Neonatal and Pediatric Respiratory Failure

Question 1

What are the five stages of fetal lung development?

Answer 1

1. Embryonic (weeks 4-7)
2. Pseudoglandular (weeks 5-17)
3. Canalicular (weeks 16-25)
4. Saccular (weeks 24-birth)
5. Alveolar (week 36 to age 8)

Question 2

What occurs in the embryonic stage (weeks 4-7) of lung development?

Answer 2

Lung bud forms, develops into trachea, bronchial buds, and mainstem bronchi. Errors can lead to tracheoesophageal fistula.

Question 3

What occurs in the Pseudoglandular (weeks 5-17) of lung development?

Answer 3

• Endodermal tubules transition to terminal bronchioles.
• Surrounded by modest capillary network.

Question 4

At what stage do pneumocytes start developing?

Answer 4

Week 20 in the canalicular phase.

Question 5

At what week is respiration viable?

Answer 5

Around week 25, when alveolar ducts and primitive air sacs start forming (saccular phase) where alveolar ducts and terminal sacs begin to develop. The terminal sacs are separated by 1° septae.

Question 6

What major changes occur at birth to transition from fetal to neonatal respiration?

Answer 6

Air replaces lung fluid, leading to a decrease in pulmonary vascular resistance.

Question 7

What are the cardinal symptoms for respiratory distress in newborns?

Answer 7

• Tachypnea
• Grunting
• Nasal flaring
• Subcostal and intercostal retractions

Question 8

What is bronchopulmonary dysplasia (BPD)?

Answer 8

A chronic lung disease of premature infants characterized by prolonged oxygen dependence and lung injury. Infants born prematurely have arrested lung development, typically during the saccular stage (week 26-birth) when terminal sacs normally form and undergo septation. Disrupted alveolarization leads to decreased number and septation of alveoli, resulting in reduced surface area for gas exchange. In addition to prematurity, another risk factor for BPD is prolonged mechanical ventilation, which is associated with fibrotic lung injury and scarring. However, with increased use of noninvasive ventilation techniques and avoidance of oxygen toxicity, fibrocystic changes are less common and usually associated with more severe disease. BPD is diagnosed clinically in a premature infant with findings persistent oxygen requirement for ≥28 days, clinical signs of respiratory disease (eg, tachypnea, retractions, crackles, wheeze), and a chest x-ray with diffuse hazy infiltrates with variable lung volumes (low or normal in most cases). Treatment is supportive and includes optimizing nutrition, restricting fluids, and weaning supplemental oxygen as tolerated.

Question 9

What are the highest risk factors for developing bronchopulmonary dysplasia?

Answer 9

Prematurity (most commonly), low birth weight, mechanical ventilation, and oxygen toxicity. The primary risk factor for this chronic lung condition is prematurity; the incidence of BPD is inversely correlated to gestational age, and most patients are born at gestational age <28 weeks.

Question 10

How does bronchopulmonary dysplasia typically present in neonates?

Answer 10

Tachypnea, retractions, rales, and persistent oxygen requirement beyond 28 days after birth.

Question 11

What imaging finding is characteristic of bronchopulmonary dysplasia?

Answer 11

Diffuse lung opacities with areas of atelectasis and hyperinflation on chest X-ray.

Question 12

What is the primary management strategy for bronchopulmonary dysplasia?

Answer 12

Keep oxygen levels LOW, mechanical ventilation with minimal settings, fluid restriction, and diuretics if necessary.

Question 13

How does lung function change in bronchopulmonary dysplasia patients as they age?

Answer 13

Lung function improves over months to years, with complete development by 8 years old.

Question 14

What causes neonatal respiratory distress syndrome (NRDS)?

Answer 14

Insufficient surfactant production leading to alveolar collapse (atelectasis). What is deficient are lamellar bodies.

Question 15

What are the risk factors for neonatal respiratory distress syndrome?

Answer 15

Prematurity, C-section delivery, and maternal diabetes.

Question 16

What is the pathognomonic chest X-ray finding in neonatal respiratory distress syndrome?

Answer 16

Diffuse ground-glass opacities and low lung volumes.

Question 17

What is the treatment for neonatal respiratory distress syndrome?

Answer 17

CPAP, supplemental oxygen, surfactant administration, and mechanical ventilation if severe.

Question 18

What are the complications of neonatal respiratory distress syndrome?

Answer 18

PDA and bronchopulmonary dysplasia.

Question 19

How can neonatal respiratory distress syndrome be prevented in premature infants?

Answer 19

Antenatal corticosteroids (e.g., betamethasone) given to mothers before preterm delivery.

Question 20

What causes transient tachypnea of the newborn (TTN)?

Answer 20

Delayed clearance of alveolar fluid leading to mild pulmonary edema.

Question 21

What are the risk factors for transient tachypnea of the newborn?

Answer 21

TTN is a condition caused by retained fetal lung fluid after delivery. Prematurity, C-section delivery, maternal diabetes are the main risk factors. Newborns have respiratory distress and the imaging findings consistent with transient tachypnea of the newborn (TTN). Patients born prematurely or by cesarean section are at increased risk, as typical resorptive mechanisms are activated at term and during labor. TTN also occurs more frequently in infants born to mothers with diabetes due to impaired fluid clearance in the diabetic fetal lung. TTN presents shortly after birth with tachypnea, increased work of breathing (eg, retractions, nasal flaring), and often cyanosis. However, breath sounds are usually clear on examination.

Question 22

What chest X-ray finding is seen in transient tachypnea of the newborn?

Answer 22

Bilateral perihilar linear streaks. Hyperinflation (ie, flattened diaphragm), mild cardiomegaly, prominent vascular markings, fluid in the interlobar fissures, and pleural effusions may be seen on chest x-ray.

Question 23

How is transient tachypnea of the newborn managed?

Answer 23

Supportive care with supplemental oxygen; self-resolves in 24-72 hours. The symptoms usually resolve spontaneously within 72 hours with no long-term complications.

Question 24

What is the pathophysiology of persistent pulmonary hypertension of the newborn (PPHN)?

Answer 24

Failure of normal pulmonary vascular resistance decline, leading to persistent right-to-left shunting.

Question 25

What are the risk factors for persistent pulmonary hypertension of the newborn?

Answer 25

Meconium aspiration, perinatal asphyxia, congenital diaphragmatic hernia.

Question 26

What is the unique clinical sign of persistent pulmonary hypertension of the newborn?

Answer 26

Differential cyanosis: oxygen saturation is higher in the right hand than in the lower extremities.

Question 27

What is the treatment for persistent pulmonary hypertension of the newborn?

Answer 27

100% oxygen, inhaled nitric oxide, sildenafil, or ECMO in severe cases.

Question 28

What causes meconium aspiration syndrome?

Answer 28

Aspiration of meconium-stained amniotic fluid causing airway obstruction and chemical pneumonitis.

Question 29

What is the hallmark chest X-ray finding in meconium aspiration?

Answer 29

Patchy infiltrates with hyperinflation.

Question 30

How is meconium aspiration syndrome managed?

Answer 30

Intubation with suction avoidance, oxygen support, antibiotics for possible secondary infection.

Question 31

What is a significant long term complication of meconium aspiration syndrome?

Answer 31

Permanent neurocognitive impairment is a severe complication of birth asphyxia due to meconium aspiration syndrome, which presents at delivery with respiratory distress from meconium-stained amniotic fluid.

Question 32

What is apnea of prematurity?

Answer 32

Cessation of breathing for >20 sec in a premature infant due to an immature respiratory drive.

Question 33

How is apnea of prematurity managed?

Answer 33

Supportive care, CPAP, caffeine therapy (methylxanthines).

Question 34

What is the most common cause for neonatal pneumonia?

Answer 34

- Before 72 hours, Group B Streptococcus (GBS) and Escherichia coli. - After 72 hours, MRSA, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter species.

Question 35

How do you differentiate a pulmonary cause from a cardiac cause of neonatal respiratory failure?

Answer 35

If supplemental oxygen improves saturation, the cause is pulmonary; if not, it is likely cardiac (e.g., congenital heart disease with right-to-left shunting).

Question 36

What is the first-line treatment if a congenital heart defect is suspected?

Answer 36

Prostaglandin E1 to keep the ductus arteriosus open.

Question 37

What is Laryngomalacia?

Answer 37

The most common congenital cause of inspiratory stridor in infants due to collapse of supraglottic structures during inspiration.

Question 38

What causes Laryngomalacia?

Answer 38

Immature, soft, and floppy laryngeal cartilage leading to dynamic airway obstruction.

Question 39

What is the most common presentation of Laryngomalacia?

Answer 39

Chronic, intermittent inspiratory stridor that worsens when supine, crying, or feeding and improves when prone.

Question 40

At what age does Laryngomalacia typically present?

Answer 40

Within the first 4-8 weeks of life.

Question 41

What position improves Laryngomalacia symptoms?

Answer 41

Prone position, due to gravity stabilizing the airway.

Question 42

How is Laryngomalacia diagnosed?

Answer 42

Clinical diagnosis confirmed by flexible laryngoscopy showing an omega-shaped epiglottis and inspiratory collapse of supraglottic structures.

Question 43

What is the treatment for mild Laryngomalacia?

Answer 43

Reassurance and close follow-up, as it resolves spontaneously by 12-18 months.

Question 44

When is surgical intervention needed for Laryngomalacia?

Answer 44

Severe symptoms such as feeding difficulties, apnea, significant hypoxia, or failure to thrive warrant supraglottoplasty.

Question 45

What associated condition should be considered in Laryngomalacia?

Answer 45

Gastroesophageal reflux disease (GERD), as it can exacerbate symptoms.

Question 46

What is the surgical procedure for severe Laryngomalacia?

Answer 46

Supraglottoplasty.

Question 47

What is the differential diagnosis for Laryngomalacia?

Answer 47

Vascular rings (biphasic stridor, feeding difficulties), Tracheomalacia (expiratory stridor), and Foreign body aspiration (sudden onset, localized wheezing).

Question 48

What is the prognosis for infants with Laryngomalacia?

Answer 48

Excellent prognosis; symptoms typically resolve by 12-18 months as the laryngeal cartilage matures.

Question 49

How does Laryngomalacia differ from Tracheomalacia?

Answer 49

Laryngomalacia causes inspiratory stridor, while Tracheomalacia causes expiratory stridor.

Question 50

What classic finding is seen on laryngoscopy in Laryngomalacia?

Answer 50

Omega-shaped epiglottis and inspiratory collapse of supraglottic structures.

Question 51

Why does Laryngomalacia worsen when supine?

Answer 51

Increased airway collapse due to gravity affecting the weak supraglottic structures.

Question 52

Why is GERD often associated with Laryngomalacia?

Answer 52

GERD can contribute to inflammation and worsening airway collapse, exacerbating symptoms.

Question 53

How is GERD managed in infants with Laryngomalacia?

Answer 53

Acid suppression therapy such as H2 blockers or PPIs if significant reflux symptoms are present.

Question 54

What is the typical age group for foreign body aspiration?

Answer 54

1-3 years old.

Question 55

What are the symptoms of foreign body aspiration?

Answer 55

Sudden onset of coughing, wheezing, stridor, and unilateral decreased breath sounds. Children can also assume the tripod position.

Question 56

How can signs and symptoms guide the acute management for airway obstruction?

Answer 56

- For a partial obstruction, the worst signs are simply coughing and/or gagging. - For a complete obstruction, the worst signs are respiratory distress and cyanosis, along with hands clutched at throat with the inability to breath, cough or speak.

Question 57

What are the immediate steps for a child who has a complete airway obstruction?

Answer 57

- Children age <1 should be placed face and head down on the rescuer's arm and receive 5 back blows and then turned on the back and receive 5 chest thrusts; abdominal thrusts are generally avoided due to potential damage to the liver in infants. Chest thrusts are not recommended in children age ≥1. - In children age ≥1, abdominal thrusts (Heimlich maneuver) should be performed to dislodge the aspirated object. The rescuer should stand behind the child, lean the child forward, and perform upward thrusts into the abdomen just above the navel; this produces a rapid increase in intrathoracic pressure and may dislodge the object. As an alternative, 5 back blows alternating with 5 abdominal thrusts can be performed with the child leaning forward in front of the rescuer.

Question 58

How is foreign body aspiration diagnosed?

Answer 58

Chest x-ray with inspiratory/expiratory views or CT scan if equivocal.

Question 59

What is the management for partial obstruction?

Answer 59

Flexible bronchoscopy.

Question 60

What is the management for complete obstruction?

Answer 60

Back blows (infants), Heimlich maneuver (older children), emergent rigid bronchoscopy.

Question 61

What are the risk factors for foreign body aspiration in children?

Answer 61

Playing with small objects, eating while running, lack of molars.

Question 62

Foreign bodies in the pharynx or laryngeal inlet can often be extracted by

Answer 62

Magill forceps These are used after laryngeal exposure with a standard laryngoscope. The patient will usually vomit, so suction is mandatory.

Question 63

Bronchial foreign bodies will require ______ for removal.

Answer 63

Operative bronchoscopy Occasionally, a tracheotomy will be required, such as for a patient who has aspirated a partial denture with imbedded hooks. These patients can present as airway emergencies, although they more typically present with unexplained cough or pneumonia.

Question 64

If a ball-valve obstruction results, hyperinflation of the obstructed lobe or segment can occur and this is easier to visualize on __________ .

Answer 64

inspiration-expiration films

Question 65

hyperinflation of the obstructed lobe or segment following an aspiration is due to to a ... ?

Answer 65

ball-valve obstruction