Airway obstruction can be subtle and is often poorly recognised. Snoring, choking, gurgling noises or stridor (harsh high pitched sound occurring on inspiration or expiration), are signs of partial airway obstruction.
Complete airway obstruction will be silent as there will be no air movement. Paradoxical ‘see-saw’ movement of the abdomen and chest will occur due to inspiratory effort against a closed airway. Normally, when you breathe, the chest moves outwards, and synchronously the abdomen moves outwards due to the downward movement of the diaphragm. In paradoxical breathing, the abdomen moves outwards as the diaphragm moves downwards but the negative pressure generated against the obstructed airway draws the chest inwards. This paradoxical pattern can occur with increasing partial airway obstruction and is a sign that measures should be taken to open the airway. Patients attempting to breathe against an obstruction may also be using accessory muscles of breathing and there may be intercostal and subcostal recession and a tracheal tug.
While a patient with a partial airway obstruction may be panicked and agitated, beware the still patient whose chest is silent due to a completely obstructed airway. Hypoxia due to airway obstruction is an ominous sign and signifies imminent respiratory arrest.