Neonatology Flashcards
What is the newborn period defined as?
First 28 days of life
Key components of newborn medical history?
- Parents medical/genetic hx
- Maternal past obstretic hx
- Current antepartum and intrapartum obstretic hx
What is the Apgar score?
Infant evaluation at birth (0 is not good, 2 is good)
- HR
- Respiratory effort
- Muscle tone
- Response to catheter in nostril
- Color
Describe circumcision’s place in medicine
Elective procedure to be performed only in healthy, stable infants
Medical benefits of circumcision
- Prevention of phimosis, paraphimosis, balanoposthitis, UTI
- Later benefits: decreased penile cancer, STIs
Risks of circumcision
- Local infection
- Bleeding
- Removal of too much skin
- Urethral injury
What circumcision techniques are preferred?
Ones that allow visualization (Plastibell and Gomco clamps) preferred over blind techniques (Mogen clamp)
Mogen clamp use in circumcision
- Blind technique
- Not preferred
- Risk of glans amputation
Contraindications to circumcision
Infants with genital abnormalities (e.g. hypospadia)
How are newborns screened for hearing abnormalities?
Universal screening with auditory brainstem recording
General causes of pathologic unconjugated hyperbilirubinemia
- Overproduction of bilirubin (either hemolytic or nonhemolytic)
- Decreased rate of conjugation
What are the hemolytic causes of increased bilirubin production?
- Immune mediated (positive Coombs)
- Nonimmune (negative Coombs)
- Bacterial or viral sepsis
How to tell if the overproduction of bilirubin is hemolytic or nonhemolytic?
- Hemolytic causes will have an increased retic count
- Nonhemolytic causes will have normal retic count
Nonhemolytic causes of increased bilirubin production?
- Extravascular hemorrhage (cephalohematoma)
- Polycythemia
- Exaggerated enterohepatic circulation (bowel obstruction)
- Breast feeding associated jaundice (inadequate intake)
Main causes of decreased rate of bilirubin conjugation
- Crigler-Najjar syndrome (rare and severe)
- Gilbert syndrome (common, milder)
- Hypothyroidism (maybe?)
What is MC: Crigler-Najjar or Gilbert syndrome?
Gilbert syndrome
What do Crigler-Najjar and Gilbert syndromes cause?
Decreased rate of bilirubin conjugation
What is kernicterus? What is it characterized by?
Chronic bilirubin encephalopathy of the neonatal period
- Extrapyramidal movement disorder
- Gaze abnormality
- Auditory disturbances
What is considered neonatal hypoglycemia?
Blood glucose under 45 mg/dL
Clinical presentation of hypoglycemia in infants
- May be asymptomatic
- Lethargy, poor feeding, irritability, seizures
Which infants are at risk for hypoglycemia?
- Large for gestational age (LGA)
- Small for gestational age (SGA)
- Preterm
- Stressed
Clinical presentation of respiratory distress in a term infant
- Tachypnea (RR over 60)
- Intercostal and sternal retractions
- Expiratory grunting
- Cyanosis in room air
Describe neonatal murmurs
Heart murmurs are common in the first days of life and do not usually signify structural heart problems
What does a murmur present at birth indicate?
A valvular problem
What is recommended to identify congenital heart disease in newborns?
Pulse ox prior to discharge (anything under 95% at sea level needs echo)
MC birth injuries?
- Soft tissue bruising
- Fractures (clavicle, humerus, femur)
- Cervical plexus palsies
Features observed in fetal alcohol syndrome
- Short palpebral fissures
- Thin vermillion of upper lip
- Pre and postnatal growth deficiency
- Microcephaly
- Optic nerve hypoplasia
Why have multiple births increased in the US?
Assisted reproductive technologies
What type of twins are more at risk for twin-twin transfusion syndrome and congenital anomalies?
Monochorial (identical)
What is twin to twin transfusion syndrome?
- Disease of the placenta that affects identical twins
- Disproportionate blood supply
When can intrauterine growth restriction start in twins?
32 weeks
When can intrauterine growth restriction start in triplets?
26-27 weeks
Cerebral palsy is MC in what type of twins?
Monochorial (identical)
How does the length of gestation relate to multiple births?
More fetuses typically results in shorter gestation period
What are potential obstretic complications in multiple births?
- Polyhydramnios
- Pregnancy induced HTN
- PROM
- Abnormal fetal presentations
- Prolapsed umbilical cord
When asphyxia occurs at birth, what best predicts neurologic outcome (risk of CP)?
10 min Apgar score (better predictor than the 5 min score)
What is the MC cause of respiratory distress in preterm infants?
Hyaline membrane disease (RDS type 1)
Describe hyaline membrane disease (RDS type 1)
- Surfactant deficiency in alveoli (in production and inactivation due to protein leak)
- MC cause of resp distress in preterm infants
CXR findings of hyaline membrane disease
- Hypoaerated
- Air bronchograms
- Ground glass (reticulogranular)
Describe transient tachypnea of the newborn (RDS type 2) including how to treat
- AKA retained fetal lung fluid
- A/w precipitous or C-section without labor
- O2 support w/resolution usually in 12-24 hrs
What is bronchopulmonary dysplasia?
- Major sequelae of neonatal respiratory distress
- Used to be MC in premies that required prolonged mechanical ventilation
- Less severe now bc of surfactant, prenatal glucocorticoids, revised ventilation strategies
What is the pathology of bronchopulmonary dysplasia?
Inflammation, hypercellularity then fibrosis
Risk factors for bronchopulmonary dysplasia
- Oxygen required over 28 days
- History of PPV or CPAP
- Premature gestational age
What reduces the risk of bronchopulmonary dysplasia in newborns?
Early use of surfactant
Signs of PDA?
- Hyperdynamic precordium
- Widened pulse pressure
- Hypotension
When does PDA usually present in a newborn?
Days 3-7 as the respiratory distress from hyaline membrane disease (HMD) is improving
Treatment of PDA
- Medical ligation (initially effective in 2/3 pts, indomethacin)
- Surgical ligation if indomethacin fails (mortality of 1-10%)
What is the MC acquired GI emergency in the newborn?
Necrotizing enterocolitis (NEC)
Risk factors for NEC
- Preterm infants
- Full term infants with polycythemia, congenital heart disease, birth asphyxia
Signs of NEC
- Feeding intolerance w/gastric residuals
- Vomiting
- Bloody stools
- Abd distention/tenderness
- Pneumatosis intestinalis on KUB
Symptoms of anemia in infants
- Poor feeding
- Lethargy
- Tachycardia
- Poor weight gain
- Periodic breathing (?)
What to know about treatment of an asymptomatic infant with low hematocrit?
Transfusion is NOT indicated
Clinical presentation of intraventricular hemorrhages in infants?
- Small bleeds can be asymp
- Larger cause hypotension, metabolic acidosis, altered neuro status
Periventricular-intraventricular hemorrhage occurs almost exclusively in _____
Premature infants (20-30% in infants under 31 weeks EGA and under 1500 g)
Describe an intraventricular hemorrhage
Ischemia with reperfusion injury to the capillaries in the germinal matrix in the immediate perinatal period
CNS complications a/w an intraventricular hemorrhage are MC in which pts?
Preterm infants exposed antenatally to intrauterine infection
Describe retinopathy of prematurity (ROP)
Occurs only in the incompletely vascularized premature retina
Describe the risk of severe ROP
Inversely proportional to gestational age
How is ROP graded?
Stages of abnormal vascular development and retinal detachment
Rate of preterm births in the US?
Increased over 30% in the past 30 years
Which type of preterm births have increased the most in the US?
Late preterm births (34 0/7 to 36 6/7 weeks EGA)
How do cyanotic congenital heart defects present in newborns?
- Cyanosis (initially w/o associated resp distress)
- Failure to increase PaO2 w/supplemental O2
- Decreased lung markings on CXR suggests R heart obstruction
What CXR finding suggests right heart obstruction?
Decreased lung markings
What are the cyanotic congenital heart defects?
- Truncus arteriosus
- Transposition of great vessels
- Tricuspid atresia
- Tetralogy of Fallot
- Total anomalous pulm venous return
Describe acyanotic heart disease in newborns
- Most have L sided outflow obstruction
- Metabolic acidemia
CXR findings of acyanotic heart disease in newborns
Large heart and pulmonary edema
Describe persistent pulmonary hypertension
- Newborn with some pulm condition (aspiration of meconium, pneumonia)
- Pulm vascular resistance does NOT decrease
- This leads to hypoxia with poor response to high concentrations of inspired oxygen
What is persistent fetal circulation most often associated with?
Parenchymal lung disease
Which infants are MC affected by persistent fetal circulation?
Full term or postterm
Treatment goals of persistent fetal circulation
- Increase systemic arterial pressure
- Decrease pulm arterial pressure to reverse the R-L shunt
Treatment of persistent fetal circulation
- Oxygen/ventilation and crystalloid infusions (1st)
- Systemic pressors if compromised cardiac function (2nd line)
- Correction of metabolic acidemia
Why does metabolic acidemia need to be corrected in persistent fetal circulation?
Acidemia exacerbates pulmonary vasoconstriction
If conventional therapy fails, what should be used as treatment for persistent fetal circulation?
Extracorporeal membrane oxygenation (ECMO) - lungs put at rest
Complications of persistent fetal circulation
10-15% will develop neuro sequelae:
- Cerebral palsy or cognitive delays
- Chronic lung disease, sensorineural hearing loss, feeding problems (all less common)
MC arrhythmias seen in newborns?
PACs (less often PVCs)
Describe PACs in newborns
- Irregularly irregular
- Common during 1st few days of life
- Benign and resolve within 1st week
Treatment of tachyarrhythmias in newborns?
- Ice to the face (vagal)
- IV adenosine
- Long term therapy is digoxin or propranolol
Describe intestinal atresia in newborns. How is it diagnosed? What can cause it?
- Narrowing or absence of a portion of intestine
- Surgical emergency!
- Often diagnosed prenatally by US
- Can be caused by polyhydramnios
X-ray findings of intestinal atresia
Double bubble
Clinical presentation of intestinal atresia
Bilious (green, yellow) vomiting and distention soon after birth
What do most cases of intestinal atresia present with?
Other congenital anomalies (54% of cases)
Treatment of intestinal atresia
Duodenoduodenostomy
Clinical presentation of intestinal malrotation
- Usually present in first 3 wks of life with bilious vomiting
- Later presentations may be undiagnosed (intermittent obstruction, malabsorption, diarrhea)
Imaging of intestinal malrotation
- Plain film (double bubble or just no distal gas)
- UGI (gold standard, 96% sensitive)
- Barium enema for confirmation (to locate cecum)
What is the gold standard imaging for intestinal malrotation?
UGI - 96% sensitive
What is the Ladd procedure?
- Treatment of intestinal malrotation
- Duodenum mobilized
- Mesenteric root extended
- Bowel fixed in more normal layout
Treatment of intestinal malrotation
Ladd procedure
Describe cystic fibrosis
- Autosomal recessive
- 1 in 40 people are carriers
- Causes defects in water and salt movement leading to thick secretions
Effects of CF on lungs, GI, and male reproductive?
- Lungs: mucus plugging, poor clearance
- GI: meconium ileus, pancreatic insufficiency
- Male infertility
Clinical presentation of CF in infants
- Meconium ileus (15% pts)
- Failure to thrive (FTT) with good appetite and frequent stools
- Chronic airway infections start in 1st year leading to bronchiectasis
Describe Hirschsprung disease
- Congenital megacolon
- Absence of ganglion cells in colon
Clinical presentation of Hirschsprung disease
- Colonic muscles fail to relax in front of advancing bolus
- Vomiting, distention, failure to pass meconium
- Toxic megacolon in 50% pts (enterocolitis w/fever, explosive diarrhea)
Diagnosis of Hirschsprung disease
Unprepped barium enema
-Shows distinct transition point between narrow distal and dilated proximal colon
Treatment of Hirschsprung disease
Surgical resection with diversion or pull through
What is an omphalocele?
- Abdominal wall defect
- Membrane covered herniation of abd contents into base of umbilical cord
What do most cases of omphalocele present with?
Either an abnormal karyotype or an associated syndrome (over 50% cases)
What is gastroschisis?
- Abdominal wall defect
- Uncovered intestine through abdominal wall to the right of umbilical cord
- NO membrane or sac (like omphalocele)
How does gastroschisis differ from omphalocele?
Both are abdominal wall defects in newborns, but omphalocele is membrane covered and gastroschisis is UNCOVERED
Epidemiology of gastroschisis
- Prevalence increasing worldwide
- Environmental risk factors: illicit drugs (meth, cocaine) and COX inhibitors (ASA, ibuprofen)
Treatment of gastroschisis
- Silastic bowel bag to decrease fluid and electrolyte losses
- Surgery
Prognosis of gastroschisis
Bowel motility, especially duodenal, may be slow to return
Describe congenital diaphragmatic hernia
- Abdominal wall defect
- Herniation of abd contents through posterolateral defect
- Failure of diaphragm fusion
- Bowel blocks space for lungs to grow resulting in lung hypoplasia
- 80% involve L diaphragm
Clinical presentation of congenital diaphragmatic hernia
- Can be found incidentally at autopsy
- Respiratory distress with scaphoid abdomen
How to treat congenital diaphragmatic hernia
Early intubation WITHOUT bag and mask (this causes bowel to inflate and makes lung function even worse)
What should be considered in GI bleeds of newborns?
Could be maternal blood (not even from the infant)
When is GERD in an infant pathologic and should be treated?
- Failure to thrive
- Poor intake d/t dysphagia and irritability
- Apnea or cyanotic episode
- Wheezing and recurrent PNA
How to diagnose GERD in infant?
Clinical diagnosis
What should be considered in the treatment of GERD in infants?
Most antireflux therapies have NOT been studied enough in infants (especially premature)
Treatment options for GERD in the infant
- Thickened feeds
- Gastric acid suppressants
- Prokinetic agents are of little benefit and have significant side effects
- Aging (GERD improves w/time)
What are the major routes of perinatal infection?
- Bloodborne transplacental
- Disruption of the barrier provided by amniotic membranes allowing infection to ascend
- Passage through an infected birth canal or exposure to infected blood at delivery
What provides passive protection to a fetus against some infectious organisms?
Transfer of IgG across the placenta (particularly during 3rd trimester)
Describe early onset sepsis in a newborn including presentation
- First 7 days of life
- Resp distress MC
- Hypotension, acidemia, neutropenia
Describe late onset sepsis in a newborn
- More subtle than early onset
- Poor feeding, lethargy, hypotonia, temp instability, altered perfusion
What increases newborn infection rates?
- ROM over 24 hrs prior to delivery
- Early rupture w/chorioamnionitis
- Preterm infant (5 times higher risk)
MC pathogens of early onset infection in newborns?
- Group B hemolytic strep (GBS)
- Gram neg enteric (E coli)
MC pathogens of late onset sepsis in newborns?
Coagulase-negative staph (MC in infants w/indwelling central lines)
Treatment of early onset infections in newborns
Ampicillin and aminoglycoside (or 3rd generation cephalosporin)
Treatment of late onset infections in newborns
- Same coverage as early onset but expanded coverage for staph
- Vancomycin esp for preterm infants w/indwelling line
Describe neonatal meningitis
- Low risk for infant presenting in first 24 hrs
- Late onset infection is MC
- MC organisms are GBS and gram negative enteric (E coli)
Early onset neonatal infection is usually associated with what?
Pneumonia
Neonatal pneumonia is usually a/w what type of infection?
- Early onset infection
- May be bacterial OR viral
Describe neonatal UTIs
- UNCOMMON in first days of life
- Can suggest GU anomalies
- MC Gram negative enteric (E. coli) or Enterococcus
Describe neonatal omphalitis
- Infection of the umbilical stump
- Strep, staph, or gram negative organisms
- Erythema and edema around stump
Possible complications of neonatal omphalitis
- Septic thrombophlebitis
- Hepatic abscess
- Necrotizing fasciitis
- Portal vein thrombosis
Describe neonatal conjuctivitis caused by N. gonorrhoeae
- Colonizes an infant during passage through infected canal
- Presents at 3-7 days w/copious purulent conjunctivitis
Describe neonatal conjuctivitis caused by C. trachomatis
- Acquired at birth after passage through infected birth canal
- Presents at 5 days to several weeks of age w/congestion, edema, minimal discharge
Topical optho treatment of neonatal conjunctivitis caused by C. trachomatis?
Alone it will NOT eradicate nasopharyngeal carriage and leaves risk for pneumonitis
Which infants are MC affected by Vit K deficiency?
Exclusively breast fed children
How can early (0-2 weeks) vitamin K deficiency bleeding be prevented?
Either parenteral or oral vit K
How can late (2 wks-6 mos) vit K deficiency be prevented?
Parenteral vit K
Describe neonatal thrombocytopenia
- Platelets under 10-20,000
- Generalized petechiae, oozing at cord or puncture sites
In a well infant, what should be suspected if thrombocytopenic?
Isoimmune thrombocytopenia
In a sick or asphyxiated infant, what should be suspected if thrombocytopenic?
DIC
Treatment of neonatal thrombocytopenia
Transfusion of platelets indicated if:
- Clinical bleeding
- Plt ct under 10-20,000
- Preterm infant at risk for intraventricular hemorrhage (or plt under 40-50,000)
Prognosis of infants who have mothers with ITP?
Low risk for serious hemorrhage despite thrombocytopenia
Describe neonatal anemia and causes
Hct under 40% at term birth
- Acute blood loss
- Chronic blood loss
- Hemolytic anemia
Labs to work up neonatal anemia?
- CBC
- Blood smear
- Retic count
- Type
- Direct and indirect Coombs
How does neonatal polycythemia present?
Plethora, tachypnea, retractions, hypoxemia
Pathophys of polycythemia
Hyperviscosity with decreased perfusion of capillary bed
Etiology of neonatal polycythemia
50% are appropriate weight for gestational age (AGA) so etiology is indeterminant
Treatment of neonatal polycythemia
Only recommended for symptomatic
-Isovolemic partial exchange transfusion with normal saline (decreases Hct)
Clinical presentation of neonatal renal failure
- Birth depression, hypovolemia, hypotension, shock
- Low or delayed urine output
- Rising serum Cr
Role of prenatal US for renal issues?
Identifies many renal anomalies prior to birth - MC hydronephrosis
Describe neonatal stroke
- Often occurs antenatally
- MC clinical presentation: seizures (focal or generalized)