Upper airway respiratory difficulties – July 2015
When assessing a patient with any illness, it is a good rule to always assume the worst. In this way there can be little chance of underestimating the severity of the illness. Respiratory diseases are certainly no different. Some of them can be easily underestimated. Some have potential to deteriorate quickly and with little warning.
Just as the respiratory system can be divided into the major components so too can diseases that affect it. Breathing difficulty can be divided into problems with the upper, middle and lower airway, the control mechanisms and the mechanical structures. At the back of the upper airway is the vocal cords and the much narrower start of the middle airway elements – the trachea and bronchi. This makes this a particularly vulnerable point for airway blockage.
The diseases discussed here are not exhaustive of all airway problems. These are the most commonly encountered pre-hospital causes of breathing difficulty. Many people with these diseases will manage themselves at home. First responders will be called for acute presentations of these problems not able to be managed. Transport to hospital should be expected in most cases.
Problems with the upper airway are numerous and essentially involve different obstructions to the lower airway. They may be physical, medical or traumatic in origin.
There are several causes of physical upper airway obstruction. Recall that the tongue and epiglottis are designed to occlude the middle airway during swallowing. These are part of the normal airway reflexes. The tongue is a large muscle and when not controlled by the brain will become floppy. The unconscious patient left supine will have the tongue fall back and block the airway. To help counter this, patients in an altered conscious state with less effective protective airway reflexes are rolled onto their side. The tongue falls forward and away from the middle airway.
One distinctive clue that the tongue is a problem is the patient may be snoring. Snoring suggests a partial blockage of the top of the middle
An oropharyngeal airway (OPA) can assist to help pull the tongue forward. These are not always essential but will provide useful support where there is no gag reflex. The OPA becomes even more useful where the patient must be kept supine and there is no other way to displace the tongue forward such as during a cardiac arrest.
Foreign bodies in the upper airway can occlude the opening to the middle airway. These may be a solid object introduced into the mouth such as food or small toy. Or it could be gastric content already in the stomach that regurgitates back up into the mouth. In either case the lateral position helps to allow some foreign material to escape from the mouth. The OPA does not help protect from this problem. The only solution is to remove the object.
Removal of foreign body airway obstructions (FBAO) may require choosing from a number of methods. Management of any FBAO will depend on the conscious state. Patients who are conscious and able to cough need to have that coughing encouraged. The spontaneous cough is the strongest force to expel any FBAO so use it. A cough is pressure formed below an upper airway obstruction that then violently bursts outward pushing the object out with it.
Where the patient is conscious but no longer able to cough then alternating back slaps and chest thrusts are used. Back slaps are hard force between the shoulder blades to make the patient suddenly cough or grunt. They are usually grouped in sets of five and reassessed afterward. Chest thrusts are similar to what used to be called abdominal thrust (Heimlich manoeuvre). Except they are performed on the chest and not the abdomen. Essentially the rescuers arms are wrapped around the patient, a fist is placed over the sternum and pulled back in sharply in to produce a sudden forceful grunt.
Where the patient is no longer conscious, the patient will be collapsed. If a pulse can be felt then short groups of ‘CPR’ like chest compression are commenced with the patient lying on their back. This is trying to create an artificial cough and push the FBAO back out. If the pulse is lost at any time then continuous chest compressions are started.
The FBAO may dislodge during therapy and upper airway suction may remove it. Suction may also be used to remove fluid and vomit. If the patient has no cough or gag airway reflexes then suction might be easy. If the sucker is pushed in too far it might cause a patient to cough or gag. It might also cause injury to the soft and delicate back of the throat.
Paramedics might use a device called a laryngoscope to lessen this risk. The blade, essentially a tongue depressor, is inserted into the mouth. It has a light on it to allows the rescuer to see inside the mouth more clearly and careful suctioning to occur. They might also use large tweezers called Magill’s forceps to try to grab on to solid objects too big for the suction to capture.
Key elements in assessment include loss of consciousness and hence airway reflexes when the patient is found supine. In some cases of FBAO the patient may have been recently eating or collapsed in or near a dining room.
Medical upper airway obstructions are encountered infrequently but can still be problematic. Perhaps the best known include croup and epiglottitis in children or throat tumours in adults. For the first two, inflammation is caused by infection causing these structures to swell and reduce the size of the upper airway. Epiglottitis is caused by the hemophilus influenza bacteria. It is rare now that it is immunised against. Children look very sick and lethargic with drooling and snoring breathing. The epiglottis is designed to cover the rest of the airway during swallowing so when inflamed in children it can be life threatening. Gentle handling and not irritating the child is important including no attempt to inspect the airway.
Croup is much more common with its distinctive barking cough. Occasionally a stridor may be heard when the patient is not coughing. It is usually caused by a viral infection but may be bacterial. The infection is in the very top of the middle airway just beyond where the vocal cords are. Because this is where the airway narrows considerably, any swelling will cause problems.
Children can be mildly affected or have severe difficulty breathing. Although it can cause severe difficulty breathing it is rarely life threatening. However it can be very distressing for both the child and the parents. When it is severe enough adrenaline can be administered using a nebuliser in the same way as salbutamol is. This can cause constriction of the blood vessels in the throat where the problem is so reducing the swelling.
Tumours tend to be more of an adult problem and less likely to cause acute emergencies. However on occasion they can cause a stridor and difficulty breathing. There isn’t much the pre-hospital responder can do but in some cases nebulised adrenaline might help.
Arguably the most common medical upper airway obstruction is the neck swelling caused by anaphylaxis. This is managed along with the normal anaphylaxis management.
Traumatic upper airway obstruction can occur from facial trauma from assault, motor vehicle accident or ballistic trauma. Each of these can cause injury to any part of the upper airway creating mechanical obstruction. These can be the most confronting and challenging airway complications to manage. Typically trauma may be to the face or neck.
There may be very little the first responder can do to manage traumatic upper airway obstruction. Use of suction may help clear blood. Oropharyngeal airways or even nasopharyngeal airways may be of help in keeping the tongue displaced. However they may not be able to be inserted if the patient is biting their teeth firmly (trismus) or if the nose and potentially the skull is damaged.
Jeff Kenneally www.prehemt.com
Jeff is the author of the 2014 – 2016 Ambulance Victoria First Responder clinical practice protocols and accompanying education program.