Pre-hospital trauma care varies greatly throughout the world. Developing countries may have no structured pre-hospital trauma services, whereas more affluent first-world economies may have advanced systems comprising multiple levels of response. This article will investigate these systems as a part of holistic and integrated trauma care, the role of paramedical staff within them, and discuss an ideal model of pre-hospital response to trauma that balances responsible health service delivery with improvements in morbidity and mortality.
Background
Trauma is a common cause of death in underdeveloped, developing and developed nations. In developed nations such as Australia, injury from suicide, transport accidents and unintentional falls represents the majority of trauma-related hospital presentations (Henley and Harrison, 2009). Typically, young adult males are overrepresented in all trauma-related deaths.
Whilst foremost acknowledging the significant emotional cost of traumatic injury to the patient and their support network, traumatic injury also comes at a significant financial cost to society. Disability secondary to traumatic injury can incur a lifetime of financial burden on families, the healthcare system, support services and society as a whole. Connelly and Supangan (2006) estimated that the total cost (including healthcare and support services, emergency response and vehicle-related costs) of road trauma to Australia was $17 billion each year—2.3% of the nation's gross domestic product. Improvements in trauma care delivery are aimed at not only limiting human suffering, but reducing the financial burden on society.
The concept and delivery of pre-hospital trauma care is not new. Much of the understanding of the management of civilian trauma has been drawn from military experience in times of war. Celsus, in De Medicina, described the management of battlefield injuries as far back as the first century. DeBakey and Simeone (1946) investigated arterial injury in World War II, and Williams et al (2007), among others, reported on trauma resuscitation, specifically fluid administration and temperature management, in the Falklands War.
Hoff and Schwab (2004) described how management of trauma in North America evolved significantly during the 1960s and 1970s during and after the Vietnam War. The concepts of highly-skilled in-field personnel, rapid intervention and helicopter evacuation saw mortality rates decrease when compared to previous conflicts. More recently, conflicts in the Middle East have seen significant advancements in out-of-hospital fluid and blood product administration, the re-emergence of the use of tourniquets, novel haemostatic agents, and the evolution of trauma management concepts such as damage control resuscitation (Eastridge et al, 2006; Holcomb et al, 2007). Many of these modern advancements are being adopted by civilian pre-hospital systems (Ambulance Victoria, 2012).
Civilian pre-hospital trauma systems evolved rapidly in concert with wartime advancements during and after the Vietnam War. Helicopter Emergency Medical Services (HEMS) were established, predominantly in North America, based on their success in rapid retrieval of casualties from the battlefield (Foster, 1969). Pre-hospital intensive care paramedic systems were introduced in many parts of the world, including pioneering services in Belfast, Seattle and Melbourne (Pantridge, 1996; Ambulance Victoria, 2009; King County, 2012). The establishment of these services was, in part, driven by an increase in road traffic accidents and resultant severe trauma (Colac Ambulance, 2009).
Trauma care pioneer R Adams Cowley is credited with coining the term the ‘Golden Hour’, a theoretical concept that describes the period of time in which a seriously injured trauma patient should ideally be delivered to definite surgery in order to survive. From this, the term the ‘Platinum 10 minutes’ evolved to describe the ideal time from extrication to the ambulance and commencement of transport. Theoretically, this then increases time available in which to deliver the patient to hospital inside the ‘Golden Hour’.
Lerner and Moscati (2001) have challenged the concept of the ‘Golden Hour’ suggesting that Cowley, although frequently using the term, had no scientific data to support this notion. Although a valid concept in ensuring pre-hospital clinicians are cognisant of the time taken to deliver major trauma patients to definitive care, questions exist as to whether rigid adherence to this principle has a place in contemporary pre-hospital trauma care.
In 1983, Donald Trunkey described a trimodal distribution of death in trauma patients. Historically, clinicians have described trauma-related death occurring either immediately, in the first hours after injury, or the ensuing days to weeks. However, more recent research has demonstrated that in contemporary, integrated trauma care systems, there is a move to either a bimodal distribution (immediate deaths largely unchanged, significant decrease in late deaths, [McGwin et al, 2009]), or no resemblance to trimodal distribution at all (Demetriades et al, 2005). Thus, how readily can we look to historical trauma-care concepts when formulating and implementing today's pre-hospital trauma care systems?
Contemporary trauma systems
Trauma centres and trauma bypass
Many jurisdictions have implemented Trauma Centres and/or introduced the concept of Trauma Bypass. Trauma centres are based on the concept that trauma and injury are illnesses unto themselves that require specialised management. Concentrating trauma services to a small number of highly specialised centres with frequent exposure to severely injured patients, ensures proficiency in managing these complex patients can be maintained, and expertise gained.
Trauma Bypass is a concept where pre-hospital services bypass smaller, non-Trauma Centre hospitals, in favour of a slightly longer transport time in order to deliver the patient to the specialised Trauma Centre. These concepts are not new. As early as 1941, the Birmingham Accident Hospital was recognised as the first trauma Centre (Brohi, 2013). The concept became popular in the United States in the 1960s and 1970s, most famously with the advent of the R Adams Cowley Shock-Trauma Centre in Baltimore, Maryland (University of Maryland Medical Centre, 2011). However, bypassing the nearest hospital for a larger, more specialised Trauma Centre may see the ‘Golden Hour’ exceeded. As stated previously, there is evidence to suggest that concepts such as the ‘Golden Hour’ and the ‘Platinum 10 minutes’ may have limited relevance in a modern, integrated trauma system.
Staffing the pre-hospital trauma response
Ambulance services around the world have varying staffing models for their pre-hospital trauma response. Developed nations commonly deploy well-trained staff via ambulance services. The United Kingdom, for example, has a blend of paramedic, volunteer physician and pre-hospital physician response, and in mainland Europe, basic level emergency medical technicians (EMTs) support pre-hospital physicians in the field (Westhoff et al, 2003). The North American model sees EMTs and intensive care paramedics as the most common responders to major trauma (NAEMT, 2013). In Australasia, Advanced Life Support and intensive care paramedics most commonly respond, with pre-hospital physicians dispatched and part of a HEMS response (Paramedics Australasia, 2012). These staffing levels are summarised in Table 1.
| Qualification | Trauma skill set |
|---|---|
| Emergency Medical Technician (EMT) or Basic Life Support (BLS) paramedic | Basic analgesia, basic airway management, splinting |
| Advanced Life Support (ALS) Paramedic | Intermediate analgesia, vascular access, fluid therapy, supraglottic airway insertion |
| Intensive Care Paramedic | Advanced analgesia, intraosseous access, endotracheal intubation, needle thoracostomy |
| Critical Care Paramedic | Additional advanced analgesia, drug-facilitated intubation, blood product administration, surgical thoracostomy |
| Pre-hospital doctor | Only limited by specialty/training and experience |
Interventions performed by pre-hospital clinicians vary with level of training, qualification and experience (see Table 1). Much controversy surrounds the effect pre-hospital interventions have on-scene time and patient outcomes. A number of studies have looked at such interventions, and have also investigated who the most appropriate clinician is to provide pre-hospital trauma care.
Garner et al (1999) compared a physician-paramedic staffed HEMS versus dual paramedic staffed HEMS in a similar geographical area. This controversial study suggested that in spite of longer scene times, the physician-staffed HEMS improved outcomes for patients suffering blunt trauma. Roudsari et al (2007) compared pre-hospital trauma systems from five developed countries possessing advanced emergency medical systems. The study focused on whether the trauma response included a physician in addition to a paramedic. Findings suggested that where a physician was dispatched to the scene, early trauma fatality rates were lower, but outcomes in other clinical measures were not significantly better. There was no specification of skill sets of the various practitioners.
Much of the literature supports the notion that a physician response enables a higher level of clinical intervention and clinical judgement (Garner et al, 1999). The latter is difficult to quantify. Comparison studies have not consistently compared the same skillset between different levels of qualification. For example, the Head Injury Retrieval Trial compared ‘standard’ pre-hospital management of traumatic brain injury by paramedics, with physician management of the same patients (Garner, 2012). In that study, the physicians were able to perform a much wider range of skills including pre-hospital anaesthesia. The paramedics were not equipped with such skills. Interestingly, the study did not demonstrate a significant benefit to those managed by pre-hospital physicians, although the data is difficult to interpret (Garner, 2012). Thus, based on available literature, it is difficult to assess whether specific interventions and training are responsible for differences in patient outcomes, or whether it is profession-dependent.
Demetriades (1996) challenged the need for advanced interventions in pre-hospital trauma care by comparing trauma patients who arrived by private means versus those who arrived by ambulance. Although having some limitations, the study showed a survival benefit to those who arrived by private means. This study raises the question of whether rapid transport, short pre-hospital times, and interventions being limited to those that are lifesaving, is the best approach to pre-hospital trauma care. No major, well-designed randomised studies have been undertaken to answer this question.
Physicians undoubtedly have a vast array of trauma-specific interventions that they can utilise in the field. These include thoracotomy, ultrasound, drug-facilitated airway management, and advanced analgesia to name a few. Pre-hospital thoracotomy has been postulated as an essential pre-hospital trauma skill in some areas. Davies and Lockey (2011) described 13 survivors of pre-hospital thoracotomy in a service exposed to a high volume of penetrating trauma. Of 71 patients receiving pre-hospital thoracotomy over 15 years, only 11 survived with good neurological outcome. A resource intensive procedure that requires significant training and skills maintenance showed a small benefit in that service, but would the benefit exist in regions where penetrating trauma is uncommon?
Some pre-hospital trauma systems rely on pre-hospital physicians to institute advanced analgesia with agents such as ketamine. Sherren et al (2013) investigated whether physicians are required during winch operations in an HEMS service. The study concluded that HEMS physicians in that service had a high (40%) rate of physician-only intervention, therefore physicians are required. The physician-only interventions were primarily the provision of ketamine for analgesia and procedural sedation in minor-moderate trauma patients.
Conversely, Jennings et al (2012) demonstrated in a randomised-controlled trial that ALS and intensive care paramedics could safely administer ketamine and an opioid analgesic to trauma patients, with a significant improvement in outcomes.
There exist numerous studies that demonstrate the ability of paramedical staff to adeptly perform interventions that have traditionally been reserved for physicians. Heegaard et al (2010) described the relative ease of training paramedics in the use and interpretation of pre-hospital ultrasound, and a review by Brooke et al (2010) suggests increasing evidence for paramedic application of ultrasound in the field.
Bushby et al (2005) noted that when intensive care paramedics performed chest decompression and endotracheal intubation in the field for severely injured trauma patients, there was a significant decrease in mortality and ‘unexpected survival’. And, in a landmark pre-hospital randomised-controlled trial, Bernard et al (2010) demonstrated that not only could highly-trained intensive care paramedicss independently and safely undertake drug facilitated endotracheal intubation in patients suffering severe traumatic brain injury, but this procedure improved functional outcome when compared to basic airway management.
The pre-hospital trauma response in any given emergency medical service will vary according to, among other elements, training, qualifications, staff availability and cost. A pre-hospital physician, paired with experienced and highly-trained paramedics is often seen as the ideal, highest level of response (Garner et al, 1999). This, however, is an exceptionally costly service to provide. The question of whether this cost translates to improved outcomes is not fully understood (Taylor et al, 2011). Additionally, many Western civilisations face significant emergency health care service delivery issues, such as emergency department access block or ‘ramping’, in-part due to insufficient medical staff (Queensland Health, 2012; Clover, 2013). As such, does an ideal pre-hospital trauma response exist?
An ideal pre-hospital model
Based on current evidence, an ideal model of pre-hospital trauma response would include basic to intermediate level practitioners for immediate trauma response. These practitioners should be proficient in immediate basic to intermediate airway, ventilation and circulatory support, and haemorrhage control. Additional highly skilled practitioners should be available to provide critical care interventions in the field as required, and ideally would be limited to small teams, to ensure maximal exposure to the most unwell trauma patients. There is some evidence to support pre-hospital physician deployment to major trauma; however, it is unknown whether the cost associated with this translates to improvement in patient outcomes and financial benefit to the health care system, or whether this valuable resource may be better placed to ease emergency department and hospital congestion.
An integrated, holistic emergency trauma care model is proposed in Figure 1.
Conclusions
Contemporary trauma systems are complex, can be costly, and are a significant undertaking to establish. However, significant reductions in morbidity, mortality, suffering and societal burden can be expected. The ideal resourcing for pre-hospital response to trauma is not known. There is some evidence to support deployment of pre-hospital physicians, yet similar levels of support for enhanced skill sets for paramedical clinicians. A tiered response, encompassing basic and advanced level providers, who ultimately deliver patients to Major Trauma Centres, appears to be current best practice.