(iv) Common clinical factors that aggravate jaundice: (a) Starvation: Insufficient glucose and lack of glucuronide to combine with bilirubin. (B) hypoxia: oxygen is required in bilirubin metabolism. Zheng Chengzhong, Department of Pediatrics, Beijing 306 Hospital (iii) Acidosis: weakening the binding of bilirubin to albumin. (iv) dehydration: blood concentration increases the concentration of bilirubin in the blood. (e) Delayed fetal excretion: increases the enterohepatic circulation of unconjugated bilirubin. (vi) internal bleeding: cranial hematoma, extensive subcutaneous bleeding, etc. increases red blood cell destruction and increases bilirubin production. V. Classification of pathological jaundice: (a) hemolytic jaundice: (b) infectious jaundice: (c) obstructive jaundice (biliary atresia) (d) breast milk jaundice: (e) other: due to genetic metabolic abnormalities caused by hemolytic, impaired secretion or mixed jaundice is rare clinically. Hazards: (a) bilirubin encephalopathy: due to the deposition of unconjugated bilirubin in brain cells, easy to invade the basal nucleus and other brain nuclei, so that the coupling of mitochondrial oxidation is disconnected, energy production is inhibited, and the cells are damaged. The rate of death is high, with 50%-75% of children dying in the acute phase, and 75%-90% of survivors suffering from severe neurological sequelae, which is an important cause of hearing impairment, visual abnormalities, and mental retardation in humans. High risk factors: bilirubin concentration; blood-brain barrier maturity; hypoxia, acidosis; hypoglycemia, hypothermia, infection Clinical stages: warning phase; spastic phase; recovery phase; sequelae (b) Tetralogy of Fallot: tachycardia, oculomotor disorders, hearing impairment, dental enamel hypoplasia Hemolytic jaundice Clinical manifestations: fetal edema, jaundice, anemia, hepatosplenomegaly, nuclear jaundice. Mechanism of occurrence: mother-infant blood group incompatibility → fetal red blood cells enter the mother’s body via the placenta → maternal blood group antibodies re-enter the fetal circulation → fetal red blood cells are destroyed. (Rh, ABO system is the most common). 1, Rh blood group incompatibility combination maternal Rh (-), son Rh (+) maternal Rh (+). Caused by anti-E and anti-C with few first births. 2. ABO blood group incompatibility combination maternal O, offspring A, B or AB. A-B, B-A combination. Can occur in the first child Maternal jaundice Etiology: not yet known, may be related to increased enterohepatic circulation of bilirubin. Diagnosis: There are no laboratory tests to rely on to confirm the diagnosis, other causes of jaundice can be ruled out first. Prognosis: previously considered good, but neurological damage has been reported, but is reversible. Infectious jaundice: Depending on the cause, jaundice appears at different times, with intrauterine infection appearing early and postnatal infection appearing slightly later, but accompanied by various manifestations of infection. Prevention and care of neonatal jaundice: The purpose: to prevent the occurrence of nuclear jaundice. Treatment: first treat the primary disease; test the bilirubin value to determine the treatment; early feeding to reduce enterohepatic circulation. (i) Drug therapy enzyme inducer: phenobarbital, induce glucuronosyltransferase activity in hepatocytes, 5-8 mg/kg/d. Niclosamide, reduce free bilirubin, increase bilirubin binding to white egg: transfusion of plasma 5-10 ml/kg times, or albumin 1.0 g/kg. inhibit hemolysis: intravenous propionic protein: block Fc receptors to inhibit hemolysis, 1 g/kg, 6-8 h. Maintain sedative dose for 8h. Correct acidosis, prevent hypoglycemia and hypothermia. Disable sulfonamides, etc., to reduce free lipid acids competing for binding to albumin. (ii) Principle of phototherapy: unconjugated bilirubin is insoluble in water and forms light isomers after exposure to light, making it easily soluble in water and excreted with bile and urine (phototherapy treats the symptoms but not the root cause). Indications: High unconjugated bilirubinemia of any cause. Indications for bilirubin attainment. Indications to be relaxed with high risk factors for nuclear jaundice. Before and after blood exchange. Methods: Choose blue light wavelength 427-475nm, single or double-sided, intensity should be more than 5μw?cm-2?nm-1, not more than 9μw?cm-2?nm-1. irradiation distance 50~75 torso 40cm, 20-25. several hours intermittent or continuous irradiation is possible. Types: including: blue light irradiation, green light irradiation, incandescent or blue light spotlight, optical fiber phototherapy blanket, light-emitting secondary tube phototherapy device, etc. Side effects of phototherapy: ①Inconspicuous water loss increases during phototherapy, up to 40% in full-term infants. Premature infants can reach 80% to 90%, and generally need to increase rehydration 10-15%. (ii) Most of the children’s blood calcium decreases during phototherapy, the specific mechanism is unclear, and calcium supplements should be given during phototherapy. ③Because the absorption peak of riboflavin is at 450 nm, the breakdown of riboflavin can be caused during phototherapy, so VitB2 should be supplemented during phototherapy. ④Because of the increase of intestinal bile salts and unconjugated bilirubin. It can cause watery diarrhea. ⑤ Skin oxidation reaction to light, prone to rash. ⑥There is a potential risk of eye damage from intense light exposure treatment, and opaque eye shields should be used to protect the eyes to prevent retinal damage. (7) In vitro experiments found that: lower wavelength light source (350~450nm) irradiation can cause DNA damage to cultured cells, so black cloth should be used to cover the scrotum during phototherapy, and green light source can also be used to reduce the potential risk of DNA damage. General care: ① Check whether the eye-mask is loose, do not fix too tight or put pressure. When feeding, remove the eye shield to observe for discharge or conjunctivitis and change the eye shield at least once a day. ②Maintain a constant body temperature of 29℃-32℃ under illumination. ③Arrange the infant to turn over the whole body so that the whole body surface is irradiated, usually once every 2 hours. ④Replenish water and calories, keep urine specific gravity below 1.015, and measure this weight daily. ⑤ Monitor bilirubin concentration: after the cessation of phototherapy, measure serum bilirubin again within 4 hours, because the reduction of jaundice after phototherapy does not reflect serum bilirubin. (vi) Observe and record side effects: drowsiness, dilute green stools, dark urine, increased body temperature, skin changes, dehydration, abdominal distension, etc. (iii) Blood exchange therapy: Indications: confirmed diagnosis of hemolytic disease, cord blood Hb< 120g/L at birth with edema, hepatosplenomegaly, heart failure. Serum bilirubin is severely elevated. Those with symptoms of early bilirubin encephalopathy, regardless of bilirubin level. The indications were relaxed for premature infants and those with severe disease in the previous birth. Methods: For ABO hemolysis, O-type red blood cells plus AB-type plasma are used, and for Rh hemolysis, Rh-negative and ABO blood is used to match the child's blood type. The blood supply was 160 ml/kg through the umbilical vein. (iv) Treatment of breast milk jaundice: Early onset: frequent breastfeeding, 8-10 times/day, bilirubin monitoring, phototherapy up to the indication. Late onset: bilirubin >15mg/dl, stop breast milk for 3-5 days; bilirubin >20mg/dl, phototherapy.