Neonate patho

Question 1

What are the stages of fetal development?

Answer 1

• Embryonal Stage (Day 26-Day 52)
  
  • Development of trachea and major bronchi
• Pseudoglandular (Day 52-Week 16)
  
  • Development of remaining conducting airways
• Canalicular (Week 17-26)
  
  • Development of vascular bed and framework of respiratory acini
  • Surfactant producing Type 2 Alveolar cells appear at 22-24 weeks gestation
• •Saccular (Week 26-36)
  
  • increased complexity of saccule
• Alveolar (Week 36 to Term)
  
  • Development of alveoli

Question 2

What is Respiratory Distress Syndrome?

Answer 2

• Characterized as respiratory insufficiency related to surfactant deficiency and/or inactivation, along with structural immaturity of the lungs
• commonly in 23-34wk
• surf insuficancy
• Signs and symptoms
  • Respiratory Distress
  • Moderate to Severe Retractions
  • Grunting
• Treatment
  
  • Exogenous Surfactant Administration
  • Support Oxygenation and Ventilation with a goal of preventing lung injury.
• Intubation and mechanical ventilation
  
  • HFV if needing high support (or prophylactic), Nasal CPAP, Nasal-IMV, NIV-NAVA
• X-ray
  
  • Diffuse reticular granular haziness
  • Air bronchograms

Question 3

What is Pulmonary Interstitial Emphysema
(PIE)>

Answer 3

• Consequence of overdistension of the distal airways.
  
  • Ruptured distal airway provide pathway for leakage into connective tissue sheaths lining the airways
  • Most infants that develop PIE are being mechanically ventilated
  • Related to high PIP/MAP/or Vt
• High Frequency Jet Ventilation (HFJV)
  
  • Very effective for treating and supporting infants with PIE
  • HFJV allows effective ventilation at lower MAP than CMV or HFOV
  • HFJV provides passive exhalation which promotes better lung healing than HFOV which has active exhalation.

Question 4

What is pulmonary hypoplasia?

Answer 4

• incomplete development of the lungs
• results in smaller than normal airways
• Causes
  
  • any condition that compresses the lungs in-utero
  • any condition that disrupts amniotic fluids levels or function
• Treatments
  
  • support oxygenation and ventilation
    
    • HFV
    • ECMO

Question 5

What is Bronchopulmonary Dysplasia?

Answer 5

• complicated form of chronic lung dz
• signs and symptoms
  
  • hyperinflation
  • cystic emphysema
  • new for O2 at 36 wk GA
  • pulmonary hypertension

Factors that contribute to development of BPD

• Prematurity
• Oxygen Toxicity
• Barotrauma/Volutrauma/Atelectrauma
• Infection/inflammation
• Nutrition
• PDA
• Fluid Balance
• Vascular remodeling
• Pulmonary Hypertension

Question 6

What is Meconium Aspiration Syndrome?

Answer 6

• occurs when first stool is passed in-utero and inhales it
• Complications of MAS include:
  • Airway obstruction
  • Pneumonitis
  • Surfactant inactivation
  • Increased Pulmonary Vascular Resistance (PVR)
  • “Ball-Valve” air trapping
• Vent strategies
  
  • minimize air trapping
  • HFOV
  • HFJV
  • ECMO
• Adjuctive therapies
  
  • iNO
  • Surf replacement

Question 7

What is congenital diaphragmatic hernia?

Answer 7

• incomplete formation of diaphragm causing the stomach to be in chest cavity
  
  • impaired gas exchange
  • lung hypoplasia
  • pulmonary hypertension
  • decreased cardiac output

Question 8

What is Persistent Pulmonary Hypertension of the Newborn

Answer 8

• Characterized by severe hypoxemia due to extrapulmonary shunt.
  
  • Increased pulmonary vascular resistance causes increased pulmonary artertial/right ventricular pressures.
  • Causes Right to Left shunting at the Atrial level, and pulmonary to systemic shunting through the ductus arteriosus
  • Pre-ductal SpO2 higher than post-ductal by at least 10%
• Vent management
  
  • HFOV, HFJV or conventional
• Adjunctive therapies
  
  • oxygen- great vasodilatior
  • iNO
  • inhaled prostacyclin (Flolan)

Question 9

What is Transient Tachypnea of the Newborn (TTN)?

Answer 9

• a self correcting time of tachypnea because of delayed absorption of fetal lung fluid
• may need O2 or CPAP

Question 10

What is Intraventricular Hemorrhage (IVH)?

Answer 10

• bleeding into the fluid filled areas of the brain (ventricles)
• begins along bases of lateral ventricles in the subependymal germinal matrix
• Germinal matrix
  
  • as GA progresses, the matrix gets smaller
  • highly cellular gelatinous matrix filled with very fragile blood vessels

Question 11

What is Perventricular Leukomalacia (PVL)?

Answer 11

• A form of white matter brain injury
• Characterized by necrosis of white matter near the lateral ventricles.
• can occur with out without IVH
• result of decreased cerebral blood flow or decreased O@

Question 12

What is cerebral autoregulation?

Answer 12

• in normal healthy newborn infants, cerebral blood flow (CBF) is protected by autoregulation
  
  • if systemic BP increases or decreases, CBF does not change
  • if autoregulation is absent, ant change in systemic pressures can negatively affect CBF
• premature infants lack an effective autoregulation system,

Question 13

What are the IVH Grades and outcomes?

Answer 13

• Grade 1
  
  • Blood in the germinal matrix
• Grade 2
  
  • Blood in the ventricles, but not enlarged
• Grade 3
  
  • Enlarged, blood filled ventricles
• Grade 4
  
  • Bleeding extends outside the ventricles into brain tissue
• Grade 1 and 2- 13% have neurodevelopmental issues
• Grade 3 and 4 (Sever IVH)
  
  • 36% will have significant neurologic sequelae
• Resultant Neurologic Disorders
  
  • Cerebral Palsy
  • Hydrocephalus
  • Blindness
  • Deafness
  • Severe learning and cognitive disorders