PPHN and respiratory distress in the newborn Flashcards
1
Q
How does PPHN usually present
A
- Usually presents within first 12 hours of birth with severe hypoxemia, cyanosis with mild respiratory
2
Q
Pathophysiology of PPHN
A
- Increased pulmonary resistance->persistence of fetal circulation
- Right to left shunt through PDA, foramen ovale
- Further reduction in lung blood flow= pulmonary vasoconstriction
3
Q
Risk factors for secondary and primary PPHN
A
1. Secondary Asphyxia Meconium aspiration Respiratory distress Sepsis Pneumonia Structural defects (diaphragmatic hernia, pulmonary hypoplasia) 2. Primary->PPHN occurs without additional risk factors
4
Q
Investigations in PPHN
A
- Measure pre and post ductal oxygen levels
2. Echo->increased pulmonary arterial pressure
5
Q
Management in PPHN
A
- ABC, oxygen
- Minimise stress
- Normalise blood gases and circulation
- Mechanical ventilation
- Nitric oxide
6
Q
Clinical presentation of respiratory distress in newborn
A
- tachypnea: RR >60/min; tachycardia: HR >160/min
- grunting, subcostal/intercostal indrawing, nasal flaring
- duskiness, central cyanosis
- decreased air entry, crackles on auscultation
7
Q
Differential diagnosis of respiratory distress in newborn
A
1. Pulmonary Respiratory distress syndrome (RDS) Transient tachypnea of the newborn (TTN) Meconium aspiration syndrome (MAS) Pleural effusions, pneumothorax Congenital lung malformations 2. Infectious Sepsis, pneumonia 2. Cardiac Congenital heart disease (cyanotic, acyanotic) Persistent pulmonary hypertension of the newborn (PPHN) 3. Hematologic Blood loss, polycythemia 4. Anatomic Tracheoesophageal fistula Congenital diaphragmatic hernia Upper airway obstruction (see Otolaryngology, OT44) Choanal atresia Pierre-Robin sequence (retrognathia ± micrognathia, cleft palate, glossoptosis) Laryngeal (malacia) Tracheal (malacia, vascular ring) Mucous plug Cleft palate 5. Metabolic Hypoglycemia Inborn errors of metabolism (amino acidemia, organic acidemia, urea cycle disturbance, galactosemia, 1° lactic acidosis) 6. Neurologic CNS damage (trauma, hemorrhage) drug withdrawal syndromes
8
Q
Investigations in respiratory distress of newborn
A
- CXR- in all infants once 02 requirements exceded 30%, repeat in prolonged or unusual
- ABG
- Echo, ECG if indicated
- FBE, BC before starting antibiotics if possible
9
Q
Etiology of respiratory distress
A
- Surfactant deficiency ->poor lung compliance due to
high alveolar surface tension ->atelectasis -> -vesurface area for gas exchange hypoxia + acidosis -> respiratory distress
10
Q
Risk factors of RDS
A
Maternal diabetes Preterm delivery Male sex Low birth weight Acidosis, sepsis Hypothermia Second born twin
11
Q
Clinical features of RDS
A
- Onset in first few hours of life
- Worsens over 24-72 hours
- Respiratory distress
- Hypoxia
- Cyanosis
12
Q
Homogenous CXR findings
A
- Homogenous ifiltrates
- Air bronchograms
- Decreased lung volumes
- May resemble pneumonia
- If severe->may have white out
- Reticulogranular pattern
13
Q
What is TTN, risks, presentation, CXR
A
- Transient tachypN of newbord
- Delayed resorption of fetal lung fluid->accumulation of fluid in peribronchial lymphatics and vascular space= tachyP
- More common in term and late preterm
- Risks
Maternal diabetes
Maternal asthma
Male
Macrosomia
Elective C section
Late preterm - TachyP w/i first few hours, resp distress, no hypoxia or cyanosis
- Perihilar infiltrates
14
Q
Treatment for RDS
A
- ABC
- Oxygen
Avoid hypoxemia->target 85-95% in 34 weeks - Ventilation
- SUrfactant after ETT
- Thermoregulation
- Antibiotics->as differential, until BC proves negative. Penicillin + gentamicin
- Temperature control
- Prevent hypoglycemia
- IV fluids
- Minimal handling
15
Q
Treatment of TTN
A
- Supportive
- Oxygen
- IV fluids and lavage feeds
- Observe for progression, consider other
- Ensure X respiratory fatigue
- Recovery usually within 3 days
