Introduction to prehospital and retrieval medicine

Definition of PHRM

ACEM defines Pre-hospital and retrieval medicine (PHRM) as ‘rapid response medical care provided to seriously sick and injured people’. ¹

This is quite a nebulous definition. Often, we retrieve patients who have relatively minor injuries but who are isolated through geography. Or: a tasking may take hours to days to setup and implement - for example, a disaster response, or a complex international retrieval.

I believe a better definition would be:

the provision of specialist medical care, coordination and oversight to patients outside of traditional medical settings, working alongside paramedical and other allied health professionals.

History of PHRM

PHRM is a new medical specialty. ACEM commenced the Diploma in Prehospital and Retrieval Medicine in 2021 and the UK launched pilot subspecialty training programs in 2014.

Prior to this, doctors have worked in conjunction with prehospital systems on a formal and informal basis - this included organisations such as BASICS ² in the UK as well as ad-hoc arrangements to transport medical specialists to needed areas such as the ‘Obstetric Flying Squad’.³

The recognition of the need to provide standardised, quality-assured medical services in an environment that is often hostile led to formalisation of training services and structures.

Rescue versus retrieval

Retrieval can be broadly thought of as the

process of moving a patient from one healthcare facility to another, usually for the purposes of escalating care.

Rescue can have many different meanings. In essence,

a medical rescue refers to a tasking where there is either immediate risk of harm to the individual, or no professional medical care has been rendered to a patient.

It should be made distinct from other forms of rescue, such a rescue crewman winching to rescue a stranded climber with no medical problems.

The tyranny of distance

Most doctors interested in this field understand the concept of the ‘golden hour’: that interventions in the first hour of a major trauma are most effective in reducing negative clinical outcomes.

The impact of distance should not be understated. For example, when I worked in the United Kingdom, distance was often of little concern. Most major trauma centres near me were within a thirty to forty minute drive, even in ‘rural’ areas. Some air taskings were only a five to ten minute flight. London HEMS has an average flight time of 7.5 minutes ⁴. This means that scenes are often ‘fresh’ and you can often be the first person on scene.

However, in many parts of Australia, this is not the case. You may arrive as the first statutory ambulance service response an hour after the first 000 call. Distance degrades outcomes simply due to the fact that transport times are long. Taskings may require refuelling stops, or multiple road transfers in various vehicles to get to a definitive retrieval platform. Thrombolysis may be given more frequently than in other parts of the world where rapid access to PCI is available.

Due consideration should be made to this when planning which retrieval assets are allocated to which tasks - for example, a commercial jet may actually be the fastest route of retrieving a patient.

On taskings, medical crew should plan and prepare for prolonged taskings: including preparing adequate supplies of drugs, oxygen and consumables as well as considering implentation of ICU-standard cares such as turning and eye care.

Private NGOs and state-based retrieval systems

There are many different operators within the PHRM sphere. Often, services are provided by non-governmental organisations: these may be ‘for-profit’ commercial organisations or ‘charitable’ organisations.

International retrievals may be coordinated by a medical assistance service, who then subcontracts the aircraft from a private ambulance whilst sourcing individual contractor medical staff to provide the medical services. When considering working in this sphere, it is important to examine your medicolegal coverage and own clinical governance mechanisms for personal equipment and medication.

State-based retrieval systems

Primary taskings that originate from the 000 999 system are often handled via a state-based coordination system. This is to streamline services, avoiding time wasted through system friction finding providers and to standardise communication and clinical practice. This is often the remit of the statutory ambulance service. As an example, Retrieval Services Queensland operates a team of a Retrieval Coordinating Consultant, with a team of nurses working closely with the statutory ambulance service to prioritise, and allocate assets to taskings across the State.

Evolution of coordination systems and drivers

Coordination was fairly poor prior to standardisation of coordination systems. This may have been as simple as an Emergency Department calling various air ambulances locally to them to see if they could accept a tasking. This has had many flaws - time wasted in critical missions, miscommunication leading to patient and aircraft harm.

A growing recognition that PHRM is not a field for the ‘interested amateur’ doctor led to a tightening of clinical governance requirements - with the overarching aim of the same standard of care in-hospital delivered pre-hospital. It is no longer sufficient to say that a doctor ‘had a go’ or ‘gave it their best shot’ - individuals working in this field need to be a useful asset to their paramedic and nursing colleagues and to strive for the best outcomes for patients.

Basic principles underlying care

Equity of access

I find this a pretty straightforward concept to examine. According to medical ethics,

justice is the principle that all persons will be treated fairly and equally.

Many PHRM emergencies are unpredictable and have serious risk of harm leading to increased morbidity and mortality. For example, early interventions that may reduce the risk of secondary brain injury may lead to downstream cost savings in neurorehabilitation.

However, PHRM services are costly and may be distributed amongst different health systems. For example, international retrieval is usually covered by travel insurance and is negotiated in a private system - the costs can be extraordinary.

The ethical dilemma here is how to recoup the cost of PHRM services - this can be in the form of general taxation, road taxation levies, subscription and insurance or private enterprise.

Safety - you, scene, team, patient

For newcomers to PHRM, scene safety will be an important learning point. Within the hospital setting, the environment is relatively safe. Outside of hospital, there are multiple hazards: the retrieval platform (e.g. helicopter/vehicle), response driving, the weather, industrial hazards, sharps, fuel spillage…the list goes on.

The main point to impress is that you do not aim to become a casualty yourself. Aside from the personal inconvenience, there is now an additional patient to care for - you. And by taking yourself offline, the mission may have to be abandoned or rescheduled leading to patient harm.

The best advice is to learn from your paramedic colleagues who work in this environment, day-in and day-out. Ask their opinions - follow their lead. Observe their dynamic risk assessment. Ask and learn.

A basic premise is to consider a risk matrix for yourself, the team and the patient. Prior to the tasking, run through what hazards may be present.

What hazards are there to yourself?

Are you fatigued?
Do you have appropriate personal protective equipment (PPE)?
Does the patient have a high risk of aggression?

What hazards are there to the team?

What is the time of day?
Do you have enough fuel to return home safely?
Are you likely to be entering an austere environment: what will your communications be like?
Are there warnings from Fire & Rescue services about chemical spillages?
Will you be flying over water: are you HUET-current?

What are the hazards to the patient?

These can be obvious, like a motorcyclist trapped under a vehicle.
Is being rescued a risk? For example, a crush injury being released.
Do they have specific pathology that makes flight dangerous - e.g. an untreated pneumothorax?

A good practice is to start by performing a ‘windscreen assessment’ as you get close to your scene. If you are in an aircraft, this involves you actively assessing hazards as you often orbit overhead looking for a suitable landing site.

If you are in a road vehicle, do not rush out in a flurry as soon as you arrive. Sit and look out of your windscreen. Make a conscious effort to assess what you see - are the roads still open and traffic flowing? Is there fuel spillage? If it is noisy in the car, it will be noisy outside - are you prepared for difficult communication? How are the other emergency vehicles parked - what are your egress options? Is there glass on the floor? Where do you envisage a kit dump being prepared?

Dynamic leadership and active team membership

One of the most enjoyable aspects about PHRM is the teamwork. Teamwork is often touted as being one of the enjoyable aspects of medical practice - for me, PHRM embodies this. I have yet to find an environment where you work so intimately with a colleague: building up a small team in challenging environments. Eventually, you will come to work almost in tandem with your paramedic or nursing colleagues - both knowing what the other is thinking and valuing what each party brings to the table.

Often at a scene, you wil become a defacto leader, by virtue of your job title. Many prehospital systems designate the first doctor on scene to be a medical incident commander in a major incident - or more simply, other members of the prehospital team will expect you to lead.

In these situations, I would direct the reader to two quotes from the Royal Military Academy, Sandhurst s document given to all officer candidates - ‘Serve to Lead’

Leadership is not imposed like authortity. It is actually welcomed and wanted by the led. Correlli Barnett Address to the Army Staff College 1977

I paraphrase this to: ‘In a crisis, everyone craves leadership’. Remember this, and the lead your team forward in adversity.

Leadership is the phenomenon that occurs when the influence of A (the leader) causes B (the group) to perform C (goal-directed behaviour) when B would not have performed C if it were not for the influence of A. Cohesion: The Human Element in Combat 1985

Conversely, it is important to accept the role of being the follower. The PHRM is an unforgiving, alien environment to the newcomer. Despite the fact that you may already be a specialist or a senior registrar in hospital, it is vital to actively listen to the advice and opinions of your paramedic/nursing colleagues. It is highly likely that they have been in the situation before - and you would be very foolish to ignore their advice.

Situational awareness, prioritisation of care and anticipation & planning

Situational awareness refers to the constant reassessment of the environment you find yourself into. Break this assessment down into safety and patient care components.

From a safety perspective, consider your nearfield and farfield. Your nearfield can be considered to be an area of around three metres in diameter around your person - assess this for immediate risks and hazards. This may be the identification of an undeployed airbag as you approach a car - or it may be the narrowing of your exit escape options as someone blocks the door in a house.

Your far-field can be considered an area five to ten metres in diameter around you. These can be hazards that may be slower to develop.

Prioritisation of care

You may attend scenes with multiple casualties. This will be covered in detail in later chapters but it is important to recognise the limitations of your team and being spread too thinly. A true major incident is one that overwhelms the capacity of local PHRM and health services. In this role, it is important to assume the role of a Major Incident Commander and not get bogged down with clinical care.

If a scene has multiple casualties, then it is important to first triage casualties using a validated system such as the NASMED trauma sieve tool or QAS triage tool before directly treating patients. It is important to notify your tasking agency at the earliest opportunity about the number and severity of casualties.

Anticipation and planning

Always consider the next step in your care - this can be considered as strategising. Pre-tasking considerations:

How many casualties?
What is the location and nearest hospitals/trauma centres?
Who is on scene and who is enroute?
What do I know about the patients - severity and illness?
What are the likely differential diagnoses?
What do I expect I will need on scene - should I draw up drugs now?

On-tasking considerations:

What does the patient need right now?
What is the best facility for this patient and by what means of transport? (It may not be the one you travelled in!)
Have I updated my tasking agency?
What treatment will truly change outcomes?
Always ask yourself: “Why am I still here?”

Post tasking

Do I need to debrief?
What do I need to restock to get back online as soon as possible?
Have I completed any required paperwork?

Transport as a treatment

This concept alludes to the final point in the ‘on-tasking considerations’ list above. Always ask yourself, “why I am I still here?” Why have I not departed for hospital yet? Verbalise your mental trajectory to your team: “In ten minutes, I want us packaged with a unit of blood administered so we can leave for hospital”.

A cheesy, but useful axiom in PHRM is “sometimes the best treatment is diesel”. It is worthwhile keeping this in mind - your goal is to upgrade the level of care your patient is receiving, and to transport them to definitive care. It is unlikely you will do the latter at the roadside.

Prehospital agencies

You will work with a variety of agencies in the PHRM field. It is worthwhile knowing their roles.

Fire and Rescue (FRS)

FRS are likely to be the agency you work most closely with. Traditionally, FRS are thought to deal with structural fires - houses, and the like. This is not true. In 2019-2020, the Queensland Fire and Rescue Service attended 2.5x the number of road crashes vs structural fires! ⁶

An excellent resource to discover the principles behind vehicle stabilisation and scene safety by FRS crews can be found here

In general, FRS crews have basic life support training and most engines have access to a defibrillator, oxygen, bag-valve-mask and basic airway adjuncts.

On arrival to any road traffic collision scene, it is important to identify the fire officer in charge. This is usually denoted by helmet markings - ask your paramedic colleagues. Before entering a scene, ask this officer:

Is the scene safe to approach?
A location for a kit dump - a safe location to place your equipment. This is usually on a piece of tarp.

Police

Depending on jurisdiction, police have the primary responsibility for scene safety. They manage access to scenes, road closures and traffic movement. At a fatality, be careful about disturbing the scene after death is pronounced as a criminal investigation may need to take place and evidence preserved. You may be required to provide professional statements about incidents. Police officers are generally very friendly and have also bailed me out by driving my car to hospital when I have had to travel with a patient!

Depending on level of training, medical skills may be limited to basic first aid or may be quite advanced (e.g. BLS with airway adjuncts, needle decompression) by firearms teams.

Volunteer ambulance officers

Volunteer ambulance officers have varying skillsets depending on jurisdiction. These are individuals who provide useful community services but may have limited clinical exposure.

Examples include:

Other volunteer agencies

You may work closely with other agencies such as :

State Emergency Service: local volunteers assisting with state emergencies, natural disasters.
Volunteer marine rescue: you may encounter these services when assisting with boating rescues or offshore searches.

Types of missions

I’ve focused on the main taskings here - ACEM also want you to consider international taskings and repatriation but I feel they are similar to an interhospital transfer

Prehospital taskings

Also known as a ‘primary’. This is a tasking that usually comes from a statutory emergency service via the 000 / 999 tasking system.

You will often be dispatched ‘on spec’, based upon very limited information. Dispatching will be covered later on, but in summary - a computer-based system called AMPDS assigns urgency criteria based upon keywords said by the caller. Therefore, your system may dispatch a critical-care team based upon very limited information and you may be stood down on route.

These missions are often time-critical. In my experience, these are often (in no order of frequency):

Motor vehical accidents
Cardiorespiratory arrest (primary cardiac, hanging, drowning)
Other major trauma - e.g. stabbings, gunshot wounds, blunt trauma (e.g. falls from height)

Interhospital taskings

Interhospital taskings are where your skills as a critical care doctor really come to shine. Effectively, you are required to provide hospital-level critical care transfers from one facility to another.

Often, this will be ICU-to-ICU or ED to ICU transfers.

Due to the tyranny of distance, another common tasking is a lysed STEMI for onward CCU care.

Occasionally, these can be from smaller hospital facilities with limited skillsets where you are upgrading the care provided and then transferring onwards.

Difficulties with these types of tasking include:

Efficient assessment, stabilisation and management of a critically unwell or undifferentiated patient.
Transfer in a platform with limited facilities and ability to intervene mid transfer

Rescue

You may be asked to attend primary non-medical search & rescue taskings such as rescue of a lost mountain climber, or a boat lost at sea. Your attendance is often requested because of a paucity of information as to why the individual has become distressed - or you may be asked to wait at base because of weight issues.