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© 2005 The Medicine Publishing Company Ltd303ANAESTHESIA AND INTENSIVE CARE MEDICINE 6:9

Pre-hospital trauma care is a highly specialized and potentially dan-gerous area of medicine. Anaesthetists are increasingly being called to provide input to hospital Forward Aid Teams. Suitable equipment and training can make this an interesting and challenging task, but without such provision, the situation can become a frightening and dangerous episode for the doctor and the casualty.

EquipmentHealth and safety legislation dictates the following absolute mini-mum personal protective equipment (PPE): • fire-retardant hi-visibility overalls (long sleeves, dual reflective

hoops on trunk, arms and legs)• boots with reinforced toecaps • gloves • labelled helmet • eye protection• PPE relevant to the working environment (e.g. noise or dust

protection). The equipment carried depends on the incident, the skills of the doctor and the likely interventions needed. Time to definitive care should be kept to a minimum. Equipment familiarity reduces intervention time and improves patient outcome.

Scene safetyThe pre-hospital environment is often cold, wet and full of potential hazards for casualty and rescuer. Protection from sharp objects and agents, such as chemicals, is mandatory throughout the extrica-tion. Unnecessarily prolonged exposure of the casualty should be avoided. Prevention of heat loss and active warming should begin as soon as possible. Accident scenes are under police control, with the fire brigade Officer in Charge (OIC, white helmet) responsible for scene safety and management. On arrival, liaise with the ambulance crew or

Ambulance Incident Officer in attendance. Ask the OIC if it is safe to approach the casualty. If you are the first on the scene, you must assess all potential risks and if there are any doubts about personal safety, do not approach the casualty until support arrives. A thorough search of the surrounding area should be made to avoid missing any casualties.

KinematicsAn accurate and complete history of the mechanism of injury allows 90% of injuries to be predicted. To gather your thoughts on the way to the accident, listen to any emergency service ‘first reports’. On arrival, look around and ask questions to ascertain hazards, events and forces involved. This information must be passed to hospital staff because, despite a casualty appearing uninjured, the accident scene may justify more extensive inves-tigation. Digital or Polaroid photographs can be invaluable in describing the scene.

ApproachIf possible, approach the casualty from the front, avoiding unneces-sary rotation of the cervical spine. Attempt to make verbal contact, by announcing who you are and asking something simple, such as ‘Do you have pain anywhere?’ A coherent response immediately tells you:• the airway is clear• breathing is at least adequate• conscious level is normal, suggesting that blood pressure is also

adequate• pain will highlight serious injuries.The application of portable pulse oximetry gives information about peripheral perfusion, pulse rate and oxygen saturation. If it fails to pick up a signal, consider shock or hypothermia because it works well even in poor climatic conditions. Little more assessment may be required. Research has shown that the best outcome is achieved if definitive care is delivered within 1 hour (the golden hour). Ideally no more than 10 min (the platinum 10) of this time should be taken up with extrication and evacuation. Further assessment and intervention should not be at the detriment of time to definitive care. Anything other than a coherent response to initial questions indicates the need for rapid identification of the cause and may warrant rapid extrication and intervention. To aid rapid extrica-tion in difficult access conditions, the fire and rescue service is increasingly applying devices such as the ‘speed board’ during first contact with the casualty, offering a degree of spinal immobiliza-tion while rapidly extricating time-critical patients.

Massive haemorrhage control To avoid a situation in which there is a clear airway, but no circulat-ing volume, a rapid attempt should be made to control any imme-diately life-threatening external haemorrhage. This may involve pressure dressings, indirect arterial pressure or tourniquets, but should not distract from airway control for more than 1 min.

Airway and cervical spine controlIf in doubt, or the kinematics suggests a spinal injury, immobilize the neck. On immediate contact, this involves manual in-line stabilization in the neutral position and a cervical collar; and on extrication, head blocks with a forehead and chin strap.

Anaesthetic priorities in pre-hospital trauma careMark Forrest

Jason van der Velde

Mark Forrest is Consultant in Anaesthesia and Critical Care in North

Cheshire Hospitals NHS Trust. He is the founder of the Royal College

approved Anaesthesia Trauma and Critical Care (ATACC) course and

Medical Director of the ATACC Medical Rescue Team. www.atacc.co.uk

Jason van der Velde is Staff Grade in Anaesthesia and Critical Care

in North Cheshire Hospitals NHS Trust. He worked for 6 years in the

ambulance service in South Africa, and is a Medical Liaison Officer for the

United Nations involved in operations coordination and control of rapid

onset humanitarian disasters.

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© 2005 The Medicine Publishing Company Ltd304ANAESTHESIA AND INTENSIVE CARE MEDICINE 6:9

with thoracic trauma a high index of suspicion and regular re-assessment should be maintained. Traditionally, if an open chest wound is identified, an occlusive dressing secured on three sides, or an Ashermann seal, is applied. Recently, two alternatives have been suggested, open thorac-ostomy, or seal the hole and observe for exacerbating pneumo-thorax. Continual re-assessment is essential. If helicopter transport is required, formal thoracostomy is the favoured option. In cases of suspected haemothorax, drainage should be attempted only in severe respiratory compromise. It is a fallacy that drain clamping tamponades bleeding, because the hemithorax will accommodate the whole circulating volume comfortably. Large haemothoraces usually require urgent thoracotomy, but despite some successful cases, the literature offers limited support for this in the pre-hospital environment. Indications for emergency thoracotomy1 are:• witnessed loss of output in penetrating chest trauma• traumatic cardiac tamponade• hilar clamping for thoracic bleeds• cross-clamping descending aorta in massive uncontrollable

subdiaphragmatic haemorrhage.

CirculationIncompressible, internal haemorrhage cannot be managed effec-tively at the roadside and evacuation to the operating theatre should not be delayed. Intravenous fluids may worsen bleeding, and, at best, they buy time to ‘scoop and run’. The current UK consensus guidelines2 recommend ‘permissive hypotension’. In blunt trauma this involves the titration of boluses of fluid until a radial pulse is present and no more. In penetrating trauma, studies have demonstrated improved survival with blood pressures of 70–80 mm Hg systolic (presence of a femoral pulse). This additionally avoids the problems of dilutional anaemia, coagulopathy, large third-space fluid loss, acute lung injury and acute respiratory distress syndrome. There has recently been renewed interest in the use of small volumes of hypertonic saline (typically 5, 7.5 or 10%), usually combined with a colloid, such as dextran or starch, to prolong the action of the fluid. A maximum of 4 ml/kg is recommended,

If the casualty is talking, his airway is obviously clear; simply apply high flow oxygen from a non-rebreathing mask. Noisy breathing, silent breathing with obvious respiratory effort, and apnoea should all raise concerns, especially if associated with unconsciousness. Simple manoeuvres can be tried first, such as jaw thrust, or a cautious chin-lift, avoiding neck extension. Con-sider airway adjuncts, remembering nasopharyngeal airways are contraindicated in suspected facial or basal skull fractures. When the airway is seriously compromised or the Glasgow Coma Score is less than 8, intubation is required. However, this may be technically difficult, hampers extrication and may be impossible during an entrapment. In these situations, the laryngeal mask airway (LMA) is becoming increasingly popular (Figure 1). There is a significant risk of aspiration, but balanced against the quality of the airway during extrication the LMA is very useful and frees the rescuer’s hands for ventilation or other interventions. Once the casualty has been extricated to a safe location, rapid-sequence induction can be performed with appropriate drugs, equipment and skilled assistance (Figure 2). The risks of rapid-sequence induction in the field should not be underestimated and they should be balanced against the risks of aspiration and inadequate ventilation during the journey to hospital. If you are prepared for rapid-sequence induction, you need to be equipped for failed intubation and have a familiar tracheostomy kit readily available.

BreathingAssessment of breathing includes overall appearance, rate, depth, pattern and equality of air entry. Feel for tracheal position, laryn-geal crepitus and surgical emphysema. Exposure must be brief, but adequate (i.e. full 360° survey for penetrating chest wall injuries). Needle thoracocentesis can be life saving, but is probably overused and should be reserved for life-threatening tension pneumothorax (i.e. SaO2 < 93% on oxygen, grossly unequal chest movements or loss of major pulses associated with major chest trauma). Classical signs, such as tracheal deviation and distended neck veins, can be unpredictable, while hyper-resonance can be difficult to detect in a noisy pre-hospital situation. In any patient

2 Pre-hospital rapid-sequence induction with appropriate equipment

and skilled assistance.

1 Airway maintained with a laryngeal mask airway in a confined space.

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© 2005 The Medicine Publishing Company Ltd305ANAESTHESIA AND INTENSIVE CARE MEDICINE 6:9

which expands the circulation by a volume equivalent to 3–4 litres of crystalloid. Despite early concerns about safety, these fluids appear to have no serious adverse effects,3 are at least as good as the current standard of care and may be better. They have the practical advantages of rapid effect, with the volume easily administered through a small-bore cannula. They may soon play a greater part in shock resuscitation, especially when associated with head injury, because they also reduce brain swelling more effectively than mannitol. Any analgesic or anaesthetic drug administered during permis-sive hypotension has a more potent effect, so doses should be reduced and effects closely monitored.

Disability and analgesiaHead injuries are common. The best pre-hospital care requires a clear airway, good ventilation and preventing hypotension (systolic pressure < 100 mm Hg). If the Glasgow Coma Score is falling, consideration should be given to immediate rapid-sequence induc-tion, tracheal intubation and control of ventilation. In the pre-hospital environment, fractures can be immobi-lized, good analgesia provided and a peripheral pulse checked. In suspected pelvic fractures, do not ‘spring’ the pelvis, assume a fracture and apply a pelvic strap for pain relief and haemorrhage control. Entonox can be useful for fractures, dislocations and painful minor injuries though caution must be used in chest or head inju-ries, scuba divers and casualties requiring more than 50% oxygen. Local blocks have limited value in this situation, though a femoral nerve block can be used for femoral fractures when long transport times are involved. Opioids and ketamine remain the cornerstones of pre-hospital analgesia. Diamorphine carefully titrated to response, in small increments, offers high quality analgesia, with a degree of anxio-lysis. Ketamine can provide more profound analgesia, with a dis-sociated state of consciousness, ideal for ‘field’ surgery or painful extrication. Emergence phenomenon or agitation may require a benzodiazepine (e.g. midazolam). Despite its reputation, ketamine reduces blood pressure and, in sufficient dose, renders the patient unconscious with potential airway compromise. Practitioners should not use drugs for the first time at the roadside.

KEY REFERENCES1 Oats T, Keogh S, Clark H et al. Prehospital resuscitative thoracotomy for

cardiac arrest after penetrating trauma: rationale and case series.

J Trauma Injury Infect Crit Care 2001; 50: 670–3.

2 Greaves I, Revell M, Porter K M. UK consensus guidelines for shock.

Resuscitation. J R. Coll Surg Edinb 2002; 47: 451–7.

3 Mauritz W A, Schimetta W B, Oberreither S C, Polz W B. Are hypertonic

hyperoncotic solutions safe for prehospital small-volume

resuscitation? Results of a prospective observational study. Eur J

Emerg Med 2002; 9(4): 315–19.