Pre-hospital resuscitation is perhaps the most challenging, complex, time-critical medical intervention that has absolute life and death consequences. It would seem natural, therefore, that we would want highly experienced, emergency medical service personnel attending to us in the event of sudden out-of-hospital cardiac arrest (OHCA).
Even in busy, urban centres, emergency medical service personnel are only exposed to a handful of OHCA per year. The issue of emergency medical service practitioners’ experience and exposure to OHCA is important and explored in this issue of Resuscitation by Dyson et al. In a comprehensive review, the discrepancies in the published literature are highlighted, with some systems reporting correlations between increased exposure and outcome, with others suggesting no difference.
Survival from OHCA largely depends on pre-hospital events. The Chain-of-Survival begins in the dispatch room on receipt of the emergency call, – an often overlooked link. Kuisma et al. demonstrated a possible survival benefit when an experienced dispatcher handles the emergency telephone call. The question of whether OHCA calls should be handed over to an ‘expert’ remains unanswered, as does whether ‘expert’ pre-hospital personnel may improve OHCA survival.
Emergency medical service personnel responding to OHCA calls vary hugely in experience, skills and training. Whilst some of the leading European centres for OHCA survival employ physician-paramedic models, equally impressive results are seen in paramedic-only systems. Some centres have identified a link between the level of experience of pre-hospital practitioner and OHCA survival, whilst other centres have seen no significant difference. A striking difference between these physician-paramedic and paramedic-only systems is the reported number of cases where resuscitation was undertaken. In these studies, the pre-hospital physicians appeared not to commence resuscitation or terminate on grounds of futility much more readily than their paramedic colleagues. This raises important questions surrounding initiation and termination of resuscitation decisions and highlights an area lacking in specific guidance.
Dyson et al. also choose a single resuscitation intervention – endotracheal intubation – to compare experience and performance. Whilst the debate on the optimum airway device for pre-hospital resuscitation rages, it comes as no surprise that a high rate of pre-hospital intubation exposure was associated with a high procedural success rate.
Yet the most important intervention emergency medical services perform is cardiopulmonary resuscitation (CPR) with timely defibrillation. Unfortunately, none of the studies reviewed by Dyson et al. undertook objective resuscitation quality measurement in the form of defibrillator downloads. Analysis of CPR quality has been shown to improve practice, with resuscitation quality shown be linked to outcome from OHCA. Without defibrillator downloads, making any objective assessment of pre-hospital resuscitation quality is impossible.
Whilst the evidence on pre-hospital exposure remains equivocal, education has been identified as key to any effective resuscitation system. Unlike in-hospital resuscitation, where resuscitation education is well established, there are currently no standards for pre-hospital resuscitation training.
Arguably, enough is never enough. Regardless of exposure, continued education, skills practice and simulation are vital for maintaining a high state of readiness in order to provide best pre-hospital practice. Minimum training standards are urgently needed. Studies have suggested at least 6-monthly training is required for healthcare workers to maintain resuscitation skills, yet training provision for emergency medical services remains hugely varied and there are no published guidelines of the optimum training regime. We urgently need to establish the optimum means of pre-hospital resuscitation training, skill retention and experience.
Whilst individual performance is important, resuscitation is a team sport and future studies should focus on the impact of differing pre-hospital systems. Non-technical skills are a key element of any team performance and are rightly gaining more attention in optimising pre-hospital resuscitation. The experienced pre-hospital provider is likely to bring much more to the party than just technical ability.
As randomised trials by practitioner would prove challenging, further research in the form of high-quality observational studies is urgently needed and we must address the challenge of establishing international registries to include pre-hospital training, exposure and quality of CPR data.
We urgently need standardised pre-hospital resuscitation training programmes, improved evidence-based guidelines on pre-hospital practice and a focus on optimising local chains-of-survival to improve outcome from OHCA.
RL is a Clinical Lead for Kent, Surry & Sussex Air Ambulance Trust; member of the Resuscitation Council (UK) Executive Committee; Medical Director of Matterhorn Medical Ltd. and provides consultancy for Zoll Medical, Physio Control and Prometheus Medical Ltd.