Neonatology 2 Flashcards
Neonate with cyanosis – test and interpretation?
Hundred percent oxygen test
If PaO2 increases less then 15, reduced pulmonary bloodflow (tetralogy of fallout or right to left shunt)
If PaO2 increases but levels less than 150, normal/increased pulmonary bloodflow (truncus arteriosus)
If PaO2 goes over 150, lung disease
Causes of cyanosis in newborns?
- Pulmonary (pneumothorax)
- Cardiac (5Ts – tetralogy of flow, transposition of great vessels, truncus arteriosus, tricuspid atresia, TAPVR)
- Hematologic (polycythemia)
- Metabolic (hypoglycemia, hypocalcemia, hypothyroid, hypothermia)
Most common pulmonary causes of respiratory distress?
- Respiratory distress syndrome (surfactant deficiency syndrome)
- Meconium aspiration syndrome
- Persistent pulmonary hypertension
Indicators of fetal lung maturity?
Lecithin: sphingomyelin ratio greater than 2:1 and presence of phosphatidylglycerol
X-ray findings of respiratory distress syndrome? Management?
Groundglass and air bronco grams
Supplemental oxygen, CPAP, exogenous surfactant
Broncopulmonary dysplasia? Criteria?
Progressive pathologic changes in immature long
- Mechanical ventilation during first two weeks
- Respiratory compromise persisting beyond 28 days
- Needs supplemental oxygen beyond 28 days
- Characteristic CXR
Persistent pulmonary hypertension of the newborn? Most common causes? Pathophys? Clinical features? Evaluation? Management?
Any condition other then congenital heart disease that reduces blood flow to the lungs
Most common causes: perinatal asphyxia and meconium aspiration syndrome
Right to left shunt
PaO2 is significantly decreased
Decreased pulmonary vascular markings on CXR and echo findings
Oxygen, mechanical ventilation, extracorporeal membrane oxygenation, inhaled nitric oxide
Meconium aspiration syndrome? Clinical features? Evaluation? Management?
Green amniotic fluid and respiratory failure
CXR shows increased lung volume with diffuse patchy pneumothorax
Suctioning, oxygen, ECMO
Apnea prematurity? Categories?
Respiratory pause without airflow lasting more than 15 seconds OR pause of any duration with bradycardia and cyanosis
- Central – complete cessation of chest wall movement
- Secondary to airway obstruction – chest wall movements without airflow
- Mixed – central and obstructive apnea (most frequent type)
Idiopathic apnea of prematurity – clinical features? Management?
24 hours after birth and resolves by post conceptional age of 33-42 weeks
Maintain thermal environment, respiratory stimulants (caffeine, theophylline), ventilation/CPAP
Jaundice in newborns – when visible?
serum bilirubin >5 mg/dL
Physiologic jaundice? Causes? Peak bilirubin concentrations and timing in term infants? In preterm infants?
Self-limited indirect hyperbilirubinemia that resolves within the first week of life
Increased bilirubin load or delayed activity of hepatic enzyme glucoronyl transferase
5-16 peaking around 3 days of life; peaks in 5-7 days in preterm infants and takes two weeks before decreasing
Non-physiologic jaundice? Types?
Jaundice secondary to pathophysiologic cause
Direct versus direct (direct is always pathologic)
Causes of indirect hyperbilirubinemia?
- Breast-feeding jaundice – increased bilirubin in the first week of life due to sub optimal milk intake (decreased milk intake needs to decrease passage of stool and decreased excretion of bilirubin)
- Breast milk jaundice – due to high levels of beta-glucoronidase and high lipase in milk. Peaks in second/third weeks of life
Differential for indirect hyperbilirubinemia?
- Physiologic jaundice
- Breast-feeding jaundice
- Breast milk jaundice
- Sepsis
- Inborn errors of metabolism (hypothyroidism)
- Inherited disorders bilirubin uptake (Gilberts, Criggler-Najjar)
- Increased red blood cell (trauma)
- Hemolysis (spherocytosis, Elliptocytosis, pyruvate kinase deficiency)
- Upper G.I. obstruction
