Transient Tachypnea of the Newborn: Causes, Symptoms, and Management
Transient Tachypnea of the Newborn (TTN)
Anatomical Alterations of the Lungs in TTN
- Excessive bronchial secretions and incomplete absorption of pulmonary fetal fluid
- Air trapping and alveolar hyperinflation
- Decreased fluid removal by pulmonary lymphatics
- Pulmonary capillary congestion
- Interstitial edema
- Compressed bronchial airways from excessive alveolar capillary interstitial fluid
Etiology of Transient Tachypnea of the Newborn
TTN affects 1 to 2 percent of all newborns. Classically, TTN is most often seen in full-term infants. Risk factors include elective cesarean section, excessive administration of fluids to the mother during labor, male gender, and macrosomia. The infant’s history often includes maternal analgesia or anesthesia during labor and delivery, or episodes of intrauterine hypoxia. TTN is also commonly associated with maternal bleeding, maternal diabetes, and prolapsed cord. TTN is occasionally seen in very small infants.
Early Clinical Manifestations of TTN:
- Tachypnea
- Retractions
- Nasal flaring
- Grunting
- Cyanosis
It is common to see respiratory rates between 80 and 120 breaths/minute (bpm). In fact, the rapid and shallow breathing pattern is often considered a hallmark clinical manifestation of TTN.
Cardiopulmonary Clinical Manifestations Associated with TTN
- Increased alveolar-capillary membrane thickness
- Excessive bronchial secretions and airway obstruction
Clinical Data Obtained at the Patient’s Bedside for TTN
Vital Signs:
- Increased Respiratory Rate (Tachypnea): Infants with TTN frequently breathe rapidly and shallowly. This rapid and shallow breathing pattern is often considered a hallmark clinical manifestation of TTN. During early stages of TTN, the respiratory rate generally is often between 60 and 100 bpm.
- Increased Heart Rate (Pulse) and Blood Pressure.
Clinical Manifestations of Negative Intrapleural Pressure
- Intercostal retractions
- Substernal retraction/abdominal distention (seesaw movement)
- Cyanosis of the dependent portion of the thoracic and abdominal areas
- Flaring nostrils
Chest Assessment Findings:
- Wheezes
- Rhonchi
- Crackles
- Expiratory Grunting
- Cyanosis
Radiological Findings in TTN
Chest Radiograph:
Initially, the chest radiograph appears normal. Over the next 4 to 6 hours, however, signs of pulmonary perihilar streaking, commonly called starbursts or sunbursts, may appear. Other findings include air bronchograms and fluid in the interlobar fissures. Air trapping and hyperinflation may occur and are manifested by peripheral hyperlucency, flattened diaphragms, and bulging intercostal spaces. Patches of infiltrates may be seen in some infants. Mild cardiomegaly and pleural effusions also may be seen.
General Management of Transient Tachypnea of the Newborn
Because of the relatively short course of TTN, treatment consists mostly of proper stabilization, close monitoring, and frequent and thorough evaluation to rule out other more serious conditions that may develop. Oxygen therapy is provided to maintain adequate oxygenation, and bronchopulmonary hygiene therapy may be administered to keep the airways clear of bronchial secretions. Lung expansion therapy is often used as a preventive measure, but mechanical ventilation is usually not required. Fluid restriction is usually ordered until the signs and symptoms associated with TTN resolve. Oral feedings are usually started as soon as the infant is able to tolerate them. Diuretics do not affect the clinical course of TTN. In cases where pneumonia is suspected, the use of antibiotics is indicated.
Respiratory Care Treatment Protocols for TTN
- Oxygen therapy protocol
- Bronchopulmonary hygiene therapy protocol
- Lung expansion therapy protocol
- Mechanical ventilation protocol