, TABLE OF CONTENT
Section I: The Normal Child
Chapter 1: Transition From Fetal to Pediatric Anesthesia
Chapter 2: Developmental Physiology and Pharmacology
Section II: Pediatric Medicines for Anesthesiologists
Chapter 3: Congenital Heart Disease
Chapter 4: Respiratory Diseases
Chapter 5: Neurologic and Neuromuscular Diseases
Chapter 6: Gastrointestinal Diseases
Chapter 7: Hematologic Diseases
Chapter 8: Oncologic Diseases
Chapter 9: Genetic and Inherited Diseases
Chapter 10: Endocrine Diseases
Chapter 11: The Premature Infant
Section III: Anesthetic Management
Chapter 12: The Formerly Premature Infant
Chapter 13: Preanesthetic Preparation of the Pediatric Patient
Chapter 14: Fluid and Blood Administration
Chapter 15: Monitoring
Chapter 16: Temperature Regulation
Chapter 17: Routine Airway Management
Chapter 18: The Difficult Pediatric Airway
Chapter 19: Management of General Anesthesia
Chapter 20: Regional Anesthesia
Chapter 21: Malignant Hyperthermia
Section IV: Pediatric Surgery
Chapter 22: ENT Surgery
Chapter 23: General Surgery
Chapter 24: Thoracic Surgery
Chapter 25: Orthopedic Surgery
Chapter 26: Neurosurgery
Chapter 27: Ophthalmologic Surgery
Chapter 28: Plastic Surgery
Chapter 29: Urologic Surgery
Chapter 30: Remote Anesthetizing Locations
Chapter 31: Postoperative Considerations
Section V: Pain Management
Chapter 32: Pediatric Pain Assessment
Chapter 33: Analgesic Medications
Chapter 34: Local Anesthetics and Adjuvant Analgesics
Chapter 35: Acute Pain Management
Chapter 36: Chronic Pain
Section VI: Critical Care
Chapter 37: Trauma and Burn Management
Chapter 38: The Critically Ill Child
,Chapter 1 – Transition From Fetal to Pediatric Anesthesia
1. What primary mechanism causes functional closure of the foramen ovale immediately after birth?
A. Rapid elevation of pulmonary vascular resistance
B. Sudden drop in systemic arterial pressure
C. Increased left atrial pressure exceeding right atrial pressure
D. Direct constriction of the muscular septum primum
Answer: C
Rationale: Functional closure of the foramen ovale occurs when left atrial pressure exceeds right atrial
pressure following the onset of breathing and cord clamping. The increased pulmonary venous return elevates
left atrial pressure, which pushes the flexible septum primum against the rigid septum secundum. Permanent
anatomic fusion occurs weeks to months later.
Keywords: foramen ovale, circulatory transition, left atrial pressure
2. Functional closure of the ductus arteriosus is primarily triggered by which physiologic event?
A. Rising arterial oxygen tension and falling circulating prostaglandins
B. Decreased systemic blood pressure and rising endothelin levels
C. Increased circulating adenosine and falling arterial oxygen saturation
D. Direct mechanical compression by the expanding left pulmonary artery
Answer: A
Rationale: Functional closure of the ductus arteriosus occurs within the first 12 to 24 hours of life in term
infants due to rising arterial oxygen tension and the clearance of circulating maternal prostaglandin E2. Oxygen
inhibits voltage-gated potassium channels in ductal smooth muscle cells, leading to calcium influx and
muscular constriction. Anatomic fibrosis seals the vessel over subsequent weeks.
Keywords: ductus arteriosus, arterial oxygenation, prostaglandin clearance
3. A term neonate undergoes umbilical vein catheterization shortly after delivery. What event causes
,the functional closure of the ductus venosus?
A. Direct compression by the rapidly contracting umbilical ring
B. Sudden increase in inferior vena cava hydrostatic pressure
C. Reflex vasoconstriction stimulated by high hepatic glucose concentrations
D. Cessation of umbilical venous blood flow following cord clamping
Answer: D
Rationale: The ductus venosus carries oxygenated blood from the umbilical vein directly to the inferior vena
cava in utero. Clamping of the umbilical cord immediately eliminates umbilical venous blood flow, causing the
ductus venosus to collapse and functionally close. Anatomic closure follows over the subsequent one to two
weeks, forming the ligamentum venosum.
Keywords: ductus venosus, umbilical cord clamping, neonatal circulation
4. Clamping the umbilical cord during delivery immediately alters neonatal hemodynamics. Which
vascular change occurs as a direct result?
A. Sudden reduction in systemic vascular resistance
B. Significant increase in systemic vascular resistance
C. Rapid elevation in pulmonary vascular resistance
D. Marked decrease in left ventricular afterload
Answer: B
Rationale: Removal of the low-resistance placental vascular bed via umbilical cord clamping immediately
increases systemic vascular resistance. This rise in systemic afterload elevates left ventricular and left atrial
pressures, facilitating the reversal of interatrial pressure gradients and contributing to foramen ovale closure.
Keywords: systemic vascular resistance, placental circulation, cord clamping
5. A full-term infant born via emergency cesarean delivery develops respiratory distress with a pre-
ductal oxygen saturation of 94% on the right wrist and a post-ductal oxygen saturation of 81% on the
left foot. What is the most accurate physiologic explanation for this finding?
A. Left-to-right shunting across an atrial septal defect
B. Left-to-right flow across a widely patent ductus arteriosus
C. Right-to-left shunting through the ductus arteriosus into descending aorta
D. Right-to-left shunting solely across an unclosed foramen ovale
,Answer: C
Rationale: A pre-ductal saturation significantly higher than the post-ductal saturation (a gradient greater than
5% to 10%) indicates right-to-left shunting across a patent ductus arteriosus into the descending aorta. This
occurs when pulmonary vascular resistance exceeds systemic vascular resistance, as seen in persistent
pulmonary hypertension of the newborn. Deoxygenated blood enters the descending aorta distal to the
brachiocephalic takeoff, lowering lower-extremity saturations.
Keywords: pre-ductal saturation, post-ductal saturation, PPHN, ductus arteriosus
6. Which stimulus is the most potent physiologic factor responsible for decreasing pulmonary vascular
resistance at birth?
A. Ventilation of the lungs and increased alveolar oxygen tension
B. Systemic release of maternal catecholamines during active labor
C. Rapid cooling of neonatal skin upon atmospheric air exposure
D. Sudden elevation in circulating arterial carbon dioxide tension
Answer: A
Rationale: Rhythmic lung expansion combined with rising alveolar oxygen tension is the primary stimulus for
the dramatic postpartum fall in pulmonary vascular resistance. Alveolar oxygen stimulates endothelial nitric
oxide synthase and prostacyclin synthesis, while lung inflation physically stretches pulmonary capillaries and
activates stretch-induced vasodilatory pathways.
Keywords: pulmonary vascular resistance, alveolar oxygen tension, lung expansion
7. An infant born at 30 weeks of gestation develops progressive tachypnea and grunting. Deficient
production of surfactant by type II pneumocytes primarily leads to which mechanical problem?
A. Excessive dynamic compliance across peripheral conduct airways
B. Marked increase in alveolar surface tension and end-expiratory collapse
C. Rapid fluid filtration across high-pressure pulmonary venules
D. Impaired systemic diffusion of carbon dioxide across alveolar septa
Answer: B
Rationale: Pulmonary surfactant, produced and secreted by type II pneumocytes, lowers surface tension at
the air-liquid interface within terminal airspaces. A deficiency in surfactant markedly increases alveolar surface
,tension, leading to alveolar instability, widespread atelectasis, reduced functional residual capacity, and
increased work of breathing.
Keywords: surfactant, type II pneumocytes, alveolar surface tension
8. How is fetal lung liquid primarily cleared from the alveolar spaces during active labor and delivery?
A. Passive hydrostatic transudation across high-resistance pleural membranes
B. Direct swallow of accumulated airway secretions into gastrointestinal tract
C. Retrograde fluid migration into conducting tracheal lymph vessels
D. Active sodium reabsorption through epithelial sodium channels in alveolar cells
Answer: D
Rationale: Prior to labor, the fetal respiratory epithelium actively secretes chloride and fluid into future
airspaces. Labor-associated surges in catecholamines and steroids trigger a switch to active sodium
absorption mediated by amiloride-sensitive epithelial sodium channels (ENaC). Water follows the osmotic
gradient into the interstitium, where it is cleared by pulmonary capillaries and lymphatics.
Keywords: lung fluid clearance, epithelial sodium channels, ENaC
9. During early embryogenesis, the primary respiratory diverticulum emerges from the foregut. What is
the defining developmental event of the embryonic stage of lung growth?
A. Formation of primitive terminal respiratory sacs with thin membranes
B. Differentiation of cuboidal epithelial cells into mature type II cells
C. Formation of the trachea and initial branching of main bronchopulmonary buds
D. Proliferation of dense capillary networks around terminal alveolar ducts
Answer: C
Rationale: The embryonic stage occurs from weeks 3 to 7 of gestation. It begins with the appearance of the
respiratory diverticulum from the ventral wall of the foregut and involves the initial formation of the trachea,
mainstem bronchi, and lobar bronchopulmonary segments.
Keywords: embryonic stage, lung development, bronchopulmonary buds
,10. A neonate is born at 23 weeks of gestation and requires immediate endotracheal intubation. The
clinical team considers the anatomic stage of lung development. Which structural limitation in the
canalicular stage most directly impairs gas exchange at this gestational age?
A. Immature capillary networks and thick diffusion barriers between capillaries and airways
B. Complete absence of central cartilaginous rings throughout large conducting airways
C. Total failure of primary bronchial division into segmental bronchopulmonary branches
D. Inability of muscular chest wall structures to maintain passive thoracic recoil
Answer: A
Rationale: The canalicular stage (roughly 16 to 26 weeks of gestation) is characterized by canalization of lung
tissue, early formation of respiratory bronchioles, and vascular proliferation. However, at 23 weeks, the
capillary network remains sparse, capillaries are not yet closely apposed to the respiratory epithelium, and the
diffusion distance is substantial, severely limiting efficient alveolar-capillary gas exchange.
Keywords: canalicular stage, limit of viability, pulmonary capillaries
11. The saccular stage of fetal lung development is primarily distinguished by which developmental
feature?
A. Appearance of the initial laryngotracheal groove along ventral foregut
B. Formation of thin-walled terminal saccules and progressive thinning of interstitium
C. Division of primitive lobar bronchi into peripheral conducting terminal bronchioles
D. Complete secondary septation of all terminal airspaces into true alveoli
Answer: B
Rationale: The saccular stage (approximately 26 to 36 weeks of gestation) is marked by the development of
thin-walled terminal saccules, thinning of the surrounding interstitial mesenchyme, and close proximity of the
capillary network to the saccular airspaces. This structural maturation markedly increases the potential surface
area available for gas exchange before true alveolarization begins.
Keywords: saccular stage, terminal saccules, lung development
12. At what point in human development does true pulmonary alveolarization primarily reach
completion?
A. Immediately prior to delivery during final four weeks of gestation
B. During the first twenty-four to forty-eight hours of extrauterine life
, C. At approximately six to twelve weeks of postnatal neonatal age
D. During early childhood, continuing up to approximately eight years of age
Answer: D
Rationale: Alveolarization begins in late fetal life (around 36 weeks of gestation) but progresses most rapidly
postnatally. Secondary septation continues to multiply the number of mature alveoli throughout infancy and
early childhood, continuing until approximately 7 to 8 years of age.
Keywords: alveolarization, postnatal lung growth, secondary septation
13. A former 26-week premature infant who received prolonged mechanical ventilation presents for
hernia repair at 6 months of age. Which histopathologic hallmark characterizes new
bronchopulmonary dysplasia in this patient?
A. Severe bronchiolar smooth muscle hyperplasia with widespread airway obstruction
B. Extensive pulmonary vascular endothelial denudation and alveolar hyaline membranes
C. Arrest of alveolar development resulting in fewer and simplified large alveoli
D. Proliferation of dense interlobular fibrotic scars throughout apical lung segments
Answer: C
Rationale: Modern bronchopulmonary dysplasia (the 'new' BPD) primarily represents an arrest of alveolar and
vascular development in infants born during the saccular stage. Rather than the severe airway injury and
fibroproliferation seen in classic BPD, new BPD is characterized by alveolar simplification—fewer, larger alveoli
with reduced surface area for gas exchange and dysmorphic microvasculature.
Keywords: bronchopulmonary dysplasia, alveolar simplification, prematurity
14. Which clinical condition is recognized as a major etiologic risk factor for persistent pulmonary
hypertension of the newborn?
A. Isolated unilateral choanal atresia with normal parenchymal lung volume
B. Uncomplicated physiologic jaundice managed with brief outpatient phototherapy
C. Meconium aspiration syndrome complicated by severe neonatal parenchymal inflammation
D. Transient hypoglycemia occurring immediately following full-term vaginal delivery
Answer: C
Rationale: Meconium aspiration syndrome is one of the most common causes of persistent pulmonary
Section I: The Normal Child
Chapter 1: Transition From Fetal to Pediatric Anesthesia
Chapter 2: Developmental Physiology and Pharmacology
Section II: Pediatric Medicines for Anesthesiologists
Chapter 3: Congenital Heart Disease
Chapter 4: Respiratory Diseases
Chapter 5: Neurologic and Neuromuscular Diseases
Chapter 6: Gastrointestinal Diseases
Chapter 7: Hematologic Diseases
Chapter 8: Oncologic Diseases
Chapter 9: Genetic and Inherited Diseases
Chapter 10: Endocrine Diseases
Chapter 11: The Premature Infant
Section III: Anesthetic Management
Chapter 12: The Formerly Premature Infant
Chapter 13: Preanesthetic Preparation of the Pediatric Patient
Chapter 14: Fluid and Blood Administration
Chapter 15: Monitoring
Chapter 16: Temperature Regulation
Chapter 17: Routine Airway Management
Chapter 18: The Difficult Pediatric Airway
Chapter 19: Management of General Anesthesia
Chapter 20: Regional Anesthesia
Chapter 21: Malignant Hyperthermia
Section IV: Pediatric Surgery
Chapter 22: ENT Surgery
Chapter 23: General Surgery
Chapter 24: Thoracic Surgery
Chapter 25: Orthopedic Surgery
Chapter 26: Neurosurgery
Chapter 27: Ophthalmologic Surgery
Chapter 28: Plastic Surgery
Chapter 29: Urologic Surgery
Chapter 30: Remote Anesthetizing Locations
Chapter 31: Postoperative Considerations
Section V: Pain Management
Chapter 32: Pediatric Pain Assessment
Chapter 33: Analgesic Medications
Chapter 34: Local Anesthetics and Adjuvant Analgesics
Chapter 35: Acute Pain Management
Chapter 36: Chronic Pain
Section VI: Critical Care
Chapter 37: Trauma and Burn Management
Chapter 38: The Critically Ill Child
,Chapter 1 – Transition From Fetal to Pediatric Anesthesia
1. What primary mechanism causes functional closure of the foramen ovale immediately after birth?
A. Rapid elevation of pulmonary vascular resistance
B. Sudden drop in systemic arterial pressure
C. Increased left atrial pressure exceeding right atrial pressure
D. Direct constriction of the muscular septum primum
Answer: C
Rationale: Functional closure of the foramen ovale occurs when left atrial pressure exceeds right atrial
pressure following the onset of breathing and cord clamping. The increased pulmonary venous return elevates
left atrial pressure, which pushes the flexible septum primum against the rigid septum secundum. Permanent
anatomic fusion occurs weeks to months later.
Keywords: foramen ovale, circulatory transition, left atrial pressure
2. Functional closure of the ductus arteriosus is primarily triggered by which physiologic event?
A. Rising arterial oxygen tension and falling circulating prostaglandins
B. Decreased systemic blood pressure and rising endothelin levels
C. Increased circulating adenosine and falling arterial oxygen saturation
D. Direct mechanical compression by the expanding left pulmonary artery
Answer: A
Rationale: Functional closure of the ductus arteriosus occurs within the first 12 to 24 hours of life in term
infants due to rising arterial oxygen tension and the clearance of circulating maternal prostaglandin E2. Oxygen
inhibits voltage-gated potassium channels in ductal smooth muscle cells, leading to calcium influx and
muscular constriction. Anatomic fibrosis seals the vessel over subsequent weeks.
Keywords: ductus arteriosus, arterial oxygenation, prostaglandin clearance
3. A term neonate undergoes umbilical vein catheterization shortly after delivery. What event causes
,the functional closure of the ductus venosus?
A. Direct compression by the rapidly contracting umbilical ring
B. Sudden increase in inferior vena cava hydrostatic pressure
C. Reflex vasoconstriction stimulated by high hepatic glucose concentrations
D. Cessation of umbilical venous blood flow following cord clamping
Answer: D
Rationale: The ductus venosus carries oxygenated blood from the umbilical vein directly to the inferior vena
cava in utero. Clamping of the umbilical cord immediately eliminates umbilical venous blood flow, causing the
ductus venosus to collapse and functionally close. Anatomic closure follows over the subsequent one to two
weeks, forming the ligamentum venosum.
Keywords: ductus venosus, umbilical cord clamping, neonatal circulation
4. Clamping the umbilical cord during delivery immediately alters neonatal hemodynamics. Which
vascular change occurs as a direct result?
A. Sudden reduction in systemic vascular resistance
B. Significant increase in systemic vascular resistance
C. Rapid elevation in pulmonary vascular resistance
D. Marked decrease in left ventricular afterload
Answer: B
Rationale: Removal of the low-resistance placental vascular bed via umbilical cord clamping immediately
increases systemic vascular resistance. This rise in systemic afterload elevates left ventricular and left atrial
pressures, facilitating the reversal of interatrial pressure gradients and contributing to foramen ovale closure.
Keywords: systemic vascular resistance, placental circulation, cord clamping
5. A full-term infant born via emergency cesarean delivery develops respiratory distress with a pre-
ductal oxygen saturation of 94% on the right wrist and a post-ductal oxygen saturation of 81% on the
left foot. What is the most accurate physiologic explanation for this finding?
A. Left-to-right shunting across an atrial septal defect
B. Left-to-right flow across a widely patent ductus arteriosus
C. Right-to-left shunting through the ductus arteriosus into descending aorta
D. Right-to-left shunting solely across an unclosed foramen ovale
,Answer: C
Rationale: A pre-ductal saturation significantly higher than the post-ductal saturation (a gradient greater than
5% to 10%) indicates right-to-left shunting across a patent ductus arteriosus into the descending aorta. This
occurs when pulmonary vascular resistance exceeds systemic vascular resistance, as seen in persistent
pulmonary hypertension of the newborn. Deoxygenated blood enters the descending aorta distal to the
brachiocephalic takeoff, lowering lower-extremity saturations.
Keywords: pre-ductal saturation, post-ductal saturation, PPHN, ductus arteriosus
6. Which stimulus is the most potent physiologic factor responsible for decreasing pulmonary vascular
resistance at birth?
A. Ventilation of the lungs and increased alveolar oxygen tension
B. Systemic release of maternal catecholamines during active labor
C. Rapid cooling of neonatal skin upon atmospheric air exposure
D. Sudden elevation in circulating arterial carbon dioxide tension
Answer: A
Rationale: Rhythmic lung expansion combined with rising alveolar oxygen tension is the primary stimulus for
the dramatic postpartum fall in pulmonary vascular resistance. Alveolar oxygen stimulates endothelial nitric
oxide synthase and prostacyclin synthesis, while lung inflation physically stretches pulmonary capillaries and
activates stretch-induced vasodilatory pathways.
Keywords: pulmonary vascular resistance, alveolar oxygen tension, lung expansion
7. An infant born at 30 weeks of gestation develops progressive tachypnea and grunting. Deficient
production of surfactant by type II pneumocytes primarily leads to which mechanical problem?
A. Excessive dynamic compliance across peripheral conduct airways
B. Marked increase in alveolar surface tension and end-expiratory collapse
C. Rapid fluid filtration across high-pressure pulmonary venules
D. Impaired systemic diffusion of carbon dioxide across alveolar septa
Answer: B
Rationale: Pulmonary surfactant, produced and secreted by type II pneumocytes, lowers surface tension at
the air-liquid interface within terminal airspaces. A deficiency in surfactant markedly increases alveolar surface
,tension, leading to alveolar instability, widespread atelectasis, reduced functional residual capacity, and
increased work of breathing.
Keywords: surfactant, type II pneumocytes, alveolar surface tension
8. How is fetal lung liquid primarily cleared from the alveolar spaces during active labor and delivery?
A. Passive hydrostatic transudation across high-resistance pleural membranes
B. Direct swallow of accumulated airway secretions into gastrointestinal tract
C. Retrograde fluid migration into conducting tracheal lymph vessels
D. Active sodium reabsorption through epithelial sodium channels in alveolar cells
Answer: D
Rationale: Prior to labor, the fetal respiratory epithelium actively secretes chloride and fluid into future
airspaces. Labor-associated surges in catecholamines and steroids trigger a switch to active sodium
absorption mediated by amiloride-sensitive epithelial sodium channels (ENaC). Water follows the osmotic
gradient into the interstitium, where it is cleared by pulmonary capillaries and lymphatics.
Keywords: lung fluid clearance, epithelial sodium channels, ENaC
9. During early embryogenesis, the primary respiratory diverticulum emerges from the foregut. What is
the defining developmental event of the embryonic stage of lung growth?
A. Formation of primitive terminal respiratory sacs with thin membranes
B. Differentiation of cuboidal epithelial cells into mature type II cells
C. Formation of the trachea and initial branching of main bronchopulmonary buds
D. Proliferation of dense capillary networks around terminal alveolar ducts
Answer: C
Rationale: The embryonic stage occurs from weeks 3 to 7 of gestation. It begins with the appearance of the
respiratory diverticulum from the ventral wall of the foregut and involves the initial formation of the trachea,
mainstem bronchi, and lobar bronchopulmonary segments.
Keywords: embryonic stage, lung development, bronchopulmonary buds
,10. A neonate is born at 23 weeks of gestation and requires immediate endotracheal intubation. The
clinical team considers the anatomic stage of lung development. Which structural limitation in the
canalicular stage most directly impairs gas exchange at this gestational age?
A. Immature capillary networks and thick diffusion barriers between capillaries and airways
B. Complete absence of central cartilaginous rings throughout large conducting airways
C. Total failure of primary bronchial division into segmental bronchopulmonary branches
D. Inability of muscular chest wall structures to maintain passive thoracic recoil
Answer: A
Rationale: The canalicular stage (roughly 16 to 26 weeks of gestation) is characterized by canalization of lung
tissue, early formation of respiratory bronchioles, and vascular proliferation. However, at 23 weeks, the
capillary network remains sparse, capillaries are not yet closely apposed to the respiratory epithelium, and the
diffusion distance is substantial, severely limiting efficient alveolar-capillary gas exchange.
Keywords: canalicular stage, limit of viability, pulmonary capillaries
11. The saccular stage of fetal lung development is primarily distinguished by which developmental
feature?
A. Appearance of the initial laryngotracheal groove along ventral foregut
B. Formation of thin-walled terminal saccules and progressive thinning of interstitium
C. Division of primitive lobar bronchi into peripheral conducting terminal bronchioles
D. Complete secondary septation of all terminal airspaces into true alveoli
Answer: B
Rationale: The saccular stage (approximately 26 to 36 weeks of gestation) is marked by the development of
thin-walled terminal saccules, thinning of the surrounding interstitial mesenchyme, and close proximity of the
capillary network to the saccular airspaces. This structural maturation markedly increases the potential surface
area available for gas exchange before true alveolarization begins.
Keywords: saccular stage, terminal saccules, lung development
12. At what point in human development does true pulmonary alveolarization primarily reach
completion?
A. Immediately prior to delivery during final four weeks of gestation
B. During the first twenty-four to forty-eight hours of extrauterine life
, C. At approximately six to twelve weeks of postnatal neonatal age
D. During early childhood, continuing up to approximately eight years of age
Answer: D
Rationale: Alveolarization begins in late fetal life (around 36 weeks of gestation) but progresses most rapidly
postnatally. Secondary septation continues to multiply the number of mature alveoli throughout infancy and
early childhood, continuing until approximately 7 to 8 years of age.
Keywords: alveolarization, postnatal lung growth, secondary septation
13. A former 26-week premature infant who received prolonged mechanical ventilation presents for
hernia repair at 6 months of age. Which histopathologic hallmark characterizes new
bronchopulmonary dysplasia in this patient?
A. Severe bronchiolar smooth muscle hyperplasia with widespread airway obstruction
B. Extensive pulmonary vascular endothelial denudation and alveolar hyaline membranes
C. Arrest of alveolar development resulting in fewer and simplified large alveoli
D. Proliferation of dense interlobular fibrotic scars throughout apical lung segments
Answer: C
Rationale: Modern bronchopulmonary dysplasia (the 'new' BPD) primarily represents an arrest of alveolar and
vascular development in infants born during the saccular stage. Rather than the severe airway injury and
fibroproliferation seen in classic BPD, new BPD is characterized by alveolar simplification—fewer, larger alveoli
with reduced surface area for gas exchange and dysmorphic microvasculature.
Keywords: bronchopulmonary dysplasia, alveolar simplification, prematurity
14. Which clinical condition is recognized as a major etiologic risk factor for persistent pulmonary
hypertension of the newborn?
A. Isolated unilateral choanal atresia with normal parenchymal lung volume
B. Uncomplicated physiologic jaundice managed with brief outpatient phototherapy
C. Meconium aspiration syndrome complicated by severe neonatal parenchymal inflammation
D. Transient hypoglycemia occurring immediately following full-term vaginal delivery
Answer: C
Rationale: Meconium aspiration syndrome is one of the most common causes of persistent pulmonary
