• Clinical science

Neonatal respiratory distress syndrome (Infant respiratory distress syndrome…)


Neonatal respiratory distress syndrome (NRDS), or surfactant deficiency disorder, is a lung disorder in infants that is caused by a deficiency of pulmonary surfactant. It is most common in preterm infants, with the incidence and severity decreasing with gestational age. Surfactant deficiency causes the alveoli to collapse, resulting in impaired blood gas exchange. Symptoms manifest shortly after birth and include tachypnea, tachycardia, increased breathing effort, and/or cyanosis. The diagnosis is suspected based on clinical features and confirmed by evaluating the extent of atelectasis via chest x-ray. Blood gases show respiratory and metabolic acidosis in addition to hypoxia. Treatment primarily involves emergent resuscitative measures, which include nasal CPAP and stabilizing blood sugar levels and electrolytes. Additionally, intratracheal surfactant is administered if ventilation alone is not successful. Most cases resolve within 3–5 days of treatment. However, complications like hypoxemia, tension pneumothorax, bronchopulmonary dysplasia, sepsis, and neonatal death may still occur. NRDS can be prevented by administering antenatal glucocorticoids to the mother if premature delivery is expected.



Epidemiological data refers to the US, unless otherwise specified.





Clinical features

  • History of premature birth
  • Onset of symptoms: usually manifests immediately after birth
  • Signs of increased breathing effort
    • Tachypnea
    • Nasal flaring and moderate to severe subcostal/intercostal and jugular retractions
  • Typical expiratory “grunting”
  • Auscultation: decreased breath sounds
  • Cyanosis due to peripheral hypoxic vasoconstriction




Differential diagnoses


The differential diagnoses listed here are not exhaustive.


Physiologic O2 saturation in neonates is around 90% instead of 100%. A saturation of 100% is considered toxic for the neonate!



Bronchopulmonary dysplasia (BPD)

Further complications


We list the most important complications. The selection is not exhaustive.


  • NRDS has a case fatality rate of 30% if not treated.
  • Most cases that have been promptly treated resolve within 3–5 days of treatment.



  • 1. Pramanik AK. Respiratory Distress Syndrome. In: Rosenkrantz T. Respiratory Distress Syndrome. New York, NY: WebMD. http://emedicine.medscape.com/article/976034. Updated January 16, 2015. Accessed May 11, 2017.
  • 2. Besnard AE, Wirjosoekarto SAM, Broeze KA, Opmeer BC, Mol BWJ. Lecithin/sphingomyelin ratio and lamellar body count for fetal lung maturity: a meta-analysis. Eur J Obstet Gynecol Reprod Biol. 2013; 169(2): pp. 177–183. doi: 10.1016/j.ejogrb.2013.02.013.
  • 3. Andreeva AV, Kutuzov MA, Voyno-Yasenetskaya TA. Regulation of surfactant secretion in alveolar type II cells. Am J Physiol Lung Cell Mol Physiol. 2007; 293(2): pp. L259–L271. doi: 10.1152/ajplung.00112.2007.
  • 4. Le T, Bhushan V, Bagga HS. First Aid for the USMLE Step 2 CK. McGraw-Hill Medical; 2009.
  • 5. Hermansen CL, Mahajan A. Newborn Respiratory Distress. Am Fam Physician. 2015; 92(11): pp. 994–1002. pmid: 26760414.
  • 6. Le T, Bhushan V,‎ Sochat M, Chavda Y, Zureick A. First Aid for the USMLE Step 1 2018. New York, NY: McGraw-Hill Medical; 2017.
  • 7. Wilmott RW, Kendig EL, Boat TF, Bush A, Chernick V. Kendig and Chernick's Disorders of the Respiratory Tract in Children. Elsevier Health Sciences; 2012.
  • 8. Sher G, Statland BE, Freer DE. Clinical evaluation of the quantitative foam stability index test. Obstet Gynecol. 1980; 55(5): pp. 617–20. pmid: 6892727.
  • 9. Radswiki, et al. Meconium Aspiration. https://radiopaedia.org/articles/meconium-aspiration. Updated January 1, 2017. Accessed November 15, 2017.
  • 10. Reuter S, Moser C, Baack M. Respiratory distress in the newborn. Pediatr Rev. 2014; 35(10): pp. 417–429. doi: 10.1542/pir.35-10-417.
  • 11. Le T, Bhushan V,‎ Sochat M, Chavda Y, Abrams J, Kalani M, Kallianos K, Vaidyanathan V. First Aid for the USMLE Step 1 2019. New York, NY: McGraw-Hill Medical.
  • 12. Kinsella JP, Greenough A, Abman SH. Bronchopulmonary dysplasia. The Lancet. 2006; 367(9520): pp. 1421–1431. doi: 10.1016/s0140-6736(06)68615-7.
  • 13. Rajiah P. Imaging in Bronchopulmonary Dysplasia. In: Lin EC. Imaging in Bronchopulmonary Dysplasia. New York, NY: WebMD. https://emedicine.medscape.com/article/406564-overview. Updated August 25, 2016. Accessed January 25, 2018.
  • 14. Romejko-Wolniewicz E, Teliga-Czajkowska J, Czajkowski K. Antenatal steroids: can we optimize the dose?. Curr Opin Obstet Gynecol. 2014; 26(2): pp. 77–82. doi: 10.1097/gco.0000000000000047.
  • Kaplan. USMLE Step 2 CK Lecture Notes 2017: Pediatrics. New York, NY: Kaplan; 2016.
  • Gibson E, Nawab U. Respiratory Distress Syndrome in Neonates (Hyaline Membrane Disease). http://www.msdmanuals.com/professional/pediatrics/perinatal-problems/respiratory-distress-syndrome-in-neonates#v1089988. Updated January 1, 2015. Accessed May 11, 2017.
  • Abman et al. Guidelines From the American Heart Association and American Thoracic Society: Pediatric Pulmonary Hypertension. Circulation. 2015; 132(21): pp. 2037–2099. doi: 10.1161/cir.0000000000000329.
  • Usta et al. Risk factors for meconium aspiration syndrome. Obstet Gynecol. 1995; 86(2): pp. 230–4. pmid: 7617354.
  • Dargaville PA. The Epidemiology of Meconium Aspiration Syndrome: Incidence, Risk Factors, Therapies, and Outcome. Pediatrics. 2006; 117(5): pp. 1712–1721. doi: 10.1542/peds.2005-2215.
  • Dishop MK. Developmental and Pediatric Lung Disease. Elsevier; 2018: pp. 99–124.e5.
last updated 04/04/2020
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