Pulmonary hypoplasia is underdevelopment of one or both lobes during embryonic development, which may be due to a lack of amniotic fluid or herniation of the diaphragm. Affected newborns experience respiratory distress and often require artificial respiration. Hernias can be corrected prenatally.
What is pulmonary hypoplasia?
Hypoplasias are genetically caused underdevelopment of tissues or entire organ parts and organs. Depending on the extent, functional failure or at least functional impairment may result from the underdevelopment. Pulmonary hypoplasia is a congenital underdevelopment of the lungs. The fetal lung does not mature sufficiently as part of the hypoplasia. One or both lungs show a reduction in size. The most common symptom of hypoplastic lungs is respiratory distress in the newborn. The cause of the manifestation can be considered to be various contexts that cause disturbances in the fetal period. The severity of lung hypoplasia can vary greatly depending on the cause. Almost symptomless, mild manifestations are just as conceivable as severe or even lethal forms. Lung hypoplasia must be distinguished from nonunion of the lung, which is never compatible with life and always results in a lethal course.
Causes
The etiology of pulmonary hypoplasia is extremely well understood. A number of different factors may play a causative role in the lack of lung development, including congenital diaphragmatic hernias. These diaphragmatic hernias are malformations of the diaphragm that do not allow for a closed separation of the thoracic space from the abdominal space. The hernias can compress the fetal lungs. As a result of this compression, the lungs are inhibited in growth. In addition to hernias of the diaphragm, bilateral renal agenesis can also cause hypoplasia of the lungs. This phenomenon is mainly present in Potter syndrome and is not compatible with life. Because the fetus drinks amniotic fluid but does not release any into the amniotic sac for reprocessing due to the failure of the kidneys to attach, amniotic fluid deficiency is present in this phenomenon, which promotes hypoplasia of the lungs. Lung hypoplasia may also be caused by amniotic fluid deficiency of a different genesis. If Potter syndrome underlies the phenomenon, the course is lethal.
Symptoms, complaints, and signs
Pulmonary hypoplasia manifests immediately after birth. Patients suffer from severe dyspnea, which may be associated with cyanosis. The skin turns bluish as part of this symptom due to the impaired lung function caused by the hypoplasia. Tissue retracts into the spaces between the ribs or above the sternum when breathing. In addition, patients groan when they exhale. When inhaling, their nostrils move strongly. Furthermore, they suffer from pathologically accelerated breathing in the sense of tachypnea, with which their organism tries to compensate for the lack of lung size. Among the most common complications of pulmonary hypoplasia and the resulting respiratory distress is the formation of emphysema and other air accumulation in the tissues, in pneumothorax, pneumomediastinum or pneumoperitoneum. The emphysema actually worsens the shortness of breath as it progresses. The circumference of the chest increases and cardiac stress may promote the development of a drop heart.
Diagnosis and disease progression
A definite diagnosis for pulmonary hypoplasia cannot occur prenatally and is made radiographically after birth. Prenatally, nevertheless, malformations can already be visualized on ultrasound. Thus, diaphragmatic hernias in connection with evidence of an oligohydramnios can make lung hypoplasia assessable even before birth. After birth, respiratory distress in newborns, in particular, makes the physician order radiographic imaging, from which the hypoplasia is readily apparent. Prognosis depends on the cause and severity of the hypoplasia.
Complications
As a result of pulmonary hypoplasia, affected individuals primarily suffer from relatively severe respiratory symptoms. In most cases, these complaints significantly limit the daily life of the affected person and also reduce the patient’s quality of life. It is not uncommon for the skin to turn blue and suffer from fatigue and exhaustion.Likewise, the resilience is significantly reduced, which can also lead to delayed child development. Furthermore, lung hypoplasia can also cause respiratory distress. Lung hypoplasia also puts a great deal of strain on the heart, which can lead to sudden cardiac death. It is not uncommon for those affected to also lose consciousness, possibly injuring themselves in a fall. Without treatment, the patient’s life expectancy may be significantly reduced. As a rule, pulmonary hypoplasia cannot be treated causally. Therefore, treatment is exclusively symptomatic and aims at limiting the symptoms. No particular complications occur. However, the affected person is dependent on surgical interventions. This can also prevent further defects and subsequent damage to the lungs.
When should one go to the doctor?
If breathing irregularities occur in a newborn, medical attention must be sought as soon as possible. There is a risk of premature death of the baby without medical treatment. In the case of inpatient delivery, the expectant mother is under uninterrupted medical care. Pediatricians or nurses determine the problems and disturbance of the child’s respiratory activity in routine examinations. The newborn’s parents do not need to take action in these cases. Measures are automatically taken to ensure that the child’s organism is supplied with sufficient oxygen. In the case of a home birth, the midwife takes over the tasks involved. If there are any abnormalities or complications, she initiates all the necessary steps to ensure adequate care for the newborn. The midwife automatically establishes contact with a doctor and ambulance transport, so that no further measures need to be taken by the parents in this form of delivery. If an unplanned and spontaneous delivery occurs without the presence of nursing staff, first aid measures must be taken. An emergency physician must be alerted immediately. The instructions of the emergency department must be followed to prevent a fatal outcome. The child’s respiratory activity must be replaced by artificial respiration. In addition, the newborn must receive immediate intensive medical care.
Treatment and therapy
In many cases, pulmonary hypoplasia cannot be treated causally and is therefore treated mainly symptomatically. The most important step in this treatment is to secure the airway. In cases of herniation of the diaphragm, endotracheal intubation is performed. The patient is artificially ventilated for the time being. In individual cases, respiratory distress syndrome may require long-term ventilation with high oxygen partial pressures and in this case involves continuous monitoring of the values. At the same time, air is often pumped out of the stomach and intestines via an attached gastric tube so that the lungs are less compressed. The final treatment of hernias is surgical and corresponds to a backward displacement of organs and a subsequent closure of the gap in the diaphragm. If the diaphragmatic defects are diagnosed before birth, fetal surgery and thus prenatal repair of the defects is usually the most promising therapeutic measure, as the hypoplasia of the lungs can thus be reduced. There are few treatment options postnatally for hypoplasia secondary to diaphragmatic defects, so all possible treatment options should be exhausted prenatally. Options include, for example, open intrauterine repair of the defects. In addition, minimally invasive tracheal occlusion using a titanium clip may be considered. If a titanium clip is used, this clip must still be removed during the birth process to avoid complications. A current area of medical research is the use of self-degrading biomaterials for prenatal repair of fetal hernias. However, this therapeutic step is not yet in the clinical phase.
Prospects and prognosis
There is no prospect of a cure for pulmonary hypoplasia. The prognosis is unfavorable because it is a genetic cause of the disease, and even in the early stages of development, the lungs are not fully formed. Human genetics must not be altered due to legal requirements. For this reason, the focus of medical treatment is not on alleviating the existing symptoms. If left untreated, the affected person risks premature death.Respiratory activity is severely restricted and can cause death in particularly severe cases. Since the patient’s quality of life is significantly reduced in pulmonary hypoplasia, the risks for the development of secondary disorders are increased. The prognosis improves if the patient actively implements self-help measures over a lifetime. The intake of harmful substances of nicotine or gases must be completely avoided. Environmental influences must be optimized to support respiratory activity. Long-term ventilation is necessary in some patients. In addition, surgical interventions may be required to improve respiratory function. Each intervention is associated with risks and side effects. If the treatment proceeds without further complications, further development improves. Nevertheless, lifelong limitations are present that must be considered when managing daily life.
Prevention
Pulmonary hypoplasia due to herniation can be prevented by performing prenatal correction of the defect during fetal surgery. For hypoplasia due to insufficient amniotic fluid, much less effective preventive measures have been available to date.
Here’s what you can do yourself
Pulmonary hypoplasia causes respiratory distress in many patients. In the worst case, this can lead to the development of an anxiety disorder or panic. The affected person should therefore maintain a healthy approach to worries and the fears at an early stage, so that the development of anxiety is prevented. At the first signs, it is helpful to face the strong worries offensively and to deal with them. Positive thoughts and an optimistic basic attitude are helpful. Relaxation techniques can also be used. As soon as fears intensify or new ones are added, therapeutic help should be sought. The environment should always be enriched with sufficient oxygen and the patient should be provided with fresh air. Walks and regular airing of the premises improve general well-being. They help with breathing and can reduce existing worries. Smoking should be avoided as a matter of principle so as not to trigger any additional stress. Likewise, stays in smoking rooms or cramped rooms should be avoided. Patients with pulmonary hypoplasia have the opportunity to exchange information with other patients in self-help groups or on the Internet in various forums. The communal exchange can be found helpful in everyday life. Mutual support for everyday questions or challenges is provided through this.
