RCP 600 CH. 22 NEONATAL PULMONARY DISEASES
1. Define Post-Menstrual Age (PMA) and explain how it is calculated for a preterm
infant. - Answers - - Post-Menstrual Age (PMA) is the combination of the infant's
gestational age at birth and the time elapsed since birth.
- Calculation: PMA = Gestational Age at Birth + Postnatal Age (weeks or days).
- Example: A baby born at 33 weeks gestation who is now 10 weeks old has a PMA of
43 weeks.
2. What is the difference between Estimated Gestational Age (EGA) and Postnatal Age
(PMA)? - Answers - - Estimated Gestational Age (EGA): The gestational age at the time
of birth (how many weeks and far along the pregnancy was when the baby was
delivered).
- Postnatal Age (PNA): The chronological age of the baby since birth after birth (days,
weeks, or months since delivery).
- PMA combines both EGA and PNA to assess overall maturity.
3. What causes Respiratory Distress Syndrome (RDS) in premature infants, and what is
its former name? - Answers - - Cause: Surfactant deficiency* due to immature lungs
(Type II alveolar cells in preterm infants do not produce enough surfactant).
- Former Name: Hyaline Membrane Disease.
4. What are the ABG goals for treating an infant with RDS? - Answers - - pH: >7.25
- PaCO₂: 40-55 mmHg
- PaO₂: 60-80 mmHg****
- SpO₂: Adjusted based on gestational age (typically 90-95% for preterm infants).
-These are the target values to assess gas exchange
5. What initial and maximum CPAP settings are used in the management of RDS? -
Answers - - Initial CPAP: 5-6 cm H₂O
- Maximum CPAP: 8 cm* H₂O
CPAP improves FRC and oxygenation and must be limited to avoid barotrauma.
6. When is mechanical ventilation indicated in RDS, and what are typical ventilator
settings for a neonate? - Answers - - Indications:
- pH <7.20
- PaCO₂ >60 mmHg
- FiO₂ requirement >40%
- Typical Ventilator Settings:
- PIP: 15-25 cm H₂O
- Tidal Volume: 4-6 mL/kg
- Rate: 20-40 breaths/min
- PEEP: 4-6 cm H₂O
- Inspiratory Time: 0.3-0.4 sec
, -Helps prevent respiratory acidosis and ensures proper oxygen.
7. What is the role of surfactant therapy in treating RDS, and what does LISA stand for?
- Answers - - Role: Replaces deficient natural surfactant, improves lung compliance,
and reduces alveolar collapse.
- LISA: Less Invasive Surfactant Administration (technique to deliver surfactant without
full intubation).
8. What long-term condition can result from prolonged oxygen therapy and ventilation in
neonates?*** - Answers - - Bronchopulmonary Dysplasia (BPD) (chronic lung disease of
prematurity to long term ventiliation).
9. How does "new" BPD differ from "old" BPD in terms of etiology and clinical features?
- Answers - - Old BPD: Caused by more damage Mechanical Ventilation
volutrauma/barotrauma/high oxygen barotrauma, oxygen toxicity to the lungs exposure
in larger preterm; features fibrosis, inflammation, and smooth muscle hypertrophy.
- New BPD: Occurs in extremely preterm infants due to arrested lung development
required minimal or even no ventilator support and relatively low FiO2 (alveolar
hypoplasia, abnormal vasculature development, decreased septation, reduction of
areas or gas exchange) even with gentle ventilation.
10. What ventilator strategies are used in infants with established BPD, and why are
larger tidal volumes and longer inspiratory times recommended? - Answers - -
Strategies:
- Larger Tidal Volumes (10-12 mL/kg) to
overcome stiff lungs.
- Longer Inspiratory Time (≥0.6 sec) to improve gas exchange.
- Lower Rates (10-20 breaths/min) to reduce air trapping.
- Reason: BPD lungs are fibrotic and obstructed, requiring higher volumes and longer
inflation times for ventilation to overcome stiff, obstructive lungs reduce dynamic airway
collapse.
11. What causes Transient Tachypnea of the Newborn (TTN), and which infants are at
highest risk? - Answers - - Cause: Delayed clearance of fetal lung fluid.
- High-Risk Infants:
- Term infants resolve 48-72 hours delivered via C-section (especially without labor).
- Rapid births.
- Infants with maternal diabetes or sedation.
12. What is a key finding on a chest x-ray in an infant with neonatal pneumonia? -
Answers - - Diffuse shadowing, consolidation, or fluid lines (especially with Group B
Streptococcus).
13. What organism is the most common cause of early-onset neonatal pneumonia? -
Answers - - Group B Streptococcus (GBS).
1. Define Post-Menstrual Age (PMA) and explain how it is calculated for a preterm
infant. - Answers - - Post-Menstrual Age (PMA) is the combination of the infant's
gestational age at birth and the time elapsed since birth.
- Calculation: PMA = Gestational Age at Birth + Postnatal Age (weeks or days).
- Example: A baby born at 33 weeks gestation who is now 10 weeks old has a PMA of
43 weeks.
2. What is the difference between Estimated Gestational Age (EGA) and Postnatal Age
(PMA)? - Answers - - Estimated Gestational Age (EGA): The gestational age at the time
of birth (how many weeks and far along the pregnancy was when the baby was
delivered).
- Postnatal Age (PNA): The chronological age of the baby since birth after birth (days,
weeks, or months since delivery).
- PMA combines both EGA and PNA to assess overall maturity.
3. What causes Respiratory Distress Syndrome (RDS) in premature infants, and what is
its former name? - Answers - - Cause: Surfactant deficiency* due to immature lungs
(Type II alveolar cells in preterm infants do not produce enough surfactant).
- Former Name: Hyaline Membrane Disease.
4. What are the ABG goals for treating an infant with RDS? - Answers - - pH: >7.25
- PaCO₂: 40-55 mmHg
- PaO₂: 60-80 mmHg****
- SpO₂: Adjusted based on gestational age (typically 90-95% for preterm infants).
-These are the target values to assess gas exchange
5. What initial and maximum CPAP settings are used in the management of RDS? -
Answers - - Initial CPAP: 5-6 cm H₂O
- Maximum CPAP: 8 cm* H₂O
CPAP improves FRC and oxygenation and must be limited to avoid barotrauma.
6. When is mechanical ventilation indicated in RDS, and what are typical ventilator
settings for a neonate? - Answers - - Indications:
- pH <7.20
- PaCO₂ >60 mmHg
- FiO₂ requirement >40%
- Typical Ventilator Settings:
- PIP: 15-25 cm H₂O
- Tidal Volume: 4-6 mL/kg
- Rate: 20-40 breaths/min
- PEEP: 4-6 cm H₂O
- Inspiratory Time: 0.3-0.4 sec
, -Helps prevent respiratory acidosis and ensures proper oxygen.
7. What is the role of surfactant therapy in treating RDS, and what does LISA stand for?
- Answers - - Role: Replaces deficient natural surfactant, improves lung compliance,
and reduces alveolar collapse.
- LISA: Less Invasive Surfactant Administration (technique to deliver surfactant without
full intubation).
8. What long-term condition can result from prolonged oxygen therapy and ventilation in
neonates?*** - Answers - - Bronchopulmonary Dysplasia (BPD) (chronic lung disease of
prematurity to long term ventiliation).
9. How does "new" BPD differ from "old" BPD in terms of etiology and clinical features?
- Answers - - Old BPD: Caused by more damage Mechanical Ventilation
volutrauma/barotrauma/high oxygen barotrauma, oxygen toxicity to the lungs exposure
in larger preterm; features fibrosis, inflammation, and smooth muscle hypertrophy.
- New BPD: Occurs in extremely preterm infants due to arrested lung development
required minimal or even no ventilator support and relatively low FiO2 (alveolar
hypoplasia, abnormal vasculature development, decreased septation, reduction of
areas or gas exchange) even with gentle ventilation.
10. What ventilator strategies are used in infants with established BPD, and why are
larger tidal volumes and longer inspiratory times recommended? - Answers - -
Strategies:
- Larger Tidal Volumes (10-12 mL/kg) to
overcome stiff lungs.
- Longer Inspiratory Time (≥0.6 sec) to improve gas exchange.
- Lower Rates (10-20 breaths/min) to reduce air trapping.
- Reason: BPD lungs are fibrotic and obstructed, requiring higher volumes and longer
inflation times for ventilation to overcome stiff, obstructive lungs reduce dynamic airway
collapse.
11. What causes Transient Tachypnea of the Newborn (TTN), and which infants are at
highest risk? - Answers - - Cause: Delayed clearance of fetal lung fluid.
- High-Risk Infants:
- Term infants resolve 48-72 hours delivered via C-section (especially without labor).
- Rapid births.
- Infants with maternal diabetes or sedation.
12. What is a key finding on a chest x-ray in an infant with neonatal pneumonia? -
Answers - - Diffuse shadowing, consolidation, or fluid lines (especially with Group B
Streptococcus).
13. What organism is the most common cause of early-onset neonatal pneumonia? -
Answers - - Group B Streptococcus (GBS).
