13. Neonatology Flashcards

Question

Describe management: Apenia (5)

Answer 1

* O₂, ventilatory support, maintain normal blood gases * tactile stimulation * correct underlying cause * medications: methylxanthines (caffeine) stimulate the CNS and diaphragm and are used for apnea of prematurity (not in term infants) * if apnea of prematurity is diagnosed, infants should receive cardiorespiratory monitoring in a neonatal intensive care unit

Answer 2

* oozing from the umbilical stump * excessive bleeding from peripheral venipuncture/heel stick sites/IV sites * large caput succedaneum * cephalohematomas (in absence of significant birth trauma) * subgaleal hemorrhage and prolonged bleeding following circumcision

Answer 3

* 4 major categories * increased platelet destruction: maternal ITP or SLE, infection/sepsis, DIC, neonatal alloimmune thrombocytopenia, autoimmune thrombocytopenia * decreased platelet production/function: pancytopenia, bone marrow replacement, Fanconi anemia, Trisomy 13 and 18 * metabolic: congenital thyrotoxicosis, inborn error of metabolism * coagulation factor deficiencies (see _Hematology_, H53): hemophilia A/B, HDNB

Answer 4

* 1 per 4000-5000 live births

Answer 5

* platelet equivalent of Rh disease of the newborn * occurs when mother is negative for HPA and fetus is positive * development of maternal IgG antibodies against HPA antigens on fetal platelets

Answer 6

* petechiae, purpura, thrombocytopenia in otherwise healthy neonate * severe disease can lead to intracranial bleeding

Answer 7

* maternal and paternal platelet typing and identification of platelet alloantibodies

Answer 8

* IVIg to mother prenatally starts in second trimester ± steroids ± fetal platelet transfusions * if transfusion required, use washed maternal platelets or donor HPA negative platelets * treat neonate with IVIg (less effective than platelet transfusions)

Answer 9

* caused by antiplatelet antibodies from maternal immune thrombocytopenic purpura (ITP) or SLE * passive transfer of antibodies across placenta

Answer 10

* similar presentation to neonatal alloimmune thrombocytopenia, but thrombocytopenia usually less severe

Answer 11

* steroids to mother for 10-14 d prior to delivery or IVIg to mother before delivery * treat neonate with IVIg (usually if platelets \<60,000) * transfusion of infant with maternal/donor platelets only in severe cases, as antibodies will destroy transfused platelets

Answer 12

* caused by vitamin K deficiency * factors II, VII, IX, X are vitamin K-dependent, therefore both PT and PTT are abnormal

Answer 13

* neonates at increased risk of vitamin K deficiency due to: * poor transfer of vitamin K across the placenta * insufficient bacterial colonization of colon at birth to synthesize vitamin K * breastfeeding (inadequate vitamin K intake) * additional risk if maternal use of antiepileptics * neonate may present with hematomas, ICH (causing apnea or seizures), internal bleeding, hematuria, bruising, prolonged bleeding (often from mucous membranes, umbilicus, circumcision, and venipunctures)

Answer 14

* vitamin K IM administration at birth to all newborns

Answer 15

* also known as chronic lung disease * clinically defined as O₂ requirement for \>28 d plus persistent need for oxygen and/or ventilatory support at 36 wk corrected GA * damage to developing lungs with prolonged intubation/ventilation, high levels O₂, infections

Answer 16

* CXR findings may demonstrate decreased lung volumes, areas of atelectasis, signs of inflammation, and hyperinflation

Answer 17

* no good treatments * gradual wean from ventilator, optimize nutrition * dexamethasone may help decrease inflammation and encourage weaning, but use of dexamethasone is associated with increased risk of adverse neurodevelopmental outcomes

Answer 18

* chronic respiratory failure may lead to pulmonary HTN, poor growth, and right-sided heart failure * patients with bronchopulmonary dysplasia may continue to have significant impairment and deterioration in lung function late into adolescence * some lung abnormalities may persist into adulthood including airway obstruction, airway hyper- reactivity, and emphysema * associated with increased risk of adverse neurodevelopmental outcomes

Answer 19

* ABGs * elevated CO₂ suggests respiratory cause * hyperoxia test (to distinguish between cardiac and respiratory causes of cyanosis): get baseline PaO₂ in room air, then PaO₂ on 100% O₂ for 10-15 min * PaO₂ \<150 mmHg: suggests cyanotic CHD or possible PPHN (see *Cardiology*, P20) * PaO₂ \>150 mmHg: suggests cyanosis likely due to respiratory or non-cardiac cause * CXR: look for respiratory abnormalities (pneumothorax, respiratory tract malformations, evidence of shunting, pulmonary infiltrates) and cardiac abnormalities (cardiomegaly, abnormalities of the great vessels)

Answer 20

* (secondary to carbon monoxide poisoning) results in impaired binding of oxygen to hemoglobin but does not discolour the blood. * Therefore it may not register on pulse oximetry and cyanosis may not be evident clinically

Answer 21

* typically reads higher on pulse oximetry than the true level of oxyhemoglobin. * Methemoglobin alters the absorption of red light at the two wavelengths that pulse oximetry uses to predict oxygen saturation

Answer 22

* developmental defect of the diaphragm with herniation of abdominal organs into thorax * associated with pulmonary hypoplasia and persistent pulmonary hypertension of newborn (PPHN)

Answer 23

* respiratory distress, cyanosis * scaphoid abdomen and barrel-shaped chest * affected side dull to percussion and breath sounds absent, may hear bowel sounds instead * heart sounds shifted to contralateral side * asymmetric chest movements, trachea deviated away from affected side * may present outside of neonatal period * often associated with other anomalies (cardiovascular, CNS, chromosomal abnormalities) * CXR: bowel loops in thorax (usually left side), displaced mediastinum

Answer 24

* immediate intubation required at birth: DO NOT bag mask ventilate because air will enter stomach and further compress lungs * place large bore orogastric tube to decompress bowel * initial stabilization and management of pulmonary hypoplasia and PPHN if present, hemodynamic support and surgery when stable

Answer 25

* glucose \<2.6 mmol/L

Answer 26

* decreased carbohydrate stores: premature, SGA, RDS, maternal HTN * endocrine: hormonal deficiencies (GH, cortisol, epinephrine), insulin excess (infant of diabetic mother, Beckwith-Wiedemann syndrome/islet cell hyperplasia), HPA axis suppression (panhypopituitarism) * inborn errors of metabolism: fatty acid oxidation defects, galactosemia * miscellaneous: sepsis, hypothermia, polycythemia

Answer 27

* signs often non-specific and subtle: * lethargy * poor feeding * irritability * tremors * apnea * cyanosis * seizures

Answer 28

* identify and monitor infants at risk (pre-feed blood glucose checks) until blood glucose stable and for at least 12 h (for infant of diabetic mother or LGA) or 36 h (if preterm or SGA) * begin oral feeds as soon as possible after birth and ensure regular feeds * if significant and/or symptomatic hypoglycemia, provide glucose IV and titrate according to blood sugar levels * if persistent hypoglycemia or no predisposing cause, send “critical blood work” during an episode of hypoglycemia: ABG, ammonia, β-hydroxybutyrate, cortisol, free fatty acids, GH, insulin, lactate, urine dipstick for ketones

Answer 29

total serum bilirubin \>95th percentile (high risk zone) on Bhutani nomogram in infants \>35 wk GA

Answer 30

* jaundice typically visible at serum bilirubin levels of 85-120 µmol/L * visual assessment is often misleading and should confirm with blood test

Answer 31

Jaundice in the first 24 h of life and conjugated hyperbilirubinemia are always **pathological**

Answer 32

if: * It occurs within 24 h of birth * Conjugated hyperbilirubinemia is present * Unconjugated bilirubin rises rapidly or is excessive for patient’s age and weight * Persistent jaundice lasts beyond 1-2 wk of age

Answer 33

* term infants: onset 3-4 d of life, resolution by 10 d of life * premature infants: higher peak and longer duration

Answer 34

* increased hematocrit and decreased RBC lifespan * immature glucuronyl transferase enzyme system (slow conjugation of bilirubin) * increased enterohepatic circulation

Answer 35

* common: due to a lack of milk production s dehydration s exaggerated physiologic jaundice

Answer 36

* 1 per 200 breastfed infants * glucuronyl transferase inhibitor found in breast milk * onset 7 d of life, peak at 2-3 wk of life, usually resolved by 6 wk

Answer 37

* Ethnic group (e.g. Asian, Indigenous) * Complications during pregnancy (infant of diabetic mother, Rh or ABO incompatibility) * Breastfeeding * Family history/previous child required phototherapy

Answer 38

* Birth trauma (cephalohematoma, ecchymoses) * Prematurity

Answer 39

* Difficulty establishing breastfeeding * Infection (sepsis, hepatitis) * Genetic factors * Polycythemia Drugs * total parenteral nutrition (TPN)

Answer 40

ALWAYS PATHOLOGIC * Hemolytic * Rh or ABO incompatibility * Sepsis * Congenital infection (TORCH) * Severe bruising/hemorrhage

Answer 41

* Physiologic, polycythemia * Dehydration (breastfeeding jaundice) * Hemolysis * G6PD deficiency * Pyruvate kinase deficiency * Spherocytosis * Bruising, hemorrhage, hematoma * Sepsis/congenital infection

Answer 42

* Physiologic ± breastfeeding * Sepsis

Answer 43

* Breast milk jaundice Prolonged physiologic jaundice in preterm * Hypothyroidism * Neonatal hepatitis * Conjugation dysfunction * e.g. Gilbert syndrome, Crigler-Najjar syndrome * Inborn errors of metabolism * e.g. galactosemia * Biliary tract obstruction * e.g. biliary atresia

Answer 44

* unconjugated hyperbilirubinemia * hemolytic workup: CBC, reticulocyte count, blood group (mother and infant), peripheral blood smear, Coombs test * if baby is unwell or has fever: septic workup (CBC and differential, blood and urine cultures ± LP, CXR) * other: G6PD screen (especially in males), TSH * conjugated hyperbilirubinemia must be investigated without delay * consider liver enzymes (AST, ALT), coagulation studies (PT, PTT), serum albumin, ammonia, TSH, TORCH screen, septic workup, galactosemia screen (erythrocyte galactose-1-phosphate uridyltransferase levels), metabolic screen, abdominal U/S, HIDA scan, sweat chloride * predicting occurrence of severe hyperbilirubinemia * measure either TSB or TcB concentration in all infants between 24 h and 72 h of life and plot on appropriate hyperbilirubinemia treatment graph. If infant does not require immediate treatment, results should be plotted on predictive nomogram to determine the risk of progression to severe hyperbilirubinemia and need for repeat measurement (refer to: [http://](http://www.cps.ca/documents/position/hyperbilirubinemia-newborn)[www.cps.ca/documents/position/hyperbilirubinemia-newbor](http://www.cps.ca/documents/position/hyperbilirubinemia-newborn)n)

Answer 45

* to prevent kernicterus * breastfeeding does not usually need to be discontinued, ensure adequate feeds and hydration * lactation consultant support, mother to pump after feeds * treat underlying causes (e.g. sepsis) * phototherapy (blue-green wavelength, not UV light) – standard intensive or multiple intensive protocol depending on severeity of hyperbilirubinemia * insoluble unconjugated bilirubin is converted to excretable form via photoisomerization * serum bilirubin should be monitored during and immediately after therapy (risk of rebound because photoisomerization reversible when phototherapy discontinued) * contraindicated in conjugated hyperbilirubinemia: results in “bronzed” baby * side effects: skin rash, diarrhea, eye damage (eye shield used routinely for prevention), dehydration * use published guidelines and nomogram for initiation of phototherapy * exchange transfusion * indications: high bilirubin levels as per published graphs based on age, weeks gestation * most commonly performed for hemolytic disease and G6PD deficiency * use of IVIg in case of severe hyperbilirubinemia (DAT+) becoming evidence-based practice

Answer 46

* unconjugated bilirubin concentrations exceed albumin binding capacity and bilirubin is deposited in the brain resulting in tissue necrosis and permanent damage (typically basal ganglia or brainstem) * incidence increases as serum bilirubin levels increase above 340 µmol/L * can occur at lower levels in presence of sepsis, meningitis, hemolysis, hypoxia, acidosis, hypothermia, hypoglycemia, and prematurity

Answer 47

* up to 15% of infants have no obvious neurologic symptoms * early stage: lethargy, hypotonia, poor feeding, emesis (bilirubin encephalopathy) * mid stage: hypertonia, high pitched cry, opisthotonic posturing (back arching), bulging fontanelle, seizures, pulmonary hemorrhage * late stage (during first year and beyond) * hypotonia, delayed motor skills, extrapyramidal abnormalities (choreoathetoid CP), gaze palsy, mitral regurgitation, sensorineural hearing loss

Answer 48

* exchange transfusion, IVIg if indicated

Answer 49

* atresia of the extrahepatic bile ducts which leads to cholestasis and increased conjugated bilirubin after the first wk of life * progressive obliterative cholangiopathy

Answer 50

* incidence: 1:10,000-15,000 live births * associated anomalies in 10-35% of cases: situs inversus, congenital heart defects, polysplenia

Answer 51

* dark urine * pale stool * jaundice (persisting for \>2 wk) * abdominal distension * hepatomegaly

Answer 52

* conjugated hyperbilirubinemia, abdominal U/S, operative cholangiogram * HIDA scan (may be bypassed in favour of biopsy if timing of diagnosis is critical) * liver biopsy

Answer 53

* surgical drainage procedure * hepatoportoenterostomy (Kasai procedure; most successful if \<8 wk of age) * two-thirds will eventually require liver transplantation * vitamins A, D, E, and K; diet should be enriched with medium-chain triglycerides to ensure adequate fat ingestion

Answer 54

* intestinal inflammation associated with focal or diffuse ulceration and necrosis * primarily affecting terminal ileum and colon

Answer 55

* affects 1-5% of preterm newborns admitted to NICU

Answer 56

* postulated mechanism of bowel ischemia: * mucosal damage and enteral feeding -\> bacterial growth -\> bowel necrosis/gangrene/perforation

Answer 57

* prematurity (immature defenses) * asphyxia, shock (poor bowel perfusion) * hyperosmolar feeds * enteral feeding with formula (breast milk can be protective) * sepsis

Answer 58

* usually presents at 2-3 wk of age * distended abdomen, diminished bowel sounds, feeding intolerance * increased amount of gastric aspirate/vomitus with bile staining * frank or occult blood in stool * signs of bowel perforation (sepsis, shock, peritonitis, DIC)

Answer 59

* AXR: pneumonitis intestinalis (intramural air is a hallmark of NEC), free air, fixed loops, ileus, thickened bowel wall, portal venous gas * CBC, ABG, lactate, blood culture, electrolytes * high or low WBC, low platelets, hyponatremia, acidosis, hypoxia, hypercapnea

Answer 60

* NPO (7-10 d), vigorous IV fluid resuscitation, decompression with NG tube, supportive therapy * total parenteral nutrition (TPN) * antibiotics (usually ampicillin, gentamicin ± metronidazole if risk of perforation x 7-10 d) * serial AXRs detect early perforation (40% mortality in perforated necrotizing enterocolitis NEC) * peritoneal drain/surgery if perforation * surgical resection of necrotic bowel and surgery for complications (e.g. perforation, strictures)

Answer 61

* persistence of fetal circulation as a result of persistent elevation of pulmonary vascular resistance * classified as primary (absence of risk factors) or secondary

Answer 62

* incidence 1.9/1000 live births

Answer 63

Usually presents within 12 h of birth with severe hypoxemia/cyanosis; may have only mild respiratory distress

Answer 64

* elevated pulmonary pressures cause R -\> L shunt through patent ductus arteriosus, foramen ovale -\> decreased pulmonary blood flow and hypoxemia -\> further pulmonary vasoconstriction

Answer 65

* secondary persistent pulmonary hypertension of newborn: * asphyxia * meconium aspiration syndrome * respiratory distress syndrome RDS * sepsis * pneumonia * structural abnormalities (e.g. diaphragmatic hernia, pulmonary hypoplasia) * more common in term or post-term infants

Answer 66

* measure pre- and post-ductal oxygen levels * hyperoxia test to exclude CHD * ECG (RV strain) * Echo reveals increased pulmonary arterial pressure and a R s L shunt across PDA and patent foramen ovale; also used to rule out other cardiac defects

Answer 67

* maintain good oxygenation (SaO₂ \>95%) in at-risk infants * O₂ given early and tapered slowly, minimize stress and metabolic demands, maintain normal blood gases, circulatory support * mechanical ventilation, high frequency oscillation in a sedated muscle-relaxed infant * nitric oxide, surfactant * extracorporeal membrane oxygenation used in some centres when other therapy fails

Answer 68

* tachypnea: RR \>60/min; tachycardia: HR \>160/min * grunting, subcostal/intercostal indrawing, nasal flaring * duskiness, central cyanosis * decreased air entry, crackles on auscultation

Answer 69

* labs: CBC, blood gas, glucose, blood culture * imaging: CXR * if indicated: ECG, Echo, LP (CSF cell count, culture, and chemistry)

Answer 70

* RDS: * Surfactant deficiency -\> poor lung compliance due to high alveolar surface tension -\> atelectasis -\> ⬇️ surface area for gas exchange-\> hypoxia + acidosis -\> respiratory distress “Hyaline membrane disease” * TTN: * Delayed resorption of fetal lung fluid -\> accumulation of fluid in peribronchial lymphatics and vascular spaces -\> tachypnea “Wet lung syndrome” * MAS: * Meconium is sterile but causes airway obstruction, chemical inflammation, and surfactant inactivation leading to chemical pneumonitis

Answer 71

* RDS: Preterm * TTN: Usually term and late preterm * MAS: Term and post-term

Answer 72

* RDS: * Maternal DM * Preterm delivery * Male sex * low birth weight LBW * Acidosis, sepsis * Hypothermia * Second born twin * TTN: * Maternal DM * Maternal asthma * Male sex * Macrosomia (\>4500 g) * Elective Cesarean section or short labour * Late preterm delivery * MAS: * Meconium-stained amniotic fluid * Post-term delivery

Answer 73

* RDS: * Respiratory distress within first few hours of life, worsens over next 24-72 h * Hypoxia * Cyanosis * TTN: * Tachypnea within the first few hours of life ± retractions, grunting, nasal flaring * Often NO hypoxia or cyanosis * MAS: * Respiratory distress within hours of birth * Small airway obstruction, chemical pneumonitis tachypnea, barrel chest with audible crackles * Hypoxia

Answer 74

* RDS: * Homogenous infiltrates * Air bronchograms * Decreased lung volumes * May resemble pneumonia (GBS) If severe, “white-out” with no differentiation of cardiac border * TTN: * Perihilar infiltrates * “Wet silhouette”; fluid in fissures * MAS: * Hyperinflation * Patchy atelectasis * Patchy and coarse infiltrates 10-20% have pneumothorax

Answer 75

* RDS: * Prenatal corticosteroids (e.g. Celestone® 12 mg q24h x 2 doses) if risk of preterm delivery \<34 wk * Monitor lecithin:sphingomyelin (L/S) ratio with amniocentesis, L/S \>2:1 indicates lung maturity * TTN: * Where possible, avoidance of elective * Cesarean delivery, particularly before 38 wk GA * MAS: * If infant is depressed at birth, intubate and suction below vocal cords * Avoidance of factors associated with in utero passage of meconium (e.g. post term delivery)

Answer 76

* RDS: * Resuscitation * Oxygen * Ventilation * Surfactant (decreases alveolar surface tension, improves lung compliance, and maintains functional residual capacity) * TTN: * Supportive * Oxygen if hypoxic * Ventilator support (e.g. CPAP) IV fluids and NG tube feeds if too tachypneic to feed orally * MAS: * Resuscitation Oxygen Ventilatory support Surfactant * Inhaled nitric oxide Extracorporeal membrane oxygenation for PPHN

Answer 77

* RDS: * TTN: * MAS:

Answer 78

* RDS: In severe prematurity and/or prolonged ventilation, increased risk of bronchopulmonary dysplasia * TTN: * Hypoxemia * Hypercapnea * Acidosis * persistent pulmonary hypertension of newborn (PPHN) * MAS: * Hypoxemia * Hypercapnea * Acidosis * PPHN * Pneumothorax Pneumomediastinum * Chemical pneumonitis Secondary surfactant inhibition * Respiratory failure

Answer 79

* RDS: Dependent on GA at birth and severity of underlying lung disease; long-term risks of chronic lung disease * TTN: Recovery usually expected in 24-72 h * MAS: Dependent on severity, mortality up to 20%

Answer 80

* consider in infants with prolonged (≥18 h) or premature rupture of membranes, maternal fever or other signs and symptoms of chorioamnionitis, or if mother is GBS positive * suspect if infant exhibits respiratory distress, temperature instability, or WBC is low (\<5 x 109/L), elevated (\>30 x 109/L, or left-shifted) * symptoms may be non-specific * CXR: hazy lung and/or distinct infiltrates (may be difficult to differentiate from RDS) * neonates with pneumonia should be admitted to the neonatal ICU (NICU) with blood and CSF cultures and antibiotics for management

Answer 81

* Vertical transmission, 95% present within 24 h after birth * Risk factors: * Maternal infection: UTI, GBS positive, previous child with GBS, sepsis, or meningitis * Maternal fever/leukocytosis/chorioamnionitis * Prolonged rupture of membranes (\>18 h) * Preterm labour * Pathogens: GBS, *E. coli*, *Listeria* are most common Pneumonia more common with early onset sepsis

Answer 82

* Acquired after birth * Most common in preterm infants in NICU (most commonly due to coagulase negative Staphylococcus) * Other pathogens implicated include GBS, anaerobes, *E. coli*, *Klebsiella*

Answer 83

**CHEAP TORCHES** * **C**hicken pox/shingles * **H**epatitis B * **E**pstein-Barr virus **A**IDS (HIV) * **P**arvovirus B19 (erythema infectiosum) * **T**oxoplasmosis * **O**ther * **R**ubella virus **C**ytomegalovirus/Coxsackievirus * **H**SV * **E**very STI * **S**yphilis

Answer 84

* no reliable absolute indicator of occult bacteremia in infants \<3 mo, most specific result has been WBC \<5 * temperature instability (hypo/hyperthermia) * respiratory distress, cyanosis, apnea * tachycardia/bradycardia * lethargy, irritability * poor feeding, vomiting, abdominal distension, diarrhea * hypotonia, seizures, lethargy * jaundice, hepatomegaly, petechiae, purpura

Answer 85

* suspicion of neonatal sepsis requires “full septic workup” * CBC, blood and urine cultures, CXR, ± LP (CSF analysis: cell count, glucose, protein, culture, and PCR for viruses) * LP must be conducted if blood culture is positive due to increased risk of meningitis

Answer 86

* supportive care * IV antibiotics: typically ampicillin + cefotaxime or ampicillin + gentamicin chosen as first-line empiric therapy * choice of antibiotic and duration of treatment dependent on symptoms, culture results, maternal GBS status, local resistance patterns * if meningitis suspected, consider IV ampicillin + cefotaxime ± vancomycin * addition of IV acyclovir if HSV infection suspected

Answer 87

* Vasomotor Response (Cutis Marmorata, Acrocyanosis) * Vernix Caseosa * Congenital Dermal Melanocytosis (‘Mongolian Spots’) * Capillary Hemangioma * Erythema Toxicum * Milia * Transient Pustular Melanosis * Nevus Simplex (Salmon Patch) * Neonatal Acne

Answer 88

## Footnote Transient mottling when exposed to cold; usually normal, particularly if premature

Answer 89

Soft, creamy, white layer covering baby at birth

Answer 90

Slate grey macules over lower back and buttocks (may look like bruises); common in dark skinned infants

Answer 91

Raised red lesion, which increases in size after birth and involutes; 50% resolved by 5 yr, 90% by 9 yr

Answer 92

Yellow-white papules/pustules surrounded by erythema, eosinophils within the lesions; common rash, resolves by 2 wk

Answer 93

Lesions 1-2 mm firm white pearly papules on nasal bridge, cheeks, and palate; self- resolving

Answer 94

Brown macular base with pustules, seen more commonly in African American infants; may be present at birth

Answer 95

* Transient macular vascular malformation of the eyelids and/or neck (“Angel Kiss” or “Stork Bite”) * most lesions disappear by 1 yr of life

Answer 96

* Inflammatory papules and pustules mainly on face * self-resolving usually within 4 mo