Respiratory distress syndrome in children

Respiratory distress syndrome in children, or “shock” lung, is a symptom complex that develops following stress and shock.

[ 1 ], [ 2 ], [ 3 ], [ 4 ], [ 5 ], [ 6 ]

What causes respiratory distress syndrome in children?

The triggers of RDS are severe microcirculation disorders, tissue hypoxia and necrosis, and activation of inflammatory mediators. Respiratory distress syndrome in children may develop with multiple trauma, severe blood loss, sepsis, hypovolemia (accompanied by shock), infectious diseases, poisoning, etc. In addition, the cause of respiratory distress syndrome in children may be massive blood transfusion syndrome, unskilled artificial ventilation. It develops after clinical death and resuscitation measures as part of post-resuscitation disease in combination with damage to other organs and systems (MODS).

It is believed that the formed elements of the blood as a result of hypoplasmy, acidosis and changes in the normal surface charge begin to deform and stick together, forming aggregates - a sludge phenomenon (English sludge - mud, sediment), which causes embolism of small pulmonary vessels. The adhesion of formed elements of the blood to each other and to the endothelium of the vessels triggers the process of DIC of the blood. At the same time, a pronounced reaction of the body to hypoxic and necrotic changes in tissues, to the penetration of bacteria and endotoxins (lipopolysaccharides) into the blood begins, which has recently been interpreted as generalized inflammatory response syndrome (SIRS).

Respiratory distress syndrome in children usually begins to develop at the end of the first or beginning of the second day after the patient is taken out of shock. There is an increase in blood filling in the lungs, hypertension in the pulmonary vascular system occurs. Increased hydrostatic pressure against the background of increased vascular permeability promotes the exudation of the liquid part of the blood into the interstitial, interstitial tissue, and then into the alveoli. As a result, the elasticity of the lungs decreases, the production of surfactant decreases, the rheological properties of bronchial secretions and the metabolic properties of the lungs as a whole are disrupted. Blood shunting increases, ventilation-perfusion relationships are disrupted, and microatelectasis of the lung tissue progresses. In advanced stages of the "shock" lung, hyaline penetrates 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 the background of decompensated shock, sepsis, however, this diagnosis in children is rarely established, interpreting the detected clinical and radiological changes in the lungs as pneumonia.

There are 4 stages of respiratory distress syndrome in children.

1. In stage I (1-2 days), euphoria or anxiety is observed. Tachypnea and tachycardia increase. Harsh breathing is heard in the lungs. Hypoxemia, controlled by oxygen therapy, develops. The chest X-ray shows increased pulmonary pattern, cellularity, and small focal shadows.
2. In stage II (2-3 days), patients are agitated, dyspnea and tachycardia increase. Dyspnea is inspiratory in nature, inhalation becomes noisy, "with a strain", accessory muscles participate in the act of breathing. Zones of weakened breathing, symmetrical scattered dry wheezing appear in the lungs. Hypoxemia becomes resistant to oxygenation. Chest X-ray reveals a picture of "air bronchography", confluent shadows. Mortality reaches 50%.
3. Stage III (4-5 days) is manifested by diffuse cyanosis of the skin, oligopnea. In the posterior lower parts of the lungs, moist rales of various sizes are heard. Severe hypoxemia is noted, torpid to oxygen therapy, combined with a tendency to hypercapnia. The chest X-ray reveals the "snow storm" symptom in the form of multiple merging shadows; pleural effusion is possible. Mortality reaches 65-70%.
4. In stage IV (later than day 5), patients experience stupor, severe hemodynamic disturbances in the form of cyanosis, cardiac arrhythmia, arterial hypotension, and gasping breathing. Hypoxemia combined with hypercapnia becomes resistant to mechanical ventilation with a high oxygen content in the supplied gas mixture. Clinically and radiologically, a detailed picture of alveolar pulmonary edema is determined. Mortality reaches 90-100%.

Diagnosis and treatment of respiratory distress syndrome in children

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

• restoration of airway patency by improving the rheological properties of sputum (inhalation of saline solution, detergents) and evacuation of sputum naturally (cough) or artificially (suction);
• Ensuring gas exchange function of the lungs. Oxygen therapy is prescribed in the PEEP mode using a Martin-Bauer bag or according to the Gregory method with spontaneous breathing (through a mask or an endotracheal tube). At stage III of RDS, the use of artificial ventilation with the inclusion of the PEEP mode (5-8 cm H2O) is mandatory. Modern artificial ventilation devices allow the use of inverted modes of regulation of the ratio of inhalation and exhalation times (1:E = 1:1, 2:1 and even 3:1). A combination with high-frequency artificial ventilation is possible. In this case, it is necessary to avoid high concentrations of oxygen in the gas mixture (P2 above 0.7). The optimal value is considered to be P02 = 0.4-0.6 with ра02 of at least 80 mmHg;
• improvement of rheological properties of blood (heparin, antiaggregating drugs), hemodynamics in the pulmonary circulation (cardiotonics - dopamine, dobutrex, etc.), reduction of intrapulmonary hypertension in stages II-III RDS with the help of ganglion blockers (pentamine, etc.), alpha-blockers;
• Antibiotics are of secondary importance in the treatment of RDS, but are always prescribed in combination.

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