Airway management in an emergency

Essentials

  • Bag-mask ventilation is the most important skill to possess when a patient’s respiratory function becomes compromised.
  • Supraglottic airway devices (laryngeal mask airway and tube) can be used to maintain a patent airway without needing to intubate the trachea. Supraglottic devices do not offer protection against aspiration and are therefore contraindicated in patients at risk of aspiration.
  • According to current guidelines, tracheal intubation should only be attempted by those who are competent in this skill and have on-going experience with the technique.
  • Sedating medication and muscle relaxants to assist intubation can only be used by doctors who have received training in anaesthesiology.
  • If airway patency cannot be maintained with these methods, emergency tracheotomy, i.e. cricothyrotomy (coniotomy), should be considered.
  • Selection of appropriate airway management device depends on training and experience. In an emergency situation one must be able to apply the device rapidly, using at maximum three attempts.

Oropharyngeal airway

  • Bag-mask ventilation can often be facilitated by the insertion of an oropharyngeal (oral) airway.
  • Oxygenation equipment and a suction device must be available.
  • Choose a size 3–4 oral airway for an adult, a smaller one for a child.
  • Insertion of an oral airway (picture 1)
    • If necessary, clean the mouth and pharynx.
    • Place the patient in the lateral position.
    • Introduce the airway 3 cm into the mouth with the concave side of the airway towards the roof of the mouth.
    • Turn the airway 180° so that the convex side is towards the roof of the mouth, and push the airway deeper into the mouth.
    • The airway is correctly inserted when its lower end rests behind the root of the tongue and the widening at the upper end rests outside the mouth in front of the upper teeth.
    • If the patient starts to cough, pull the airway back 1–2 cm.

Laryngeal mask airway (LMA)

Equipment

  • Choose a size 3–5 LMA for an adult, a smaller one for a child (table T1), with or without a handle.
    • Note! It is a good idea to choose one LMA model among the many marketed and familiarise oneself with its use.
  • A 30 ml syringe to fill the cuff
  • Sticky tape or cotton ties to secure the tube
  • Oxygenation equipment

Table 1. Choosing the size of an LMA
Patient Weight (kg) LMA size Cuff filling volume (ml)
Neonate < 5 1 4
Infant 5–10 1.5 7
Small child 10–20 2 10
Child 20–30 2.5 14
Adolescent/small sized adult 30–50 3 20
Adult 50–70 4 30
Large sized adult > 70 5 40

Technique

  • Insert the LMA according to the manufacturer's instructions (insertion of an LMA with a handle: see picture 2).

Evidence Summaries

Laryngeal tube (LT)

Equipment

  • Choose an LT based on the patient’s age and size (table T2).
  • A 30 ml syringe to fill the cuff
  • Sticky tape or cotton ties to secure the tube
  • Oxygenation equipment

Table 2. Choosing the size of an LT
Size of the patient Colour of the LT LT size
Child 12–25 kg green 2
125–150 cm orange 2.5
Adult < 155 cm yellow 3
155–180 cm red 4
> 180 cm violet 5
Technique

  • Open the patient’s mouth with one hand whilst introducing the LT with the other into the pharynx, deep enough to align the connector piece with the teeth.
  • A laryngoscope can be used to open the mouth, but it is not necessary.
  • Fill the cuff according to the manufacturer's instructions, and secure the LT with sticky tape or cotton ties.
  • See picture 3.

Tracheal intubation

Equipment

  • Laryngoscope, check light bulb operation
  • Tracheal tubes
    • Adult male patients: size 8–9
    • Adult female patients: size 7
    • Have available a tube of a smaller size than the chosen one
    • Paediatric tracheal tubes, see table T3.
  • Introducer (bougie)
  • Cotton tape to secure the tube
  • Syringe to fill the cuff
  • Stethoscope
  • Oxygenation equipment (oxygen source etc.)
  • Equipment for bag-mask ventilation (masks, oxygen tubing)
  • Equipment for emergency tracheotomy
  • Equipment for venous cannulation and fluid administration
  • Laryngeal mask airway
  • Functioning suction equipment (check!)
  • Resuscitation drugs (e.g. adrenaline, see also 1 )

Table 3. Choosing a paediatric tracheal tube
Age (years) 0 0.5 1 2 4 6 8 10 12
Tracheal tube size 3.5 4 4 4.5–5 5–5.5 5.5–6 5.5* 6* 6.5*
* Cuffed tube
Indications

  • Glasgow Coma Score < 9 2 without an easily corrected cause (e.g. hypoglycaemia/hyperglycaemia)
  • Airway management if oxygenation and/or ventilation of the patient is not successful with other means
  • Prevention of aspiration
  • Cardiac and/or respiratory arrest (treat opioid-induced respiratory depression with naloxone whilst bag-mask ventilating the patient)
  • Anticipated airway obstruction (inhalation injury, trauma to face or neck, uncontrollable haemorrhage or allergic pharyngeal oedema).

Technique

  • An assisting nurse should participate in the procedure.
  • Elevate the patient's head 3–5 cm with a pillow or other support.
  • Hold the patient's head tilted backwards with your right hand whilst inserting the laryngoscope with your left hand through the right corner of the patient’s mouth. In this way, the tongue will stay on the left side of the laryngoscope blade groove when the tip of the blade is pushed into the pocket between the epiglottis and the tongue.
  • The assistant may improve visibility by applying traction to the patient’s right mouth corner and by applying pressure to the cricoid cartilage to help improve the laryngeal view.
  • Lifting the laryngoscope in the direction of the handle to raise the tongue will usually bring the vocal cords easily into view. (Note! Do not lever the handle towards the teeth!)
  • It is important to carry out the entire intubation procedure under direct vision. This ensures that the tracheal tube passes through the vocal cords and to a suitable depth (the distance between the upper edge of the cuff and the level of the vocal cords should be about 2 cm).
  • If you cannot visualise the vocal cords within 30–60 seconds, ventilate the patient for a while with 100% oxygen, i.e. bag-mask ventilation with an attached oxygen reservoir bag. For the next intubation attempt, ask the assistant to insert an introducer into the tracheal tube in order to bend the distal tip of the tube upwards. Even in this case you should guide the tracheal tube under direct vision below (behind) the epiglottis.
  • If the patient strongly resists the intubation attempt and is able to maintain average respiratory function, abandon intubation.
  • If the patient resists intubation but is unable to maintain adequate respiratory function, a skilled intubator may consider administering intravenous benzodiazepines or opioids, e.g. diazepam 2.5–5 mg, fentanyl 0.05–0.1 mg or morphine 2–4 mg. In this situation, a doctor trained in anaesthesiology may consider the use of anaesthetic agents and muscle relaxants.

Avoiding oesophageal intubation

  • The following guidelines should be followed when intubating outside the operating theatre, or other well-equipped emergency facility, to avoid misplacing the tracheal tube into the oesophagus.
    • Always aim to intubate under direct visual control.
    • If you are unable to see the vocal cords or the arytenoid cartilage, use an introducer.
    • Auscultate the trachea, both lungs and the epigastric region. Monitor also the movements of the chest.
    • If a capnometer is available, attach it to the tracheal tube and check that the gas flowing out of the tube contains carbon dioxide thus confirming the correct position of the tube.
    • If you remain unsure about the position of the tracheal tube, extubate, bag-mask ventilate the patient with 100% oxygen and re-intubate if necessary.
    • If the patient is to remain intubated, ensure the correct depth of the tracheal tube (tip 3 cm from the carina) with chest radiography.

Evidence Summaries


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TY - ELEC T1 - Airway management in an emergency ID - 451492 BT - Evidence-Based Medicine Guidelines UR - https://evidence.unboundmedicine.com/evidence/view/EBMG/451492/all/Airway_management_in_an_emergency PB - Duodecim Medical Publications Limited DB - Evidence Central DP - Unbound Medicine ER -