Chapter 4 - Neonatology Flashcards
1
Q
What are apgar scores?
A
- they are an assessment of intrapartum stress and neurologic depression at birth
- when persistently low, the score indicates a need for resuscitation
2
Q
How are apgar scores calculated?
A
assessed at 1 and 5 minutes after birth plus every five minutes until a score of 7 or more is reached
- hear rate: absent, < 100 bpm, > 100 bpm
- respirations: absent, slow or irregular, good/crying
- muscle tone: limp, some flexion, active motion
- reflex irritability: no response, grimace, cough/sneeze/cry
- color: blue, body pink but extremities blue, all pink
3
Q
What is vernix caseosa?
A
a benign, thick, white, creamy material found covering large areas of the skin in preterm in infants
4
Q
What is acrocyanosis?
A
cyanosis of the hands and feet, which is frequent during the first 48-72 hours of life, and is indicative of vasomotor instability
5
Q
What is cutis marmorata?
A
mottling of the skin with venous prominence, an indicator of vasomotor instability
6
Q
Jaundice is always abnormal if what is true?
A
if it is detected in the first 24 hours of life
7
Q
What is milia?
A
benign, self-resolving, small cysts formed around the pilosebaceous follicles, which appear as tiny, whitish papules over the nose, cheeks, etc.
8
Q
What is pustular melanosis?
A
a benign, transient rash characterized by small, dry superficial vesicles over a dark macular base, which must be differentiated from viral and bacterial infections
9
Q
What is erythema toxic neonatorum?
A
a benign rash characterized by erythematous macule, papules, and pustules, with lesions containing eosinophils and which spare the palms and soles
10
Q
What is a nevus simplex?
A
a pink macular lesion on the neck or face, which is the most common vascular lesion of infancy
11
Q
What is a nevus flammeus?
A
- also known as a port wine stain
- a vascular malformation composed of dilated capillary-like vessels, which often become darker with age
- those associated with the ophthalmic branch of the trigeminal may be associated with CNS vascular malformations, seizures, and intracranial calcifications as part of Sturge-Weber syndrome
12
Q
What is the difference between a strawberry and a cherry hemangioma?
A
- strawberry: a benign capillary hemangioma of infancy that grows rapidly and regresses spontaneous by 5-8 years of age; requires intervention only if it compromises the airway or vision
- cherry: a benign capillary hemangioma of the elderly, which does not regress
13
Q
Compare and contrast a caput succedaneum and a cephalohematoma.
A
- caput succedaneum are diffuse edema or swelling of the soft tissue of the scalp, which crosses the cranial sutures and usually the midline
- cephalohematomas are subperiosteal hemorrhages secondary to birth trauma, which are confined and limited by the cranial sutures
14
Q
What are craniotabes?
A
soft areas of the skull with a ping-pong ball feel, which usually disappear within weeks or months of brith
15
Q
What is Pierre Robin sequence?
A
- micrognathia
- glossoptosis
- cleft palate
- obstruction of the upper airway
16
Q
What are epstein pearls?
A
small, white, epidermoid-mucoid cysts on the hard palate, which usually disappear within weeks of birth
17
Q
What is neonatal torticollis?
A
asymmetric shortening of the sternocleidomastoid, which may result from being in a fixed position in utero or from postnatal hematoma resulting from birth injury
18
Q
What is the difference between pectus carinatum and pectus excavatum?
A
- carinatum: prominent and bulging sternum
- pectus excavatum: depressed sternum
19
Q
What are five signs of respiratory distress in a newborn?
A
- respiratory rate greater than 60
- deep respirations
- cyanosis
- expiratory grunting
- retractions
20
Q
What is a periodic breathing pattern?
A
apneic bursts lasting less than 10 seconds, seen in premature infants which have no clinical significance
21
Q
What is a normal respiratory and heart rate in a newborn?
A
- respiratory rate < 60
- heart rate between 95-180
22
Q
During a newborn exam, what would diminished femoral pulses suggest? What would exaggerated femoral pulses suggest?
A
- diminished: coarctation of the aorta
- increased: patent ductus arteriosus
23
Q
Upon inspection of the umbilical cord, what would the presence of only one umbilical artery suggest?
A
congenital renal anomalies
24
Q
What is diastasic rectified?
A
- a separation of the left and right side of the rectus abdomens at the midline of the abdomen
- gradually disappears as the infant develops and the rectus abdomens muscles grow
25
How are umbilical hernias treated?
most close spontaneously, so intervention is reserved for cases that persist or become symptomatic
26
What is a persistent urachus?
a failure of the tracheal duct to close, resulting in a fistula between the bladder and umbilicus; often urine drains from the umbilicus in these cases
27
What is the difference between a meconium plug and meconium ileum?
- plug is obstruction of the left colon and rectum caused by dense, dehydrated meconium
- ileus is the occlusion of the distal ileum caused by thickened, dried, and viscid meconium, usually secondary to a deficiency of pancreatic enzymes and an abnormally high protein content of intestinal secretions
28
What is hydrometrocolpos?
- an imperforate hymen with retention of vaginal secretions
| - may present as a small cyst between the labia at birth or as a lower midline abdominal mass during childhood
29
How do hypospadias and epispadias differ apart from the location of the meatus?
- hypospadias is not associated with other urinary malformations
- epispadias is often associated with bladder extrophy
30
How is cryptorchidism managed?
- check for associated hernia, GU malformations, hypospadias, or other genetic syndrome
- most resolve within 1 year without intervention
- after 1 year, surgical correction is needed to maintain fertility and reduce the risk of future malignancy
31
Absence or hypoplasia of the radial at birth is associated with what three conditions?
- TAR: thrombocytopenia absent radii
- Fanconi anemia
- Holt-Oram syndrome
32
List frequent problems experienced by preterm infants.
- disrupted mother-father-infant interaction
- intracranial hemorrhage
- retinopathy of prematurity
- RDS or bronchopulmonary dysplasia
- anemia
- infection
- hypothermia
- hypoglycemia
- hypocalcemia, fluid and electrolyte abnormalities
- indirect hyperbilirubinemia
- patent ductus arteriosus
- perinatal asphyxia
- NEC
33
How do we define preterm and post-term deliveries?
- preterm are those occurring less than 37 completed weeks of gestation
- post-term are those occurring at 42 or more weeks gestation
34
What are the most common complications of post-term delivery?
placental insufficiency and it's consequences: intrauterine asphyxia, meconium aspiration syndrome, and polycythemia
35
How do we define small-for-gestational age, large-for-gestational age, and high birth weight babies?
- SGA: weigh below the 10th percentile
- LGA: weigh above the 90th percentile
- HBW: weigh more than 4 kg
36
Large-for-Gestational Age
- defined as any newborn with birth weight above the 90th percentile
- many are simply constitutionally large but maternal diabetes is an important pathologic etiology
- potentially complicated by need for delivery via C-section or using forceps; birth injuries like fractured clavicle, brachial plexus injury, or facial nerve palsy; or hypoglycemia
37
Small-for-Gestational Age
- defined as any newborn with birth weight below the 10th percentile
- may be due to constitutional factors, prematurity, etc.
- differs from intrauterine growth restriction because it is a diagnosis made at birth rather than during pregnancy
- may be complicated by temperature instability, inadequate glycogen stores with hypoglycemia, or polycythemia and hyperviscosity syndrome
38
What is cyanosis? At what level does it occur?
- a bluish discoloration directly related to the absolute concentration of deoxygenated or reduced hemoglobin
- appears when more than 3 g/dL of reduced hemoglobin is in arterial blood or more than 5 g/dL in capillary blood
39
What are the etiologies for cyanosis in a neonate?
- respiratory pathology
- the 5 T's of cyanotic congenital heart disease: ToF, transposition of the great vessels, truncus arteriosus, tricuspid atresia, and total anomalous pulmonary venous connection
- CNS pathology like intraventricular hemorrhage
- hematologic disorders like polycythemia
40
What is the 100% oxygen test used to evaluate cyanosis? What do the various results indicate?
it is an arterial blood gas performed after administration of 100% oxygen used to evaluate whether cyanosis is cardiac or respiratory in nature
- congenital heart disease with reduced pulmonary blood flow (e.g. ToF) will see only a slight increase in PaO2 (10-15 mmHg)
- congenital heart disease associated with normal or increased pulmonary flow (e.g. truncus arteriosus) will see a more substantial increase (15-20 mmHg)
- respiratory etiologies will have a considerable increase in PaO2, often reaching more than 150 mmHg
- the exception to respiratory pathology is infants with severe lung disease causing pulmonary hypertension, which generates a right-to-left shunt through the foramen ovale or ductus arteriosus
41
How does respiratory distress in preterm infants differ from that experienced by term infants?
- RDS is the more common etiology in preterm infants
| - meconium aspiration and persistent pulmonary hypertension of the newborn are more common in term
42
What are signs of respiratory distress in a newborn?
- tachypnea
- decreased air entry or gas exchange
- retractions
- grunting
- stridor
- flaring of the alar nasi
- cyanosis
43
Respiratory Distress Syndrome
- respiratory distress caused by lack of surfactant, which is most often seen in preterm neonates less than 37 weeks
- lack of surfactant leads to collapse of air sacs and formation of hyaline membranes
- most often due to prematurity (insufficient time to produce), c-section (less stress-induced steroid release, which otherwise triggers surfactant production and secretion), or maternal diabetes (insulin inhibits surfactant production)
- other risk factors include white, preterm, males; mother with previous RDS infant; and hypothermia or asphyxia
- CXR is diagnostic as it will show diffuse atelectasis with increased density in both lungs, a ground-glass appearance, and air bronchograms
- treat with supplemental oxygen, CPAP, or mechanical ventilation and with exogenous surfactant
- may be complicated by air leaks, NEC, respiratory acidosis, bronchopulmonary dysplasia, retinopathy of prematurity, intraventricular hemorrhage, sepsis, and patent ductus arteriosus
44
What is pulmonary surfactant? How do we assess production?
- a product of type II pneumocytes, primarily composed of dipalmitoylphosphatidylcholine (aka lecithin)
- first seen around 28 weeks gestation; adequate levels are usually reached around week 34
- can assess production using the L/S ratio since sphingomyelin levels in amniotic fluid remain relatively stable through pregnancy
- a ratio of more than 2 indicates fetal lung maturity
45
Persistent Pulmonary Hypertension of the Newborn
- any condition other than congenital heart disease that is associated with low blood flow to the lungs after birth
- this includes perinatal asphyxia, meconium aspiration, diaphragmatic hernia, hypoplastic lungs,
- these etiologies increase pulmonary vascular resistance, causing significant right-to-left shunting through the foramen ovale or ductus arteriosus, resulting in hypoxemia
- presents with respiratory distress, cyanosis, and notably different pre- and post-ductal PaO2
- diagnosed with CXR for which findings differ based on etiology and echocardiogram, which rules out heart disease and assess the degree of right-to-left shunting
- prevent hypoxemia with oxygen or ventilation and use nitric oxide as a pulmonary vasodilator
46
What is meconium?
material in the fetal gut composed of water, mucopolysaccharides, desquamated skin and GI mucosal epithelial cells, vernix, bile salts, and amniotic fluid
47
Meconium Aspiration Syndrome
- meconium, often passed as a consequence of distress in the fetus at term, becomes more frequent after 42 weeks; meconium-stained amniotic fluid may then reach distal airways and alveoli in utero if the fetus becomes hypoxic and develops gasping or deep respiratory movements
- presents with signs and symptoms of respiratory distress
- diagnosed based on history of meconium at, or before, delivery and on increased lung volume with diffuse patchy areas of atelectasis and parenchymal infiltrates on CXR
- managed with suctioning of the perineum and trachea in addition to oxygen administration
48
Idiopathic Apnea of Prematurity
- defined as a respiratory pause without airflow lasting more than 20 seconds or a pause of any duration accompanied by bradycardia, cyanosis, or desat
- can be central, in which there is a complete cessation of chest wall movements and no airflow, or secondary to airway obstruction, in which the chest wall continues to move but without airflow
- many etiologies of apnea so idiopathic apnea of prematurity is a diagnosis of exclusion
- frequency decreases with gestational age and usually resolves by 38-44 weeks corrected gestational age
- manage by maintaining a neutral thermal environment, treating hypoxia, and using caffeine, a respiratory stimulant
49
What is the cutoff for distinguishing indirect from direct hyperbilirubinemia?
- indirect: elevated bilirubin in which conjugated/direct is less than 15% of the total bilirubin
- direct: elevated bilirubin in which conjugated/direct is more than 15% of the total bilirubin
50
What are the most common causes of direct hyperbilirubinemia?
- biliary atresia
- neonatal infection (sepsis or hepatitis)
- metabolic disorders including galactosemia, hereditary fructose intolerance, tyrosinemia, a1AT deficiency
51
Jaundice should always be evaluated if one of what three conditions is met?
- jaundice appearing in the first 24 hours
- bilirubin rises more than 5-8 mg/dL in a 24 hours period or more than 0.5 mg/dL per hour (these suggest hemolysis)
- direct hyperbilirubinemia
52
How should indirect hyperbilirubinemia be evaluated from a diagnostic stand point? Direct hyperbilirubinemia?
- indirect: CBC, reticulocyte count, and smear to evaluate for sepsis and hemolysis
- direct: hepatic ultrasound, serologies for viral hepatitis, radioisotope scans of the hepatobiliary tree
53
How should hyperbilirubinemia be managed?
- requires serial bilirubin assessments; get a direct bilirubin if total bilirubin is persistently elevated
- observe, particularly for pale stools or dark urine, suggestive of biliary atresia
- reassurance can be used for physiologic jaundice with low risk of neurologic effects
- phototherapy may be indicated based on risk
- exchange transfusion is performed for rapidly rising bilirubin levels secondary to hemolytic disease
54
Describe bilirubin metabolism.
- protoporphyrin is converted to UCB
- UCB is transported by albumin to the liver
- there, it is conjugated by uridine diphosphate glucuronyl tansferase to glucuronide
- this water soluble CB is excreted in bile and into the intestine
- most CB is metabolized by intestinal flora to urobilin and excreted in stool while some is deconjugated via beta-glucuronidase and reabsorbed
55
How does bilirubin metabolism differ between neonates and adults?
- they have lower UDPGT activity
- they lack the intestinal flora that metabolize CB to urobilin for excretion
- they have meconium in the GI tract, containing beta-glucuronidase, which deconjugates the bilirubin and allows it to be reabsorbed
56
What are the features of early bilirubin-induced neurologic dysfunction, late BIND, and kernicterus?
- initially, poor suck, high-pitched cry, hypotonia, lethargy, seizures
- later, extensor hypertonia and opisthotonus
- kernicterus: abnormalities in tone and reflexes, choreoathetosis, tremor, oculomotor paralysis, sensorineural hearing loss, cognitive impairment
57
What is the difference between an ABO mismatch, incompatibility, and set-up?
- a mismatch is when the maternal and fetal blood types are different
- setup is a specific mismatch in which the mother has blood group O and the baby has a or B, but the Coombs test is negative
- incompatibility occurs when the mother has blood group O, the baby has a or B, and the direct Coombs test is positive
58
Physiologic Jaundice of the Newborn
- defined by a total bilirubin less than 15 in full-term infants who are otherwise healthy and have no other demonstrable cause for elevated bilirubin- it is benign and self-limited- usually recognized on the 2nd or 3rd day of life- pathogenesis involves increased bilirubin production since fetal RBCs are shorter-lived, relative UDPGT deficiency, lack of intestinal flora to metabolize bile, high levels of beta-glucuronidase in meconium, minimal oral intake which slows excretion of meconium
59
Breastfeeding Jaundice
- happens early in the first week of life when milk supply is relatively or absolutely low
- this limited quantity reduces oral intake, decreases GI motility, promotes retention of meconium, and increases beta-glucuronidase levels in the GI tract
- beta-glucuronidase deconjugates bilirubin and allows it to be reabsorbed via enterohepatic circulation, elevating bilirubin levels
60
Breast Milk Jaundice
- begins in the first 4-7 days of life, peaks around days 10-14, and may persist for up to 12 weeks
- most likely explanation is beta-glucuronidase present in breast milk aids enterohepatic circulation of bilirubin
61
What are three causes of antibody-positive hemolytic jaundice and two causes of antibody-negative hemolytic jaundice? What are four causes of non-hemolytic jaundice?
- Ab+: Rh incompatibility, ABO incompatibility, minor blood group antigen incompatibility
- Ab-: membrane defects like spherocytosis or enzyme defects like G6PDH
- non-hem: extensive bruising from birth trauma, large cephalohematoma, polycythemia, swallowed blood during delivery
62
List eight etiologies for jaundice.
- physiologic
- breastfeeding
- breast milk
- hemolysis
- non-hemolytic RBC breakdown
- metabolic errors (Crigler-Najjar, Gilbert syndrome, galactosemia, hypothyroidism)
- neonatal sepsis
- congenital infection
63
Which inborn error of metabolism is often associated with hyperbilirubinemia in the newborn?
galactosemia
64
What are the most common presenting signs of neonatal abstinence syndrome?
- jitteriness
- hyperreflexia
- irritability
- tremulousness
- feeding intolerance
- excessive wakefulness
65
Fetuses and newborns of drug-abusing mothers are at greater risk of mortality due to what causes?
- obstetric complications like placental abruption
- fetal demise in utero from withdrawal
- perinatal asphyxia
- congenital anomalies
- child abuse and SIDS
66
Esophageal Atresia with Distal Tracheoesophageal Fistula
- the most common TE anomaly
- presents with polyhydramnios in utero
- neonates drool, choke, and vomit at the time of their first feeding; cyanosis can occur secondary to laryngospasm, which occurs to avoid reflux-related aspiration
- the TEF allows air to enter the stomach and duodenum, which can be seen on x-ray; this helps differentiate it from esophageal atresia alone
- often associated with VACTERL defects
67
Congenital Diaphragmatic Hernia
- results from abnormal development of the diaphragm between weeks 5 and 8 of gestation and allows abdominal contents to enter the thorax
- most commonly involves the posterolateral area of the left diaphragm
- presents with scaphoid abdomen; respiratory insufficiency, hypoxemia, and respiratory acidosis from pulmonary hypoplasia; and bowel sounds within the chest
- diagnosis is typically made by ultrasound; CXR will show little or no gas in the abdomen, an absent diaphragmatic dome, significant contralateral mediastinal shift, and bowel loops in the thorax
- should never use bag-and-mask ventilation to treat as this may distend the bowel and increase compression of the lung; instead, intubate and mechanically ventilate while correcting acidosis and hypercarbia until surgical intervention is possible
68
Omphalocele
- results from a disturbance of the midgut's re-entry into the abdomen around week 10 of gestation
- it is a central defect and there is a true hernia sac as the abdominal contents are covered by the peritoneal sac
- frequently associated with other congenital anomalies
69
Gastroschisis
- results from a disturbance of the midgut's re-entry into the abdomen around week 10 of gestation
- it is located in the right paraumbilical area, is not mid-line, and has no true hernia sac
- there is an increased risk of bowel damage from exposure to amniotic fluid, but unlike omphalocele, there is no increased risk for other congenital anomalies
70
What are the three most significant differences between omphalocele and gastroschisis?
- omphaloceles are midline where as gastroschisis is usually located in the right paraumbilical area
- omphalocele has a true hernia sac while gastroschisis does not
- omphaloceles are frequently associated with other congenital anomalies while there is no such risk with gastroschisis
71
Meconium Ileus
- CF leads to an abnormal accumulation of intestinal secretions and to a pancreatic enzyme deficiency, which both increase viscosity of meconium and contribute to an occlusion of the distal ileum
- presents with abdominal distension, lack of meconium passage, and vomiting
- abdominal radiographs reveal distention with minimal air-fluid levels since air remains trapped in the meconium, sometimes giving it a soap-bubble appearance
- treat with enemas to relieve the obstruction
- monitor for complications like intestinal perforation, meconium peritonitis, and volvulus
72
Hirschsprung Disease
- defective relaxation and peristalsis of the rectum and distal sigmoid colon
- due to a congenital failure of ganglion cells (neural crest derived) to descend into the myenteric and submucosal plexuses
- strongly associated with Down syndrome and RET mutations
- clinical features, based on obstruction, include failure to pass meconium, an empty rectal vault of digital exam, megacolon, and bilious emesis
- requires a rectal SUCTION biopsy to sample the two plexuses, which aren't biopsied normally
- treatment involves resection of the involved bowel
73
Necrotizing Enterocolitis
- presents with abdominal distention and tenderness, residual gastric contents, bilious aspirate, bloody stools, abdominal erythema, metabolic acidosis, oliguria, and thrombocytopenia
- radiographs demonstrate abdominal distension, air-fluid levels, thickened bowel walls, pneumatosis intestinal, and venous portal gas
- treat with bowel rest, no PO feeds, gastric decompression, antibiotics, and parenteral nutrition; surgical management is indicated for complicated cases
- late complications include intestinal obstruction, nutritional deficiencies, and cholestasis
74
Neonatal Hypoglycemia
- defined as a glucose level below 45 mg/dL
- may be caused by maternal diabetes, insulin-producing tumors, islet cell hyperplasia (nesidioblastosis), SGA with limited hepatic glycogen stores, prematurity and poorly developed glucokneosis, inborn errors of metabolism, and endocrinopathies
- presents with diaphoresis, jitteriness, feeding problems, tachycardia, hypothermia, hypotonia, and seizures
- screen for using glucometer with a cutoff below 40, but confirm with serum or plasma glucose
- problematic even if asymptomatic because glucose is the brain's primary unit of energy, so it is important to treat even before confirmatory test comes back
- asymptomatic can be breast fed or given pumped breast milk or formula; otherwise, treat with IV dextrose
- monitor until glucose is stable and above 45 mg/dL
75
What are the complications often associated with maternal diabetes?
- various congenital anomalies, including cardiac
- large for gestational age or small for gestational age if there is placental insufficiency secondary to diabetic-induced vascular complications
- visceromegaly
- small left colon syndrome
76
What is small left colon syndrome?
- a potential complication unique to maternal diabetes
| - presents with abdominal distension and failure to pass meconium due to decreased caliber of the left colon
77
Polycythemia
- defined as a central venous hematocrit greater than 65%
- may be caused by increased EPO secondary to placental insufficiency or increased placental transfusion from delayed cord clamping amongst other things
- presents with plethora, poor perfusion, cyanosis, poor feeding, respiratory distress, lethargy, jitteriness, seizures, renal vein thrombosis, and metabolic acidosis
- increases the risk for NEC
- treat with partial exchange transfusion
