Table 2 shows how in 2014/15 OHCA patients had an 11% increase in ROSC and the rate of survival to discharge was almost double if the CARU resource was present at the resuscitation (McClelland et al, 2016).
| CARU (10 Jan 2014–9 Jan 2015) | NEAS (Study period, CARU data removed) | |
|---|---|---|
| Total OHCA | 164 | 4000 |
| Resuscitation attempts |
127 |
1536 |
| ROSC on arrival at hospital |
46 |
378 |
| Survival to discharge |
13 |
80 |
London Ambulance Service
London Ambulance Service assigns advanced paramedic practitioners (APPs) to OHCAs as a specialist resource to manage resuscitation efforts and provide enhanced care to patients. APPs are dispatched either automatically or following triage by an APP within their control room (London Ambulance Service, 2016). Training for APPs consists of a 3-day selection and assessment centre followed by 3 months of internal and university-based external education and mentoring by peers and members of the London Ambulance Service Medical Directorate (personal communication). London Ambulance Service APPs have an enhanced skill set for OHCA and these can be seen in Table 3.
| Drugs | Interventions | Skills | Equipment |
|---|---|---|---|
| Magnesium sulphate |
Advanced thoracocentesis |
Thoracostomy |
Mechanical Ventilator + CPAP |
In 2015/16, in contrast to the rest of the ambulance service, when an APP was present at an OHCA, patient ROSC-to-hospital rate increased by 4.3% to 34.2%, and survival-to-discharge rate increased by 2.3% to 11.3% (personal communication).
Discussion
The data illustrate marked improvements in patient outcomes of OHCAs when a specialist OHCA paramedic resource is present. However, the particular aspects of these enhanced interventions that led to these improvements have not yet been identified. There is a strong movement towards the importance of non-technical skills in OHCA (Bossaert et al, 2015). Although all of the resources described in the current article offer enhanced non-technical skills at OHCA resuscitations, they have all offered an extended skill set to other paramedics within their ambulance service. To identify what aspects of these resources are directly attributed to the increase in outcomes would require these established resources to withhold some aspects of their care package; for example, not using a surgical airway option or pre-hospital ultrasound. However, there is room for future resources in other ambulance services to use a step-wise approach to identify, for example, if a dedicated resource with only enhanced non-technical skills would still improve patient outcomes. If not, it may identify what part of the enhanced skill set, or combination thereof, is accountable.
It is important to highlight that these resources are not necessarily envisaged to be the initial ambulance resource on scene. They make up a specialist resource bringing expertise to the patient. Initial crews on scene may have already gained an ROSC prior to the resource arriving and, therefore, it is a good reminder to all that ROSC is not the be all and end all. Patients being discharged from hospital with good neurological outcomes should be the final goal. Post-cardiac arrest care has significant potential to reduce early mortality caused by post-cardiac arrest syndrome—haemodynamic instability, morbidity and mortality from multi-organ failure, and brain injury (Neumar et al, 2008)—and this is an area on which these specialist resources could focus, further strengthening survival rates.
Limitations
There are limitations to this concept however. All examples discussed in the current article are based within an urban setting; it is not clear if this concept would be feasible within a rural environment. The main challenges posed by a rural environment are excessive travelling times, and potential delays in early defibrillation, as well as the detrimental effect of this on patient outcomes (Chan et al, 2008; Sund et al, 2012; Drenman et al, 2014; 2016).
In addition, the author suggests that with continued pressure on UK ambulance services to meet the demands of winter pressures and increased call volumes (Quaile, 2015; Chaffin and Plimmer, 2017), dedicating a specific resource to OHCAs may not be a cost-effective option. Consequently, like the London Ambulance Service, the OHCA role could form part of the responsibilities of existing teams within UK ambulance services, such as specialist or advanced paramedics, hazardous area response team (HART) paramedics or operational officers.
In 2010, London Ambulance Service removed ETI as a core skill from their paramedics. This is not standard across ambulance services within the UK, and London Ambulance Service is in the minority (London Ambulance Service, 2010). As London Ambulance Service APPs have ETI as one of their extended skills in line with the majority of UK Ambulance services, this should be considered when interpreting their improved patient outcomes.
The assignment of APPs to OHCA in London Ambulance Service is documented as either being done automatically or by an APP within their control room who ensures APPs ‘attend those who are most likely to benefit from advanced skills’ (London Ambulance Service, 2016). Arguably this phrase could suggest that APPs are preferentially dispatched to OHCAs that have an increased likelihood of survival, internationally known as the Utstein Group (Mashiko et al, 2002), and therefore would benefit from the presence of an APP over another. Some reasons for this may include:
In 2016/17 when an APP attended an OHCA, the rate of ventricular fibrillation (VF)/ventricular tachycardia (VT) was 30.2%—which is 8.2% higher than the percentage reported for all resuscitation attempted patients (London Ambulance Service, 2016). This targeted allocation, although evidenced-based, does introduce bias into the statistics. If ‘group A’ patients are more likely to survive an OHCA than ‘group B’ patients, and APPs are sent to group A patients, their statistics are going to look better than if APPs were sent to group B patients who were less likely to survive.
It should be noted that during the study period with NEAS, two pre-hospital emergency medicine (PHEM) doctors worked with CARU providing 1 day (on average) of cover per week. They attended 11 OHCAs where resuscitation was attempted. ROSC was achieved in 64% of cases (n=7) and sustained to hospital in 27% (n=3) of cases, with 18% (n=2) survival to discharge. Additionally, CARU was largely covered during office hours, and not covered outside the hours of 07:00 to 20:00 at all. These findings must therefore consider that CARU was only available for one-third of the day (McClelland et al, 2016).
With regards to the SAS 3RU resource, the author of the current paper was informed by the service that there was no way of identifying 3RU on the system, and that the patient outcome results listed are solely based on ‘3RU’ being noted in the free text of incidents. The SAS does not obtain the patient outcomes from hospitals for its OHCA patients so survival rates are not available.
Conclusion
OHCA patient survival rates in the UK are poor and strategies need to be established to strengthen the ‘chain of survival’ and patient outcomes. Ambulance services within the UK are in a privileged and vital position where they can have a positive effect on all aspects of the ‘chain of survival’. One concept that has been shown to be effective in improving OHCA patient outcomes in UK ambulance services is that of a dedicated OHCA paramedic resource. It is still unclear what aspects of this resource are accountable for the improved outcomes. Further pre-hospital research in this area could potentially answer this question.
What is clear is that this concept has been shown to not negatively affect internal ambulance targets, and has been shown to be feasible within existing budgets. The concept has been demonstrated to directly improve patient survival from OHCA, and has been successfully implemented within UK ambulance services in different forms. The author therefore proposes that this concept should be implemented in all UK ambulance services in urban environments to improve patient outcomes of OHCA.