Airway management is the medical process of ensuring there is an open airway between a patient’s lungs and the outside world. Obstructions can occur when a person becomes unconscious and the muscles in their jaw relax and allow the tongue to obstruct the airway, but also aspiration can lead to obstruction of the airways, the risk of which can be reduce by airway management. Airway management is a primary consideration in cardiopulmonary resuscitation, anaesthesia, emergency medicine, intensive care medicine and first aid.
Airway management can be dived into two categories: Non-invasive and invasive airway management. Non-invasive techniques are simple to perform even by non-health care professionals and does not require use of medical equipment, whereas invasive techniques requires special training and medical equipment. Invasive airway management is further categories in increasing order of invasiveness into supraglottic devices, such as oropharyngeal or nasopharyngeal airways, followed by infraglottic techniques, such as tracheal intubation, and finally surgical methods.
- 1 Non-invasive airway management
- 2 Invasive airway management
- 3 Removal of vomit and regurgitation
- 4 Airway management in specific situations
- 5 See also
- 6 References
- 7 Further reading
Non-invasive airway management
Non-invasive airway management is mainly used in first aid since it is non-invasive and unlike invasive airway management does not relies on the use of medical devices. Examples of non-invasive airway management techniques are Head-tilt chin-lift, Jaw-thrust and use of the recovery position.
The head-tilt chin-lift is the primary maneuver used in any patient in whom cervical spine injury is not a concern. The simplest way of ensuring an open airway in an unconscious patient is to use a head tilt chin lift technique, thereby lifting the tongue from the back of the throat. This is taught on most first aid courses as the standard way of clearing an airway.
The jaw-thrust maneuver is an effective airway technique, particularly in the patient in whom cervical spine injury is a concern. The jaw thrust is a technique used on patients with a suspected spinal injury and is used on a supine patient. The practitioner uses their index and middle fingers to physically push the posterior (back) aspects of the mandible upwards while their thumbs push down on the chin to open the mouth. When the mandible is displaced forward, it pulls the tongue forward and prevents it from occluding (blocking) the entrance to the trachea, helping to ensure a patent (secure) airway.
The recovery position refers to one of a series of variations on a lateral recumbent or three-quarters prone position of the body, in to which an unconscious but breathing casualty can be placed. Use of the recovery position prevents aspiration.
Cervical spine immobilization
Most airway maneuvers are associated with some movement of the cervical spine. Even though collars for holding the head in-line can cause problems maintaining an airway and maintaining a blood pressure, it is unrecommended to remove the collar without adequate personnel to manually hold the head in place.
Invasive airway management
Unlike non-invasive airway management such as head-tilt or jaw-thrust maneuver, invasive airway management relies on the use of medical device equipment. Invasive airway management can be performed "blind" or with visualization of the glottis e.g. by the use of a laryngoscope. It is frequently performed in critically injured, ill or anesthetized patients to facilitate ventilation of the lungs, including mechanical ventilation, and to prevent the possibility of asphyxiation or airway obstruction.
In roughly increasing order of invasiveness are the use of supraglottic devices such as oropharyngeal or nasopharyngeal airways, followed by infraglottic techniques such as tracheal intubation and finally surgical methods.
Supraglottic techniques includes the use of supraglottic tubes, such as oropharyngeal (OPA) and Nasopharyngeal airways (NPA), and supraglottic devises such as laryngeal masks. Common for all supraglottic devises are that the are introduced into the pharynx, ensuring the upper respiratory tract remains open, without passing through the glottis and thereby entering the trachea.
Nasopharyngeal airways is a soft rubber or plastic hollow tube that is passed through the nose into the posterior pharynx. Patients tolerate NPAs more easily than OPAs, so NPAs can be used when the use of an OPA is difficult, such as when the patient's jaw is clenched or the patient is semiconscious and cannot tolerate an OPA. NPAs are generally not recommended if there is suspicion of a fracture to the base of the skull, due to the possibility of the tube entering the cranium. However, the actual risks of this complication occurring compared to the risks of damage from hypoxia if an airway is not used are debatable.
Oropharyngeal airways are rigid plastic curved devices, which are inserted trough the patients mouth. It prevents the patients tongue from covering the epiglottis and thereby obstructing the airway. An oropharyngeal airway should only be used in a deeply unresponsive patient because in a responsive patient they can cause vomiting and aspiration by stimulating the gag reflex.
Supraglottic airways (or extraglottic devices) are a family of devices that are inserted through the mouth to sit on top of the larynx. Supraglottic airways are used in the majority of operations performed under general anaesthesia. Compared to a cuffed tracheal tube (see below), they give less protection against aspiration but are easier to insert and cause less laryngeal trauma. The best-known example is the Laryngeal Mask Airway or LMA™. A laryngeal mask airway is an airway placed into the mouth and set over the glottis and inflated. Other variations include devices with oesophageal access ports, so that a separate tube can be inserted from the mouth to the stomach to decompress accumulated gases and drain liquid contents. Some devices can have an endotracheal tube passed through them into the trachea.
Unlike supraglottic devices; infraglottic devices pass through the glottis and thereby enter the trachea. Tracheal intubation, often simply referred to as intubation, is the placement of a flexible plastic or rubber tube into the trachea to maintain an open airway or to serve as a conduit through which to administer certain drugs. The most widely used route is orotracheal, in which an endotracheal tube is passed through the mouth and vocal apparatus into the trachea. In a nasotracheal procedure, an endotracheal tube is passed through the nose and vocal apparatus into the trachea.
Surgical methods for airway management rely on making a surgical incision is made below the glottis in order to achieve direct access to the lower respiratory tract, bypassing the upper respiratory tract. Surgical airway management is often performed as a last resort in cases where orotracheal and nasotracheal intubation are impossible or contraindicated. Surgical airway management is also used when a person will need a mechanical ventilator for a longer period. Surgical methods for airway management include cricothyrotomy and tracheostomy.
A cricothyrotomy is an incision made through the skin and cricothyroid membrane to establish a patent airway during certain life-threatening situations, such as airway obstruction by a foreign body, angioedema, or massive facial trauma. A cricothyrotomy is nearly always performed as a last resort in cases where orotracheal and nasotracheal intubation are impossible or contraindicated. Cricothyrotomy is easier and quicker to perform than tracheotomy, does not require manipulation of the cervical spine and is associated with fewer complications.
A tracheotomy is a surgically created opening from the skin of the neck down to the trachea. A tracheotomy may be considered where a person will need to be on a mechanical ventilator for a longer periode. The advantages of a tracheotomy include less risk of infection and damage to the trachea such as tracheal stenosis.
Removal of vomit and regurgitation
In the case of a patient who vomits or has other secretions in the airway, these techniques will not be enough. Suitably trained clinicians may elect to use suction to clean out the airway, although this may not always be possible. An unconscious patient who is regurgitating stomach contents should be turned into the recovery position when there is no suction equipment available, as this allows (to a certain extent) the drainage of fluids out of the mouth instead of down the trachea.
Airway management in specific situations
The best method of airway management during CPR is controversial. There has been less emphasis on airway management (including simple mouth-to-mouth or invasive methods) during CPR, since it was shown that people receiving initial chest-compression-only CPR were more likely to survive than those who had standard CPR. People who are resuscitated with basic bag-mask ventilation may also be more likely to survive than those who are intubated or have a supraglottic airway inserted. However, in children, or where the cause of the arrest was an airway or breathing problem, or where the arrest is prolonged, airway management is still important.
In basic life support, many people can be reluctant to start mouth-to-mouth resuscitation. The American Heart Association now supports "Hands-only"™ CPR, which advocates chest compressions without any airway management for teens or adults. Bystanders who see an adult suddenly collapse should call for help and move to chest compressions straight away. It is likely that later in resuscitation care by trained professionals, simple methods as well as supraglottic and tracheal airways each have a role, depending on the skills of the person performing them and the equipment or environment they are working in.
In prehospital environments, airway management is controversial, with intubation and supraglottic airways each having advantages and disadvantages. Trauma victims are often not fasting so there is an increased risk of aspiration, but blood and other material may make it difficult to see the larynx to intubate.
- Tracheal intubation
- Laryngeal mask airway
- Laryngeal tube
- Endotracheal tube
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|The Wikibook First Aid has a page on the topic of: Airway Management|
- Daniel Limmer; Keith J. Karren; Brent Q. Hafen; John Mackay; Michelle Mackay (2006). Emergency Medical Responder (Second Canadian Version). Brady. pp. 92–97. ISBN 0-13-127824-X.