AUTHOR AND EDITOR INFORMATION

Section 1 of 8  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• Ultrasound
• Intervention
• Multimedia
• References

INTRODUCTION

Section 2 of 8  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• Ultrasound
• Intervention
• Multimedia
• References

Background

Transient tachypnea of the newborn appears soon after birth. It may be accompanied by chest retractions, by expiratory grunting, or by cyanosis. (This last manifestation can be relieved with minimal oxygen.) Recovery usually is complete within 3 days.

Radiologically, this syndrome frequently is termed wet lung disease. In the medical literature, discussions concerning transient tachypnea of the newborn also can be found under the following names: retained fetal lung liquid, retention of fetal lung fluid, respiratory distress syndrome type II, transient respiratory distress of the newborn, and neonatal retained fluid syndrome.

Pathophysiology

During fetal life, the lungs are expanded with an ultrafiltrate of the fetal serum. In the course of neonatal transition, this ultrafiltrate must be removed and replaced with air. The classic explanation for how this occurs was that passage through the birth canal would, by squeezing the thorax, help eliminate the liquid in the lungs, with the remaining fluid being removed by pulmonary capillaries and the lymphatics. Currently, however, the bulk of this clearance is thought to be mediated by transepithelial sodium reabsorption through sodium channels in the alveolar epithelial cells, with only a limited contribution from mechanical factors and Starling forces. Changes in the hormonal milieu of the fetus and its mother, brought about mainly by the onset of spontaneous labor, prepare the fetus for the neonatal transition to air breathing.

Transient tachypnea of the newborn occurs when the liquid in the lung is removed slowly or incompletely; this phenomenon correlates with a decreased thoracic birth squeeze or diminished respiratory effort in the newborn. Transient tachypnea has been identified as occurring with cesarean birth and infant sedation. Longer labor intervals, macrosomia of the fetus, and maternal asthma also have been associated with a higher frequency of transient tachypnea of the newborn.

Frequency

United States

Incidence of transient tachypnea is 11 per 1000 live births.

Mortality/Morbidity

By definition, transient tachypnea of the newborn entails no mortality or morbidity. However, it prolongs the neonate's hospital stay and is associated with an increased risk of asthma development during childhood. If radiographic resolution is not complete by the third day or if respiratory symptoms persist longer than 5 days, an alternative diagnosis should be sought (see Differentials).

Sex

Transient tachypnea occurs more frequently in males.

Age

Transient tachypnea is seen in neonates, usually those born at term.

Anatomy

The lungs usually are affected diffusely and symmetrically. The condition is commonly accompanied by a small pleural effusion.

Clinical Details

Mild or moderate respiratory distress typically is present at birth or within 6 hours after birth.

Tachypnea (ie, respiratory rate exceeding 60/min) may be accompanied by chest retractions, expiratory grunting, or cyanosis. Cyanosis can be relieved with minimal oxygen.

The clinical course of transient tachypnea is relatively benign when compared with the severity suggested by chest films. Radiographic resolution by the second or third day characterizes this entity and differentiates it from other possible disorders. Respiratory symptoms persist for 2-5 days (see Image 2, Image 3).

Preferred Examination

Standard chest radiography is the preferred radiologic examination.

Limitations of Techniques

Initially, it may be difficult to distinguish transient tachypnea from other causes of respiratory distress of the newborn.

DIFFERENTIALS

Section 3 of 8  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• Ultrasound
• Intervention
• Multimedia
• References

Other Problems to be Considered

Respiratory distress syndrome
Congenital lymphangiectasia
Congenital heart disease
Polycythemia
Cerebral hyperventilation
Anemia/hypovolemia

RADIOGRAPH

Section 4 of 8  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• Ultrasound
• Intervention
• Multimedia
• References

Findings

Findings on chest radiographs may include mild, symmetrical lung overaeration; prominent perihilar interstitial markings; and small pleural effusions (see Image 1). Occasionally, the right side may appear more opacified than the left.

Radiographic appearance at times can mimic the diffuse, granular appearance of hyaline membrane disease but without pulmonary underaeration. Neonates with transient tachypnea usually are at term. Radiographic lung changes also may resemble the coarse, interstitial pattern of other causes of pulmonary edema or the irregular pattern of lung opacification seen in meconium aspiration syndrome.

Degree of Confidence

The degree of confidence is rather low. Clinicoradiologic correlation helps confirm the diagnosis. Timing also is a key diagnostic factor.

ULTRASOUND

Section 5 of 8  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• Ultrasound
• Intervention
• Multimedia
• References

Findings

A persistent radiographic finding of cardiomegaly should raise suspicions of congenital heart disease. Evaluation by a pediatric cardiologist and echocardiographic imaging should follow.

INTERVENTION

Section 6 of 8  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• Ultrasound
• Intervention
• Multimedia
• References

Special Concerns

• Differentiation from other causes of neonatal respiratory distress may take time. Initial evaluation, monitoring, and basic supportive care must cover all diagnostic contingencies. Following immediate postnatal cultures, a course of antibiotic therapy may be initiated and then terminated at 72 hours if cultures are negative and the clinical condition is improving.

MULTIMEDIA

Section 7 of 8  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• Ultrasound
• Intervention
• Multimedia
• References

Media file 1:  Neonate at age 6 hours. Overaeration and streaky, bilateral, pulmonary interstitial opacities and prominent perihilar interstitial markings are seen along with mild cardiomegaly.
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Media type:  X-RAY

Media file 2:  Same patient as in Picture 1 at age 2 days. Cardiomegaly has disappeared. Pulmonary parenchymal abnormalities are diminishing, but perihilar, streaky markings persist.
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Media type:  X-RAY

Media file 3:  Same patient as in Pictures 1 and 2 at age 4 days. Normal heart size and clear lungs are seen.
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Media type:  X-RAY

REFERENCES

Section 8 of 8

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• Ultrasound
• Intervention
• Multimedia
• References

• Birnkrant DJ, Picone C, Markowitz W. Association of transient tachypnea of the newborn and childhood asthma. Pediatr Pulmonol. Oct 2006;41(10):978-84.
• Cleveland RH. A radiologic update on medical diseases of the newborn chest. Pediatr Radiol. 1995;25(8):631-7. [Medline].
• Demissie K, Marcella SW, Breckenridge MB, Rhoads GG. Maternal asthma and transient tachypnea of the newborn. Pediatrics. Jul 1998;102(1 Pt 1):84-90. [Medline].
• Jain L, Dudell GG. Respiratory transition in infants delivered by cesarean section. Semin Perinatol. Oct 2006;30(5):296-304.
• Jain L, Eaton DC. Physiology of fetal lung fluid clearance and the effect of labor. Semin Perinatol. Feb 2006;30(1):34-43.
• Kuhn JP, Fletcher BD, DeLemos RA. Roentgen findings in transient tachypnea of the newborn. Radiology. Mar 1969;92(4):751-7.
• Miller MJ, Fanaroff AA, Martin RJ. Respiratory disorders in preterm and term infants. In: Fanaroff AA, Martin RJ, eds. Neonatal-Perinatal Medicine: Diseases of the Fetus and Infant. 6th ed. St Louis, Mo: Mosby-Year Book;1997:1040-65.
• Newman B. Imaging of medical disease of the newborn lung. Radiol Clin North Am. Nov 1999;37(6):1049-65. [Medline].
• Rawlings JS, Wilson JL, Garcia J. Radiological case of the month. Wet lung syndrome (transient tachypnea of the newborn). Am J Dis Child. Dec 1985;139(12):1233-4. [Medline].
• Rawlings JS, Smith FR. Transient tachypnea of the newborn. An analysis of neonatal and obstetric risk factors. Am J Dis Child. Sep 1984;138(9):869-71. [Medline].
• Riskin A, Abend-Weinger M, Riskin-Mashiah S. Cesarean section, gestational age, and transient tachypnea of the newborn: timing is the key. Am J Perinatol. Oct 2005;22(7):377-82.
• Shaw D. The chest. In: Carty H, Shaw D, Brunelle F, Kendall B, eds. Imaging children. Edinburgh: Churchill Livingstone;1994:1-165.
• Whitsett JA, Pryhuber GS, Rice WR. Acute respiratory disorders. In: Avery GB, Fletcher MA, MacDonald MG, eds. Neonatology: Pathophysiology and Management of the Newborn. 4th ed. Philadelphia, Pa: Lippincott-Raven;1994:429-52.

Article Last Updated: Jan 12, 2007