Airway management and assisted ventilation in an emergency
- Respiratory insufficiency is managed by ensuring a patent airway and assisting ventilation. The most common causes of loss of airway patency and/or respiratory insufficiency are cardiac arrest, impaired consciousness or critical respiratory distress.
- The simplest way to ensure airway patency and to assist ventilation is to open the airway manually and to start assisting ventilation using a bag-mask attached to oxygen.
- The airway must be kept patent and maintained using an airway device, such as an oropharyngeal (oral) or supraglottic airway, an endotracheal tube or by an emergency tracheotomy.
- An oral airway can be used initially for assisted ventilation with a bag-mask.
- A supraglottic device should be used as the primary airway device.
- Tracheal intubation should only be performed by anaesthesiologists, intensive care, prehospital or other emergency care specialists, who are well acquainted with and competent in this skill.
- In patients with cardiac arrest or impaired consciousness, assisted ventilation should primarily be started using a bag-mask attached to oxygen.
- If in hospital, always ask for further assistance.
- In primary health care, act according to local guidelines and/or call the emergency number (112) to get support from emergency services for treatment and to have them take the patient for further treatment, as necessary.
- To facilitate bag-mask ventilation, an oral airway should be inserted, as necessary (Image (Insertion of an oral airway)).
- Choose a size 3–4 oral airway for an adult, a smaller one for a child. The correct length is the distance from the corner of the patient’s mouth to the earlobe.
Choice of airway device
- Laryngeal mask airway, LMA
- The correct size depends on the manufacturer and the model.
- Laryngeal tube, LT
- For choice of size, see Table T1.
The most common problems
- Placement of the laryngeal mask airway (LMA) does not result in a good seal.
- Wrongly chosen size of device
- Device introduced obliquely into the pharynx
- Fix the problem by reinserting the device.
- The laryngeal tube (LT) does not produce a good seal.
- Make sure that the cuff is intact and the air volume correct.
- Check the correct depth (deflate slightly, as necessary, insert at correct depth, fix carefully).
Table 1. Choosing the size of laryngeal tube (LT-D)
|Patient’s weight/height||LT-D colour*||LT-D no.|
|Adult||< 155 cm||yellow||3|
|> 180 cm||purple||5|
|* The corresponding colour on the syringe shows the maximum cuff filling volume.|
- After inserting the airway device, continue assisted ventilation using a bag attached to the airway device.
- The tidal volume for an adult patient is approx. 500 ml and the respiratory rate 15 per minute.
- Make sure that the patient’s chest rises with each ventilation and that the ventilation is effective (Table T2).
- All patients should have
- 3-lead ECG monitoring
- expiratory carbon dioxide monitoring (etCO2, capnograph) with graph display.
- If the patient has a rhythm with pulse, a SpO2 sensor and automatic pneumatic noninvasive blood pressure (NIBP) monitoring should be used in addition to monitoring the rhythm.
Table 2. Monitoring the success of ventilation
|Observation||Issues to be observed|
|Does the chest rise?||Does the mask sit tightly on the face?|
|Is the mask of the right size?|
|Are the head position and the grip correct?|
|Is the oral airway of the right size?||The oral airway must be measured before insertion. The correct length is the distance from the corner of the patient’s mouth to the earlobe.|
|If the oral airway is of the wrong size, it will obstruct rather than open the airway.|
|Is air going into the stomach?||Make sure that the airway is patent.|
|Sufficiently long inspiration (approx. 1 s) synchronized with compression (in the case of cardiac arrest)|
|Is the airway device (supraglottic or endotracheal tube) in the correct position?||Correct positioning must be ensured immediately after insertion primarily based on the expiratory carbon dioxide flow curve.|
|Auscultate breath sounds.|
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