What happens in the lungs
Surfactant is produced by special cells of the alveoli starting from about the middle of pregnancy, but sufficient amounts accumulate only in the last weeks. This substance reduces surface tension and keeps the alveoli open between breaths. When there is a lack of it, the alveoli collapse, the gas exchange area decreases sharply, and the child has to open the lungs again each time. The work of breathing increases many times over, the baby quickly becomes exhausted, oxygen drops in the blood and carbon dioxide accumulates. Dense deposits form on the walls of the alveoli, which is why the disease was previously called hyaline membrane disease.
- Surfactant keeps the alveoli open
- Its production increases towards the end of pregnancy
- With deficiency, the alveoli collapse
- The work of breathing increases sharply
- Lack of oxygen and excess carbon dioxide develop
Who's at risk
The main factor is the timing of birth: the lower the gestational age, the higher the likelihood and severity of the disease. The syndrome is rare in children born close to term. Diabetes mellitus in the mother increases the risk, since high levels of insulin in the fetus delay the maturation of the lungs, as well as cesarean section performed before the onset of labor: during natural childbirth, a hormonal surge helps the lungs prepare. Additionally significant are asphyxia during childbirth, cooling of the child, multiple pregnancies and cases of this syndrome in brothers and sisters.
- Prematurity is a leading risk factor
- Maternal diabetes mellitus
- Caesarean section before contractions begin
- Asphyxia and cooling during childbirth
- Multiple pregnancy
- Male gender of the child
- Cases of RDS in previous children
Symptoms
Signs appear in the first hours after birth and usually increase during the first or second day. The child breathes frequently and shallowly; when inhaling, the intercostal spaces are retracted, the area under the sternum and above the collarbones, the wings of the nose are inflated. A characteristic sign is groaning or grunting as you exhale: this is how the baby instinctively creates resistance to keep the lungs open. The skin and mucous membranes acquire a bluish tint, the baby is lethargic and sucks poorly. Without treatment, pauses in breathing and decreased blood pressure occur.
- Frequent breathing in the first hours of life
- Retraction of the compliant areas of the chest
- Moaning exhale
- Nose flaring
- Blueness of the skin and mucous membranes
- Lethargy and refusal to feed
- Episodes of apnea in severe cases
Diagnostics
The diagnosis is made by a neonatologist based on the clinical picture and examination data, begun right at the child’s bedside. Pulse oximetry shows blood oxygen saturation, blood gas analysis shows the degree of respiratory failure and acidity. A chest x-ray shows a characteristic picture of reduced airiness of the lungs with a fine-grained pattern and visible lumens of the bronchi. It is important to exclude other causes of respiratory disorders: congenital pneumonia and sepsis, transient tachypnea, heart and lung defects, therefore blood is taken for inflammatory markers and culture.
- Respiratory assessment and pulse oximetry
- Chest X-ray
- Blood gases and acid-base status
- Blood glucose and electrolytes
- Inflammatory markers and blood cultures
- Echocardiography to exclude heart disease
Treatment and prevention
The mainstay of treatment is early non-invasive continuous positive pressure respiratory support through nasal prongs, which helps keep the alveoli open. If the effect is insufficient, surfactant preparations are administered directly into the respiratory tract; Modern techniques make it possible to do this without transferring the child to artificial ventilation. Oxygen is given strictly according to indicators, since its excess is harmful to the eyes and lungs. At the same time, temperature, nutrition and glucose levels are maintained. The best prevention is a course of corticosteroids for the mother if there is a threat of premature birth, which accelerates the maturation of the fetal lungs.
- Early CPAP support via nasal prongs
- Administration of surfactant preparations
- Artificial ventilation in severe cases
- Controlled oxygen therapy
- Temperature and nutrition maintenance
- Antenatal corticosteroids for threatened preterm birth
- Refusal from elective surgeries up to 39 weeks without indication
