Bacterial epiglottitis

Definitions & Key takeaways

Bacterial epiglottitis is a rare, vaccine-preventable, life-threatening form of epiglottitis caused by bacteria, usually, Haemophilus influenzae type B. Symptoms typically include fever, sore throat, difficulty swallowing, and difficulty in breathing in case the airway becomes obstructed by the inflamed epiglottis. The epiglottis is a flap of cartilage at the back of the throat that helps to keep food from entering the airways. In bacterial epiglottitis, the epiglottis becomes infected and swells, blocking the airway.

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Introduction0:00–0:42

With Epiglottitis, “itis” means inflammation and epiglottis is a flap of elastic cartilage that sits at the top of the larynx or voice box.
The epiglottis keeps food and liquid going down the esophagus and prevents it from going down the trachea by accident. So bacterial epiglottitis is when bacteria infect this flap of tissue and cause it to get swollen.
This can be life threatening because it can flop down and block the trachea, making it impossible to breathe. This infection is actually thought to have been the cause of death for George Washington, America’s first president.
Now, the larynx is located in the bottom portion of the neck, just below where the pharynx splits into the trachea and the esophagus.

Physiology0:42–1:39

The larynx is also called the voice box because it contains the vocal cords, which are two folds of mucous membrane that can open and close like curtains.
Just like the rest of the respiratory tract, the walls of the larynx are made up of mucosal epithelium. The epiglottis extends from the base of the tongue and anchors to the anterior rim of the thyroid cartilage, which is just in front of the larynx.
The lateral borders of the epiglottis connect to the aryepiglottic folds, which have ligamentous and muscular fibers. This allows the epiglottis to act like a lid on a box and serve as the guardian of the airways.
During swallowing, the epiglottis covers the larynx, preventing food and liquids from entering the airway; and during breathing, the epiglottis opens the larynx, allowing air to flow in and out.Epiglottitis happens when the epiglottis, aryepiglottic folds, and other adjacent tissues become infected.

Pathology1:39–2:55

Most commonly, epiglottitis is caused by Haemophilus influenzae, a gram negative rod bacterium, but in settings where Haemophilus influenzae type b vaccine is used commonly, other bacteria like Group A Streptococcus can also cause the infection.
These bacteria are spread person-to-person by direct contact or through respiratory droplets that are created when people cough or sneeze.
Once the bacteria enter the body, they can get through the epithelial layer of the epiglottis. Immune cells in the epiglottic tissue detect the invading bacteria and release cytokines, like Tumor necrosis factor-alpha, or TNF-alpha.
The cytokines cause blood vessels to become more permeable to fluid which results in local inflammation or swelling. As the inflammation gets worse, the swollen epiglottis starts to fatten up and block the larynx which obstructs airflow, and if the infection is severe, it can quickly lead to respiratory failure.
In severe cases, respiratory failure can lead to a respiratory acidosis, which is a buildup of carbon dioxide in the blood.Symptoms of epiglottitis can worsen quickly.

Symptoms2:55–3:26

As the infection becomes severe - it can lead to fevers, and it can cause trouble breathing and some describe it like a person talking with a hot potato in their mouth!
There can be signs of airway obstruction like a high-pitched noise on inspiration, called stridor, retractions which is where ribs show through as they breathe, and a person often tripods which means that they lean forward leaning on their arms to keep their airway open.

Diagnosis3:26–4:00

Diagnosis of epiglottitis in a person who is stable and breathing comfortably, is done with an X-Ray which will show an epiglottis and aryepiglottic folds that look a lot fatter than normal - like a thumb print.
A CT scan would also show a narrow airway from tissue swelling, but lying flat for a CT can be dangerous because it can make the epiglottis further obstruct the airway.
Finally, an endoscope, which is a long tube with a camera at the end, can be used to look directly at the epiglottis which typically appears swollen and cherry red in color from the inflammation.

Treatment4:00–4:56

Treatment for epiglottitis, first and foremost, is always about airway management. Individuals are often given extra oxygen, and in severe cases, they might need tracheal intubation, which is when a tube is sent through the vocal cords to keep the airway from closing shut.
In some rare cases, if tracheal intubation isn’t possible, a needle or surgical cricothyroidotomy might be needed, both of which are techniques to open up the cricothyroid membrane - creating a passageway for air to go into the trachea below the level of the larynx.
Once the airway is stable, antibiotics can be used to treat the infection, and intravenous steroids can be used to decrease the swelling from the immune response.
Finally, immunization against Haemophilus influenzae type b can be used to prevent that bacteria from causing epiglottitis in the first place - and this is an intervention that has nearly wiped out the disease in vaccinated children.

Review4:56–5:24

Alright as a quick recap… Bacterial epiglottitis is a vaccine preventable disease that’s most often caused by Haemophilus influenzae.
Symptoms include a hot-potato voice, stridor, retractions, and tripoding, and classically on an Xray the epiglottis can look like a thumb print.
The infected epiglottis can cause severe airway obstruction, and in really severe cases, can require tracheal intubation or