A term male is born at 38 weeks through a scheduled repeat cesarean section prior to the onset of labor. The infant’s mother had good prenatal care including vaginal cultures negative for group B Streptococcus. At the delivery, the amniotic fluid was clear and was not foul-smelling. Apgar scores are 8 at 1 minute and 8 at 5 minutes. Within the first hour of birth, he has tachypnea, nasal flaring, and mild retractions. Chest auscultation reveals good air movement bilaterally; a few rales are noted.
What is the most likely diagnosis?
What is the best management for this condition?
ANSWERS TO CASE 48: Transient Tachypnea of the Newborn
Summary: A term newborn born by cesarean section has respiratory distress.
• Most likely diagnosis:Transient tachypnea of the newborn (TTN).
• Treatment: Supportive care including supplemental oxygen, if necessary.
ANALYSIS
Objectives
1. Know the presentation of TTN.
2. Understand the medical care for TTN.
Considerations
This infant presents soon after birth with mild respiratory distress following an uneventful pregnancy and delivery. Evaluation of this infant begins with auscultation of the lungs and heart.
APPROACH TO:
Transient Tachypnea of the Newborn
DEFINITIONS
TRANSIENT TACHYPNEA OF THE NEWBORN:Slow absorption of fetal lung fluid with resultant tachypnea. The condition more commonly is associated with cesarean section deliveries.
MECONIUM ASPIRATION SYNDROME: Aspiration of meconium during delivery resulting in respiratory distress. Radiographic findings include hyperinflation with patchy infiltrates. As meconium may plug small airways, areas of air trapping are often present and may lead to the development of pneumothorax.
RESPIRATORY DISTRESS SYNDROME: A condition seen in premature infants resulting from surfactant deficiency. Radiographic findings include a characteristic reticulonodular “ground glass” pattern with air bronchograms and decreased aeration.
CONGENITAL DIAPHRAGMATIC HERNIA (CDH): The condition of herniation of abdominal contents through the posterolateral foramen of Bochdalek into the thoracic cavity. The incidence is approximately 1 in 5000 live births.
EXTRACORPOREAL MEMBRANE OXYGENATION (ECMO): A system using a modified heart-lung machine utilized in severe pulmonary failure. Cannulation of the carotid artery and jugular vein is required to link the neonate to the system.
CLINICAL APPROACH
Transient tachypnea of the newborn is a self-limited condition usually occurring in a term infant after an uneventful cesarean section (more commonly) or vaginal birth. It is felt to be caused by slow absorption of fetal lung fluid. Infants with TTN develop respiratory distress shortly after birth with tachypnea, mild retractions, nasal flaring, and in more severe cases grunting and cyanosis. Chest radiography reveals perihilar streaking and fluid in the fissures; lungs are aerated. Most infants with TTN have resolution of their tachypnea in 24 to 96 hours.
For a few infants with TTN, oxygen saturations drop and supplemental oxygen is required; rarely does the oxygen requirement exceed 40%. In the rare, more severe case of TTN consideration for ongoing increased pulmonary vascular resistance leading to persistent pulmonary hypertension must be entertained. Infants with TTN do not require antimicrobial therapy; failure of the infant to follow the expected course of mild respiratory distress indicates the need to evaluate the child for more serious pathology.
Infants with respiratory distress syndrome (RDS) are usually born prematurely (less than 34 weeks gestational age); these infants have a deficiency of surfactant. Shortly after birth they present with symptoms of respiratory distress including poor oxygenation, grunting, retracting, and poor air movement. Radiographically they have findings including a reticulonodular pattern with air bronchograms and decreased aeration of the lungs. Supportive care includes supplemental oxygen as needed to maintain oxygen saturation of 90% to 95% and intravenous fluids or nasogastric feeding to maintain hydration as the degree of tachypnea usually precludes oral feeding. Exogenous surfactant is available and is administered by the resuscitation team in an effort to ameliorate the effects of surfactant deficiency.
COMPREHENSION QUESTIONS
48.1 A term male is born to a 33-year-old woman who had little prenatal care. Immediately after birth he has cyanosis and respiratory distress. Chest auscultation in the delivery room reveals right-sided heart sounds and absent left-sided breath sounds. Which of the following is the most appropriate next step?
A. Assess the abdomen to evaluate for possible congenital diaphragmatic hernia.
B. Order a computed tomography of the chest.
C. Order ultrasonography of the chest.
D. Perform a needle thoracostomy for possible pneumothorax.
E. Prepare the infant for ECMO.
48.2 A term female is born via repeat cesarean section to a 30-year-old woman. Immediately after birth she has mild respiratory distress. Chest auscultation in the delivery room reveals clear breath sounds. Which of the following is the most appropriate next step?
A. Endotracheal intubation with direct suction.
B. Begin intravenous antibiotic therapy.
C. Deliver surfactant therapy.
D. Observe and administer supplemental oxygen as needed.
E. Bag-and-mask ventilation.
48.3 A term male is born vaginally to a 22-year-old primigravida woman; the pregnancy was uncomplicated. Just prior to delivery, fetal bradycardia was noted, and at delivery thick meconium is found. The infant has hypotonia and brady-cardia. Which of the following is the first step in resuscitation?
A. Administration of epinephrine through endotracheal tube
B. Bag-and-mask ventilation
C. Endotracheal intubation with direct suction
D. Oxygen delivered by cannula in close proximity to the nares
E. Tracheostomy
48.4 After the infant discussed in Question 48.3 is stabilized and admitted to the neonatal intensive care unit, a chest radiograph reveals bilateral patchy infiltrates with coarse streaking and flattening of the diaphragm. He abruptly has an increased oxygen requirement. Physical examination reveals decreased right-sided breath sounds. Which of the following is an accurate statement?
A. High positive end-expiratory pressure (PEEP) is useful in this condition.
B. Needle thoracostomy is contraindicated.
C. Chest radiography is likely to reveal CDH.
D. Chest radiography is likely to reveal a diffuse reticulonodular pattern.
E. Transillumination of the chest is likely to transmit excessive light on the right side.
ANSWERS
48.1 A. Evaluation of neonates born with respiratory distress and unilateral breath sounds includes an abdominal examination. With asymmetrical breath sounds, pneumothorax and CDH are considered. This infant’s scaphoid abdomen suggests CDH; needle thoracostomy is avoided because intestinal perforation may occur. The patient is stabilized and the need for ECMO is ascertained after the infant’s initial therapy response is evaluated. Many cases of CDH are diagnosed by prenatal ultrasound.
48.2 D. As this infant most likely has TTN the next step is to observe and administer supplemental oxygen as needed.
48.3 C. Endotracheal intubation with direct suction is performed in a depressed infant with thick meconium noted at delivery. Bag-and-mask ventilation or endotracheal intubation without suction may increase the volume of meconium aspirated. A vigorous infant with a heart rate greater than 100 beats per minute, strong respirations, and good muscle tone with meconium-stained need not be suctioned immediately after birth.
48.4 E. This infant likely has a right-sided pneumothorax; excessive light transmission by transillumination and right-sided hyperresonance with auscultation are expected. Infants with meconium aspiration and respiratory distress are at higher risk for pneumothorax, especially if high PEEP is used for oxygenation. A chest tube for the pneumothorax may be needed. Infants with severe respiratory distress or circulatory involvement may require emergent needle aspiration.
CLINICAL PEARLS
Transient tachypnea of the newborn (TTN) is associated with birth by cesarean section.
TTN is managed with supportive care and does not lead to chronic lung disease.
REFERENCES
Carlo WA, Ambalavanan N. Respiratory distress syndrome (hyaline membrane disease). In: Kliegman RM, Stanton BF, St. Geme JW, Schor NF, Behrman RE, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: WB Saunders; 2011:581-590.
Galarza MG, Sosenko IRS. Abnormalities of the lungs. In: Rudolph CD, Rudolph AM, Lister GE, First LR, Gershon AA eds. Rudolph’s Pediatrics. 22nd ed. New York, NY: McGraw-Hill; 2011:201-206.
Gross I. Meconium aspiration syndrome. In: McMillan JA, Feigin RD, DeAngelis CD, Jones MD, eds. Oski’s Pediatrics: Principles and Practice. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2006:315.
Gross I. Transient tachypnea of the newborn. McMillan JA, Feigin RD, DeAngelis CD, Jones MD, eds. Oski’s Pediatrics: Principles and Practice. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2006:311.
Hansen TN, Hawgood S. Respiratory distress syndrome. In: Rudolph CD, Rudolph AM, Lister GE, First LR, Gershon AA eds. Rudolph’s Pediatrics. 22nd ed. New York, NY: McGraw-Hill; 2011:233-235.