I. Overview of acute epiglottitis
Acute epiglottitis is a disease with sudden onset, rapid development, and easy to cause upper respiratory tract obstruction, and can be divided into two categories: acute infectious epiglottitis and acute allergic epiglottitis.
Acute infectious epiglottitis is an acute nonspecific inflammation of the laryngeal mucosa in the supraglottic region, mainly in the epiglottis. The inflammation not only involves the epiglottis, but also involves more or less all structures in the supraglottic region, hence the name “acute supraglottic laryngitis”. It can occur in both adults and children, more in men than in women, with a male to female ratio of about 2-7:1. It is more common in early spring and late autumn.
Acute metaplastic epiglottitis is a type I metaplastic reaction. The antigens are mostly drugs, serum, biological products or food. Among the drugs, penicillin is the most common, followed by aspirin, iodine or other drugs; among the foods, shrimp, crab or other seafood are the most common, and some people are allergic to other foods as well. It occurs mostly in adults and often recurs.
Second, the etiology of acute epiglottitis
1, the causes of acute infectious epiglottitis
(1) Infection: the most common cause, with the most Haemophilus influenzae type B. Lower body resistance, trauma to the larynx, the elderly and infirm are susceptible to bacterial infection and disease. Other common pathogenic bacteria include Staphylococcus aureus, Streptococcus, S. pneumoniae, Neisseria catarrhalis, Corynebacterium diphtheriae, etc. Infections can also be mixed with viruses, such as respiratory syncytial virus, rhinovirus and influenza A virus. A variety of pathogenic bacteria can be inhaled from the respiratory tract, but also by bloodstream infection or spread from adjacent organs.
(2) Trauma: foreign body, trauma, irritating food, harmful gas, radiation injury, etc. can cause inflammatory lesions of the supraglottic mucosa.
(3) Infection of neighboring tissues: such as acute tonsillitis, pharyngitis, stomatitis, rhinitis, etc. spread and invade the supraglottic mucosa. It can also be secondary to acute infectious diseases.
2. Etiology of acute metaplastic ecclesiitis
Acute metaplastic epiglottitis is a type I metaplastic reaction. The antigens are mostly drugs, serum, biological products or food. Among the drugs, penicillin is the most common, followed by aspirin, iodine or other drugs; among the foods, shrimp, crab or other seafood are common, and some people are also allergic to other foods. It occurs mostly in adults and often recurs.
Clinical manifestations of acute epiglottitis
Acute infectious epiglottitis has a rapid onset, often occurring suddenly at night, and the history of the disease rarely exceeds 6~12h; most patients have chills and fever, with a body temperature of 37.5℃~39.5℃ and a few up to 40℃ or more; the patient is irritable, depressed, and weak; there is pain in the throat, difficulty in swallowing, and difficulty in breathing. In severe cases, fainting and shock. There may be enlarged cervical lymph nodes. First, note the patient’s general condition, the presence of symptoms such as chills and fever, salivation, laryngeal tinnitus and slurred speech, ask him/her about the onset of the disease, and then perform the following examinations.
(1) External laryngeal examination
(1) External laryngeal examination: (1) First, observe the appearance of the neck and then palpate. In severe cases of acute epiglottitis, the inflammation spreads to the adjacent tissues, and the skin of the anterior neck is red and swollen, with pressure pain at the thyroid hyoid membrane. Lymph nodes of one or both sides of the deep upper neck group are enlarged with pressure pain. The pressure pain is obvious in the upper part of the cervical hyoid bone and thyroid cartilage.
(2) Examination of the pharynx;
(3) Indirect laryngoscopy;
(4) rigid tube (or fiber) laryngoscopy, electronic laryngoscopy is feasible if available.
(5) Laboratory tests: increased total white blood cell count, increased neutrophils, and leftward nuclear shift.
(6) Imaging: CT and MRI may show swelling of supraglottic structures such as the epiglottis, reduced shadow of the laryngopharyngeal cavity with clear boundaries, reduced laryngeal vestibule like a funnel, and occlusion of the epiglottic valley. It also helps to identify the abscess cavity.
Acute metaplastic epiglottitis has a rapid onset, often within half an hour of drug administration or 2 to 3 h of eating, and progresses rapidly. The main symptoms are a feeling of laryngopharyngeal obstruction and slurred speech, but no change in voice. There is no chill or fever, no pain or pressure, and other tests are mostly normal. Although the symptoms and signs are not obvious, the potential danger is great. Sometimes, after coughing or deep inspiration, or even when the patient changes position, the edematous tissue is embedded in the vocal folds and sudden asphyxiation occurs, which can lead to death if not rescued in time. On examination, it can be seen that the epiglottis is obviously edematous, some of them become round ball-shaped, pale in color and loose in tissue. The aryepiglottic folds and aryepiglottic cartilage also show obvious edema. Laboratory tests: ① eosinophilic increase to 3%~7% in peripheral blood or eccrine secretion smear; ② allergen intradermal test is mostly positive. CT examination shows swelling of the epiglottis.
Diagnosis and differential diagnosis of acute epiglottitis
For those who have acute laryngomalacia, pain that worsens when swallowing, no specific lesions on oropharyngeal examination, or inflammation in the oropharynx but not enough to explain their symptoms, acute infectious epiglottitis should be considered, and indirect laryngoscopy should be done. Early diagnosis is important due to the life-threatening nature of the disease. Acute infective epiglottitis is easily confused with other acute upper respiratory tract diseases and must be differentiated from acute laryngotracheobronchitis, laryngeal diphtheria, and epiglottic cysts.
Acute metaplastic epididymitis is not difficult to diagnose, but is easily missed or misdiagnosed when symptoms are atypical. Attention should be paid to the distinction between acute infectious epididymitis and acute metaplastic epididymitis.
V. Treatment of acute epididymitis
1, the treatment of acute infectious epiglottitis: acute epiglottitis in adults is more dangerous, can quickly occur fatal respiratory obstruction. Treatment is based on the principle of anti-infection and keeping the respiratory tract unobstructed. Outpatient examination should first pay attention to the degree of epiglottis redness and swelling, the size of the vocal cords and the degree of respiratory distress. Serious cases should be admitted to the hospital on an emergency basis, with a tracheotomy kit at the bedside.
(1) Infection control
(1) Use powerful antibiotics and glucocorticoids in adequate doses: cephalosporin antibiotics are preferred because the causative organisms are often Haemophilus influenzae type B, Staphylococcus, Streptococcus, etc. The dose of dexamethasone can be 0.5~lmg/(kg?d).
②Local medication: The purpose of local medication is to keep the airway moist, dilute sputum and anti-inflammatory. Commonly used drug combinations are: 1) gentamicin 160,000 units, dexamethasone 5mg, α-chymotrypsin 5mg; 2) kanamycin 1g, cortisone acetate 25mg, ephedrine 40mg. the above two combinations with distilled water to 10ml, sprayed into the throat with a nebulizer or oxygen, ultrasound nebulized inhalation, 4~6 times a day.
(3) Incision and drainage of pus: If an abscess forms on the lingual surface of the epiglottis, or if the abscess is still poorly drained even though it has ruptured, oxygen can be administered, and the abscess wall can be bitten through with a laryngeal knife or vocal fold polyp clamp under the guarantee of airway patency (e.g. laryngeal intubation, tracheotomy), and the pus can be quickly aspirated to avoid flowing under the vocal fold.
(2) Keep the airway unobstructed Establishing an artificial airway (cricothyrotomy, tracheotomy or tracheal intubation) is an important method to ensure the patient’s airway is unobstructed, and different methods should be selected for different patients.
(3) Others Maintain water-electrolyte acid-base balance, pay attention to oral hygiene, prevent secondary infection, and encourage diet.
2. Treatment of acute metaplastic epiglottitis
(1) Anti-allergic treatment should be given first. Adults should be given subcutaneous injection of 0.1% epinephrine 0.1~0.2ml, along with intramuscular or intravenous injection of hydrocortisone 100mg or dexamethasone 10mg, or flumethasone 5mg.
(2) If the edema of the epiglottis and arytenoid folds is very serious, l~3 incisions should be made immediately at the obvious edema to reduce the degree of edema. After 1h, if the blockage is not reduced or the edema is still obvious, prophylactic tracheotomy can be considered.
(3) If the vocal valve is blocked by surrounding edematous tissue and is difficult to find, laryngeal intubation or rigid tube bronchoscopy can be used to open the airway, or emergency tracheotomy or cricothyrotomy can be chosen, and artificial respiration should be performed at the same time if asphyxia is present.
(4) In acute metaplastic epiglottitis, if the child coughs, inhales deeply or changes position, the edematous tissue can be embedded in the vocal cords and sudden asphyxiation, vigilance should be raised and timely resuscitation.
VI. Prevention and prognosis of acute infectious epiglottitis
The use of Haemophilus influenzae combined with vaccination can effectively prevent acute epiglottitis and other Haemophilus influenzae infections (meningitis, pneumonia, etc.) in infants and children. The prognosis is closely related to the patient’s resistance, the type of infecting bacteria and the treatment method. If diagnosed and treated in time, the prognosis is generally good. In recent years, due to the application of powerful broad-spectrum antibiotics and the improvement of medical technology, the mortality rate is less than 1%, and the proportion of emergency tracheotomies has also decreased.