II. Epidemiology
- Most common cause of Newborn Respiratory Distress (40% of cases)
- Responsible for up to 10% of NICU admissions of term infants
- Incidence: 5-6 per 1000 births
III. Pathophysiology
- Benign cause of Newborn Respiratory Distress
- Response to residual alveolar fluid following delivery (delayed reabsorption)
- Prostaglandin release typically increases with Vaginal Delivery
- Prostaglandins trigger lymphatic dilation and aid alveolar fluid clearance
-
Surfactant deficiency may play a role
- However, surfactant replacement is not indicated
IV. Precautions
- Transient Tachypnea is a diagnosis of exclusion
- Carefully consider differential diagnosis (e.g. Pneumonia, Respiratory Distress Syndrome in the Newborn)
V. Risk Factors
- Maternal factors
- Cesarean Section delivery (esp. elective Cesarean Section without labor, RR 3)
- Gestational Diabetes
- Maternal Asthma history
- Rapid delivery
- Newborn factors
- Male gender
- Fetal Macrosomia
- Term and postterm infants
VI. Signs
- Barrel shaped chest
-
Tachypnea
- Onset: Within 2 to 6 hours of delivery
- Duration: Hours to Days (typically resolves within 48 hours)
- Initial higher Respiratory Rates predict a longer course
VII. Imaging
-
Chest XRay
- Prominent perihilar pulmonary vasculature (sunburst pattern)
- Heart with surrounding "wet silhouette"
- Intralobar fluid
- Lung Hyperexpansion
- Imaging findings may persist up to 7 days (lagging clinical improvement)
- Bedside Lung Ultrasound
- B-Line Artifacts suggest interstitial fluid
VIII. Differential Diagnosis
- See Respiratory Distress in the Newborn
- See Neonatal Distress Causes
-
Delayed Transition from Fetal Circulation
- Respiratory Rate 60 to 80 breaths/min
- Mild increased work of breathing
- Improves rapidly after first 4 hours (contrast with TTN which typically lasts up to 48 hours)
IX. Management
- See Respiratory Distress in the Newborn
- See Newborn Resuscitation
- Supportive care - generally improves spontaneously
- Mixed efficacy (but do not appear to reduce hospitalization lengths)
- Nebulized Albuterol
- Reduces TTN duration and need for Supplemental Oxygen
- Consider fluid restriction
- Nebulized Albuterol
- Avoid potentially harmful or unhelpful measures
- Furosemide (Lasix) is not effective
X. Complications
- Aspiration risk when Respiratory Rate >80 breaths/min
- Childhood Asthma higher risk
XI. Prevention
- Avoid cesarean delivery before 39 weeks
- If cesarean delivery before 39 weeks cannot be avoided
- Corticosteroids (Betamethasone or Dexamethasone) at 48 hours before Cesarean Delivery (37-39 weeks)