Anaesthesia and pre-hospital emergency medicine

Authors


A. Steel
Email: a-steel@doctors.net.uk

Summary

Major trauma is a leading cause of death and disability in the UK, particularly in the young. Pre-hospital emergency medicine (PHEM) involves provision of immediate medical care to critically ill and injured patients, across all age ranges, often in environments that may be remote and are not only physically challenging but also limited in terms of time and resources. PHEM is now a GMC-recognised subspecialty of anaesthesia or emergency medicine and the first recognised training program in the UK commenced in August 2012. This article discusses subspeciality development in PHEM, the competency based framework for training in PHEM, and the provision of pre-hospital emergency anaesthesia.

A 28-year-old motorcyclist is riding along the A47 in Norfolk when she is struck by a car pulling out from a junction. She is trapped beneath the car. She has sustained severe head, chest and limb injuries. Her Glasgow Coma Score is 7 and she is hypoxic from an obstructed airway, a flail chest and a pneumothorax. The Ambulance Service is called.

A highly trained paramedic working on the Trauma Desk mobilises the closest Helicopter Emergency Medical Service (HEMS) team consisting of a senior flight paramedic and an ST6 Anaesthetic Trainee subspecialty in pre-hospital emergency medicine (PHEM). They arrive at the scene 15 min after the incident. They perform a rapid primary survey, recognise life-threatening injuries and plan to administer a pre-hospital emergency anaesthetic to provide neuroprotection and ventilatory support.

Multi-modality monitoring is applied and the team use a well-rehearsed pre-induction checklist to ensure the safest possible conditions for an emergency anaesthetic. Ketamine 1 mg. kg−1 and suxamethonium 1.5 mg. kg−1 are given intravenously and the airway is secured with a tracheal tube. Bilateral open thoracostomies are performed and the limbs fractures are reduced and tractioned. Anaesthesia is maintained using morphine, midazolam and atracurium. Mechanical ventilation is commenced using a lung-protective strategy.

The incident has occurred 12 min from the nearest trauma unit. The major trauma centre (MTC) is 50 min away by road and 25 min by air. The team call the duty PHEM consultant for advice regarding the destination hospital. Together they agree that the MTC, with neurosurgical facilities, is the most appropriate hospital. The team embark on a primary transfer by air, maintaining anaesthesia and ventilatory support. They land at the MTC and hand over the patient’s care to an awaiting trauma team using regionally agreed procedures.

The team’s performance and the patient’s clinical condition is followed up and reviewed at the regional PHEM governance meeting. The trainee and her educational supervisor discuss the case and record an assessment in the trainee’s online portfolio. The patient is discharged from hospital six weeks later with a minor cognitive deficit and a left brachial plexus injury. A year later she is living and working independently.

Care of the severely injured

The commonest cause of death of young people in the UK is external causes such a major trauma or suicide [1]. The mortality and disability of those that do survive is improved by the provision of pre-hospital medical support [2–8].

The NHS Ambulance Services in the UK have the statutory responsibility for caring for patients during the pre-hospital phase and conveying them to hospital. Whilst paramedic training and advanced training courses such as Pre-Hospital Trauma Life Support (PHTLS) go some way to managing the majority of injured patients, a significant number have such severe injuries that their immediate needs cannot, at present, be adequately met without the use of physician-based interventions. In the UK, a paramedic may manage an average of just two severely injured patients per year, limiting opportunities to gain expertise. The technical skill of endotracheal intubation, for example, is initially learnt by performing a small number of in-hospital intubations [9]. A typical paramedic will subsequently perform one to two intubations per year [9]. Given the evidence suggesting that trachel intubation needs to be performed approximately 80 times before a 95% success rate is achieved, it is clear that this is a skill in which most paramedics are unlikely to gain proficiency [10]. For this reason, the Joint Royal Colleges Ambulance Liaison Committee (JRCALC) report of June 2008 stated “paramedic tracheal intubation cannot be recommended as a mandatory component of paramedic practice and should not be continued to be practiced in its current format” [9]. Advanced pre-hospital airway management requires specialist, typically physician-based, resources.

For decades, doctors have been offering voluntary support to the ambulance service to care for critically ill and injured patients. With mounting evidence of the inadequate care that this group of patients receive pre-hospital, the last few years have seen national recognition of the need for the provision of high-quality medical care integrated into the ambulance response [11].

In 1988, a working party report by the Royal College of Surgeons highlighted “serious deficiencies in the management of severely injured patients” [12]. In 2000, a joint report from the Royal College of Surgeons of England and the British Orthopaedic Association recommended that standards of care for the severely injured patient should be nationally coordinated and systematically audited [13]. It also recommended that standards and outcome measures be developed, against which institutions can audit the outcome of treatment. The standards of care recommended in the report include the use of advance warning systems by the ambulance service, the establishment of trauma teams, the involvement of an appropriately skilled senior doctor from the outset and criteria for the activation of the trauma team. The overall purpose of these recommendations was to improve the care of severely injured patients in terms of reduced mortality and unnecessary morbidity.

One of the recommendations of the 2000 report was the establishment of a National Trauma Service trauma hub and spoke network between hospitals in each geographic area [14].

In 2007, NCEPOD published a report, Trauma: Who Cares?, acknowledging that the deficiencies identified decades before persisted (Box 1) [15]. Recognising that the chance of survival and the completeness of recovery were highly dependent on the care that followed, it stated that, “To be effective all processes, including Advanced Trauma Life Support (ATLS) and other components of care of severely injured patients must be embedded in practice at every stage: the scene of the accident; alerts to the hospital; the journey from scene to the emergency department; preparations made there; expertise accessible on arrival and at all subsequent stages, including transfer to specialist services” [15].

Table 1. 
 Box 1
The current structure of pre-hospital management is insufficient to meet the needs of the severely injured patient. There is a high incidence of failed intubation and a high incidence of patients arriving at hospital with a partially or completely obstructed airway. Change is urgently required to provide a system that reliably provides a clear airway with good oxygenation and control of ventilation [15].

In 2010, in support of better trauma care, the Department of Health, forming a National Clinical Advisory Group (NCAG), set out a number of recommendations (Box 2).

Table 2. 
 Box 2
The Major Trauma NHS Clinical Advisory Group recommendations [16]:
• Enhanced care teams (teams capable of delivering the full spectrum of medical interventions including, for example, emergency anaesthesia) should be available 24/7 to provide care to the patient with major trauma
• Patients with injuries suggestive of major trauma should be taken to a major trauma centre. Those who are within 45 min travelling time from the centre should be taken there directly, bypassing other units
• Some patients will be further than 45 min travel from a major trauma centre, or be trapped, or will have an injury pattern or airway compromise that means that enhanced care needs to be provided before they can get to the major trauma centre. This could be through an enhanced care team or via a closer designated trauma unit
• Patients with major trauma who are taken to a local major unit should be transferred promptly to a major trauma centre after initial assessment and optimisation in the emergency department

Enhanced care teams

Enhanced care teams (ECTs) first gained popularity in the UK in the 1990s. London HEMS established a doctor-paramedic model of care that has subsequently been adopted by much of the UK. Most ECTs are funded through charitable donations, predominantly through air ambulance charities. The Emergency Medical Retrieval Service in Scotland is the UK’s first 24/7 government funded ECT provider.

Most ECTs are mobilised as part of a region’s air ambulance service. Air ambulances themselves are not funded through the NHS and instead rely on charitable donations. Whilst physician-based ECTs have been shown to reduce morbidity and mortality, air ambulances are extremely costly [17–21]. Helicopters have the advantages of speed over longer distances, thus enabling the scarce resources of ECTs to cover large areas. Helicopters can be used to deploy teams to patients quickly for rapid provision of specialist clinical care. It will not always be advantageous in terms of time, practicality or safety to convey the patient by air and the teams in the UK frequently transport the patients to the appropriate hospital using land ambulances. Air ambulance availability cannot be guaranteed as limitations in terms of weather mean that there are times when HEMS missions are not possible. ECTs need land-based transport available to maintain a 24/7 service. There are currently very few services in the UK that are able to undertake HEMS missions outside of daylight hours.

Pre-hospital emergency medicine sub-specialty development

Recognising that existing pre-hospital medical training was ad hoc and unregulated, the Faculty of Pre-hospital Care of the Royal College of Surgeons of Edinburgh set about establishing a professional route to sub-specialisation [22, 23]. In 2011, the General Medical Council (GMC) formally recognised PHEM as a sub-specialty of both Anaesthesia and Emergency Medicine [24]. Also central to the provision of high quality PHEM is the development of specialist paramedic practitioners in PHEM, which is outside of the scope of this article.

It has been estimated that up to 250 whole-time equivalent (WTE) PHEM consultants across the UK would provide the service and training required for the provision of medical support and ECTs. PHEM consultants would spend the majority of time in their base specialty; therefore 600-700 would be required to provide the equivalent of 250 WTEs [25]. In 2012, the first formally admitted PHEM trainees began specialist training [25].

Pre-hospital emergency medicine training

The specialty of PHEM encompasses the knowledge, technical skills and non-technical (behavioural) skills required to provide safe pre-hospital critical care and safe transfer [26].

Pre-hospital emergency medicine specialty training involves 12 months of full-time equivalent out-of-programme training, typically to be interwoven with base specialty training. Trainees must have completed 5 years (> ST4) of parent specialty (anaesthesia/emergency medicine) training before commencing formal PHEM training. Currently the majority of interested candidates are emergency medicine trainees. It is anticipated that there will be approximately 25 training posts per year nationally. Whilst opportunities exist for PHEM training elsewhere, the UK is the first in the world to recognise the sub-specialty formally and to provide training focused on providing PHEM consultants.

The Intercollegiate Board for Training in PHEM is responsible for training and assessment in PHEM on behalf of the College of Emergency Medicine, the Royal College of Anaesthetists and the Faculty of Pre-hospital Care at the the Royal College of Surgeons of Edinburgh [25–27].

The PHEM curriculum divides into 10 themes with four generic cross-cutting and six specialty-specific themes (Fig. 1).

Figure 1.

 Ten themes of the pre-hospital emergency medicine competence-based curriculum. Four non-clinical ‘cross-cutting’ themes are placed centrally, with the six clinical themes placed peripherally. Each theme is further divided into units and elements. Each element represents a discrete item of knowledge or a technical/non-technical skill. (Figure reproduced with permission from the Intercollegiate Board for Training in PHEM).

Although PHEM as a specialty has only recently been recognised, a number of services within the UK have been providing structured training for doctors for many years (e.g. London HEMS, Magpas, Scotland’s Emergency Medical Retrieval Service). The current PHEM training model used by a number of services within the UK involves a period of intense classroom and simulator-based training followed by a period of supervision, initially direct supervision provided by a consultant with extensive experience in PHEM and then progressing to indirect and remote supervision. The extensive PHEM curriculum, one of the requirements for GMC recognition of the sub-specialty, is a means of ensuring that all trainees completing PHEM specialty training have a known spectrum of competences. Such competences include clinical (e.g. resuscitative thoracotomy) technical (e.g. the ability to use a range of ventilatory devices) and behavioural (e.g. maintaining situational awareness). Further examples are given in Table 1; PHEM trainees will be expected to gain competences across the breadth of the curriculum before becoming a PHEM consultant.

Table 1. The six pre-hospital emergency medicine specialty-specific themes with examples of a competency contained within them.
Specialty-specific PHEM themesExample of competence
Theme 1 – Working in emergency medical systemsDemonstrates ability to provide effective on-line clinical support
Theme 2 – Providing pre-hospital emergency careDemonstrates ability to undertake resuscitative thoracotomy
Theme 3 – Using pre-hospital equipmentDemonstrates ability to use devices for controlling haemorrhage
Theme 4 – Supporting rescue and extricationDemonstrates ability to make a rapid assessment of the clinical needs of a trapped patient
Theme 5 – Supporting safe patient transferDemonstrates ability to integrate patient diagnosis with the physiological effects of transport
Theme 6 – Supporting emergency preparedness and responseDemonstrates ability to competently perform the role of a tactical level medical commander

Many of the competences are covered by a single parent specialty, but no one parent specialty includes the full spectrum of competences required for comprehensive PHEM practice – a defining criterion for the creation of a new sub-specialty. Furthermore, while a given competence may have been achieved through parent specialty practice, for example the provision of emergency anaesthesia, the pre-hospital environment is so different from that in-hospital that additional training is required.

Pre-hospital emergency medicine training is typically delivered in two phases – an initial developmental highly supervised phase followed by a period of consolidation training with less direct supervision. Progression through these phases is supported by the use of formative and summative assessments. Mirroring in-hospital practice, successful completion of work-place-based assessments such as Clinical Evaluation Exercises (CEX), Case-Based Discussions (CBDs) and Direct Observation of Procedural Skills (DOPS), is required. Educational supervision is provided by consultants experienced in PHEM practice.

Training is blended, using a combination of on-line study, simulation, multi-agency training days, clinical case discussions, and direct and indirect supervision by PHEM educational and clinical supervisors. The simulation training combines a mixture of low fidelity/part-task simulations covering specific skill (examples include the use of pre-hospital tourniquets, limb splintage, or pre-hospital surgical airways) and high fidelity simulations. High fidelity simulation involves full immersion whole-team, multi-professional training, often outdoors and in austere environments. These expose the trainee to the complexity of managing a critically ill patient in challenging time-pressured situations, from tasking of a case through to handover. High fidelity simulation is used to train for common high-risk events such as road traffic collisions, as well as rarer events such as mountain, marine, rail, chemical and confined-space incidents.

Pre-hospital emergency anaesthesia

Pre-hospital emergency anaesthesia (PHEA) is one of the most controversial of interventions provided by PHEM specialists. Pre-hospital tracheal intubation of severely injured patients has been shown to be potentially harmful, particularly if delivered without appropriate drugs, monitoring, equipment, training and clinical governance [28–31]. However, a number of well-designed studies have shown that there can be a functional and survival benefit associated with PHEA [3, 5, 6, 32–38]. Recognising that many patients should not have this intervention with-held, the Association of Anaesthetists of Great Britain and Ireland (AAGBI), in partnership with a number of national organisations, published guidance on the standards required for the safe provision of PHEA. In essence, those standards are the same as those used in hospital (including capnography), recognising the limitations of the operating environment [39].

Those services that have been routinely providing PHEA have developed systems to improve the safety of these high-risk interventions (Table 2). The use of ‘challenge and response’ checklists is now routine practice in many systems and has been shown to reduce the number of safety critical events [40].

Table 2. Suggestions for organisational attributes that may improve the safety of pre-hospital emergency anaesthesia (PHEA).
  1. PHEM, pre-hospital emergency medicine.

• The use of clear standard operating procedures including equipment governance, indications for PHEA, checklists for PHEA procedure
• Immediately available PHEM consultant advice
• Post-incident ‘hot debrief’
• Regular morbidity and mortality meetings
• Regular audit leading to changes in practice

The induction agents used by UK PHEM services continues to evolve. A decade ago, etomidate was used almost exclusively for patients for PHEA induction but more recently many services have commenced using intravenous or intraosseus ketamine (1.0–2.0 mg. kg−1 depending on injuries and co-morbidities) [41]. Many publications and texts state that ketamine worsens secondary brain injury through a rise in intracranial pressure. More recent evidence suggests that secondary brain injury is lessened, not only by the avoidance of systemic hypotension commonly seen with other induction agents, but also because ketamine attenuates the haemodynamic response to intubation and appears to also have neuroprotective properties, provided that normocapnia is achieved with controlled mandatory ventilation [42–45].

Suxamethonium is the most commonly used neuromuscular blocking agent (NMBA). The use of rocuronium is increasing, in part reflecting increasing confidence of services in providing systems for failed-intubation training and management. Sugammadex reversal is unlikely to be of benefit as generally patients who meet the criteria for PHEA are already compromised in terms of ventilation, oxygenation or conscious levels and most services currently routinely using rocuronium at induction of anaesthesia do not carry sugammadex. Maintenance of anaesthesia is commonly achieved by intravenous morphine and midazolam boluses, although a number of increasingly sophisticated systems are able to provide infusions, enabling the use of propofol infusions, or target controlled infusions, for ongoing sedation during transfer [41].

Conventional direct laryngoscopy is preferred for ‘Plan A’ by most PHEM services (Fig. 2). Many carry videolaryngoscopes for the initial management of a failed intubation (‘Plan B’), and there is increasing evidence, albeit simulator or hospital-based, that videolaryngoscopes would be useful for patients requiring in-line spinal immobilisation. However, a study of one type of videolaryngoscope known for high rates of in-hospital success showed a success rate of only 47% (compared with 99% using direct laryngoscopy) when used by experienced practitioners during PHEA [46]. Pre-hospital tracheal intubation success rates by PHEM teams compare favourably with in-hospital emergency department rates [47, 48]. Most systems train teams to provide a surgical airway in the event of a ‘can’t intubate, can’t oxygenate’ scenario, with the incidence of surgical airway provision in the order of 1% of patients requiring pre-hospital advanced airway support [49]. Airway compromise in association with facial trauma is the commonest indication for performing a pre-hospital surgical airway, with laryngeal trauma and burns injuries as other common indications [50]. Most pre-hospital surgical airways are established using cuffed tracheal tubes, although needle cricothyroidotomies and narrow uncuffed tubes have been used with varying degrees of success [50]. Simple methods of obtaining a surgical airway in the pre-hospital environment with high success rates have been described – these include use of a scalpel, forceps (or finger) and a bougie [51].

Figure 2.

 Emergency airway algorithm for pre-hospital emergency anaesthesia (PHEA). This was developed by the authors to follow the Difficult Airway Society’s ‘failed intubation, failed ventilation’ guidelines [52] as far as possible, but recognising some of the limitations and hazards of the pre-hospital environment. ED, emergency department.

Pre-hospital trauma care follows ATLS principles. In addition to early advanced airway management and cervical spine control, ventilatory support (including the use of bilateral open thoracostomies rather than chest drains for mechanically ventilated patients with significant chest injuries), and circulatory support (including the use of aggressive haemorrhage control, permissive hypotension, minimal fluid resuscitation, early blood and blood component transfusions, and early anti-fibrinolytic therapy) are fundamental to the provision of high quality critical care that many patients require in the pre-hospital phase preceding timely transfer to definitive care.

It is likely that the best outcomes are seen when PHEA is used as part of a bundle of care incorporating high quality provision of PHEM by highly trained personnel. This includes facilitation of extrication, haemorrhage control, damage control resuscitation, lung protective ventilatory support, neuroprotection and correct decision-making in terms of tempo, timely critical clinical interventions, appropriate transport platform and appropriate hospital destinations.

Inter-hospital transfers

Increasing numbers of secondary transfers are being undertaken by ECTs that have traditionally only undertaken primary (from scene) transfers. The PHEM curriculum requires practitioners to have competences for both primary and secondary transfers and ECTs are developing expertise in this area. The increasingly sophisticated operations allow for both land- and air-based transfers.

With the implementation of the trauma networks, patients who are more than 45 min from a MTC will be taken to the nearest trauma unit. Many of these will then require urgent secondary transfer to the MTC. There is comprehensive guidance on the management of interhospital transfers available [53, 54].

Trauma networks

Although major trauma is a leading cause of death and disability, it represents less than 2 per 1000 attendances in emergency departments in the UK [55]. Several national reports have revealed the sporadic and unstructured provision of trauma care in many parts of the UK and highlighted the poor outcomes in terms of morbidity and mortality [56–58].

The National Confidential Enquiry into Patient Outcome and Death (NCEPOD) report of 2007 found deficiencies in all areas of trauma care including pre-hospital services, in terms of both organisation and delivery of care [15]. It emphasised the need for major trauma patients to be treated in designated major trauma centres. As trauma represents such a small proportion of the workload of UK emergency departments, MTCs with a high caseload to maintain excellence in trauma are widely spaced. The challenge in improving services involved not only improvements in clinical care, but in massive structural reorganisation with the development of trauma networks. In 2009 the UK’s first National Clinical Director for Trauma Care, Professor Keith Willett, was appointed to lead this process.

Regionalisation of trauma services relies on several key elements: the ambulance service; pre-hospital services; emergency interhospital transfer services; trauma units (other emergency departments within the network); the MTC; network coordination; and rehabilitation services. NHS Choices has produced a detailed map that illustrates that the nearest MTC may be a significant distance away and much of the challenge is in early identification of major trauma and facilitating safe, rapid transfer [59]. Clear guidance regarding on-scene triage of major trauma patients and hospital bypass are provided by most networks.

Development and organisation of trauma networks requires regionalised coordination. For example, one innovation being adopted by some regional trauma networks is the creation of a network coordination service. This is a dedicated 24/7 telephone-based single point of contact that coordinates all elements of trauma care from the pre-hospital phase through to rehabilitation. It provides immediate clinical advice from an experienced trauma physician as well as a link to bed bureau services (including critical care and specialist services beds) and a directory to services related to the management of complex injuries. Networks are also used to follow patient flow and monitor performance of organisations within it.

Pre-hospital emergency medical care funding

The majority of ECTs in the UK are mobilised as part of an air ambulance response and are governed, supported and funded by air ambulance charities. It is unclear at the present time how clinical commissioning will affect future models of service delivery.

Despite recommendations from NCEPOD and similar reports calling for NHS funding of specialist services, current economic restraints mean that at least in the medium term charity funding will be central to PHEM provision in the UK. Organisational collaboration between NHS and non-NHS providers is essential for developing trauma networks, not only for the provision of high quality clinical care but also for the training and development of PHEM specialists. Such close collaboration already exists in many parts of the UK.

The future of pre-hospital emergency medicine

Pre-hospital emergency medicine specialists are essential for providing high quality clinical care, strong medical leadership, professional training and firm governance of pre-hospital care and interhospital transfer services [27]. Anaesthetists, already central in the management of ill and injured patients, have a great deal to offer the sub-specialty and are ideally placed to help reduce mortality and to relieve pain and suffering, both in and out of hospital.

Competing interests

No external funding or competing interests declared.

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