Ep 5: Transient Tachypnea of the Newborn (TTN)

Learning Objectives

By the end of this episode, NICU Grads will be able to:
1. Determine the optimal strategies for prevention and management of an infant with TTN

Transient tachypnea of the newborn (TTN)

• Mechanism of Action
  • Caused by ineffective absorption of fetal lung fluid
  • See Ep 4: Fetal Lung Fluid Clearance to review normal physiology
  • Failure or delay in clearance of intra-alveolar fluid in patients with TTN is due to:
    • Lack of ENaC expression or activity
      • Lack of active labor and its associated hormonal changes
      • Ineffective lung distention and lack of alveolar air interface 
    • Immaturity of ENaC 
      • Especially relevant in the late preterm infant

• Incidence
  • 5.7 per 1000 births in term infants
• Risk factors for TTN

• Symptoms
  • Clinical presentation is reflection of decreased lung compliance associated with pulmonary edema and ineffective fetal lung fluid clearance
  • Tachypnea (most consistent finding)
  • Increased work of breathing
  • Mild degrees of hypoxia
  • Timing:
    • Onset: Present very early after birth 
    • Duration: 2- 3 days 

• DDx:
  • Surfactant deficiency, meconium aspiration syndrome, neonatal pneumonia, early-onset sepsis, and congenital cardiac anomalies

• Radiographic findings of TTN
  • Interstitial edema (Most commonly seen)
    • Fluid in the interlobar fissure
    • Prominent vascular markings–> Represents engorgement of the periarterial lymphatics
  • Mildly hyperexpanded lungs
  • Atelectasis
  • Minimal pleural effusion can also be seen (Less commonly seen)
  • Radiographic changes resolve by 48- 72 hours
• Management
  • Supportive
  • Resolves by 72 hours of age
  • Does not medical require antibiotics for treatment
    • However, TTN is a diagnosis of exclusion and it is hard to differentiate TTN from other etiologies such as infectious early on. As a result, many patients are placed on antibiotics that are discontinued after 48 hours if cultures are negative and the diagnosis of TTN is more evident.
  • Effective efforts to ameliorate TTN have included:
    • Fluid restriction
      • Fluid restriction may be beneficial in the management of TTN (PREP Pearls) 
      • Fluid restriction may be associated with:
        • Decrease in duration of respiratory support and hospitalization costs among individuals with severe TTN (needing respiratory support for > 48 he) (Stroustrup A et al, 2012)
        • Evidence delineating the exact degree of fluid restriction in TTN is limited. 
  • Ineffective efforts to ameliorate TTN have included:
    • Deep suctioning after birth
      • No impact on lung fluid clearance
    • Albuterol
      • Insufficient evidence 
    • Administration of furosemide
      • A 2015 Cochrane systematic review suggests there is no benefits of diuretic use in TTN (Kassab M et al, 2015)
    • Inhaled corticosteroids  
      • Double-blind, randomized, placebo-controlled, multicenter pilot study demonstrated no significant benefits in the incidence rates of TTN when provided with early inhaled steroids in late preterm and term population (Vaisbourd Y et al, 2017).
• Prevention
  • Delaying elective c-section until 39-40 weeks’ gestation or until spontaneous labor starts 
•  Prognosis
  • Overall good prognosis
  • Emerging data suggests TTN may be associated with wheezing syndrome early in life. More studies are needed to better establish this relationship

References:

• Hagen E, Chu A, Lew C. Transient tachypnea of the newborn. Neoreviews. 2017;18(3):e141-146. doi: http://dx.doi.org/10.1542/neo.18-3-e141
• Kassab M, Khriesat WM, Anabrees L. Diuretics for transient tachypnoea of the newborn. Cochrane Database Syst Rev. 2015(11):CD003064. doi: http://dx.doi.org/10.1002/14651858.CD003064.pub3
• Machado LU, Fiori HH, Baldisseratto M, Ramos Garcia PC, Vieira AC, Fiori RM. Surfactant deficiency in transient tachypnea of the neonate. J Pediatr. 2011;159(5):750-754. doi: http://dx.doi.org/10.1016/j.jpeds.2011.04.023
• Moresco L, Bruschettini M, Cohen A, Gaiero A, Colevo MG. Salbutamol for transient tachypnea of the newborn. Cochrane Database Syst Rev. 2016;5:CD011878. doi: http://dx.doi.org/10.1002/14651858.CD011878.pub2
• Stroustrup A, Trasande L, Holzman IR. Randomized controlled trial of restrictive fluid management in transient tachypnea of the newborn. J Pediatr. 2012;160(1):38-43. doi: http://dx.doi.org/10.1016/j.jpeds.2011.06.027
• Vaisbourd Y, Abu-Raya B, Zangen A, et al. Inhaled corticosteroids in transient tachypnea of the newborn: a randomized, placebo-controlled study. Pediatr Pulmonol. 2017; 52(8):1043-1050. doi: http://dx.doi.org/10.1002/ppul.23756
• Golshantafti, Mohammad et al. “Risk of Wheezing Attacks in Infants With Transient Tachypnea Newborns.” Iranian journal of pediatrics vol. 26,1 (2016): e2295. doi:10.5812/ijp.2295
• Alhassen Z, Vali P, Guglani L, Lakshminrusimha S, Ryan RM. Recent Advances in Pathophysiology and Management of Transient Tachypnea of Newborn. J Perinatol. 2020. doi:10.1038/s41372-020-0757-3

Credits

• Written and Produced by: Neena Jube-Desai MD, MBA FAAP
• Cover Art by: Neena Jube-Desai MD, MBA FAAP
• Infographic by: Piyawat Arichai MD
• Host: Neena Jube-Desai MD, MBA FAAP
• Editor: Neena Jube-Desai MD, MBA FAAP
• Guest: Simranjeet Sran, MD FAAP