Topic -physiology of Jaundice in newborn

Patel sohan

3rd course GMF

SEMEY STATE MEDICAL UNIVERSITY

PLAN

• INTRODUCTION• NORMAL PHYSIOLOG• NEW BORN JAUNDICE• TYPE OF JAUNDICE• CAUSE OF JAUNDICE• BREAST FEEDING JAUNDICE

• Incidence Term—60% Preterm—80%• Bilirubin Source – Hb – 75% Non Hb – 25% (Myoglobin)

Normal Physiology• Bilirubin -breakdown of hemoglobin• Unconjugated bilirubin (insoluble in water)

transported to liver- Bound to albumin • Transported into hepatocyte (Ligandin / y-

protein ) & conjugated - With glucuronic acid → now water soluble

• Secreted into bile

Normal Physiology

• Secreted into bile• In ileum & colon, converted to stercobilin • 10-20% (Deconjugated by β glucuronidase)

reabsorbed into portal circulation (Enterohepatic circulation )and re-excreted into bile or into urine by kidneys - urobilinogen

Bilirubin Metabolism

Glucuronyl TransferaseUnconjugated

(Bilirubin Diglucuronide)

NEWBORN JAUNDICE(PHYSIOLOGICAL)

Etiology1. Decreased RBC survival 90 days, increased RBC

vol /Kg, polycythemia of NB2. Poor hepatic uptake due to immature liver-

decreased ligandin or Y- protein3. Poor conjugation due to enzyme deficiency-

UDPG-T activity

NEWBORN JAUNDICE(PHYSIOLOGICAL)

4. Increased enterohepatic circulation due to - High level of intst beta-glucoronidase - delayed colonization by bacteria - Decreased gut motility5.Decreased hepatic excretion of bilirubin

PHYSIOLOGICAL JAUNDICE• Seen both in term and preterms• Self limiting• Develops after 24 hours • Peaks by day 4- 5 in terms and day 7-8

in preterms• Peak levels -12mg/dl in term & 15mg/dl

in preterm• Gradually subsides by 10-14 days • No Treatment necessary

PATHOLOGICAL JAUNDICESuspect if...• Jaundice in first 24 hours

• Rise of >5mg/24 hours or 0.5 mg/dl/hr

• Jaundice beyond physiological limits

• Conjugated bilirubin- >2mg or 20% of total

• Beyond 2 weeks• Signs of underlying illness ++

Pathological Jaundice - Hemolytic causes (unconjugated)

Coombs' test positive

–Rh incompatibility

–ABO incompatibility

Coombs' test negative

–Red blood cell membrane defects

–Red blood cell enzyme defects

–Drugs–Hemoglobinopath

ies–Sepsis

Pathological Jaundice – Defective

Conjugation(unconjugated)• Crigler-Najjar syndrome types 1 and

2 • Gilbert syndrome • Hypothyroidism • Breast milk jaundice

Causes of Jaundice –as per time of onset

Within 24 hrs• HDN—Rh, ABO Incompatibility• IU infections-CMV, HSV, Toxo, Syphilis• RBC Enzyme deficiencies-G-6PD defi, pyruvate kinase deficiency• Drugs—large dose of vit k , syntocin drip, Salicylates, sulphas etc• Hereditary Spherocytosis• Criggler-Najjar syndrome• Alpha thalassemia

24-72 hrs—Physiological Jaundice Exaggerated Physiological Jaundice

(MATERNAL FACTORS)• -Blood type ABO or Rh incompatibility • -Breastfeeding • -Drugs: Diazepam, Oxytocin • -Maternal illness: gestational diabetes

Exaggerated Physiological Jaundice

(neonatal factors)• Birth trauma: cephalohematoma,

cutaneous bruising, instrumented delivery • Drugs: Erythromycin, Chloramphenicol • Immaturity ▪ Birth asphyxia Acidosis ▪ Cretinism

• Hypothermia • Hypoglycemia• Hypothyroidism • Polycythemia

After 72 hrs (within 2 weeks)

• Septicemia• Neonatal Hepatitis, other IU infections• Extra hepatic Biliary atresia• Breast milk jaundice• Metabolic diseases—galactosaemia, CF, alpha-

1 antitrypsin deficiency, hypothyroidism• Hypertrophic Pyloric stenosis

. General exam

• Cramer’s Index1.Face-4-6 mg/dl2.Chest &Upper trunk – 8-10 mg/dl3.Lower abdomen,thigh-12 -14mg/dl4.Forearms &lower legs -15 -18 mg/dl• Palms & sloes->15-20 mg/dl

Flow chart Jaundice >12mg/dl,age <24 hrs

<12mg/dl,age>24 hrs ↓ DCT............................. Negative ↓ ↓Positive Direct bilirubin ↓ >2mg/dlRh, ABO ,Others Hepatitis, TORCH, Sepsis, Biliary obstruction

Negative

Positive

Breast milk jaundice

• Late onset• Due to factors in breast milk –Interfere with

bilirubin conjugation: - Pregnanediol - Free fatty acids - β-glucoronidase• Instead of ↓by 7 days it continues to rise may

go upto 20-30mg/dl by 2nd-3rd wks of age & return to normal by 4-12 wks

Breast feeding jaundice

• Decreased intake of milk leads to increased enterohepatic circulation

• Higher levels on day 4 compared to formula fed babies due decreased intake of milk

References

• Lacture of physiology• Text book of physiology r m bijlani• Text book of physiology- k simbuligam • www.pubmed.com

Thank you for attention