When considering causes of airway obstruction, it is useful to consider the airway in three regions: Upper Airway (above the Larynx), Larynx and Lower Airway (below the larynx).
Upper Airway: In a player with a reduced conscious level, the airway is considered to be compromised. In other words that player is unable to protect his/her own airway. A GCS of 8 or below, or P on the AVPU scale, is traditionally taken to mean that the airway is at risk. This is not an absolute and clinical judgement must be used. If the player is unable to protect his/her own airway, then there is a significant risk of aspiration (foreign material passing down into the lungs). This can cause obstruction, laryngospasm, bronchospasm, infection, pneumonitis and ventilation-perfusion mismatch. Commonly aspirated matters include blood, vomit, gastric contents and dislodged teeth. It is essential that rapid steps be taken to prevent/minimise aspiration.
A player with a reduced conscious level is also at risk of airway occlusion by the player’s own tongue. The tongue is a large muscular structure that sits on the floor of the mouth. When a player with a reduced conscious level is laid supine, the tongue will fall backwards causing airway occlusion.
External materials such as gum shields or chewing gum may also cause airway obstruction. It is essential that these are recognised and managed appropriately in a timely manner.
Larynx: The larynx is relatively narrow, and if foreign matter passes through the upper airway, it may lodge at the larynx causing partial or complete airway obstruction. In a conscious player this will present as “choking” but in the unconscious player it may not be as obvious and a high index of suspicion must be maintained.
Another cause for airway obstruction at this level is laryngospasm. This reflex action causes the vocal cords to tightly close, thereby occluding the airway. A further problem at this level is direct laryngeal trauma. A laryngeal fracture has the potential to cause rapid airway obstruction and is potentially a very difficult situation to manage due to distorted anatomy from subcutaneous emphysema, however this can be managed by the techniques described in this chapter.
Lower Airway: Anything which can pass through the larynx can cause a lower airway problem. Typically this is liquid matter (blood, vomit or gastric contents) but can include foreign matter, for example a dislodged tooth.
If matter is aspirated into the lower airways it can cause bronchospasm, infection, pneumonitis, significant ventilation-perfusion mismatch, and collapse of distal lung. If a player is thought to have aspirated any matter (or if a tooth has been dislodged but cannot be accounted for) then the player requires Emergency Department assessment.
Recognition of Airway Obstruction
Formal assessment of the airway requires a “look, listen and feel” approach to be used. However, in reality, if a player can talk with no respiratory distress, no abnormal sounds and a normal voice, then the airway is unlikely to be compromised. In a player with a reduced conscious level, or in whom there is any concern around the airway, then a “look, listen and feel” approach should be employed.
Look: The player’s chest and abdominal movement should be observed. During inspiration, the chest should be seen to rise as the lungs inflate. The abdomen should also rise as the diaphragm contracts, moving downwards forcing the anterior abdominal wall to rise.
If the airway is occluded, the chest may still rise due to chest wall muscle activity, but the abdomen will be “sucked” inwards due to the negative intrathoracic pressure generated by the chest wall movement. This creates a so-called “see-saw” pattern of respiration.
“Look” also involves inspecting the oropharynx for foreign matter, and for evidence of trauma.
Listen: It is important to listen carefully at the player’s mouth. In particular, the practitioner must listen for the presence of breath sounds, as well as the presence of added sounds. Gurgling noises imply fluid in the airway. This may be secretions, blood, vomit or gastric contents. Snoring or stridulous noises imply the presence of upper airway obstruction. Wheeze implies lower airway obstruction. It is important not to be falsely reassured by the complete absence of any sounds, or by initial obstruction noises becoming quieter –This may simply be complete (or near complete) airway obstruction.
Feel: The practitioner should feel for expired air from the player’s mouth and nose.
These three manoeuvres can conveniently combined into one. The Practitioner should hold his/her head above the players head, turned to look down the chest. This will allow inspection of the chest and abdomen for movement, at the same time as listening for breath sounds and abnormal airway noises, at the same time as feeling for expired air on the cheek.