Prehospital emergency care

Essentials

• Initially evaluate the patient's level of consciousness on a scale awake / arousable / unarousable. The level of consciousness should be further specified at a later stage using the Glasgow Coma Scale (GCS; see table ), but only after the patient's airway and breathing have been secured and circulation evaluated.

A. Airway

• Identify and correct possible airway obstruction:
  • Chin lift/jaw thrust (picture )
  • Remove any foreign bodies
  • Insert an oropharyngeal airway (picture ) or, if necessary, a supraglottic airway device (laryngeal mask or tube; pictures ), or intubate .

B. Breathing

• Identify and treat respiratory failure (oxygenation and ventilation).
• Be aware of the most common conditions causing respiratory distress (failure) and treat accordingly.
  • Pulmonary oedema
  • Exacerbation of asthma and COPD
  • Pneumonia
  • Pulmonary embolism
  • Hyperventilation
  • Tension pneumothorax
• Administer oxygen to all high-risk patients.

C. Circulation

• Identify and treat circulatory failure.
• Arrest external bleeding by compression or, in case of a bleeding limb, by a tourniquet.
• IV-access to all high risk patients
• Treat life-threatening arrhythmias (ventricular fibrillation, ventricular tachycardia) before transportation.

D. Other

• Specify the level of consciousness accurately, i.e. GCS.
• Prevent further trauma (skeletal support, vacuum mattress).
• Minimize heat loss (electric or regular blanket, warm fluids, warming up of the vehicle).
• Start pain relief as necessary with i.v. opioids or S-ketamine.
  • If placing of an intravenous line is difficult, medications may also be administered through intraosseous, nasal or buccal route.
• Choose whether to 'load and go' or 'stay and play'.

E. Abstain from treatment when the patient has no chance of recovery

• Lifeless (= no breath or heart sounds and unresponsive) trauma patients, when the initial rhythm is asystole or PEA (pulseless electrical activity)
  • Provided that the situation, personal skills and the available equipment allow (e.g. an emergency physician), bilateral thoracostomy and, if required, thoracotomy may be performed in a haphazardly encountered trauma patient.
• Normothermic lifeless adult (unwitnessed collapse), when the initial rhythm is asystole
• At least 15 minutes since cardiac arrest with no attempts at resuscitation
• Secondary signs of death evident
• Lifeless trauma patient with cranial crush injury or outflow of brain substance

When to intubate at the scene?

• Cardiac and/or respiratory arrest (when respiratory arrest is associated with heroin overdose treat by mask ventilation and i.v. naloxone)
• Low level of consciousness (GCS < 9) without readily treatable cause (hypoglycaemia, hypoxia, hypercapnia, bradyarrhythmia or tachyarrhythmia, hypotension, heroin or benzodiazepine overdose)
• Airway management, oxygenation and/or ventilation not successful or otherwise adequate by other means (oropharyngeal airway, oxygen therapy, CPAP/BiPAP, ”Ambu-bag” and mask ventilation). Prevention of aspiration.
• Anticipated airway obstruction (inhalation burn, trauma to the facial or neck region, uncontrolled bleeding or allergic pharyngeal swelling)
• If you have performed intubation only rarely, the use of a supraglottic airway device is recommended .
  • iGel laryngeal mask
  • Laryngeal mask airway (LMA, picture )
  • Laryngeal tube (LT, picture )

When to stabilize haemodynamics before transportation?

• Systolic blood pressure (BP) < 90 mmHg or > 220 mmHg, and the patient has cerebral manifestations
• Diastolic BP > 140 mmHg
• Heart rate < 40 or > 120/min, if it causes haemodynamic instability
• Even more readily in the presence of chest pain, dyspnoea, pulmonary oedema or altered level of consciousness
• Remember disturbed autoregulation of cerebral circulation in patients with cerebral trauma, infarction or bleeding. A high blood pressure is usually compensatory because cerebral perfusion pressure is dependent on systemic blood pressure; blood pressure should not be lowered aggressively during the prehospital phase (recommended upper limits: aneurysmal subarachnoid haemorrhage 160/95, intracranial bleed 180/100, cerebral infarction 220/120 mmHg). The safest medication for blood pressure reduction is labetalol in boluses of 10–20 mg i.v.; nifedipine may even be harmful!

When is transfer to hospital urgent?

• Load and go: the patient will benefit from rapid transportation to the final point of care.
  • Sharp trauma (shooting, stabbing) in the trunk or neck region.
  • Blunt trauma, if suspicion of continuing bleeding into a body cavity.
  • Other uncontrolled bleeding and/or signs of shock.
  • Clinical suspicion of massive pulmonary embolism.
  • Clinical suspicion of acute stroke (thrombolysis may be considered at the hospital).
• Stay and play: the patient's condition should be stabilized at the scene before transportation.
  • Resuscitation
    • If resuscitation of a patient with positive prognosis but recurring ventricular fibrillation is not successful, one may consider transporting the patient under resuscitation for an emergency invasive cardiology procedure (PCI).
  • Respiratory distress and facilities are available for symptomatic treatment (asthma, COPD, pulmonary oedema).
  • Bradyarrhythmia (atropine, external pacemaker) or tachyarrhythmia (cardioversion, antiarrhythmics).
  • Acute ST-segment elevation myocardial infarction, if thrombolytic therapy can be administered and there is no treatment unit which can offer emergency invasive coronary interventions (PCI) in the area.
  • Lowered level of consciousness, when the underlying cause is treatable (hypoglycaemia, hypoxia, hypotension, hypercapnia, bradyarrhythmia or tachyarrhythmia, certain intoxications) and adequate treatment facilities are available.
  • The patient meets the criteria for intubation (see above).
  • Needle thoracocentesis for tension pneumothorax (picture ) or bilateral thoracostomy using a knife
    • Notice that in most people a normal intravenous cannula is not long enough to release pneumothorax, and a longer cannula should be used instead.
  • Mechanical ventilation should not be instigated in a patient with pneumothorax without a chest drain in situ (risk of tension pneumothorax).
  • A patient with a cranial/cerebral trauma will benefit from early anaesthesia/ intubation and controlled (EtCO₂) ventilation.

Equipment of an ambulance

• See table .
• The requirements and the level of equipment needed for ambulances are based on local agreements and regulations.

Emergency care of the most common patient groups

• Establish venous access in all patients. Administer oxygen if required, monitor the patient's vital signs and continually observe the cardiac monitor, pulse oximetry as well as the patient's level of consciousness.

Resuscitation

• See .
• In ventricular fibrillation and pulseless ventricular tachycardia defibrillation is vital and must be carried out without delay.

Chest pain and myocardial infarction

• 14-lead ECG is essential. If ECG is not available, only administer basic therapy and transport the patient to the nearest care facility.
• Basic therapy (all patients): rest (the patient should not be forced to walk), half-sitting position, supplemental oxygen if required, ASA 250 mg p.o. (if not contraindicated: allergy for aspirin, asthma patients and active GI-bleeding) and isosorbide dinitrate (ISDN) spray (if systolic blood pressure > 100), i.v.-line, continuous ECG-monitoring
• Treatment of unstable angina pectoris. If ST depression and/or T wave inversion is evident on a 14-lead (V4R+V8!) ECG, beta-blockade only if required (e.g. metoprolol 1 mg i.v. until heart rate down to 60-70/min), nitrate infusion if long distance transportation to the hospital (starting dose 20 µg/min, the dose is increased by 10 µg/min at a time, targeting a systolic BP reduction of about 15% in normotensive and 25% in hypertensive patients, diastolic BP must remain > 60), opioids (morphine 4–6 mg i.v., until pain-free)
• Acute ST elevation myocardial infarction
  • Thrombolytic therapy, if not contraindicated and there is no emergency percutaneous coronary intervention (PCI) available within 90 minutes. Other therapy: see treatment of unstable angina pectoris . Enoxaparin 30 mg i.v. before thrombolytic therapy and 1 mg/kg s.c. after it, before transportation.
  • Enoxaparine should not be administered i.v. to patients older than 75 years because of increased risk of haemorrhaging. Give enoxaparine 0.75 mg/kg s.c.
  • If immediate defibrillation (and preferably external pacing) facilities are not available, thrombolytic therapy should not be administered outside the hospital.
  • Reperfusion arrhythmia often occurs after successful thrombolytic therapy and it may convert to ventricular tachycardia or fibrillation.
    • In such case the treatment is immediate defibrillation by 200 J.

Arrhythmias

• The patient is haemodynamically unstable if his/her BP < 90 and he/she complains of chest pain and/or has respiratory distress/pulmonary oedema and/or lowered level of consciousness.

Bradyarrhythmias (heart rate < 40/min)

• Atropine 0.5 mg i.v., up to 3 mg for all bradyarrhythmias!
• External pacing in Mobitz type II and total heart block irrespective of haemodynamic state, at least by using the “on demand” function (the condition sometimes worsens during transportation).
• In other bradyarrhythmias, external pacing is usually applied only if the patient is haemodynamically unstable or has a recent history of syncope.
• If external pacing is ineffective, consider dopamine (5–15 µg/kg/min) and/or adrenaline infusion (0.02–0.2 µg/kg/min), both titrated according to response.
• In hospital, treatment with isoprenaline is started or a temporary pacemaker is inserted.

Tachyarrhythmias (heart rate > 120/min)

is indicated if the patient is h"?>Haemodynamically unstable patient: electrical cardioversion
• If the patient is unresponsive and no carotid pulses can be felt (see Resuscitation ), administer a non-synchronized direct current shock at the device's maximum energy setting.Aloita 50&#x2013;100 J, ad 200 J (bifaasisella energiamuodolla).
• A synchronized direct current shock is indicated if the rate is fast (whether broad or narrow complex, heart rate usually more than 150/min) and the patient's condition is unstable. Start with 50–100 J, increasing up to 200 J (biphasic defibrillator). Sedation is usually required (e.g. S-ketamine in 25 mg boluses. S-ketamine causes only minor haemodynamic changes and spontaneous breathing remains. Be prepared for a brief respiratory arrest.
• If the patient is haemodynamically stable, pharmacological therapy is indicated.
  • Supraventricular tachycardia (narrow-complex, regular): try first with carotid massage / Valsalva manoeuvre. Pharmacological therapy: adenosine 6(+12) mg i.v. (as a rapid bolus into the antecubital or jugular vein, flushed with 20 ml of Ringer's solution/NaCl 0.9%). If adenosine is not effective, give verapamil 5(+5) mg i.v.
  • Broad-complex, regular tachycardia in a cardiac patient is usually ventricular tachycardia. If the patient remains stable treat with beta-blocker (e.g. metoprolol 5–10 mg) / amiodarone 150–300 mg i.v., otherwise cardioversion. In rare cases, SVT + aberrant accessory conduction pathway or WPW re-entry with antidromic conduction.
  • Recent-onset atrial fibrillation does not usually require treatment outside the hospital, unless the patient is haemodynamically unstable. Beta-blockers can be used to slow down the ventricular response.
  • In WPW syndrome, cardioversion is the safest alternative (avoid digoxin, verapamil, beta-blockers).
  • Atrial flutter can be slowed with beta-blockers or verapamil.
    • In the differential diagnosis of atrial flutter and supraventricular tachycardia, adenosine may be used to make the potentially slowing rhythm easier to interpret.

Respiratory distress

• You must be able to differentiate between the most common conditions that cause respiratory distress and tension pneumothorax as well as foreign bodies in the airways.
• Note whether the patient is able to speak in sentences/only use single words/unable to speak, record the respiratory rate, I/E ratio, breath sounds, SpO₂, skin colour and the possible use of accessory muscles.

Emergency treatment at the scene

Exacerbation of asthma or COPD

• The underlying disease (asthma or COPD ) is usually known. A forward-leaning position will help.
• Inhaled bronchodilators (e.g. salbutamol 5 mg + ipratropium bromide 0.5 mg × 1–2), methylprednisolone 125 mg i.v. and racemic adrenaline inhaled in a severe attack
  • Levo-adrenaline (= concentration used in resuscitation, i.e. 1 mg/ml) by inhalation, dose 0.5 mg/kg up to 5 mg at a time (like in the treatment of severe laryngitis)
• A COPD patient also requires supplemental oxygen in hypoxia, use a Venturi mask with adequate flow; a conscious patient does not stop breathing while receiving supplemental oxygen. The SpO₂ target is about 90% or the patient's own earlier level. If the level of consciousness deteriorates and/or the respiratory rate drops, reduce inspired oxygen fraction. A high carbon dioxide concentration does not kill the patient, but inadequate oxygenation will!
• Noninvasive mask ventilation (NIV) if the situation is severe

Pulmonary oedema

• Consider aetiology, i.e. cardiogenic or non-cardiogenic (sepsis/pneumonia, intoxication, hepatic failure, pre-eclampsia, airway obstruction).
• Start CPAP at 1 cmH₂O/10 kg and a nitrate infusion with 20 µg/min (if cardiogenic aetiology and the patient is peripherally cold and systolic BP > 100). In the presence of underlying ischaemia caused by tachycardia, administer beta-blockers with caution (metoprolol in 1 mg i.v. boluses), and morphine 4–6 mg i.v.

Pulmonary embolism

• In pulmonary embolism give oxygen and transport to the nearest diagnostic unit (pulmonary CT). Consider heparinization (e.g. enoxaparin 40 mg i.v.).
• In circulatory insufficiency (systolic BP < 90 mmHg), optimize preload (fluid bolus 10–20 ml/kg), dopamine or noradrenaline infusion 5–10 µg/kg/min if needed.
• Favourable case reports have been obtained with early thrombolytic treatment in resuscitation situations.
  Thrombolytic treatment is administered in the same way and using the same medications as in the thrombolytic therapy of myocardial infarction.

Pneumonia

• The patient is usually febrile with gradually worsening respiratory distress, unilateral rales on pulmonary auscultation .
• Oxygen therapy usually improves oxygenation; if not sufficient: CPAP is needed.
• In circulatory insufficiency: fluid bolus 10–20 ml/kg (may be repeated once), consider dopamine or noradrenaline infusion.

Foreign body in the airways

• Usually evident from the history: preceding meal, paediatric patients
• First aid: urge the patient to cough, sharp blows on the back, Heimlich manoeuvre for adults
• If the patient becomes lifeless, start CPR according to normal protocol.
  • The pressing increases pressure in the pulmonary cavity which may remove the foreign body from the airways.
  Unconscious patient: laryngoscopy and removal of the foreign body under visual control. If not helpful, intubation and manipulation of the foreign body into another main bronchus.

Pneumothorax

• Spontaneous pneumothorax: acute respiratory distress, sudden sharp or general chest pain and unilateral quiet breath sounds. If breathing is not too laboured and oxygenation remains good, give oxygen and send the patient to hospital .
• Remember the possibility of tension pneumothorax, particularly in trauma patients. The signs and symptoms include: severe respiratory distress and increased respiratory effort, tracheal deviation towards the contralateral side, tympany on percussion and decreased/absent ipsilateral breath sounds, distended neck veins and, finally, circulatory collapse.
• Treatment of tension pneumothorax (see ; picture )
  • Immediate needle thoracocentesis, thoracostomy and, if needed, insertion of a chest drain before transportation (at least if mechanical ventilation is indicated).
  • Needle thoracocentesis fails in as many as every third of cases (so-called false negative result), which should be kept in mind when planning further treatment!
  • In most people a normal intravenous cannula is not long enough to reach the pleural space, and therefore the puncture needs to be carried out using a longer cannula.

Lowered level of consciousness and seizures

• Recognize the most common, readily treatable conditions that cause disturbances of conscious level, i.e. hypoglycaemia (i.v. glucose), a low blood pressure and/or too fast/slow heart rate (see Haemodynamic therapy), hypoxia (oxygenation), hypercapnia (ventilation), intoxication (opiates, benzodiazepines; antidotes).
• If the cause is not easily treatable, see above for criteria of intubation at the scene.
• Remember that hypothermia may explain the lowered level of consciousness (the so-called urban hypothermia may develop even whilst the patient remains at home in room temperature).
• Seizures can usually be treated with a benzodiazepine administered through buccal, nasal, intravenous or intraosseous route; remember the post-ictal state (exclude hypoglycaemia as a possible cause for seizures). If the maximal dose of a benzodiazepine is not enough to end the seizures, saturation dose of a second line drug is given (e.g. phosphenytoin, levetiracetam, lacosamide). If seizures still continue the patient should be intubated under anaesthesia (requires the presence of an anaesthetist or emergency medicine physician).
  • Seizures can be regarded as having ended only when the patient returns to the previous level of consciousness or by confirming it with EEG investigation.
• The MIDAS mnemonic can be used for assessing the aetiology of decreased level of consciousness (Meningitis/encephalitis, Intoxication, Diabetes/metabolic reasons, Anoxia, Subarachnoidal haemorrhage/Subdural haematoma; see ).

Intoxication

• See
• Emergency treatment should be targeted at respiratory and circulatory support as described above. Do not hesitate to intubate if needed.
• Give activated charcoal (orally if conscious, and by nasogastric tube when the level of consciousness is impaired) if less than 2 hours have elapsed from the ingestion, if the substance is highly toxic, if the substance is known to depress intestinal functioning (opioids, tricyclic antidepressants) or when sustained release medications have been ingested.
• Antidotes for emergency treatment (administered according to response):
  • naloxone 0.04–0.2 mg i.v. (opioids, heroine), see also
  • flumazenil 0.1–1.0 mg i.v. (benzodiazepines)
  • glucagon 5–10 mg i.v. (0.1 mg/kg)+ infusion 3–5 mg/h (beta-blockers, calcium-channel blockers)
  • calcium chloride 1 g/5 min i.v., the dose can be repeated at 10–20 min intervals or given as an infusion 3–4 g/h (calcium-channel blockers)
  • hydroxycobalamin 5 g/30 min i.v. (cyanide, combustion gases).
• In cases of carbon monoxide poisoning, ending exposure and administering 100% oxygen are the vital components of treatment (use an oxygen mask with an oxygen reservoir. Note: a conventional oxygen mask only delivers about 35–40% FiO₂). Consider hyperbaric oxygen therapy (HBOT) if the patient remains symptomatic despite oxygen therapy of 4-6 hours duration. HBOT is always indicated in serious cases (impaired conscious level, circulatory failure)"?>. Conflicting evidence exists regarding hyperbaric oxygen therapy .

Trauma patients

• For transportation tactics see section ’When is transfer to hospital urgent’?
• A patient with a high-energy trauma usually needs two (or more) large calibre venous cannulas (diameter 1.7–2.0 mm). Take blood samples during cannulation.
• In a patient who is bleeding into a body cavity systolic blood pressure of around 80 mmHg is probably sufficient, but in cranial/cerebral trauma blood pressure should be kept higher (120 mmHg).
• If the patient bleeds, give 1 g of tranexamic acid intravenously .
• Fluid therapy: crystalloid until the target blood pressure is reached, a patient with cranial/cerebral trauma probably benefits from hypertonic saline.
• Give burn patients Ringer's solution or NaCl 0.9% at the rate of 1000 ml/h or according to Parkland’s formula.
• Intubation criteria: see above
• Remember the possibility of tension pneumothorax in a trauma patient. Treatment consists of immediate needle thoracocentesis.
• A patient with chest trauma requiring mechanical ventilation will need a chest drain before transportation.
• Consider all unconscious patients, those thrown out of a car and those with trauma to the head/neck region to have cervical spine injuries until proven otherwise.

Multiple-casualty incident

• Multiple-casualty incident (MCI) refers to an incident with two or more injured persons.
• Major incident refers to an incident the management of which will considerably increase the normal workload of health care providers.
• A Major Incident Plan is to be drawn up by local authorities to ensure the provision of medical assistance to casualties. The Regional Medical Officer will decide when to dispatch a medical or stand-by group to the site of the incident, unless written instructions are in force giving the Dispatch Centre the right to dispatch such a group without a formal request. In order to gain experience medical and other stand-by groups should also be used for the routine management of accidents. On the way to the scene of the incident, verify the type of accident, estimated number of casualties and the amount of ambulance equipment already summoned to the scene. If necessary, make a request for further assistance via the Dispatch Centre (ambulances and crew members, medical staff or other stand-by groups from neighbouring regions) and if a true major incident has occurred alert local hospitals accordingly. At the incident scene, report to the rescue leader (the chief fire officer) and take responsibility for the medical operations.

Triage during a major accident

1. Primary triage

• Primary triage is carried out by the first medical team at the scene.
• In primary triage, patients are quickly assessed and divided into four treatment categories (picture ) according to urgency of treatment. The assessment should not take more than 20 seconds/patient; the two patient interventions allowed during the assessment include turning an unconscious patient into a recovery position and arresting massive external bleeding.
• The patients are colour or letter coded according to their relative priority for treatment :
  • A red (critical)
  • B yellow (urgent)
  • C green (minor injuries, able to walk)
  • X black (dead = not breathing after opening of an airway, unresponsive, absent carotid pulse).
• In a major incident, a place is to be designated where the casualties are moved after primary triage (for emergency treatment).
• Emergency treatment is initiated for patients in the red (I) group according to available resources.
• Walking patients (green group III) are assembled in a separate area (a bus or other feasible alternative, if available).

2. Secondary triage

See table
• After emergency treatment, the patients are re-triaged at the scene according to their injury.
• Triage is repeated again as the patients arrive at hospital.
• After emergency treatment, a patient may be allocated to a different group, e.g. an unconscious patient with airway obstruction moves from red to yellow after airway has been secured (intubation).

Related resources

• Cochrane reviews
• Other evidence summaries

Ədəbiyyat

1. Fitzgerald M, Mackenzie CF, Marasco S, Hoyle R, Kossmann T. Pleural decompression and drainage during trauma reception and resuscitation. Injury 2008 Jan;39(1):9-20.
2. Davies GE, Lockey DJ. Thirteen survivors of prehospital thoracotomy for penetrating trauma: a prehospital physician-performed resuscitation procedure that can yield good results. J Trauma 2011;70(5):E75-8.