What is Supraglottic Airway Obstruction?
Supraglottic obstruction is an urgent medical or surgical problem. It can make breathing difficult and lead to respiratory distress, which is difficulty in catching one’s breath. In severe cases, it can also lead to life-threatening heart and lung failure. Swiftly addressing the root cause of the obstruction can help to restore normal breathing and improve the heart’s function and the patient’s mental wellbeing.
Children, in particular, are more susceptible to severe outcomes from this type of obstruction. This is due to the smaller size and unique structure of their airways, the location of the voice box or larynx, the presence of a comparatively large tongue, and the lower muscle tone typical in pediatric patients. The situation can rapidly escalate from normal breathing to partial obstruction and eventually complete obstruction. It is critical to quickly recognize these changes, swiftly correct the problem, and take actions to restore normal breathing, which can save lives.
Supraglottic obstruction can either come on suddenly or develop gradually over time. It can cause either partial or complete obstruction of the airway. It’s important to carefully evaluate the condition of the airway, while ensuring not to stress or upset the patient as this could worsen their breathing problems.
What Causes Supraglottic Airway Obstruction?
Airway blockages can happen suddenly, known as ‘acute’, or they can develop and last for a long time, known as ‘chronic’. Acute problems that can block your airway above the voice box or ‘supraglottic’ include conditions like croup, blockage due to something a person breathes in, infection of the tissue above the windpipe, swelling in tissues under the skin, infection of the windpipe, burns in the face or mouth, an abscess behind the throat, and an abscess around the tonsils. Chronic issues that can block the airway above the voice box include conditions like a floppy voice box, a floppy windpipe, cysts in the voice box, abnormally large blood vessels, sleep apnea, and gradually compressing growths. A harsh vibrating sound heard best during breathing in, known as ‘stridor’, often indicates an airway blockage. The loudness of this sound can often tell us how severe the blockage is. The exact cause can sometimes be hard to identify at first, and it’s important to consider the patient’s history and physical examination results.
In patients who are unresponsive or ‘obtunded’, the most common cause of upper airway blockage is the tongue. Causes of airway blockages can be classified into either infection-related, inflammation-related, due to foreign objects, or due to growths. Stridor while breathing in points to a blockage above the voice box, while stridor while breathing out points to a blockage at or below the level of the voice box; this can be difficult to accurately assess in a patient who is breathing very fast. Temporary swelling of the lips, tongue, back of the mouth, and voice box can be caused by angioedema. This swelling can happen fast and may urgently obstruct the airway.
In newborns, several birth defects related to head and face shape can cause airway blockage. These include defects like craniofacial clefts, Pierre Robin sequence, midface hypoplasia, achondroplasia, and Down syndrome. Such complex patients could have a small jaw, sleep apnea, or a tongue-based blockage, in addition to other issues with the nervous system or airway that can cause distress.
Risk Factors and Frequency for Supraglottic Airway Obstruction
In children, upper airway obstruction is often caused by viruses like influenza. Less common are bacterial causes like diphtheria, bacterial tracheitis, and epiglottitis, particularly thanks to the introduction of vaccines such as Haemophilus influenzae type b (Hib) and Pneumococcal vaccines. Boys are a bit more likely to suffer from croup than girls.
There are some sources of airway obstruction that aren’t due to infection. Little kids between the ages of 2 to 5 often inhale foreign objects which can block their airways. Laryngomalacia, a condition leading to “noisy breathing,” is a common long-term cause of upper airway obstruction in infants and the most common laryngeal anomaly in this age group. It doesn’t always create significant airway problems, though.
The presence of severe throat pain, or odynophagia, could signal infections or abscesses around the tonsils, tongue, or back of the throat.
Signs and Symptoms of Supraglottic Airway Obstruction
How a patient experiences an airway obstruction can depend on their age. Generally, younger patients may have more severe symptoms. How sudden the obstruction is, as well as whether it’s a one-time occurrence or a recurring problem, can also affect a patient’s experiences.
Common symptoms of an airway obstruction include:
- Cough
- Loud, difficult breathing (stridor)
- Difficulty breathing
- Respiratory distress, which can be mild, moderate, or severe
If the obstruction is very severe and makes breathing very difficult, the patient may also:
- Bob their head
- Experience changes in mental status
- Feel very weak (lethargic)
- Fall into a coma
- Lose consciousness
This condition can cause severe drops in oxygen levels (hypoxemia) or carbon dioxide levels (hypocarbia) in the blood. Initial signs a doctor may notice include obvious distress, increased effort to breathe, signs of anxiety, and a sucking in of the chest with each breath (chest retractions). The doctor can often hear stridor, which becomes louder if the patient is upset or crying. Wheezing is rare in airway obstruction cases, and it usually indicates a problem in the lower airway or chest.
Testing for Supraglottic Airway Obstruction
If a child seems to be having trouble breathing, there are several ways that doctors can check to see how serious the issue is. They’ll look at the child’s overall condition, including whether they are alert or potentially confused. They’ll watch how hard the child is working to breathe, check how quickly they are breathing, and monitor the level of oxygen in the child’s system. They may also use a stethoscope to listen for unusual sounds when the child breathes. By looking at all of these factors together, doctors can tell how much strain the child’s respiratory system is under. If the child is unusually tired or disoriented without any obvious signs of breathing issues or rapid breathing, it may be a warning of serious complications with the respiratory or heart system.
Next, the doctors will check the child’s airway to see if there’s anything blocking it. They might rate the child’s airway using a scoring system, like the Mallampatti score or the American Society of Anesthesiologists’ measure. This evaluation plays a crucial role in making decisions about the child’s care.
Lastly, if the child is experiencing severe throat pain while swallowin, it may indicate the possible presence of an abscess (pocket of pus) either at the back of the mouth or further down in the throat.
Treatment Options for Supraglottic Airway Obstruction
If a person is having trouble breathing due to a blockage in the upper airway, there are a series of steps that a healthcare provider might take to help them. Initially, it’s important to keep the person calm and comfortable. The healthcare provider will then assess the person’s airway, breathing, and circulation. If there’s an immediate cause of the blockage – for instance, a foreign object in the mouth or throat – the healthcare provider will try to remove it carefully, while avoiding any procedures that might cause distress or irritation to the person.
Medication might also be used to help relieve the blockage, especially if it’s caused by swelling or inflammation in the airway. This is the case in conditions such as croup. Corticosteroids can help to reduce inflammation and swelling and racemic epinephrine can be given using a nebulizer to relax the muscles of the airway, making it easier for air to flow in and out.
If the blockage can’t be relieved using these methods, there are additional interventions that can be carried out. Devices can be inserted into the mouth or nose to help maintain an open airway. If the person is really struggling to breathe, a mask can be used to assist with breathing. In extreme cases, a procedure known as endotracheal intubation might be needed. This involves inserting a tube into the windpipe through the mouth or nose to allow the person to breathe.
In rare cases, when other attempts to relieve the blockage are not successful, a surgery on the airway might be necessary. This could be a tracheostomy, which involves creating a hole in the windpipe through the neck, or a cricothyroidotomy, which is an emergency procedure that also involves creating a hole, but higher up in the windpipe. These procedures should only be performed by an experienced healthcare provider and are generally only used in specific circumstances, such as if the person has suffered burns or trauma to the face, or has inhaled a foreign object that can’t be removed with other methods.
What else can Supraglottic Airway Obstruction be?
When it comes to identifying the cause of certain symptoms, doctors may need to rule out a variety of conditions. These could include:
- Angioedema (swelling underneath the skin)
- Foreign body (an object lodged in the body)
- Ludwig’s angina (a type of skin infection)
- Supraglottic, epiglottic or neck abscess (a collection of pus in these areas)
- Tumor (an abnormal growth)
What to expect with Supraglottic Airway Obstruction
The future outcome of a condition with blocked airways varies greatly depending on the cause and the level of severity.
For the sudden blocking of airways above the voice box (known as acute onset supraglottic airway obstruction), it is crucial to identify and address the issue promptly for the best outcome. If the symptoms are mild and noticed early, the patient might be able to maintain open airways while the appropriate treatment starts (like steroids for swelling, or antibiotics for an infection). However, if symptoms become more severe or are changing quickly, the physician must act immediately to keep the airway open, potentially through a breathing tube or surgical procedure to avoid serious consequences. Once the airway is secure, the long-term outcome relies on treating the root cause of the blockage.
For a more gradual, long-standing upper airway blockage (chronic supraglottic airway obstruction), the outcomes can greatly vary, also depending on the specific cause. For example, laryngomalacia (a quite common cause of noisy breathing in young children) often has a successful outcome and may not need any treatment if the symptoms are mild. On the other hand, airway blockage due to a tumor would depend on the type and stage of the tumor for predicting the overall outcome. Similarly, scarring above the voice box after radiation therapy or after inhalation injury might lead to long-lasting effects, and potentially poor results due to recurrent and hard-to-treat narrowing of the airway.
Possible Complications When Diagnosed with Supraglottic Airway Obstruction
The most serious complication to worry about is a blocked airway, which can rapidly progress and potentially be fatal. Even minor symptoms may worsen quickly, as the patient can become exhausted from the extra effort required to breathe. Hence, doctors act fast and take severe measures once an obstructed airway is identified.
The first intervention is usually endotracheal intubation, which involves inserting a tube either directly or with the help of optical fibres. This procedure must be done very carefully, especially for patients with blocked airways, and it’s usually performed by the most experienced doctor on hand. Certain issues such as bleeding from easily torn throat lumps or dislodged foreign bodies can complicate matters and completely close off the airway. Ideally, this procedure is done in the operating room where a tracheostomy kit can be quickly accessed. However, in dire situations, it can’t always be done in the operating room due to time constraints.
Sometimes, it may be too dangerous or impossible to perform endotracheal intubation, in which case, a controlled-awake tracheostomy is prioritized over an emergency surgical airway. The patient is taken to the operating room, and under local anesthesia, a tracheostomy is done in a controlled manner, which helps to reduce potential complications associated with a tracheostomy.
Potential Complications:
- Failure of the procedure
- Bleeding
- Pneumothorax – a condition involving collapsed lung
- Difficulty finding the airway
In emergency situations, however, entering the airway on time may fail, causing a procedure failure, bleeding, and a collapsed lung.
Preventing Supraglottic Airway Obstruction
In simple terms, the type of guidance given to a patient will depend on the specific cause of their upper airway blockage. For instance, if a child is diagnosed with laryngomalacia (a condition where the voice box is soft and collapses into the airway), the parents might receive advice on the best sleeping and feeding positions that can make breathing easier until the child outgrows the condition.
On the other hand, if someone has a tumor in the upper airway, doctors will advise them about signs of difficulty breathing or changes in voice. These individuals should immediately seek medical re-evaluation when these symptoms arise to decrease the risk of a sudden, severe blockage in the airway.
Patients who have had a tracheostomy (a surgical procedure that creates an opening in the neck for direct access to the windpipe), need detailed instructions on how to take care of the opening, how to suction out their airways, and prevent build-up of mucus. They will also be told what steps to take if the tracheostomy tube gets blocked (which includes immediately removing it and heading to the nearest Emergency Room).
