TTN Flashcards
What is Transient Tachypnea of the Newborn (TTN)?
TTN is a parenchymal lung disorder characterized by pulmonary edema resulting from delayed resorption and clearance of fetal alveolar fluid.
TTN typically presents in near term and term infants.
What physiological change occurs during labor that affects fetal lung fluid clearance?
A fetal catecholamine surge causes a switch from active chloride and fluid secretion to active sodium resorption.
This change is crucial for the resorption of fetal lung fluid.
What happens when sodium channels are inactivated or ineffective in the context of TTN?
A larger volume of lung fluid is present, inhibiting gas exchange and increasing work of breathing, leading to hypoxia and tachypnea.
Hypoxia is a significant concern in TTN.
List some risk factors associated with Transient Tachypnea of the Newborn.
- Elective C-Section with or without labor
- Excessive maternal sedation
- Prolonged labor or precipitous deliveries
- Maternal fluid overload
- Breech delivery
- Male sex
- Macrosomia (BW > 4500 g)
- Perinatal/birth asphyxia
- Infants of Diabetic Mothers (IDM)
Each of these factors can contribute to the development of TTN.
What is a common clinical presentation of TTN?
Tachypnea with respiratory rate of 60-120 bpm, may have rales, grunting, flaring, retracting, and varying degrees of cyanosis.
Usually, there are no signs/symptoms of sepsis.
What findings might be seen on a chest X-ray of an infant with TTN?
- Hyperexpansion
- Prominent perihilar streaking
- Depression of the diaphragm
- Fluid in the minor fissure and possibly in the pleural space
- Occasional mild to moderate cardiomegaly
Air leaks are rarely seen, and no areas of consolidation are present.
What is the differential diagnosis for TTN?
- Pneumonia
- Heart disease
- Respiratory Distress Syndrome (RDS)
- Metabolic disorders
- Polycythemia
TTN is a diagnosis of exclusion; other causes of tachypnea should be ruled out first.
What is a distinguishing feature of RDS compared to TTN?
RDS typically presents in premature infants, requires higher respiratory support, and has a characteristic X-ray pattern with reticulogranular pattern and underexpansion of the lungs.
Infants with TTN are often misdiagnosed with RDS.
What is the primary management strategy for TTN?
Supportive care, including adequate oxygenation, may involve hood O2 or nasal cannula.
If O2 needs exceed 30%, nasal CPAP may be used.
What are some supportive measures for infants diagnosed with TTN?
- NPO if RR > 80 to decrease stress of nipple feeding
- Fluids/Glucose to maintain metabolic homeostasis
- NTE to prevent metabolic problems related to hypothermia
These measures help manage the infant’s condition effectively.
True or False: TTN usually resolves within 48-72 hours.
True
Although some infants may have a persistent oxygen requirement at high altitude.
