1. CONGENITAL AND ACQUIRED RESPIRATORY DISORDERS IN INFANTS

2. OBJECTIVES n Review of Cardio-Pulmonary Development. n Define changes that occur during transition to extra-uterine life with emphasis on breathing mechanics. n Identify infants at risk for and who have respiratory distress n Review of common neonatal disease states.

3. STAGES OF NORMAL LUNG GROWTH Embryonic - first 5 weeks; formation of proximal airways Pseudoglandular - 5-16 weeks; formation of conducting airways Canalicular - 16-24 weeks; formation of acini Saccular - 24 - 36 weeks; development of gas- exchange units Alveolar - 36 weeks and up; expansion of surface area

4. Pseudoglandular 6-16 weeks

5. Canalicular Phase 16-24 weeks

6. Saccular Phase 24-34 weeks

7. PHYSIOLOGIC MATURATION (Surfactant Production) n Type 2 pneumocytes appear at 24-26 weeks n Responsible for reduction of alveolar surface tension. u LaPlace’s Law n Lipid profile as indicator of lung maturity u L/S Ratio u Flourescence Polarization - FLM n Many other factors influence lung maturation

10. Maturational Factors n Stimulation u Glucorticoids, ACTH u Thyroid Hormones, TRF u EGF u Heroin u Aminophyline,cAMP u Interferon u Estrogens n Inhibition u Diabetes (insulin, hyperglycemia, butyric acid) u Testosterone u TGF-B u Barbiturates u Prolactin

11. FETAL CIRCULATION

12. TRANSITION TO EXTRA-UTERINE LIFE n Fetal Breathing n Instantaneous; liquid filled to air filled lungs n Maintenance of FRC n Placental blood flow termination n Decreased PVR n Closure of fetal shunts

13. MECHANICS OF BREATHING n Respiratory Control Center...CNS u Metabolic Needs n Negative pressure breathing n Compliance and Resistance u Inspiratory Muscles u Rib Cage F “Compliability becomes a liability”

14. Signs of Respiratory Distress n Tachypnea n Intercostal retractions n Nasal Flaring n Grunting n Cyanosis

15. When is it abnormal to show signs of respiratory distress? n When tachypnea, retractions, flaring, or grunting persist beyond one hour after birth. n When there is worsening tachypnea, retractions, flaring or grunting at any time. n Any time there is cyanosis

16. Causes of Neonatal Respiratory Distress n Obstructive/restrictive - mucous, choanal atresia, pneumothorax, diaphragmatic hernia. n Primary lung problem - Respiratory Distress Syndrome (RDS), meconium aspiration, bacterial pneumonia, transient (TTN). n Non -pulmonary - hypovolemia/hypotension, congenital heart disease, hypoxia, acidosis, cold stress, anemia, polycythemia

17. Infants at Risk for Developing Respiratory Distress n Preterm Infants n Infants with birth asphyxia n Infants of Diabetic Mothers n Infants born by Cesarean Section n Infants born to mothers with fever, Prolonged ROM, foul-smelling amniotic fluid. n Meconium in amniotic fluid. n Other problems

18. Evaluation of Respiratory Distress n Administer Oxygen and other necessary emergency treatment n Vital sign assessment n Determine cause-- physical exam, Chest x-ray, ABG, Screening tests: Hematocrit, blood glucose, CBC n Sepsis work-up

19. Principles of Therapy n Improve oxygen delivery to lungs-- supplemental oxygen, CPAP, assisted ventilation, surfactant n Improve blood flow to lungs-- volume expanders, blood transfusion, partial exchange transfusion for high hematocrit, correct acidosis (metabolic/respiratory) n Minimize oxygen consumption-- neutral thermal environment, warming/humidifying oxygen, withhold oral feedings, minimal handling

20. DISEASE STATES n Respiratory Distress Syndrome n Transient Tachypnea of the Newborn n Meconium Aspiration Syndrome n Persistent Hypertension of the Newborn n Congenital Pneumonia n Congenital Malformations n Acquired Processes

21. RESPIRATORY DISTRESS SYNDROME Surfactant Deficiency Tidal Volume Ventilation Pulmonary Injury Sequence

22. CLINICAL FEATURES OF RDS n Tachypnea/Apnea n Dyspnea n Grunting/Flaring n Hypoxemia n Radiographic Features n Pulmonary Function Abnormalities

23. Early RDS

24. Progressive RDS

25. Late RDS

26. Hyaline Membrane Disease

27. THERAPY FOR RDS n Oxygen - maintain PaO2 > 50 torr n Nasal CPAP n Intermittent Mandatory Ventilation n Surfactant Replacement n High Frequency Ventilation n Intercurrent Therapies

28. PIE

29. PIE Pathology

30. PIE Histology

31. Pneumothorax/PIE

32. Pneumothorax

33. Pneumopericardium

34. TRANSIENT TACHYPNEA OF THE NEWBORN n Delayed Fluid Resorption n Hard to differentiate early on from RDS both clinicaly and radiographicaly especially in the premature infant n Initial therapy similar to RDS, but hospital course is quite different

35. Wet Lung

36. MECONIUM ASPIRATION SYNDROME n Chemical Pneumonitis n Surfactant Inactivation n Potential for Infection n Potential for Pulmonary Hypertension n Management varies on severity

37. Meconium Aspiration

38. PERSISTENT PULMONARY HYPERTENSION n Usually secondary to primary pulmonary disease state n Pulmonary Vascular Lability n Treat the underlying problem n Maintain normo-oxygenation n Selective Pulmonary Vasodilators n Pray for good luck

39. PPHN

40. CONGENITAL PNEUMONIA n Infectious; primarily GBS n Amniotic Fluid aspiration n Viral etiology n Surfactant inactivation

41. GBS Pneumonia

42. CONGENITAL MALFORMATIONS n Choanal Atresia n Tracheal Atresia/stenosis n Chest Mass u Diaphragmatic hernia u CCAM u Sequestration u Lobar emphysema

43. CCAM

44. Lobar Emphysema

45. Diaphragmatic Hernia

46. Chylothorax

47. Phrenic Nerve Paralysis

48. ACQUIRED DISEASES n Infections n Bronchopulmonary Dysplasia n Sub-glottic stenosis n Apnea of Prematurity

49. Early BPD

50. Progressive BPD

51. Late BPD

52. APNEA Definition: cessation of breathing for longer than a 15 second period or for a shorter time if there is bradycardia or cyanosis

53. Babies at Risk for Apnea n Preterm n Respiratory Distress n Metabolic Disorders n Infections n Cold-stressed babies who are being warmed n CNS disorders n Low Blood volume or low Hematocrit n Perinatal Compromise n Maternal drugs in labor

54. Anticipation and Detection n Place at-risk infants on cardio- respiratory monitor n Low heart rate limit (80-100) n Respiratory alarm (15-20 seconds)

55. Treatment n Determine cause: n x-ray n blood sugar n body and environmental temperature n hematocrit n sepsis work up n electrolytes n cardiac work up n r/o seizure

56. Treatment n CPAP n Theophylline/Caffeine therapy n Mechanical ventilation n Apnea monitor