Mod VI: Congenital Abnormalities Associated with Respiratory Disorders

Question 1

_{Congenital Abnormalities Associated with Respiratory Disorders}

Malformation of the diaphragm allowing herniation of abdominal contents into the thoracic cavity

Answer 1

Congenital Diaphragmatic Hernia

Results in Prevention of prenatal lung development/lung hypoplasia

Question 2

_{Congenital Diaphragmatic Hernia}

Congenital Diaphragmatic Hernia may result in Prevention of prenatal lung development/lung hypoplasia. What’s a consequence of this?

Answer 2

Hypoxemia → persistent pulmonary HTN

→ ↑ RV pressures → R-to-L shunting thru PDA/PFO

Question 3

_{Congenital Diaphragmatic Hernia}

What’s the Mortality rate in Congenital Diaphragmatic Hernia?

Answer 3

High mortality rate: 50% not surviving

Question 4

_{Congenital Diaphragmatic Hernia}

Incidence of Congenital Diaphragmatic Hernia:

Answer 4

1:4,000 live births

Question 5

_{Congenital Diaphragmatic Hernia}

Which side of the diaghragm is mostly affected by Congenital Diaphragmatic Hernia? Why?

Answer 5

Left side

90% occur on left side

Left side Foramen of Bochdalek closes later than right

Question 6

_{Congenital Diaphragmatic Hernia}

T/F: Congenital Diaphragmatic Hernia Often detected during prenatal ultrasound

Answer 6

True

Question 7

_{Congenital Diaphragmatic Hernia}

Clinical features of Congenital Diaphragmatic Hernia

Answer 7

Scaphoid abdomen

Breath sounds absent on involved side

Lung hypoplasia = respiratory distress syndrome

Question 8

_{Congenital Diaphragmatic Hernia}

Treatment: Respiratory and CV support

Answer 8

Intubated immediately in delivery room

^{to ↓ air entry into stomach/intestine}

Intubating while spontaneous breathing = minimizes air insufflation

If neonate apneic = minimize airway pressures during ventilation with bag and mask to reduce gastric distention

Insert NGT immediately to decompress gut

Question 9

_{Congenital Diaphragmatic Hernia}

Medical management: PAST vs CURRENT

Answer 9

PAST: Surgical emergency

CURRENT: Delayed closure

Stabilized first with medical & ventilatory treatment

^{(ECMO, HFV with NO, permissive hypercapnia )}

Question 10

_{Congenital Diaphragmatic Hernia}

Anesthetic Considerations w/ Congenital Diaphragmatic Hernia

Answer 10

AFOI

^{if not already intubated (post GI decompression) followed by smooth induction}

Avoid PPV

^{(prevents further bowel distention)}

Maintain low inspiratory pressures (< 25 cm H2O)

^{with high ventilatory rates (prevent pneumothorax)}

Avoid increases in PVR

^{(acidosis/hypoxemia/PEEP)}

Insert contralateral chest tube

^{(if Pneumothorax suspected)}

Avoid N20

“Gentle Ventilation” with permissive hypercapnia strategies

Inhaled NO

Monitor SaO2

^{RUE (preductal) - LLE (postductal)}

^{Aid in detection of R-to-L shunting due to persistent PHTN}

Place A-line

^{for frequent assessment of acid-base balance and oxygenation/ventilation}

Acidotic?: Hyperventilate/NaHCO3

Maintain body temperature

Selection of technique dependent of stability and hemodynamics of the neonate

Question 11

_{Congenital Diaphragmatic Hernia}

“Gentle Ventilation” with permissive hypercapnia strategies aim to:

Answer 11

Limit peak inspiratory pressure and minimize barotrauma

^{Postductal PaCO2 55-60 mmHg - Goal pH >7.35}

^{Preductal SaO2 > 85%}

^{Limit PIP to < 25}

Question 12

_{Congenital Diaphragmatic Hernia}

Benefits of inhaled NO include:

Answer 12

Improve oxygenation

Decrease intrapulmonary shunting

Question 13

_{Congenital Diaphragmatic Hernia}

SaO2 measured fro the RUE is categorized as:

Answer 13

Preductal

Question 14

_{Congenital Diaphragmatic Hernia}

SaO2 measured fro the LLE is categorized as:

Answer 14

Postductal

Question 15

_{Congenital Diaphragmatic Hernia}

Monitor pre and post-ductal SaO2 Aid in detection of:

Answer 15

R-to-L shunting due to persistent PHTN

Question 16

_{Congenital Abnormalities Associated with Respiratory Disorders}

The obstruction of airway passages between nasal cavity and nasopharynx, where all breathing becomes oral, and could lead to ASPHYIXIATION is also known as:

Answer 16

Choanal Atresia

Question 17

_{Choanal Atresia}

Incidence of Choanal Atresia:

Answer 17

1 : 8,000 live births

Question 18

_{Choanal Atresia Co-existing anomalies}

Think: “CHARGE”

Answer 18

C: Coloboma (eye defect)

H: Heart (TOF, PDA, DORV, VSD, A-V canal)

A: Atresia of choanae

R: Retarded growth (other CNS anomalies)

G: Genital (hypogonadism)

E: Ear anomalies

Question 19

_{Choanal Atresia}

Choanal Atresia is a PEDIATRIC EMERGENCY. How is it managed?

Answer 19

Present with oral airway or OET since birth: maintain airway

Oral RAE: avoid interfering with surgery

Question 20

_{Meconium Aspiration Syndrome}

Meconium staining occurs in what percentage of births?

Answer 20

10% of births

Associated with asphyxia/fetal death

Question 21

_{Meconium Aspiration Syndrome}

Etiology of Meconium Aspiration Syndrome

Answer 21

Chronic fetal hypoxia during 3rd trimester

^{Passage of meconium into amniotic fluid}

Swallowed by fetus into trachea/lungs prior to or during birth

^{Thick, tenacious}

^{Obstructs tracheobronchial tree}

Question 22

_{Meconium Aspiration Syndrome}

Pathogenesis of Meconium Aspiration Syndrome

Answer 22

Complete obstruction: distal atelectasis

Partial obstruction: overinflation of distal airspaces = pneumothorax

Bile = chemical pneumonitis

Meconium inhibits surfactant

Hypoxemia → PPHTN

Question 23

_{Meconium Aspiration Syndrome}

Management of Meconium Aspiration Syndrome

Answer 23

Decrease effects of aspiration

Routine oropharyngeal suctioning immediately at time of delivery

Apgar 7-9:

requires no additional airway management

Apgar < 7:

Tracheal suction prior to 1st breath

Intubate and suction prior to instituting PPV

Mechanically ventilate

^{Long expiratory times to decrease air trapping if partial obstruction}

^{HF oscillatory ventilation to recruit closed segments if complete}

Induce alkalosis

Inhaled NO

Exogenous surfactant

Question 24

_{Bronchopulmonary Dysplasia (Chronic Lung Disease)}

T/F: Bronchopulmonary Dysplasia (Chronic Lung Disease) Develops following respiratory distress syndrome and resultant lung injury

Answer 24

True

Question 25

_{Bronchopulmonary Dysplasia (Chronic Lung Disease)}

Principle Risk factors for Bronchopulmonary Dysplasia (Chronic Lung Disease) are:

Answer 25

Low birth weight (1500 g)

Gestational age (more immature)

Question 26

_{Bronchopulmonary Dysplasia (Chronic Lung Disease)}

Consequential Risk factors for Bronchopulmonary Dysplasia (Chronic Lung Disease) are:

Answer 26

O2 toxicity (High FiO2 for > 28 days)

Development of pneumothorax or interstitial emphysema

Iatrogenic fluid overload

Mechanical injury (MV for first 3 days or more of life)

Presence of PDA

Question 27

_{Bronchopulmonary Dysplasia (Chronic Lung Disease)}

Other additional causes of Bronchopulmonary Dysplasia (Chronic Lung Disease) are:

Answer 27

Pneumonia

Sepsis

Persistent pulmonary HTN

Pulmonary hypoplasia

Apnea of prematurity

Question 28

_{Bronchopulmonary Dysplasia (Chronic Lung Disease)}

What the Pathophysiology of Bronchopulmonary Dysplasia (Chronic Lung Disease)?

Answer 28

Pulmonary immaturity + Surfactant-deficit alveoli

=> Respiratory distress syndrome

Question 29

_{Bronchopulmonary Dysplasia (Chronic Lung Disease)}

How does maintaining oxygenation/ventilation in the Treatment of Bronchopulmonary Dysplasia (Chronic Lung Disease) produces pulmonary injury?

Answer 29

High FiO2 and continued supplemental O2→O2 free radicals→ Oxygen toxicity = airway inflammation

PPV of surfactant deficit alveoli→ overdistention (barotrauma) and transudation of fluid into alveoli (hyaline membrane disease)

Bronchoconstriction develops in 80%

Question 30

_{Bronchopulmonary Dysplasia (Chronic Lung Disease)}

Clinical presentation of Bronchopulmonary Dysplasia (Chronic Lung Disease):

Answer 30

Tachypnea with retractions

Rales/wheezing

Increased PVR→ ↑PAP→ RV hypertrophy = Cor pulmonale

Persistent requirement for supplemental O2

Hypercarbia

“BPD” spells

^{(Sudden severe bronchospasm with cyanosis with physical agitation or stimulation)}

Question 31

_{Bronchopulmonary Dysplasia (Chronic Lung Disease)}

Anesthetic considerations w/ Bronchopulmonary Dysplasia (Chronic Lung Disease)

Answer 31

Pulmonary function should be optimized if possible

Prevalence of bronchospasm and airway reactivity should be considered when planning anesthetic

^{LMA preferred to ET - Deep extubation - Regional}

Hand ventilation

^{Allows determination of pulmonary compliance}

^{Decreases risk of pneumothorax}

Avoid events that aggravate pulmonary HTN

^{Acidosis - Hypoxia - Hypercarbia - Hypothermia}

Question 32

_{Persistent Pulmonary Hypertension}

Pathogenesis of Persistent Pulmonary Hypertension:

Answer 32

Increased PVR→ Pulmonary HTN

→ R-L shunting across patent foramen ovale→ cyanosis

Question 33

_{Persistent Pulmonary Hypertension}

Etiology of Persistent Pulmonary Hypertension

Answer 33

Hypoxemia

Acidosis

Respiratory distress syndrome

Meconium aspiration

Question 34

_{Persistent Pulmonary Hypertension}

Treatment of Persistent Pulmonary Hypertension

Answer 34

Tx is aimed at Decreases PVR, Decreased R-L shunting

Intubation with mechanical ventilation

Induce respiratory/metabolic alkalosis

^{(Will decrease PVR)}

Support BP (fluids/pressors)

Inhaled NO

^{Decreases PVR, R-L shunting, increases systemic oxygenation}

ECMO*

Question 35

_{Persistent Pulmonary Hypertension}

When is ECMO* indicated in the treatment of Persistent Pulmonary Hypertension?

Answer 35

Reserved for severe hypoxemia

Requires heparinization and platelet infusion during use

Mortality due to intraventricular hemorrhage

_{http://circ.ahajournals.org/content/109/25/3106.full}

Question 36

_{Persistent Pulmonary Hypertension}

In the treatment of Persistent Pulmonary Hypertension, what are contraindications to using ECMO*?

Answer 36

Intraventricular hemorrhage

Severe neurological impairment

Cyanotic CHD

_{http://circ.ahajournals.org/content/109/25/3106.full}