1. Neonatal Diseases
RC 290

2. Respiratory Distress Syndrome (RDS)
Also known as Hyaline Membrane Disease
(HMD)

3. Occurrence 1-2% of all births 10% of all premature births
Greatest occurrence is in the premature and low birth weight infant

4. Etiology & Predisposing Factors
Prematurity
Immature lung architecture and surfactant deficiency
Fetal asphyxia & hypoxia
Maternal diabetes
Increased chance of premature birth
Possible periods of reflex hypoglycemia in the fetus causing impaired surfactant production

5. Pathophysiology Surfactant deficiency Decreased FRC Atelectasis
Increased R-L shunt
Increased W.O.B.
Hypoxemia and eventually hypercapnia because of V/Q mismatch

6. Pathophysiology (cont.)
Atelectasis keeps PVR high
Increased PAP
Lung hypoperfusion
R-L shunting may re-occur across the Ductus Arteriosus and the Foramen Ovale

7. Hypoxia/hypoxemia results in anaerobic metabolism and lactic acidosis
This damages the alveolar-capillary membrane causing formation of hyaline membranes. Hyaline membranes perpetuate all of the problems in the lung

8. The cycle continues until surfactant levels are adequate to stabilize the lung
Symptoms usually appear 2-6 hours after birth
Why not immediately?
Disease peaks at hours
Recovery usually occurs 5-7 days after birth

9. Clinical findings: Physical
Tachypnea (60 BPM or >)
Retractions
Nasal flaring
Expiratory grunting
Helps generate autoPEEP
Decreased breath sounds with crackles
Cyanosis on room air
Hypothermia
Hypotension

10. Clinical Findings: Lab
ABGs: initially respiratory alkalosis and hypoxemia that progresses to profound hypoxemia and combined acidosis
Increased Bilirubin
Hypoglycemia
Possibly decreased hematocrit

11. CXR: Normal

12. RDS CXR: Ground Glass Effect

13. RDS CXR: Air Bronchograms & Hilar Densities

14. Time constant is decreased since elastic resistance is so high
Increased elastic resistance means decreased compliance!

15. RDS Treatment: Primarily supportive until lung stabilizes
NTE, maintain perfusion, maintain ventilation and oxygenation
O2 therapy, CPAP or mechanical ventilation
May require inverse I:E ratios if oxygenation can not be achieved with normal I:E ratio
Surfactant instillation!!!
May cause a sudden drop in elastic resistance!

16. Prognosis/Complications
Prognosis is good once infant makes it past the peak (48-72 hours)
Complications possible are:
Intracranial Bleed
BPD (Bronchopulmonary Dysplasia)
PDA (Patent Ductus Arteriosus)

17. Transient Tachypnea of the Newborn (TTN)
Also known as Type II RDS or Retained Lung Fluid

18. Occurrence: Similar to RDS
More common in term infants!

19. Etiology & Predisposing Factors
C-section
These infants do not have the fluid expelled from their airways as occurs in vaginal delivery
Maternal Diabetes
Increased chance of C-section due to LGA
Cord Compression
Anesthesia

20. TTN Pathophysiology Primary problem = retained lung fluid
Fluid not expelled from airways because of C-section
Poor absorption of remaining fluid by pulmonary capillaries and lymphatics
If retained fluid is in interstitial spaces, compliance and TC are decreased
If retained fluid is in airways,airway resistance and TC are increased
TTN can be restrictive , obstructive, or both!
Fluid usually clears by itself after hours after birth

21. Clinical Signs Tachypnea (usually rate is greater than seen in RDS)
Minimal (if any) nasal flaring or expiratory grunting
ABG’s: mild hypoxemia. PaCO2 depends on whether problem is restrictive or obstructive

22. TTN CXR Coarse peri-hilar streaks Prominent lung vasculature
Flattened diaphragms if fluid is causing obstruction/air-trapping

23. TTN Treatment: Like RDS, it is primarily supportive
Monitoring and O2 therapy
Possibly CPAP or mechanical ventilation

24. Prognosis/Complications
Prognosis is very good
Main complication is pneumonia
Often initial diagnosis

25. Lab Time!

26. Patent Ductus Arteriosus -PDA_
Failure of the D.A. to close at birth or a re-opening of the D.A. after birth. Allows shunting between the pulmonary artery and the aorta

27. Occurrence
1 per 2000 term babies
30-50% of RDS babies

28. Etiology & Predisposing Factors
Prematurity
D.A. not as sensitive to increasing PaO2
Hypoxia
Decreasing PaO2 allows it to re-open for up to three weeks after birth
Thus, a PDA can occur in a premature infant who is NOT hypoxic or in a term baby who is hypoxic
Worst case is a premature infant who is hypoxic!

29. Pathophysiology D.A. fails to close or it re-opens
Then shunting occurs between the pulmonary artery and the aorta
The direction of the shunt depends on which vessel has the higher pressure
A PDA can cause L-R shunting or R-L shunting!
Clinically, most PDA’s refer to a L-R shunt

30. Clinical Signs Tachypnea, bounding pulses, hyperactive pre-cordium
Decreased breath sounds and possibly some crackles
Possible murmur over left sternal border
Murmur is loudest when D.A. just starts opening or when it is almost closed

31. Clinical Signs (cont.) ABGs – hypoxemia with respiratory acidosis
If R-L shunting, the PaO2 in the upper extremities, ie pre-ductal, will be greater than the PaO2 in the umbilical artery, ie post-ductal!
TC – decreased if L-R shunting causes pulmonary edema; increased if fluid spills into airways and increases airway resistance
CXR – if L-R shunt, butterfly pattern of pulmonary edema with possible cardiomegaly

32. PDA Treatment
Basic – NTE, O2, may require CMV if not already on the ventilator
Medical
L-R shunt that fails to close: Indomethacin (Indocin)
R-L shunt: Priscoline (Tolazoline) to decrease PVR; also nitric oxide
Surgical –if medical treatment fails, the PDA may be surgically ligated

33. Prognosis/Complications
Good prognosis when baby responds to medical treatment
May develop :
Shock
CHF
Necrotizing Enterocolitis (NEC)

34. Meconium Aspiration Syndrome -MAS-
Syndrome of respiratory distress that occurs when meconium is aspirated prior to or during birth

35. Occurrence 10-20% of ALL births show meconium staining
10-50% of stained babies may be symptomatic
More common in term and post-term babies

36. Etiology & Predisposing Factors
Intra-uterine hypoxic or asphyxic episode
Post-term
Cord compression

37. Pathophysiology: Check Valve Effect
Causes gas trapping (obstruction)
If complete obstruction, then eventually atelectasis occurs
Irritating to airways, so edema and bronchospasm
Good culture ground for bacteria, so pneumonia possible

38. Pathophysiology (cont.)
V/Q mismatch leads to hypoxia and acidosis which increases PVR
TC increases because it increases airway resistance
Meconium is usually absorbed in hours; there are still many possible complications

39. Clinical Signs Respiratory depression or distress at birth
Hyperinflation
Pallor
Meconium stained body
Possible cyanosis on room air
Moist crackles
ABGs – hypoxemia with combined acidosis
CXR – coarse, patchy infiltrates with areas of atelectasis and areas of hyperinflation
May see flattened diaphragms if obstruction is severe

40. M.A.S. Treatment
Amnioinfusion – artificial amniotic fluid infused into uterus to dilute meconium
Proper resuscitation at birth(clear meconium from trachea before stimulating respiration)
Oro-gastric tube
NTE O2
NaHCO3 if severe metabolic acidosis
Broad spectrum antibiotics
Bronchial hygiene
May need mechanical ventilation
Slow rates and wide I:E ratios because of increased TC
Low level of PEEP may help prevent check valve effect
May need HFO

41. Prognosis & Complications
Good prognosis if there are no complications
Complications:
Pneumonia
Pulmonary baro/volutrauma
Persistent Pulmonary Hypertension (PPHN)

42. Persistent Pulmonary Hypertension -PPHN-
Also known as Persistent Fetal Circulation
-PFC-

43. Results in R-L shunting across the D.A. and the Foramen Ovale
Failure to make the transition from fetal to neonatal circulation or a reversion back to the condition where pulmonary artery pressure exceeds aortic pressure
Results in R-L shunting across the D.A. and the Foramen Ovale

44. Occurrence Usually term and post-term babies
Females more often than males
Symptoms may take hours after birth to develop

45. Etiology & Predisposing Factors
M.A.S – most common
Hypoxia and /or acidosis, eg RDS
Any condition that causes PVR to increase

46. Pathophysiology Primary problem is pulmonary artery hypertension
Infants arterial walls are thicker and they are more prone to vasospasm
If pulmonary artery pressure gets high enough, blood will shunt R-L across the D.A. and Foramen Ovale
Remember, conditions that drive up PAP usually make the D.A. open
Lung is hypoperfused resulting in refractory hypoxemia and hypercapnia

47. Clinical Signs Refractory hypoxemia and cyanosis Shock and tachypnea
Murmur possible
Pre-ductal PaO2 > post-ductal PaO2
Hypoxemia with combined acidosis
CXR usually OK when compared to infants condition

48. PPHN Treatment NTE and O2 Nitric Oxide
Often in conjunction with HFO
Priscoline, Indocin may also be used
If completely unresponsive to therapy ECMO may be tried

49. Prognosis & Complications
Prognosis depends on how well infant responds to treatment
Complications
Shock
Intracranial bleed
Internal bleeding
Especially a problem if Priscoline is used

50. Wilson – Mikity Syndrome -Pulmonary Dysmaturity-
Respiratory distress that develops after the first week of life and presents with definite CXR changes

51. Occurrence
Usually in <36 weeks gestational age and birth weight <1500 grams
After first week of life
No prior symptoms

52. Etiology & Predisposing Factors
Exact etiology unknown
Appears to be due to immature lung and airways trying to function
Not due to O2 toxicity or mechanical ventilation!

53. Pathology Immature alveoli and T-B tree causes V/Q mismatch
Areas of atelectasis and hyperinflation develop

54. Pathology (cont.) 3 Stages Stage 1 Stage 2 Stage 3
1-5 weeks after birth
Diffuse areas of atelectasis and hyperinflation
Stage 2
1-5 months after birth
Cystic (hyperinflated) areas coalesce and cause flattening of the diaphragms
Stage 3
5-24 months after birth
Cystic areas start to clear up

55. Clinical Signs Tachypnea Cyanosis on room air
Some retractions and/or nasal flaring
Decreased breath sounds with crackles
ABGs – respiratory acidosis with hypoxemia
CXR consistent with the stage of the disease

56. Wilson – Mikity Treatment
Is purely supportive-there is no medicinal or surgical treatment
O2 and NTE
Some cases require mechanical ventilation
Maintain fluids/electrolytes and caloric intake
Watch for infection

57. Prognosis & Complications
Prognosis good if infant survives stage 2
Complications
PDA
Cor Pulmonale
CNS damage

58. Bronchopulmonary Dysplasia -BPD-
A result of RDS and/or its treatment that results in areas of fibrosis, atelectasis, and hyperinflation

59. Etiology & Predisposing Factors
RDS and prematurity
Triad of O2, ET tube, and mechanical ventilation

60. Pathology: 4 Stages Stage 1 Stage 2 Stage 3 Stage 4 Acute phase of RDS
4-10 days after the onset of RDS
Areas of atelectasis and hyperinflation
Stage 3
2-3 weeks after RDS
Hyperinflated areas start to coalesce
Fibrosis starts to develop
Stage 4
1 month after the onset of RDS
Diaphragms start to flatten
Interstitial fibrosis evident on CXR
PPHN may start to develop
O2 dependency develops

61. Clinical Signs Tachypnea Persistent retractions A-B spells
Cyanosis on room air
Decreased breath sounds with crackles
ABGs – respiratory acidosis (may be compensated) with hypoxemia
CXR – consistent with stage of disease

62. Interstitial fibrosis and flattened diaphragms
BPD: Stage 4 CXR
Interstitial fibrosis and flattened diaphragms

63. BPD Treatment
Prevention is best! Use the least amount of intervention for the least amount of time!
Supportive care
O2, NTE, bronchial hygiene, maintain fluids/electrolytes
Diuretics if needed to prevent fluid overload and heart failure
Possibly vitamin E

64. Prognosis & Complications
Good if infant survives to age 2
50% mortality if PPHN develops
Complications
PHTN
Cor Pulmonale
Respiratory Infections
CNS damage

65. Diaphragmatic Hernia
Congenital malformation of the diaphragm that allows abdominal viscera into the thorax

66. Occurrence
1 per 2200 births

67. Etiology & Predisposing Factors
Exact unknown but may be related to vitamin A deficiency

68. Pathology Usually occurs during the 8-10th week of gestation
80% occur on the left at the Foramen of Bochdalek
Abdominal viscera enters thorax and compresses developing lung
As baby attempts to breathe after birth, the stomach and bowel fill with air and cause further compression of the lung
Severe restriction!

69. Clinical Signs Cyanosis
Severe respiratory distress with retractions and nasal flaring
Bowel sounds in chest
Uneven chest expansion
Decreased breath sounds on affected side
ABGs – profound hypoxemia with combined acidosis
CXR – loops of bowel in chest with shift of thoracic structures towards unaffected side, eg dextrocardia

70. Diaphragmatic Hernia CXR

71. Diaphragmatic Hernia Treatment
Immediate ET tube and NG tube
No BVM – it will make things worse!
Surgical repair
Post operative ECMO and/or HFO
May need NO with HFO

72. Prognosis & Complications
50% mortality
Complications
Pneumothorax
PDA
Hypoplastic lung

73. Pulmonary Barotrauma & Air Leak Syndromes

74. 4 Main Types Pneumothorax Pneumomediastinum Pneumopericardium
PIE (Pulmonary Interstitial Emphysema)
Gas from ruptured alveoli dissects along perivascular and interstitial spaces
Causes airway compression (obstruction) and alveolar compression (restriction)
May lead to pneumothorax, pneumomediastinum, or pneumopericardium

75. 1-2% of all births (not all are symptomatic)
Occurrence
1-2% of all births
(not all are symptomatic)

76. Etiology & Predisposing Factors
Positive pressure ventilation
Increased airway resistance/airway obstruction
RDS

77. Clinical Signs Sudden cyanosis (except with PIE) Respiratory distress
Mediastinal shift
Sudden hypotension (except with PIE)
Crepitus (if sub-Q emphysema develops)
Unequal chest expansion
Decreased breath sounds and hyperressonance
ABGs – hypoxemia with respiratory acidosis
Transillumination

78. Transillumination
Small Pneumothorax

79. Transillumination
Big Pneumothorax

80. CXR: Pneumothorax

81. CXR: Pneumomediastinum
Note how air does NOT outline the apex of the heart

82. CXR: Pneumopericardium
Note how air completely outlines the heart

83. CXR: PIE

84. Air Leak Syndrome Treatment
Prevention! Use the least amount of intervention for the shortest time possible!
Chest tube for pneumothorax
HFO may help prevent and/or resolve PIE

85. Prognosis and Complications
Good as long as shock and/or cardiac tamponade does NOT occur
PIE puts infant at risk for BPD

86. Necrotizing Enterocolitis -NEC-
Necrosis of the intestinal mucosa

87. Occurrence 20% of all premature births Males = Females
Most common in low birth weight babies who experience perinatal distress

88. Etiology & Predisposing Factors
Exact cause unknown but seen with the following:
Intestinal ischemia
Bacterial colonization
Early formula feeding

89. Pathology
Intestinal ischemia due to hypoperfusion, eg shock, or vascular occlusion, eg, clot from umbilical artery catheter
Bacterial colonization after ischemia starts necrosis
Early formula feeding may provide substrate needed for further bacterial growth and further necrosis

90. Clinical Signs Abdominal distention Poor feeding
Blood in fecal material
Lethargy
Hypotension
Apnea
Decreased urine output
Bile stained emesis
CXR – bubbles in intestinal wall

91. NEC Treatment NPO and NG suction IV hydration and hyperalimentation
Broad spectrum antibiotics
Ampicillin, Gentamycin
Minimum pressure on abdomen
No diapers or prone positioning
Monitor for/treat sepsis
Necrotic bowel may need surgical resection

92. Prognosis & Complications
Mortality is 20-75%
Best prognosis if infant does NOT require any surgery
Main complication is sepsis
Infants who have bowel resection may develop malabsorption syndrome

93. Congenital Cardiac Anomalies

94. Tetralogy of Fallot VSD Over-riding aorta Pulmonary valve stenosis
Right ventricular hypertrophy
Significant cyanosis because of R-L shunt

95. Complete Transposition of the Great Vessels
Pulmonary artery arises from left ventricle and Aorta arises from right ventricle
R-L shunt through PDA, ASD, or VSD needs to be present for infant to survive until corrective surgery
Balloon septostomy during cardiac catheterization

96. Truncus Arteriosus Aorta and pulmonary artery are the same vessel
Large VSD
Requires MAJOR surgical repair
Mortality is 40-50%

97. Case Study Time

98. Never Stop Being Inquisitive!