Upper Airway Edema - Causes, Clinical Features, and Management

Introduction:

The upper airway involves the nose, mouth, pharynx, and larynx. If any blockage occurs over these areas, it can cause upper airway obstruction. One such cause of obstruction is edema of the upper airways. Upper airway edema (swelling) can lead to swelling of the face, lips, and larynx. Asphyxia (a condition where there is oxygen deprivation in the body leading to unconsciousness and death in some cases) and aphonia (inability to talk due to the damaged voice box or larynx) can be a result of this condition. This topic describes upper airway edema, its clinical features, triggering factors, and management of upper airway edema.

What Is the Upper Airway?

The upper airway is the upper respiratory tract. The human respiratory system consists of two airways, one is the upper airway, and the other is the lower airway. The upper airways consist of the nose, mouth, sinuses, pharynx (throat), and larynx (voice box). And whereas the lower respiratory airways consist of the trachea (windpipe), bronchioles (small air tubes present in the lungs), and lungs.

The functions of the upper airway are:

• The upper airways cleans the air passing to the lower airways.

• It also protects the lower respiratory airways.

• It works in the formation of sound by the vocal cords.

• It also connects the nasal cavity with the oral cavity.

What Causes the Blockage in the Upper Airways?

The upper airways can get blocked when the upper respiratory tract gets narrowed. There are many reasons that are involved in blocking the upper airways. Some of the prevalent reasons are infections, allergic reactions, injuries to the upper respiratory tract, chemical burns, asthma attacks (a respiratory condition where the airways become narrow, swollen, causing breathing difficulty with mucus secretion), throat cancers, peritonsillar abscesses (a pus-filled cavity formation in the tonsils and the infection spreads to regions beyond the tonsils like neck and chest), vocal cord problems, and tracheomalacia (which involves the trachea cartilages as they get weakened).

What Causes Upper Airway Edema?

Upper airway edema is caused by many factors. Some of the commonly associated causes of upper airway edema are hereditary angioedema and laryngeal edema (swelling), which is caused by the Pseudoterranova species.

• Laryngeal edema by Pseudoterranova species is a severe condition in which bacterial or viral infections are involved in causing the edema along with allergic reactions like anaphylaxis (a life-threatening allergic reaction).

• Hereditary angioedema is an autosomal disorder resulting in repeated swelling in the upper respiratory tract, skin, and the gastrointestinal tract. It is caused due to mutations in the genes that are encoded with factor XII proteins. It is a very rare disorder. Such mutations can cause the dysfunction of the cascade system, like the complement system, and the release of bradykinin. The bradykinin release here leads to extravasation of plasma into the space present interstitially and thus leads to the formation of edema.

What Are the Clinical Features Involved in Upper Airway Edema?

Clinical features that are involved in upper airway edema are:

• Sore and scratchy throat

• Itchy throat.

• The sensation of a lump in the throat.

• Throat tightness.

• Dysphagia (difficulty while eating or swallowing).

• Voice changes.

• Hoarseness in the voice.

• The roughness of voice.

• Cough.

• Stridor (a high-pitched breathing sound resembling whistling).

• Dyspnea (breathing difficulty).

• Feeling of suffocation.

• Aphonia.

• Sometimes, the affected person is unable to speak, breathe, or even cough.

• Anxiety.

• Edema on the lips or face can occur.

What Are the Main Symptoms of Upper Airway Edema?

The one main symptom of upper airway edema involves angioedema. Angioedema involves the swelling of the face, lips, tongue, mucous membranes of the nose, and larynx or throat. It can be severe in cases where it involves the larynx. However, its initiation is not known, but it can be due to insect bites or drugs, or even allergens.

What Is the Clinical Course of Upper Airway Edema?

Upper airway edema involves the swelling of the face, lips, tongue, and severe swelling involving the larynx too. When it starts evolving, it takes nearly eight hours to develop a severe condition. The course of development of this severe condition is quite sooner in children than in adults. It is because children have small diameters of airways with less physiological reserves, and the fatigability of muscles of respiration is easier as even a minor swelling in the airways of the child patient can cause the severity of a condition with breathing difficulty. Along with these, tonsil swelling and inflammation also lead to dysphagia (difficulty in swallowing) and dyspnea of the case.

What Are the Triggering Factors Related to Upper Airway Edema?

There are many triggering factors that can lead to upper airway edema. Some of them are:

• Mechanical trauma.

• Emotional stress.

• Surgical procedures that involve the head and neck region only. Surgical procedures like endotracheal intubation.

• Diagnostic procedures that involve the head and neck region only.

• Hormonal imbalance involving the period of puberty, menstruation, and pregnancy.

• Certain food items.

• Certain medicine that alters the hormones, such as estrogen-containing contraceptives like oral contraceptives.

• Dental surgery.

How Are the Management of Upper Airways Edema Done?

Management of the upper airway edema:

• Plasma replacement therapy is required in these cases. Drugs like Icatibant, which is a bradykinin antagonist, and Ecallantide (a medicine to treat acute acute attacks in angioedema cases) are given intravenously or as subcutaneous injections. The results will be seen in 30 to 60 minutes.

• If these are not available, then frozen plasma can also be used.

• Cricothyroidotomy is an emergency surgical procedure where a cut is made through the cricothyroid membrane and skin to create a patent airway in some life-threatening circumstances.

• Percutaneous tracheostomy (PCT) is also one of the surgical procedures used in the management of this condition.

What Could Be the Prophylaxis for Upper Airway Edema?

• Prophylaxis can be done, by eliminating the triggering factors. The factors that evolve further upper airway edema like mechanical trauma or hormonal changes, or oral contraceptives. All these factors need to be eliminated to control upper airway edema.

• Oral treatments can also be used as an alternative, like androgens.

• The use of fresh frozen plasma is also an alternative to emergency treatment.

Conclusion:

Upper airway edema is basically fluid in the interstitial spaces of the airways leading to swelling in the upper airway. It is accompanied by angioedema which is the swelling of the face, lips, tongue, and larynx. There are many triggering factors that evolve upper airway edema. And, by following the management and prophylaxis technique’s discussed above the living condition of the patient can be improved.