pedia2 20100513 neo 2 - respiratory disorders of nb

8/9/2019 PEDIA2 20100513 Neo 2 - Respiratory Disorders of NB

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Respiratory Disorders of theRespiratory Disorders of the

NewbornNewborn

Arnold M. Lintag, M.D.,

DPPS


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I. Transition to PulmonaryI. Transition to Pulmonary

RespirationRespiration


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II. First BreathII. First Breath

Problems with LBW infants

A. Compliant chest wall

B. FRC is small

C. Abnormalities in ventilation perfusion ratio


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III. Periodic BreathingIII. Periodic Breathing

Periodic Breathing

A. Pattern

B. Found in prematures up to 36th

week

C. Considered normal


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A. Due to primary disorders

B. Idiopathic Apnea of Prematurity

1. Upper airway obstruction

2. Immaturity

3. Mixed

C. Short apnea - central

D. Long apnea - mixed

IV. Apnea > 20 sec. plus bradycardiaIV. Apnea > 20 sec. plus bradycardia


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CNS

Respiratory

Infectious

Gastrointestinal

IVH, drugs, seizures, hypoxic injury, herniation,neuromuscular disorders

Pneumonia, obstructive airway lesions,atelectasis, extreme prematurity (


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Metabolic

Cardiovascular

Idiopathic

Glucose, calcium, PO2, sodium,

ammonia, organic acids, ambient temperature,hypothermia

Hypotension, hypertension, heart failure,anemia, hypovolemia, vagal tone

Immaturity of respiratory center, sleep state,upper airway collapse


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IV. ApneaIV. Apnea

E. Clinical manifestations

1. Rare on first day

2. Apnea with prematurity occurs on 2nd -

7th day of life

3. 2nd week - warrants investigation

F. Treatment:

1. Theophylline

2. Treat the underlying cause


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A. Incidence

1. 50% of all neonatal deaths

2. 60 to 80% < 28 wks.

3. 15-30% 32-36 wks.

4. 5% beyond term

5. Term - IDM

6. Preterm male

7. Reduced incidence - maternal hypertension,

PROM, opiate addiction, antenatal corticosteroid

use

V. Hyaline Membrane Disease orV. Hyaline Membrane Disease or

Respiratory Distress SyndromeRespiratory Distress Syndrome


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B. Pathophysiology

1. Insufficient amounts of surfactant

a. 20 weeks - good concentration - does

not reach surface of the lungs

b. 28-32 weeks - not enough amounts

reaching the surface

c. > 35 weeks - mature amounts




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B. Pathophysiology

2. Components of Surfactants

3. Surfactant synthesis depends on:

a. Normal pH

b. Temperature

c. perfusion




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4. Important synthesis maybe depressed by:

a. asphyxia c. pulmo. ischemia

b. hypoxemia

hypovolemia hypoglycemia cold

stress

d. epithelial lining maybe injured by high oxygen




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B. Pathophysiology

4. Ischemia -- necrosis -- damage

capillary endothelium -- transudation of

fluids into alveoli entrapping necrotic

tissue, RBG, proteins-- hyaline

membrane




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C. Clinical Manifestations:

1. Golden Period - 72 hours after delivery

2. Sign Symptoms of respiratory distress

which worsens3. Occasional rales, decreased breath sounds




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D. Prevention

1. Prenatal check-ups

2. L/S ratio

3. Betamethasone to mothers in their < 32nd

week of gestation and may deliver within 42-

72 hours. L/S ratio shows lung maturity

4. Surfactant Therapy




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E. Diagnosis: Chest X-ray -- white out appearanceF. Treatment

1. Mechanical ventilation

2. Supportivea. temperature

b. oxygenation

c. acidosisd. electrolytes

e. blood glucose

3. Antibiotics

V. Hyaline Membrane Disease orV. Hyaline Membrane Disease orRespiratory Distress SyndromeRespiratory Distress Syndrome


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VI. Interstitial Pulmonary FibrosisVI. Interstitial Pulmonary Fibrosis

(Bronchopulmonary Dysplasia: Wilson Mikity

Syndrome

A. Found in prematures < 32 weeks

B. Found in terms with a history of Meconium

Aspiration

C. Clinical Manifestations


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D. Increasing dependency on O2

E. Roentgenogram: hyper lussent bubbly

appearance because several small areas of

atelectasis-cystic lesions

F. Treatment Supportive

VI. Interstitial Pulmonary FibrosisVI. Interstitial Pulmonary Fibrosis


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A. Usually in Cesarean deliveries

B. slow absorption of fetal lung fluids

VII. Transient Tachypnea of theVII. Transient Tachypnea of the

NewbornNewborn

C. Clinical Manifestation

1. Tachypneic

2. Cyanosis relieved by Oxygen

3. Recovers after 3 days

D. Treatment is supportive


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A. Pneumothorax

1. Incidence

a. 1 - 2%

b. males

c. term and postterm

d. Meconium aspiration

e. mechanical ventilation

f. vigorous resuscitation

g. RDS

VIII. Air Leak SyndromesVIII. Air Leak Syndromes


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A. Pneumothorax2. Pathogenesis

a. alveolar rupture - pulmonary interstitial

emphysema


b. alveolar rupture - perivascular sheaths

pneumomediastinum


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A. Pneumothorax

3. Clinical Manifestations

a. asymptomatic - hyperresonance,

decreased breath sounds, crepitant rales

b. symptomatic - dyspnea, tachypnea, cyanosis

- displacement of the heart

towards the unaffected side



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A. Pneumothorax

4. Diagnosis

Chest x-ray - hyperlucency on the affected

side

5. Treatment

a. supportive

b. observe if air leak is small

c. Chest tube attached to underwater seal

if severe



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A. Fetal distress and hypoxia in term or

postterm

B. Pathogenesis

1. First Breath - aspirate

2. Small airway obstruction, ball-valve

effect

3. Chemical pneumonitis

IX. Meconium AspirationIX. Meconium Aspiration


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C. Clinical Manifestations

--- tachypnea, grunting, cyanosis, retractions

after delivery

D. Diagnosis

1. History

2. Chest X-ray: flattening of the diaphragm,

patchy infiltrates on both lungs



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E. Treatment:

1. Direct laryngoscopy and suction

2. Mechanical ventilation

3. Supportive


F. Complications:1. Pneumothorax

2. Persistent fetal circulation


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A. Found in term and post term infants with:

1. Birth asphyxia

2. MAS

3. Hypoglycemia

4. Polycythemia

5. Pulmonary hypoplasia --- diaphragmatic hernia

6. Oligohydramnios

7. Pleural effusions

8. Idiopathic

X. Persistent fetal CirculationX. Persistent fetal Circulation


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B. Pathophysiology

--- increased pulmonary vascular resistance -

persistence of R to L shunting


C. Clinical Manifestations: (within 12 hours)

1. Tachypnea

2. Severe cyanosis

3. Retractions

4. Shock


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D. Diagnosis

1. Hypoxia is labile and out of proportion -

chest roentgenograms

2. Unresponsive to oxygen by cannula or

hood

3. Right to left shunting by Doppler flow

studies in foramen ovale and ductus

arteriosus


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E. Treatment:

1. Treat underlying cause

2. Mechanical ventilation-hyperventilation-

decrease pCO2

3. Tolazoline-alpha adrenergic antagonist- increase fluids plus dopamine

4. Extracorporeal Membrane Oxygenation



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XI. Pulmonary HemorrhageXI. Pulmonary Hemorrhage

A. Found in ICU patients with stormy

courses

B. Bleeding through endotracheal tube, nostrils,

month usually reddish and frothy

C. Indicative of a terminal course

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