Stenotic laryngotracheitis (croup syndrome)

Stenosing laryngotracheitis is one of the most common emergency conditions in young children (3 months to 3 years), accompanied by croup syndrome. Croup, croup syndrome in children (old-fashioned croupe - to croak) can develop at any age, but most often in the first 2 years of life.

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What causes stenosing laryngotracheitis?

Stenosing laryngotracheitis, or croup in recent years, is dominated by acute respiratory viral infections: influenza, parainfluenza, respiratory syncytial (RS), adenovirus infection, etc. Diphtheria of the oropharynx as a cause of croup is very rare today. Croup may develop with herpes infection (aphthous stomatitis), measles, chickenpox. Due to the small diameter of the upper respiratory tract in young children, even a slight swelling of the mucous membrane leads to a pronounced narrowing of their lumen with an increase in resistance to air flow.

Pathogens of the disease:

• influenza A virus;
• parainfluenza virus types I and II;
• RS infection;
• adenoviral infection;
• diphtheria;
• other bacterial infections;
• chemical burn due to poisoning.

Stenosing laryngotracheitis is caused by inflammatory edema developing below the glottis, in the subglottic space. Of additional importance are the exudate accumulating in the lumen of the respiratory tract and the spasm of the laryngeal muscles, which increases with hypoxia.

Other causes of croup

Acute bacterial tracheitis (ABT) is also called acute purulent stenosing, obturating laryngotracheobronchitis, secondary or late croup. In its etiology, the main role is played by Staphylococcus aureus, to a lesser extent - Pfeiffer's bacillus, pneumococcus. ABT occurs as a result of the layering of purulent infection on acute viral damage to the mucous membrane of the larynx and trachea. In domestic literature, it is described as secondary croup in acute respiratory viral infections, influenza, measles, etc.

Croup occurs more often in children over 3 years of age. It is characterized by high body temperature, which persists for a long time and often takes on the character of a remittent or hectic, a gradual increase in croup symptoms and their slow reverse development; leukocytosis and neutrophilia are detected in the blood, staphylococci are isolated from sputum.

Treatment consists of oxygen administration, inhalation of mucolytics (trypsin, chymopsin, DNAse, etc.), high-dose intravenous antibiotics (protected penicillins, 2nd-3rd generation cephalosporins), often in combination, antistaphylococcal hyperimmune drugs, and IT to maintain water balance and detoxification. Purulent complications often develop: pneumonia, pleurisy, abscess, sepsis, etc.

Croup syndrome or its clinical imitation is also observed in a number of diseases, for the timely detection of which it is necessary to promptly carry out differential diagnostics followed by specific therapy.

Laryngeal diphtheria is a classic example of inflammatory laryngitis, stenosis of the larynx, the mechanism of which is based on mucosal edema, spasm of the laryngeal muscles and the presence of fibrinous films that significantly reduce the lumen of the respiratory tract. Localized or widespread laryngeal diphtheria is currently observed in adult patients or unvaccinated young children. Laryngeal stenosis gradually and steadily progresses to the stage of asphyxia. The main means of treating diphtheria croup is the introduction of antitoxic antidiphtheria serum in a total dose of 30-60 thousand units, regardless of age, for 1-2 days.

Retropharyngeal abscess often develops in infants and young children against the background of acute respiratory viral infections due to the addition of a bacterial infection caused by Haemophilus influenzae. The resulting bulging of the posterior pharyngeal wall is an obstacle to the passage of air and often imitates the clinical manifestations of laryngeal stenosis or EG. When examining the pharynx, hyperemia of the mucous membrane and its bulging into the pharynx can be detected. Radiologically, in the lateral projection of the neck, an increase in the retropharyngeal or retrotracheal space is observed.

At the onset of the disease, large doses of penicillin, as well as semi-synthetic penicillins and cephalosporins are effective. If necessary, surgical intervention is performed.

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Symptoms of stenosing laryngotracheitis

Stenosing laryngotracheitis occurs mainly in children aged 1-6 years on the 1-2nd day of a respiratory infection. It develops as a result of swelling of the larynx below the glottis, which is expressed in inspiratory stridor. Swelling of the vocal cords manifests itself as dysphonia (hoarseness of voice).

As a result of the reduction in the diameter of the airways, resistance to air flow increases and the work of breathing increases: tachypnea, inclusion of additional muscle groups in the work of breathing. As obstruction progresses, gas exchange may be disrupted, followed by the development of hypoxemia, cyanosis and accumulation of carbon dioxide. These are late signs of croup - harbingers of complete obstruction of the airways and respiratory arrest.

Symptoms of stenosing laryngotracheitis often develop at night. Characteristic features include inspiratory dyspnea - prolonged, noisy inhalation, dysphonia (hoarse voice and rough, "barking" cough) or aphonia (loss of voice and the appearance of a silent cough). With increasing obstruction of the upper respiratory tract, dyspnea and the participation of accessory muscles in the act of breathing increase, there is a retraction of the pliable areas of the chest during inhalation, cyanosis, arterial hypoxemia with subsequent accumulation of CO2 and the development of a comatose state, asphyxia.

According to observations by V. F. Uchaikin, in the genesis of stenosing laryngotracheitis in children with stenosing laryngotracheitis, the allergic disposition of the mucous membranes of the larynx and trachea and their increased sensitivity to any irritants, even to air flow, are of certain importance.

The severity of stenosing laryngotracheitis is determined by the degree of narrowing of the upper respiratory tract or laryngeal stenosis. There are 4 degrees of laryngeal stenosis. With stenosis of the first degree, noisy breathing (on inspiration) is detected only when the child is restless, his motor activity increases; with stenosis of the second degree, respiratory failure, inspiratory dyspnea, participation of accessory muscles in the act of breathing are detected even during sleep, which becomes restless. 8a02 does not decrease less than 90%, metabolic acidosis, moderate hypocapnia are detected. With stenosis of the third degree, the child hardly sleeps due to the feeling of lack of air, suffocation. Dyspnea becomes mixed (inspiratory-expiratory), acrocyanosis appears. The efforts applied by the child during breathing are maximum possible (his hair becomes wet with sweat), however, they do not ensure gas exchange balance. A decrease in PaO2 < 90% is observed, metabolic acidosis increases, hypocapnia begins to give way to hypercapnia. The threat of exhaustion of the child's physical strength and the development of asphyxia is real.

Clinical manifestations of laryngeal stenosis depending on its severity

Degree	Symptoms
I	Rough, "barking" cough, hoarseness, noisy breathing in the inspiratory phase. Accessory muscles do not participate in the act of breathing, respiratory failure manifests itself when the child is restless
II	Breathing is noisy, audible at a distance, moderate retraction of the pliable areas of the chest on inhalation. Attacks of difficulty breathing often occur, moderately pronounced inspiratory dyspnea is observed at rest
III	Breathing is constantly difficult, dyspnea is mixed (inspiratory-expiratory), the pliable areas of the chest and the sternum are noticeably drawn in at the moment of inspiration. Constant anxiety, pallor with acrocyanosis, sweating, tachycardia, possible loss of the pulse wave on inspiration. Severe ARF
IV	Adynamia, loss of consciousness, diffuse cyanosis, decreased body temperature, shallow breathing or apnea, dilated pupils (hypoxic coma)

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Treatment of stenosing laryngotracheitis

Treatment of stenosing laryngotracheitis is aimed at removing previously liquefied mucus from the respiratory tract, reducing swelling in anatomically narrow areas, and reducing muscle spasm. The treatment algorithm is as follows:

1. give oxygen, humidified and heated to 30-35 °C, in a concentration of 30-40% through a mask or in a tent. In mild forms of croup, aerotherapy is sufficient; in case of grade III stenosis, the child is recommended to be constantly in an atmosphere of air saturated with up to 100% water vapor, enriched with oxygen in a concentration of 30-40% (steam-oxygen tent);
2. sedative therapy with diazepam at a dose of 0.2 mg/kg is carried out. In compensated forms of croup, the following can be used: valerian extract, solutions of bromine salts; in case of pronounced edema of the larynx tissue, inhalations of 0.1% adrenaline solution (or 0.05-0.1% naphthyzine) at a dose of 0.3-1.0 ml, diluted in 3-5 ml of physiological solution are used; in case of bronchial muscle spasm, inhalations of bronchodilators (salbutamol, atrovent, |berodual) can be used;
3. Maintenance of water balance with IT in some cases facilitates expectoration. Glucocorticoids (eg, dexamethasone) at the stages of sub- and decompensation of external respiratory function are used at a dose of 2-10 mg/kg. Prednisolone or dexazone are usually administered as a bolus intravenously or intramuscularly.

Tracheal intubation (extended nasotracheal) is performed using thermoplastic tubes (their diameter should be 0.5-1 mm less than the age size).

Indications for tracheal intubation are a decrease in paO2> 60 mm Hg and an increase in paCO2> 60 mm Hg. Tracheal extubation is usually performed after 2-5 days. Indications for it are temperature normalization, elimination of hypoxemia when breathing atmospheric air. Relapse of croup is possible due to reactive laryngeal edema with the need for reintubation. In this case, tubes of a smaller diameter are used (by 0.5 mm or 1 size).

Indications for tracheostomy are persistence or progression of hypoxemia against the background of intubation. Management of patients with nasotracheal intubation without complications for 3-4 weeks.

Treatment of croup

The effectiveness of treatment for acute laryngeal stenosis depends on the timeliness of their use. Intensive therapy for acute respiratory failure should be started with aerosol inhalations of coarse aerosols with high sedimentation. Treatment of grade I laryngeal stenosis is symptomatic: administration of sedatives (diazepam 4-5 mg/kg), alkaline steam inhalations, oxygen therapy with humidified 40% O2 _, dexamethasone 0.3 mg/kg intramuscularly, broad-spectrum antibiotics. With increasing stenosis (grades II-III), therapy begins with intramuscular or intravenous administration of dexamethasone 0.3-0.5 mg/kg or prednisolone 2-5 mg/kg; Inhalation corticosteroids (budesonide 1-2 mg or fluticasone 50-100 mcg) using a nebulizer, oxygen therapy with humidified 40-100% O ₂, and broad-spectrum antibiotics are indicated. Antihistamines are used only in case of concomitant allergic conditions. In case of stage IV stenosis, stenosing laryngotracheitis is treated with inhalation of epinephrine 0.1%-0.01 mg/kg (or, as a last resort, instillation into the nasal passages in a dilution of 1 to 7-10), then dexamethasone 0.6 mg/kg is administered intravenously. If hypoxia increases, cardiopulmonary resuscitation, tracheal intubation, artificial ventilation, oxygen therapy with humidified 100% O ₂ are used. Conicotomy in subglottic stenotic laryngotracheitis is usually ineffective due to the fact that the stenosis extends below the subglottic space. If tracheal intubation is not feasible, tracheotomy is performed.

Diphtheria of the pharynx against the background of gradually progressing stenosis of the larynx is characterized by filmy whitish-yellowish or grayish plaques, appearing first within the vestibule of the larynx, then in the area of the glottis, leading to the development of stenosis. Submandibular and posterior cervical regional lymph nodes are sharply enlarged, painful, the tissues around them are edematous.

Hospitalization is mandatory for any degree of croup; transportation is carried out with the upper body in an elevated position.

In case of laryngeal diphtheria, emergency hospitalization in the infectious diseases department is always required against the background of treatment of acute respiratory failure depending on the degree of stenosis. Regardless of the stage of the disease, antidiphtheria serum is immediately administered. The dose of serum (15,000 to 40,000 AE) is determined by the prevalence of the process and the stage of the disease.

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