From the Guidelines
Tachypnea in late preterm newborns is most commonly caused by respiratory distress syndrome (RDS), transient tachypnea of the newborn (TTN), and pneumonia, with RDS being a major contributor due to surfactant deficiency, as supported by the 2014 Pediatrics study 1. The causes of tachypnea in late preterm newborns can be multifactorial, including:
- Respiratory distress syndrome (RDS) due to surfactant deficiency, which is a major cause of morbidity and mortality in preterm infants, as noted in the study 1
- Transient tachypnea of the newborn (TTN) resulting from delayed clearance of fetal lung fluid after birth
- Pneumonia, which may develop from maternal infections or exposure to pathogens during or after delivery Other potential causes include:
- Meconium aspiration syndrome, though less common in preterm infants
- Congenital heart defects causing pulmonary overcirculation
- Persistent pulmonary hypertension
- Metabolic acidosis
- Sepsis Management of tachypnea in late preterm newborns depends on the underlying cause and severity, and may include:
- Supplemental oxygen
- Continuous positive airway pressure (CPAP)
- Mechanical ventilation
- Antibiotics if infection is suspected
- Surfactant replacement therapy, which has been shown to substantially reduce mortality and respiratory morbidity in preterm infants with RDS, as stated in the study 1 Close monitoring of respiratory rate, work of breathing, oxygen saturation, and blood gases is essential in these patients.
From the Research
Causes of Tachypnea in Late Preterm Newborns
- Tachypnea in late preterm newborns is often caused by transient tachypnea of the newborn (TTN), which is characterized by delayed clearance of lung fluid at birth 2, 3, 4.
- Respiratory distress syndrome (RDS) is another cause of tachypnea in late preterm newborns, particularly in those with lower gestational age, male gender, and caesarean section 5.
- Other risk factors associated with respiratory morbidity in late preterm infants include exposure to peripartum antibiotics, overweight and nulliparous mothers 5.
Pathophysiology of TTN
- TTN is caused by delayed clearance of lung fluid, which leads to respiratory distress and tachypnea 2, 3, 4.
- The condition is more common in late preterm infants, particularly after elective cesarean section 4.
- The physiology of normal fetal lung fluid clearance at birth involves the absorption of lung fluid by the lymphatic system and the onset of breathing, which helps to clear the fluid from the lungs 4.
Treatment Strategies for TTN
- Conventional treatment for TTN involves supplemental oxygen, withholding enteral feeds, and administration of intravenous fluids and antibiotics 4.
- Non-invasive respiratory support, such as continuous positive airway pressure (CPAP), may be used to reduce respiratory distress and improve lung fluid clearance 2, 6, 3.
- Salbutamol, a beta-agonist, may reduce the duration of tachypnea in TTN, but the evidence is limited and of low certainty 3.
- Other potential therapies for TTN, such as furosemide, racemic epinephrine, and inhaled beta-agonists, have been studied, but their routine administration cannot be recommended without additional data 4.