Respiratory distress syndrome in children

Respiratory distress syndrome in children, or "shock" lung, is a symptom complex that develops after a stress, shock.

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What causes respiratory distress syndrome in children?

RDS triggers are gross violations of microcirculation, hypoxia and necrosis of tissues, activation of inflammatory mediators. Respiratory distress syndrome in children can develop with multiple trauma, severe blood loss, sepsis, hypovolemia (accompanied by shock phenomena), infectious diseases, poisoning, etc. In addition, the cause of respiratory distress syndrome in children may be a syndrome of massive blood transfusion, unskilled carrying out mechanical ventilation. It develops after the clinical death and resuscitation as a component of postresuscitative disease in combination with the defeat of other organs and systems (SPON).

It is believed that the uniform elements of blood as a result of hypoplasmia, acidosis and changes in the normal surface charge begin to deform and adhere to each other, forming aggregates - the sludge phenomenon, which causes embolism of small pulmonary vessels. The adhesion of blood cells with each other and with the vascular endothelium triggers the ICE process. At the same time, the body reacts strongly to hypoxic and necrotic changes in tissues, to the penetration of bacteria and endotoxins (lipopolysaccharides) into the blood, which has recently been treated as a syndrome of the generalized inflammatory respiratory syndrome (SIRS).

Respiratory distress syndrome in children, as a rule, begins to develop at the end of 1-early 2-day after the removal of the patient from the state of shock. There is an increase in blood filling in the lungs, there is hypertension in the system of pulmonary vessels. Increased hydrostatic pressure against the background of increased vascular permeability promotes the swelling of the liquid part of the blood in the interstitial, interstitial tissue, and then into the alveoli. As a result, the extensibility of the lungs decreases, the production of the surfactant decreases, the rheological properties of the bronchial secretion and the metabolic properties of the lungs are generally violated. Increased shunting of blood, violated ventilation-perfusion relationships, progressing micro-telecrafting of lung tissue. In the far-reaching stages of the "shock" lung, hyaline enters the alveoli and hyaline membranes are formed, sharply disrupting the diffusion of gases through the alveolocapillary membrane.

Symptoms of respiratory distress syndrome in children

Respiratory distress syndrome in children can develop in children of any age, even in the first months of life against a background of decompensated shock, sepsis, but this diagnosis is rarely established in children, treating the detected clinico-radiological changes in the lungs as pneumonia.

There are 4 stages of respiratory distress syndrome in children.

1. Euphoria or anxiety is observed in stage I (1-2 days). Increase tachypnea, tachycardia. Strong breathing is heard in the lungs. Develops hypoxemia, controlled by oxygen therapy. On the X-ray of the lungs, the intensification of the pulmonary pattern, cellularity, and small-focal shadows are determined.
2. In Stage II (2-3 days) patients are excited, dyspnea, tachycardia are worse. Dyspnoea is inspiratory in nature, the breath becomes noisy, "with tear", in the act of breathing auxiliary muscles participate. In the lungs there are zones of weakening of respiration, symmetrical scattered dry rales. Hypoxemia becomes resistant to oxygenation. On the roentgenogram of the lungs, a picture of "air bronchography" and draining shadows are revealed. Mortality reaches 50%.
3. Stage III (4-5th day) is manifested by diffuse cyanosis of the skin, oligopnea. In the lower part of the lungs, damp, various-throat rales are heard. There is pronounced hypoxemia, torpid to oxygen therapy, combined with a tendency to hypercapnia. The chest radiograph shows a symptom of a "snow storm" in the form of multiple merging shadows; possible pleural effusion. Mortality reaches 65-70%.
4. In IV stage (later the 5th day), the patients have a sopor, sharply expressed violations of hemodynamics in the form of cyanosis, cardiac arrhythmias, arterial hypotension, and gas-breathing. Hypoxemia in combination with hypercapnia becomes resistant to oxygenated ventilation with a high oxygen content in the feed gas mixture. Clinically and radiologically, a detailed picture of the alveolar edema of the lungs is determined. Mortality reaches 90-100%.

Diagnosis and treatment of respiratory distress syndrome in children

Diagnosis of RDS in children is quite a complicated task, requiring the doctor to know the prognosis of the course of severe shock of any etiology, clinical manifestations of the "shock" lung, the dynamics of blood gases. The general scheme of treatment of respiratory distress syndrome in children includes:

• Restoration of airway patency by improving the rheological properties of sputum (inhalation of saline, detergents) and sputum evacuation by natural (cough) or artificial (suction);
• providing gas exchange function of the lungs. Assign oxygen therapy in PEEP with a Martin-Bauer sac or Gregory's method for spontaneous breathing (through a mask or intubation tube). In the III stage of RDS, the use of mechanical ventilation with the inclusion of a PEEP regime (5-8 cm H2O) is mandatory. Modern ventilators allow the use of the inversed regimes of regulation of the ratio of inspiratory and expiratory times (1: E = 1: 1.2: 1 and even 3: 1). Combination with high-frequency ventilation is possible. It is necessary to avoid high concentrations of oxygen in the gas mixture (P2 above 0.7). Optimal is considered P02 = 0,4-0,6 at р02 not less than 80 ммрт. P.
• improvement of rheological properties of blood (heparin, disaggregating drugs), hemodynamics in a small circle of blood circulation (cardiotonics - dopamine, dobrex, etc.), reduction of intrapulmonary hypertension in the II-III stage of RDS with the help of ganglion blockers (pentamine, etc.), a-adrenoblockers;
• antibiotics in the treatment of RDS are of secondary importance, but are always prescribed in combination.

[7], [8], [9], [10], [11], [12], [13], [14]