Respiratory Distress in Newborn

1. Respiratory Distress in Newborn Leena Mane PGY 3 Resident Emory Family Medicine Rhea Mane Specialist

2. Question • A male infant weighing 3000 g (6 lb 10 oz) is born at 36 weeks' gestation, with normal Apgar scores and an unremarkable initial examination. At 48 hours of age he is noted to have dusky episodes while feeding, and does not feed well. On repeat examination the child is tachypneic, with subcostal retractions. Lung sounds are clear and there is no heart murmur.

3. What Next ?

4. Tests & labs… • Pulse oximetry on room air is 82%. • Arterial blood gases on 100% oxygen show a pCO2 of 26 mm Hg (N 27-40), a pO2 of 66 mm Hg (N 83-108), • blood pH of 7.50 mg/dL (N 7.35-7.45), and a base excess of -2 mmol/L (N -10 to -2).

5. Labs… • Hemoglobin- 22.0g/dl (N13.0- 20.0) • Hematocrit- 66 % (N 42- 66) • WBC- 19,000/mm3 (N9000-30,000) • Blood cultures- Pending. • Chest X-ray- Increased vascular marking, Large thymus.

6. Most likely diagnosis • 1- Transient tachypnea of newborn • 2- Congenital heart disease • 3- Hyaline membrane disease • 4- Neonatal sepsis • 5- Hyperviscosity syndrome

7. Transient Tachypnea of Newborn • Most common cause of respiratory distress. • 40% cases. • Residual fluid in fetal lung tissues. • Risk factors- maternal asthma, c- section, male sex, macrosomia, maternal diabetes

8. TTN • Tachypnea immediately after birth or within two hours, with other predictable signs of respiratory distress. • Symptoms can last few hours to two days. • Chest radiography shows diffuse parenchymal infiltrates, a “ wet silhouette” around heart, or intralobar fluid accumulation

9. X-ray Fluid in the fissure

10. Respiratory Distress Syndrome • Also called as hyaline membrane disease • Most common cause of respiratory distress in premature infants, correlating with structural & functional lung immaturity. • 1/3 infants born between 28 to 34 weeks, but less than 5% of those born after 34 weeks. • Pathophysiology- surfactant deficiency- increase in alveolar surface tension- decrease in compliance.

11. RDS • Hyaline membrane- combination of sloughed epithelium, protein & edema. • Diagnosis of respiratory distress should be suspected when grunting, retraction or other typical distress symtoms occur in premature infant. • CXR- homogenous opaque infiltrates & air bronchograms.

12. Meconium Aspiration Syndrome • Incidence- 1.5- 2 % in term or post term infants. • Meconium is locally irritative, obstructive & medium for for bacterial culture • Meconium aspiration causes significant respiratory distress. Hypoxia occurs because aspiration occurs in utero. • CXR- Patchy atelectasis or consolidation.

13. Infections • Pneumonia & Sepsis have various manifestations including typical signs of distress as well as temperature instability. • Common pathogen- Group B Streptococcus, Staph aureus, Streptococcus aureus, Streptococcus Pneumoniae,Gm neg rods

14. Infections ctd. • Risk factors- prolonged rupture of membranes, prematurity,& maternal fever. • CXR- bilateral infiltrates suggesting in utero infection.

15. Other causes- • Congenital malformations-Pulmonary hypoplasia, congenital emphysema, esophageal atresia & diaphragmatic hernia. • Neurological causes- hydrocephalus & intracranial hemorrhage. • Metabolic derangements-hypoglycemia, hypocalcaemia, polycythemia.

16. Congenital Heart disease • Cyanotic Heart Disease- • Tetralogy of fallot- ( VSD, Pulmonary stenosis, overriding aorta, RVH) • Tricuspid atresia • Transposition of great vessel • Total anamolous pul. venous return • Truncus arteriosus.

17. Hyperoxia Test • Obtain ABG–> Then place the patient on 100% O2 for 10 minutes then repeat ABG , If the cyanosis is pulmonary , the PaO2 should be increased by 30 mm of Hg. If the cause is cardiac , there will be minimal improvement in PaO2.

18. Treatment • Can be generalized & disease specific • Oxygenation can be enhanced by blow by oxygen, nasal canula or mechanical ventilation in severe cases. • Surfactant administration may be required. • Antibiotics are often indicated if bacterial infection is suspected clinically or because of leucocytosis, neutropenia or hypoxia.

19. Treatment • Fluids should be restricted in acute phase • Fluids should be limited for insensible losses & replacement of Urine output. • Mortality & morbidity is lower in premature infants who were fluid restricted as compared to similar infants

20. Transient Tachypnea of Newborn • Rx is supportive because the condition is usually self limited. • Oral lasix has not shown to significantly improve status. • Prenatal administration of steroids 48hrs before elective C- section @ 37- 39 weeks gestation reduces TTN but this has not become common practice.

21. Respiratory distress Syndrome • General intervention for oxygenation. • Prenatal administration of corticosteroids between 24- 34 wks gestation reduces risk of respiratory distress when risk of preterm delivery is high. • Post natal steroids may decrease mortality but may increase risk of cerebral palsy.

22. Meconium Aspiration Syndrome • Use minimal stimulation & keep head down to prevent breathing of meconium • Standard practice of suctioning the mouth & nares upon head delivery before body delivery is not recommended. • Amnioinfusion does not decrease the incidence of meconium aspiration syndrome & perinatal death.

23. Algorithm

24. Evaluation • Detailed history • Differential diagnosis changes with EGA, GBS status & prophylaxis, duration of rupture of membrane, color of amniotic fluid, maternal temperature, maternal tachycardia, fetal heart tracing • Physical signs- look for apnea, tachypnea or cyanosis, cardiac auscultation for murmur. • Lung auscultation - asymmetrical chest movements- in pneumothorax ,crackles in pneumonia, clear in TTN, & persistent pulmonary HTN.

25. Algorithm

26. Treatment • Mild distress- observation & pulse oximetry • Severe distress- immediate resucitation, CXR, and laboratory tests • Tests- blood culture, blood gas, blood glucose, CBC with Diff,lumbar puncture if indicated, pulse oximetry.

27. Answer • Cyanotic congenital heart disease can appear at the time of ductus closure. A heart murmur is not usually audible, and murmurs heard this early are usually not due to heart disease. The failure to correct hypoxemia with 100% oxygen is diagnostic for abnormal mixing of blood from the right and left circulations. • Transient tachypnea presents earlier, and the hypoxia corrects with supplemental oxygen. • Hyaline membrane disease can occur at 36 weeks, but would cause problems in the first hours of life. It can make oxygenation difficult, but would cause extreme distress with CO2 retention in such cases.

28. Answer • This patient has the energy to hyperventilate and has slight respiratory alkalosis as a result. Neonatal sepsis can cause V/Q mismatching and hypoxia, and can have a delayed presentation. Concern would be high enough in this case that the patient would probably receive broad-spectrum antibiotics while awaiting culture results. On the other hand, the clinician would not want to be distracted from the evidence for congenital heart disease. • The baby is polycythemic from poor intake in the first 2 days of life. The hyperviscosity syndrome can occur when the hematocrit is over 65%. It can cause poor feeding, tachypnea, and sluggishness, but does not cause hypoxia.

29. Thank You …