新生儿黄疸(英文)课件

1、Neonatal Jaundice(Hyperbilirubinemia)Neonatal Jaundice(HyperbilirIntroduction All babies develop elevated serum bilirubin (SBR) levels, to a greater or lesser degree, in the first week of life. This is due to: increased production (accelerated RBC breakdown); decreased removal (liver enzyme insuffic

2、iency) Increased reabsorption (enterohepatic circulation). Introduction All babies deveIntroduction 60% of infants become clinically jaundiced in 1st wk Bili levels peak at 35 days in full term infants 1/6 of formula fed infants have bili levels over 12 1/3 of breast fed infants have bili levels ove

3、r 12 Over 80% of all infants with bili levels12.9 mg/dl in the first four days of life are breast fedIntroduction 60% of infants bBilirubin Metabolism derived from the catabolism of proteins that contain heme the most important source is the breakdown of Hb from RBC native bilirubin is relatively in

4、soluble in water at physiologic pH, but it is very lipid soluble bilirubin circulates bound to albumin in equilibrium with its unbound or free fractionthe unbound fraction that readily crosses the blood-brain barrier and results in neurotoxicityBilirubin Metabolism derived fBilirubin Metabolism Bili

5、rubin is made more water-soluble in the liver by conjugation with glucuronic acid to form conjugated or direct-reacting bilirubin, then cleared through the bile into the intestines and out through the feces. Phototherapy works by producing photoisomers of bilirubin that are more water soluble, and t

6、hat can be cleared directly in bile or urine without conjugation in the liver.“enterohepatic circulation”: b-glucuronidase in the gut hydrolysis the conjugated bilirubin into unconjugated bilirubin, and reabsorbed into liverBilirubin Metabolism BilirubinCharacteristics of Neonatal Bilirubin Metaboli

7、sm Increased bilirubin production 8.8mg/kg daily vs 3.8mg/kg in adults Insufficiency of bilirubin transportation acidosis, hypoalbuminemia Immature of liver function lower ingestion (y, z protein); lower UDPGT activity Increased “enterohepatic circulation” lower in gut bacteria; higher b-glucuronida

8、se activityCharacteristics of Neonatal Bi“Physiological” Jaundice Seen in 60% of term infants and over 80% of preterm Serum values reaches maximum at 6mg/dl on 45d in term and 1012mg/dl on 57d in premature infants Jaundice declines gradually, reaching normal values within 2 wks in term, and 34w (12m

9、) in preterm Causes no damage in term infants Up limit for abnormal? Undefined(Term 12mg/dl, or term13, preterm1215mg/dl, or 5mg/dl/day Sustained jaundice (term2w, preterm4w ) Recurrence of jaundice Increased serum conjugated bilirubin (1.52mg/dl) Characteristics of PathologicaPathological Jaundice

10、Infectious diseasesNeonatal hepatitis (Torch infection)Neonatal septicemia Non-infectious diseasesHemolytic diseasesBiliary atresiaBreast milk jaundiceGenetic metabolic diseases: G6PD, a1-antitrypsin, CFDrugs induced: Vitamin K3, K4Pathological Jaundice InfectioBreast Milk JaundiceOccurs infrequentl

11、y (1%), peaks in 23wk, may persist at moderately high levels for 3-4 weeks before declining slowly It is a diagnosis of exclusionIn an otherwise well infant, it is considered a benign condition. If breast feeding stopped, the serum bilirubin usually fallsThe potential harms of stopping breast feedin

12、g would outweigh any risks of a mild or moderate hyperbilirubinaemiaAetiology is unknown, some hormonal in the milk may acting on the infants hepatic metabolism, or enzyme (lipase) facilitating intestinal absorption of bilirubin. Breast Milk JaundiceOccurs infBreast-feeding Jaundice increased biliru

13、bin levels seen during the first week of life in infants who are breast feddue to both caloric deprivation (mostly) and some fluid deprivation (a small part) during the first few days of lifeThe more frequently breast feeding occurs during the first few days, the lower are subsequent bili levelscan

14、be prevented by teaching effective breast-feeding practices and support policiesBreast-feeding Jaundice increaClinical Investigation: Kramers RuleZone12345SBR (mmol/L)100150200250250Cephalocaudal Progression of JaundiceClinical Investigation: KramerClinical Investigation Total SBR conjugated SBR ful

15、l blood count - may reveal spherocytes or septic Group & Direct Coombs test hemolytic jaundice high TSH & low T4 - suspect thyroid disease G6PD screen - male and appropriate ethnic group sepsis screen if indicated galactosaemiaClinical Investigation Total SRhesus isoimmunisation Rh antigen: C, D, E,

16、 c, d, e most common type is RhD Rh (-) refers to D- Rare in un-transfused 1st pregnancy In severe cases fetal anaemia develops, causing congestive cardiac failure (hydrops fetalis) The fetus is protected with placental removal of bilirubin, following rapidly rising SBR after birth Rhesus isoimmunis

17、ation Rh antiABO Incompatibility Most often seen in the setting of mother being group O and the baby being groups A or B Milder that Rhesus disease, rarely affects the fetus Jaundice that becomes apparent on day 1 or 2 Diagnosis with blood groups and direct Coombs Test Responds well to phototherapy

18、Rarely requires exchange transfusion1/5 for ABO, 1/20 for Rh incompatibility will becoming hemolyticABO Incompatibility Most oftenClinical Manifestation Jaundice: within 24h in 77% of Rh, 28% in ABO Anemia Hepatosplenomegaly Bilirubin encephalopathy (Kernicterus)Early (27d): more in preterm, include

19、s hypertonia, lethargy, feeding difficulty, seizures, 1/3 death, bilirubin staining of the basal gangiaLate: Survivors may go on to develop sensorineural hearing loss and cerebral palsy, often with ataxia and choreoathetosis; disorders in eye movement; enamel hypoplasiaClinical Manifestation Jaundic

20、Diagnosis Family history: still birth, abortion, jaundice Parents ABO/Rh typing, antibody Ultrasound for hydrops fetalis Postnatal: jaundice, anemia, neurological symptom Blood type and antibodyDirect Coombs, Antibody release, & Free antibody TestDiagnosis Family history: stilManagement Prenatal: Rh

21、 (-), monitoring antibody, bilirubin, etcTerminate pregnancy when lungs are maturedPlasma transfusion to remove antibodyIntrauterine blood transfusionMaternal use of phenobarbitone to induce enzymeManagement Prenatal: PhototherapyIsomerisation of unconjugated bilirubin Wave length: 427475nm (blue), 510530nm (green)Blue light, green light/day lightProtection of eyes/gonadInvisible water lossSide effects: skin rash, fever, diarrheaBeware of conjugated hyper