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Respiratory Disorders of the Newborn

Respiratory distress is a common problem during the first few days of life. Respiratory distress may present with tachypnea, nasal flaring, sternal and intercostal retractions, cyanosis, and apnea. The most common respiratory disorders of the newborn are transient tachypnea of the newborn.

Transient Tachypnea of the Newborn

Transient tachypnea of the newborn (TTN) usually presents as early respiratory distress in term or preterm infants. It is caused by delayed reabsorption.

TTN is a very common, and it is often seen following cesarean section.

Treatment of TTN consists of oxygen therapy. Infants will usually recover fully.

Respiratory Distress Syndrome

RDS is a lung disease caused by pulmonary surfactant deficiency. It occurs almost always in preterm infants who are born before the lungs are able to produce adequate amounts.

Surfactant is produced by pneumocytes in the lung. It lowers the surface tension of the alveolus. The preterm neonate whose lungs are deficient in surfactant will develop diffuse atelectasis because of decreased lung compliance (stiff lungs).

Respiratory distress usually begins at, or soon after, delivery and tends to worsen over time. Infants will have tachypnea, nasal flaring, intercostal and sternal retractions, and expiratory grunting. Tiny preterm infants who lack pulmonary surfactant may fail to initiate ventilation in the delivery room.

Chest radiography shows diffuse atelectasis, which appears as reduced lung volume, with homogeneous haziness or the "ground glass" appearance of lung fields, and air bronchograms. Positive pressure ventilation can reverse the radiographic findings.

Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic lung disease characterized by hypoxia, hypercarbia, and oxygen dependence that persists beyond 1 month of age. The chest radiograph shows hyperexpansion and focal hyperlucency, alternating with strands of opacification.

BPD is extremely common among infants who have severe RDS treated with mechanical ventilation. The incidence of BPD is inversely proportional to birthweight. The combination of pulmonary immaturity, positive pressure ventilation, oxygen therapy.

RDS is the most common pulmonary disease causing BPD. Other neonatal diseases requiring oxygen and mechanical ventilation may also cause BPD, including immature lungs, meconium aspiration syndrome.

Signs of BPD include tachypnea and retractions, after extubation. Blood gas measurements show respiratory acidosis with elevated PaVCO₂; increased HCO₃ indicates metabolic compensation. Higher inspired oxygen concentration is required to maintain normal oxygenation.

Management of BPD consists of minimizing barotrauma. Adjustments in peak pressure should deliver adequate, but not excessive, tidal volume; acceptable minute ventilation can be maintained by monitoring the PaCO₂. A moderate degree of respiratory acidosis should be allowed in order to decrease the amount.

Nutrition. Nutrition is crucial in promoting repair and growth of lung tissue. Infants who have BPD may not tolerate even normal fluid intakes. Total fluid intake should be limited to approximately 120 mL/kg/day. Adding supplemental fat or carbohydrate to 24 kcal/oz of formula increases caloric intake.

Antibiotics. Intubated infants who have BPD are susceptible to pneumonia. Close observation for pneumonia and prompt treatment with antibiotics, when pneumonia is suspected.

Chest physiotherapy, with chest percussion, postural drainage and suctioning should be performed as needed.

Diuretic Therapy

Furosemide (1 mg/kg q 24 h IV or PO) may be used. Milder diuretics such as chlorothiazide (10-20 mg/kg per dose q12h PO) and spironolactone (1-2 mg/kg per dose q12h PO) may help reduce airway resistance and improve pulmonary compliance.

If diuretics are used over the long term, especially furosemide.