Pulmonary diseases also impact newborns and the disorders are often unique from those that affect adults.
Infant respiratory distress syndrome most commonly occurs in less than six hours after birth in about 1% of all births in the United States. The main risk factor is prematurity with the likelihood of it occurring going up to 71% in infants under 750g. Other risk factors include infant of a diabetic mother (IDM), method of delivery, fetal asphyxia, genetics,
prolonged rupture of membranes (PROM), maternal toxemia,
chorioamnionitis, and male sex. The widely accepted pathophysiology of respiratory distress syndrome is it caused by insufficient surfactant production and immature lung and vascular development. The lack of surfactant makes the lungs
atelectatic causing a ventilation to perfusion mismatch, lowered compliance, and increased air resistance. This causes hypoxia and respiratory acidosis which can lead to
pulmonary hypertension. It has a ground glass appearance on an x-ray. Symptoms can include tachypnea, nasal flaring, paradoxical chest movement, grunting, and subcostal retractions.
Meconium Aspiration Syndrome occurs in full term or post-term infants who aspirate
meconium. Risk factors include a diabetic mother, fetal hypoxia, precipitous delivery, and maternal high blood pressure. Its diagnosis is based on meconium stained amniotic fluid at delivery and staining on the skin, nails, and umbilical cord. Aspiration can cause airway obstruction, air-trapping, pneumonia, lung inflammation, and inactivated surfactant. It presents as patchy atelectasis and hyperinflation on an x-ray with a
pneumothorax of pneumomediastinum also possible. This is the only syndrome that inhaled nitric oxide is approved for by the FDA.
Transient Tachypnea of the Newborn is caused by the retention of alveolar fluid in the lungs. It commonly occurs in infants who are delivered via
caesarean section without the onset of labor because absorption of amniotic fluid in the lungs has not yet commenced. Other risk factors are male sex,
macrosomia, multiple gestations, and maternal asthma. It usually presents with tachypnea and increased work of breathing. On an x-ray diffuse infiltrates, interlobar fissures, and sometimes
pleural effusions can be seen. It is a diagnosis of exclusion because of its similarity to other diseases and frequently CPAP is used to help push the lung fluid into the pulmonary vasculature.
Pulmonary interstitial emphysema is the condition of air escaping overdistended alveoli into the pulmonary interstitium. It is a rare disease that occurs most often in premature infants, even though it is possible to appear in adults. It often presents as a slow deterioration with the need for increased ventilatory support. Chest x-ray is the standard for diagnosis where it is seen as linear or cystic translucencies extending to the edges of the lungs. The virus infects the cells causing ciliary dysfunction and death. The debris, edema, and inflammation eventually leads to the symptoms. It is the most common reason for admission of children under the age of one year. It can present widely from a mild respiratory infection to respiratory failure. Since there is no medication to treat the disease, it is only managed supportively with fluids and oxygen. ==Diagnosis== Respiratory diseases may be investigated by performing one or more of the following tests: •
Biomarker tests •
Biopsy of the lung or pleura •
Blood test •
Bronchoscopy •
Chest X-ray •
CT scan, including
high-resolution computed tomography •
Culture of microorganisms from secretions such as sputum •
Ultrasound scanning can be useful to detect fluid such as
pleural effusion •
Pulmonary function test •
Ventilation–perfusion scan ==Epidemiology==