Hyaline membrane disease is synonymous with the so-called respiratory distress syndrome (RDSN). Such a clinical diagnosis is made by a premature newborn with respiratory failure and those who have respiratory difficulties and tachypnea, including.
In children, while inhaling room air, chest retraction and the development of cyanosis are recorded, which persists and progresses during the first forty-eight to ninety-six hours of life. In the case of an X-ray examination of the chest, a characteristic external picture takes place (the reticular network along with the peripheral air bronchogram). The clinical course of the disease of hyaline membranes directly depends on the weight of the child, and in addition, on the severity of the disease, the implementation of substitution treatment, the presence of concomitant infections, the degree of blood bypass through the arterial open duct and the implementation of mechanical ventilation.
Causes of pathology
Hyaline membrane disease is observed mainly in children born to mothers who suffer from diabetes mellitus, cardiac and vascular ailments, and uterine bleeding. Intrauterine hypoxia in combination with asphyxia and hypercapnia can contribute to the development of the disease. Due to all these causes of hyaline membrane disease, a violation of the pulmonary circulatory system is quite likely, against the background of which there is impregnation of the alveolar septum with serous fluid.
A certain role in the occurrence of the disease in question has a microglobulin deficiency along with the development of disseminated as well as local blood coagulation. All pregnant women between the twenty-second and thirty-fourth weeks of gestation in the case of premature birth are considered as patients who necessarily require antenatal prophylaxis with glucocorticoids. This contributes to the maturation of the lung surfactant in the fetus preparing for birth.
Symptoms
Clinical manifestations with existing signs of prematurity include frequent grunting labored breathing, which appears immediately or within a couple of hours after giving birth, with bloating of the nasal wings and retraction of the sternum. In the event that atelectasis and respiratory failure progress, and the symptoms worsen, then cyanosis occurs in combination with lethargy, respiratory failure and apnea. The skin is bluish.
Newborns whose mass is less than 1000 grams can have such rigid lungs that they will simply not be able to support the baby’s breathing in the delivery room. As part of the inspection, inhalation noise is attenuated. The peripheral pulse is minimal, swelling occurs, and at the same time, diuresis decreases.
Diagnostics
In the process of studying the condition of a newborn with signs of prematurity, a clinical assessment is made, the gas composition of arterial blood is studied (we are talking about hypoxemia and hypercapnia). In addition, doctors perform a chest x-ray. Diagnosis is based on clinical symptoms, including risk factors. An X-ray of the chest reveals diffuse atelectases.
Differential diagnosis is aimed at eliminating sepsis and pneumonia, due to infection with streptococcus transient tachypnea, persistent pulmonary hypertension, aspiration and pulmonary edema due to congenital malformations. As a rule, newborns need blood culture and, possibly, an aspirate from the trachea. Clinically differentiating pneumonia, which is caused by streptococci from a disease of hyaline membranes, is extremely difficult. Thus, as practice shows, antibiotics are prescribed even before the result of sowing.
Features of the survey
Hyaline membrane disease in newborns can be assumed prenatally by performing fetal lung maturity tests. The analysis is carried out using amniotic fluid obtained by amniocentesis or collected from the vagina (in the case of rupture of the amniotic membrane). This helps determine the optimal term for delivery. This technique is appropriate for elective birth until the thirty-ninth week, when the fetal heart rate along with the level of chorionic gonadotropin and ultrasound can not establish gestational age. A study of amniotic fluid may include:
- Determination of the ratio of lecithin and sphingomyelin.
- Analysis of the foam stability index.
- The ratio of surfactant to albumin.
The risk of illness of hyaline membranes in newborns is significantly lower if lecithin and sphingomyelin are less than 2, with a foam stability index of 47. Surfactant and albumin should be greater than 55 milligrams per gram.
Treatment
If the premature baby does not open the lungs, therapy includes the following methods:
- The use of surfactant.
- Extra oxygen as needed.
- Carrying out mechanical ventilation.
The prognosis for the treatment is good, mortality in this case is less than ten percent. In the case of competent respiratory support, the formation of a surfactant occurs over time, as soon as its formation has begun, the disease of the hyaline membranes in the newborn is resolved for only four or five days. But severe hypoxia can lead to the development of multiple organ failure and even death.
Special therapy for hyaline membrane disease includes intratracheal surfactant treatment. It requires tracheal intubation, which may be required to achieve proper ventilation and oxygenation. Premature infants, whose weight is less than a kilogram, and children with an oxygen demand of less than forty percent, can respond well to additional O 2 , as well as to treatment with continuous nasal pressure in the airways. The surfactant early treatment strategy predetermines a significant reduction in the duration of mechanical ventilation and a decrease in the manifestation of bronchopulmonary dysplasia.
Surfactant accelerates recovery and reduces the risk of pneumothorax, intraventricular hemorrhage, interstitial emphysema, pulmonary dysplasia and death within one year. But unfortunately, newborns who receive similar treatment for this pathology have an increased risk of premature apnea.
Preparations for opening the lungs in premature babies
Supplemental substitutes for sufractant include Beractant, along with Poractant Alpha, Kalfactant, and Lucinocant.
The drug "Beractant" is a lipid extract of bovine lung, which is supplemented with proteins "C", "B", as well as colfosceryl palmitate, tripalmitin and palmitic acid. The dosage is 100 milligrams per kilogram of weight every six hours, as needed, up to four doses.
"Poractant" acts as a modified extract obtained from minced pork lung. The drug contains phospholipids in combination with neutral lipids, fatty acids and surfactant-related proteins B and C. Dosage is as follows: 200 milligrams per kilogram with a further transition to two doses of 100 milligrams per kilogram of body weight every twelve hours as needed.
“Kalfactant” serves as an extract from the calf’s lungs, contains phospholipids along with neutral lipids, fatty acids and surfactant-related proteins B and C. The dose is 105 milligrams per kilogram of body weight every twelve hours to three doses as needed.
“Lucinactant” serves as a synthetic substance, including the synapultide peptide, phospholipids and fatty acids. The dosage is 175 milligrams per kilogram of body weight every six hours for up to four doses.
It is worth noting that the total lung elongation in a newborn can quickly improve after such treatment. The breathing apparatus pressure may need to be quickly reduced to reduce the risk of air leakage.
Prevention
To prevent such a deviation, such as hyaline membrane disease, special drugs are prescribed for pregnant women. When the fetus should be born between the twenty-fifth and thirty-fourth weeks, the mother requires the introduction of two doses of "Betamethasone" 12 milligrams, which is done intramuscularly with an interval of exactly one day.
Or, “Dexamethasone” is used, 6 milligrams intramuscularly every twelve hours for at least two days before delivery. Due to this, the risk of developing the disease in question is reduced or its severity is reduced. Thanks to this prophylaxis, the risk of neonatal death from respiratory arrest in babies is minimized along with some forms of pulmonary morbidity (for example, pneumothorax).
Pathology Features
This pathology is due to insufficiency of pulmonary surfactant, which, as a rule, is observed exclusively in newborns who were born before the thirty-seventh week of pregnancy. In general, failure is exacerbated as the degree of prematurity increases.
Due to a deficiency of surfactant, the alveoli can close, due to which diffuse atelectases appear in the lungs, which cause inflammation and swelling of this organ. In addition to provoked respiratory failure, the risk of hemorrhage, bronchopulmonary dysplasia, intense pneumothorax, sepsis, and in addition, death, is increased.
In the event that a woman in labor is expected to prematurely relieve the burden, then it is necessary to assess the maturity of the lungs by analyzing the amniotic fluid for the ratio of sphingomyelin, lecithin, as well as surfactant and albumin. In the case of pathology, intratracheal surfactants and respiratory support as needed are required.
The expectant mother needs several doses of corticosteroids (we are talking about "Betamethasone" and "Dexamethasone") in the event that she must give birth at a period of twenty-fourth to thirty-fourth weeks. Corticosteroids cause the production of surfactant in the fetus with a certain degree of prematurity and reduces the risk of hyaline membrane diseases.
Effects
As complications, the patient may subsequently experience persistent arterial duct, interstitial emphysema, rarely pulmonary hemorrhage, and pneumonia. The occurrence of chronic bronchopulmonary dysplasia, lobar emphysema, recurrent respiratory tract infections and cicatricial stenosis of the larynx as a result of intubation is not ruled out.
What increases the risk
The risk of developing the disease in question increases depending on the degree of prematurity. In accordance with this criterion, the baby’s lungs may be partially or completely immature and therefore not able to provide adequate respiratory functions due to the absence or due to insufficient volume of surfactant produced. In such situations, newborns are shown to perform therapy that replaces this substance.
"Dexamethasone" - what is this drug?
Many are interested in what is prescribed "Dexamethasone" in injections. The presented drug is currently widely in demand in medicine and is a synthetic glucocorticosteroid, which has strong anti-inflammatory and immunosuppressive properties. In addition, it is able to effectively penetrate the nervous system. Due to such opportunities, this medication can be used in the treatment of patients suffering from cerebral edema and any inflammatory eye pathologies. That's what Dexamethasone injections are for.
The medication in the form of tablets and injection is included in the list of essential medicines. It is able to stabilize cell membranes. Increases their resistance to various damaging factors. In this regard, it is used to open the lungs of babies with a threat of hyaline membrane disease.
As a rule, unless otherwise prescribed by a doctor, the medicine is prescribed 6 milligrams intramuscularly every twelve hours for two days. Given that in our country, “Dexamethasone” is distributed mainly in ampoules of 4 milligrams, doctors recommend its intramuscular administration in this dosage three times for two days.
Chest inspiration
Against the background of the pathology of the hyaline membranes, the anterior chest wall is retracted, which causes a symmetric or asymmetric funnel-shaped deformation. Against the background of a deep breath, the depth of the funnel becomes larger due to paradoxical breathing, which is due to the underdevelopment of the sternum of the diaphragm.
The early signs of the disease in question, as a rule, include the presence of shortness of breath in premature babies with a respiratory rate of more than sixty times per minute, which is observed in the first minutes of life. Against the background of the progression of the pathology, symptoms also increase, for example, cyanosis intensifies, disseminated crepitus can occur, apnea is present along with foamy and bloody discharge from the mouth. As part of assessing the severity of respiratory distress, doctors use the Downs scale.
Respiratory arrest in this pathology
The severe nature of the disease of hyaline membranes can lead to respiratory arrest. In this case, a drug is prescribed for mechanical ventilation (mechanical ventilation). This measure is used for such indicators:
- Arterial blood acidity is less than 7.2.
- PaCO 2 equals 60 millimeters of mercury and higher.
- RaO 2 is 50 millimeters of mercury and lower at an oxygen concentration in the inhaled air of from seventy to one hundred percent.
Thus, the considered disease in newborns is caused by a deficiency in the lungs of the so-called surfactant. This is most often found among babies born before the thirty-seventh week. Moreover, the risk increases significantly with the degree of prematurity. Symptoms, first of all, include shortness of breath along with the involvement of auxiliary muscles and bloating of the wings of the nose, which occurs shortly after birth. Prenatal risk can be assessed by performing a fetal lung maturation test. The fight against pathology consists in surfactant therapy and supportive treatment.