Neonatology, Prematurity, and SIDS

1. Neonatology, Prematurity, and SIDS April 2003 Dr. Kevin Levere Preceptor: Dr. Jeff Plant

2. Objectives • An overview of common complaints seen in the ED during the neonatal period • Fever, resuscitation covered previously • A summary of issues of prematurity that affect the ED physician • A review of SIDS and related issues • Apnea • ALTE • Home monitoring

3. What is a Neonate? • Birth to 28 days old (or one month) • Typical vitals for a neonate born at term • HR 85-205 • RR 30-60 • BP systolic (5th%ile) 60 • Term: >37, <42 weeks GA

4. Fetal to Neonatal Transition • Umbilical ligation initiates dramatic change • Initial respiration • Triggered by hypoxia, acidosis, hypercarbia, external stimuli • PVR falls as lungs expand, PaO2 rises and PaCO2 falls • SVR increases with loss of the low pressure umbilicus • PFO pressed closed; fused closed after months • PDA (shunted 90% of flow from lungs) functionally closes within the first 24hrs; fibroses within weeks • Response to rising PaO2 and falling PaCO2 • Cardiovascular adaptation takes months

5. Transition continued • Rapid fluid shifts, up to 30ml/kg • Particularly absorbed from lung airspace • Weight falls up to 10% from birth • Regains birth weight by 7-10 days • All these transitions occur more slowly and with more difficulty in premature infants

6. Organ immaturity • CNS • Poor thermoregulation, immature brainstem function, incomplete myelination • CVS • Relatively few contractile elements, therefore cardiac output especially rate dependent • Pulmonary • Ongoing alveolar multiplication (to school age) and interstitial development, very compliant chest • Can double adult O2 needs for weight – shorter interval to desaturation

7. Organ immaturity continued • GI • Immature gut motility, liver (drug metabolism); low nutrient stores (glycogen, fat) • GU • Immature renal function (drug metabolism), poor concentrating effect • Hematology • Immunologic immaturity; physiologic anemia typically follows neonatal period • Skin • Large SA, thin, lacking subcutaneous depth

8. What is a Preemie? • Born at <37 weeks GA • Not necessarily IUGR/SGA • LBW < 2500 gm • VLBW < 1500 gm • ELBW < 1000 gm • Prematurity and IUGR both increase neonatal morbidity and mortality

9. Causes of Premature Delivery • Fetal • Distress, multiple gestation, congenital anomalies, hydrops fetalis • Placental • Previa, abruption • Maternal • Preeclampsia, medical illness, infection, drug use, uterine anomalies • Other • PROM, iatrogenic, trauma, polyhydramnios

10. Prematurity • More extreme organ immaturity • Exposes preemies to specific problems • Also similar problems as other neonates • Increased severity or risk • Even more indistinct presentation • Increased incidence of congenital anomalies

11. Prematurity to the ED MD • By 36 weeks GA • Typically develop adequate suck-swallow ability to “feed and grow” at home • The majority have outgrown apnea of prematurity • Thermoregulation is adequate to handle ambient temperatures

12. Prematurity to the ED MD • Significance • They might be discharged • YOU might be the next MD to see them

13. Issues down the road • ICH, PVL, increased HIE • CP, seizures, developmental delay, hydrocephalus • CLD, hypoplasia • Reduced pulmonary reserves, more hypoxia, FTT • Persistent Fetal Circulation • Hypoxic-ischemic insults, FTT • GI incoordination, increased NEC • Strictures, malabsorption, FTT • Increased incidence of SIDS

14. Chronic Lung Disease • Formerly described as BPD • Defined by O2 required after 36 weeks GA • Result of RDS (HMD) • Due to surfactant deficiency • Complications of HMD • Mortality • Much reduced with surfactant • Iatrogenic subglottic stenosis • PFC – hypoxia and acidosis maintain PDA • CLD – mostly in ventilated and oxygenated infants • Incidence not changed by surfactant • Nephrolithiasis – sequela of diuretics and TPN

15. More on CLD • Airway obstruction, hyperactivity and hyperinflation may be demonstrated into adolescence • Preterm infants who do not have BPD are likely to have pulmonary function at school age that is similar to that of healthy term children • Preterm infants who have BPD are significantly more likely to have abnormal pulmonary function at 7 years of age • Gross SJ, et al. Effect of preterm birth on pulmonary function at school age: a prospective controlled study. J Pediatr 1998

16. A bit on PFC • Ongoing R-L shunting via PFO and PDA • Due to PPHN • Results in cyanosis, respiratory distress • Causes • Asphyxia, meconium aspiration, sepsis, HMD, hypoglycemia, polycythemia, pulmonary hypoplasia • Often idiopathic • Therapy • O2, correct pH, permissive mild hypercapnia; inotropes, NO; ECMO (needed in 5-10%) • Prognosis • Related to response of PPHN or associated HIE

17. Delivery Problems • Meconium aspiration • Residual lung problems are rare but include symptomatic cough, wheezing, and persistent hyperinflation for up to 5-10 yr • Prognosis depends on the extent of CNS injury from asphyxia and the presence of associated problems such as pulmonary hypertension

18. Delivery Trauma • Caput succedaneum • Scalp edema, crosses sutures • Cephalohematoma • Subgaleal hematoma • Fracture of clavicle • Peripheral nerve injuries • C5-6 = Erb-Duchenne paralysis • C7-8 = Klumpke paralysis • Prognosis depends on whether neurapraxia or neurotmesis • Facial nerve palsy - hemifacial • DDx central injury (lower 2/3 of face affected) vs agenesis of facial nucleus (Mobius syndrome) – bilateral effect

19. Millions in Pearls

20. Pass the Clearasil

21. Pustulence

22. Red Herring

23. Spot on

24. Skin problems of no concern • Milia • Tiny keratin collections, midline palatal occurrences called Epstein’s pearls • Baby acne • Acne, care of maternal hormones • Pustular melanosis • Present at birth, sterile granulocytic collections that slough, leaving hyperpigmented base • Erythema toxicum • Idiopathic onset day 2-3, eosinophilic collections on a red base, fade over a week • Mongolian spot • Benign patch present from birth, fades over years

25. Hyper Billy • Alert 5 day old boy • Jaundiced from 3rd day of life • Greedy breastfeeding to date • No perinatal risk factors for infection • Family Hx negative • Normal cardiopulmonary exam • Normal fontanelle and tone, symmetric Moro, rooting • Do you call this an emergency?

26. Hyperbilirubinemia • Jaundice (aka icterus) • In neonates at 80-150 micromol/L (60%) • Occurs at low end in preemies, rises slower, lasts longer • Unconjugated bilirubin • Lipid soluble; unbound crosses BBB • Kernicterus – level of risk not strictly known • Conjugated bilirubin • Unbound is renally excreted • Increased if >20% total bilirubin

27. Approach to Neonatal Jaundice

28. Unconjugated Hyperbilirubinemia • Hemolytic disease • Sepsis, UTI • Hereditary or acquired • Decreased hepatic conjugation • Decreased hepatic intake • Breast milk, hypothyroidism • Decreased hepatocellular function • Hepatitis • Physiologic, Crigler-Najjar, Gilbert • Enterohepatic recirculation

29. Phototherapy • Address exacerbating causes • Empiric levels for phototherapy vs exchange transfusion based on risk of kernicterus • Early signs • Lethargy, hypotonia, irritability • Later signs • Posturing, hypertonicity, seizures

30. Conjugated Hyperbilirubinemia • Biliary atresia • Commonest cause of liver failure in pediatrics • CF • Bile/mucous plug ("inspissated bile") • Management • Disease specific • No response to phototherapy or exchange transfusion

31. Early Anemia (first few days) • RBC destruction • Hemolytic • Immune – erythroblastosis fetalis, TORCHS • RBC loss • Transplactental • Hemorrhage vs transfusion • Hemorrhagic disease – “early” or “classic” < 1 week • Vitamin K deficiency, intrapartum anticoagulant and antiepileptic drug use • IVH, liver laceration

32. Later Anemia • Physiologic • Nadir at 8-12 weeks • RBC destruction • Hemolytic • Immune • Congenital (RBC membrane or enzyme anomalies, Hgb) • RBC loss • Iatrogenic • RBC depressed production – rare • Diamond-Blackfan etc.

33. Polycythemia • Hematocrit > 65% • Placental transfusion at delivery • Placental insufficiency in utero • Maternal GDM • Dehydration • Idiopathic • Rehydration • Partial exchange transfusion

34. Thrombocytopenia • Increased consumption • Immune (PLA-1 antibody) • Sepsis, DIC, TORCHS • Vasculopathic (hemangiomas) • Rarely decreased production • TORCHS • Rarely loss • Exchange transfusion

35. Metabolic Emergencies • Hypoglycemia • Neonates tolerate lower glucose concentration in the first few days • Nonspecific result of physiologic stress • Prematurity, sepsis, asphyxia, polycythemia • Specific result of metabolic disorders • Galactosemia, glycogen storage disease, AA disorders, mitochondrial disease • Hyperinsulinemia • GDM mother, Beckwith-Wiedemann Syndrome

36. Hypoglycemia • Manifestation • Lethargy, jitteriness, seizure, apnea • Management • Acute treatment • 0.25-0.5 gm/kg, e.g. 2.5-5 ml/kg D10W • Glucagon 0.025 mg/kg IM (max 1 mg) • Little role since lack of stores, especially if SGA • Maintenance goal • 4-6 mg/kg/min (hence D10W, not D5W) • Address underlying cause

37. Metabolic Emergencies • Hypocalcemia • Early (<72 hours) • Preemies • DiGeorge Syndrome • Infants of GDM mothers • Birth asphyxia • Late (end of first week) • High PO4 containing formulas • Hypomagnesemia • Hypoparathyroidism

38. Hypocalcemia • Manifestation • Lethargy, jitteriness, seizure, laryngospasm, tetany; prolonged QTc • Management • Acute treatment • Ca gluconate (10%) • 1-3 ml/kg, 1ml/minute lest bradycardia • Address underlying cause

39. Metabolic Emergencies • Hyponatremia and hyperkalemia • Think congenital adrenal hyperplasia • Look for female virilization • Salt-wasting crisis can occur as neonate • DDx • Gastroenteritis • Pyloric stenosis • Hypochloremic metabolic alkalosis • +/- hyponatremia • +/- hypokalemia

40. CAH • Management • ABCD’s • Work-up • Serum cortisol, aldosterone, 17-OHP • Glucocorticoid and mineralocorticoid replacement • 2 mg/m2 Dexamethasone vs 100 mg/m2 Hydrocortisone • Admit

41. Vomiting • Causes • Infection • Gastroenteritis, NEC, septicemia, meningitis, and urinary tract infections • Milk allergy • Obstruction (if bile, think volvulus) • Congenital anomalies (e.g. CDH, malrotation) • Metabolic • Adrenal hyperplasia of the salt-losing variety, galactosemia, hyperammonemias, organic acidemias • Increased intracranial pressure

42. Constipation • 90% pass meconium in the 1st 24hrs of life • If not, or if constipation during neonatal period • Hirschsprung’s • CF • Hypothyroidism • Anal stenosis

43. Neonatal Seizures • Atypical manifestation • Immature cortical organization and myelination • Focal seizures with general insult • Electroclinical dissociation common • Common subtle presentations • Lip smacking/chewing • Pedaling • Eye deviation • HR changes

44. Perinatal Causes • HIE • Hemorrhage • Intraventricular vs subarachnoid • Infection • TORCHS included • Metabolic • Hypoglycemia, hypocalcemia, hyponatremia • Pyridoxine deficiency • Cerebral malformation • Trauma • Drug withdrawal

45. Management • ABCD’s • FSWU • CBCd, C+S (blood, urine, CSF), CXR • Metabolic screen • Blood pH, Ca, PO4, sugar, electrolytes, renal function, NH3 • CNS imaging • Address abnormalities • Benzodiazepines usually effective • Phenobarbital, phenytoin second line

46. Lessa G • 2 week old girl born at term • Lethargic • No symptoms • No signs until Neuro exam • Babinksi present • Is this significant?

47. Lethargy • Top of differential? • Infection • Neurologic injury or anomaly • Metabolic disorder

48. The Misfits • T—Trauma/non accidental trauma • H—Heart disease (congenital)/Hypovolemia • E—Electrolyte disturbances • M—Metabolic disturbances • I—Inborn errors of metabolism • S—Sepsis • F—Formula dilution or over concentration • I—Intestinal catastrophes • T—Toxins (home remedies) • S—Seizures/CNS abnormalities

49. Lethargy • Critically ill until proven otherwise • ABCD’s • FSWU • CBCd, C+S (blood, urine, CSF), CXR • Metabolic screen • Blood pH, Ca, PO4, sugar, electrolytes, renal function, NH3

50. Last etiology to R/O – Sepsis • Treatment of sepsis empiric • GBS, E.coli, Listeria • Staph, Strep • Amp and Gent vs Amp and Cefotax • TORCH • Treatment not always possible • Avoidance sometimes is