Newborn Hemolytic Screening

Neonatal hemolysis screening is an important check in newborn screening. Neonatal hemolytic disease, also known as fetal erythroblastosis, belongs to the same family of immunological hemolytic anemia, which refers to immune hemolytic anemia caused by blood group antibodies. It is caused by the incompatibility of maternal and child blood types, and it is one of the most common causes of neonatal hyperbilirubinemia, and it has an early onset and rapid progress. In severe cases, it can cause jaundice, so it is a disease worthy of attention. . The incidence rate of the first child accounts for 40% to 50%. Basic Information Specialist classification: cardiovascular examination classification: blood examination Applicable gender: whether men and women apply fasting: fasting Tips: Newborns are difficult to pump, it is best to pump arterial blood. Normal value Due to the large difference in the degree of ABO hemolytic disease, the degree of serum bilirubin is also inconsistent, and serum total bilirubin is more than 1/4 above 342 μmol/L (20 mg/dl). In short, the degree of jaundice in ABO hemolytic disease is relatively mild. The bilirubin value of 86 cases of ABO hemolytic disease was statistically calculated. The average value was (131.7±83.8) μmol/L [(7.7±4.9) mg/dl], and 66 cases of ABO hemolytic disease newborns, the average bilirubin. The value was (126.5 ± 71.8) μmol / L [(7.4 ± 4.2) mg / dl]. In serum bilirubin, the increase in unconjugated bilirubin is dominant. Clinical significance Abnormal result Fetal edema Severe cases of fetal edema, mainly in Rh hemolytic disease, a large number of red blood cells destroyed in the fetal period, children with systemic edema, pale, skin ecchymosis, pleural effusion, ascites, low heart sound, fast heart rate, difficulty breathing, liver and spleen Swollen. The placenta is also obviously edematous, and the ratio of placental weight to neonatal weight can reach 1: (3 to 4). In severe cases, stillbirth can occur. The cause of fetal edema is related to heart failure caused by severe anemia, hypoproteinemia caused by liver dysfunction, and increased capillary permeability secondary to tissue hypoxia. jaundice In children with hemolytic disease, jaundice appears early, and jaundice usually occurs within 24 hours after birth, and it develops rapidly. Serum bilirubin is mainly unconjugated bilirubin. However, there are also a small number of children with a marked increase in bilirubin in the recovery phase of the disease, and a bile-viscosity syndrome. Some ABO hemolytic disease jaundice is milder and similar to physiological jaundice. anemia Children with hemolytic disease have varying degrees of anemia, and Rh hemolytic disease is more obvious. If the blood type antibody persists, hemolysis can continue to occur. The child develops anemia (Hb<80g/L) 3 to 5 weeks after birth, which is called late anemia. It is more common in untransformed and premature infants who have undergone blood transfusion. Liver and splenomegaly Severe cases of extramedullary hematopoiesis, liver and spleen enlargement. Bilirubin encephalopathy Neonatal hemolytic disease can occur bilirubin encephalopathy, full-term bilirubin more than 18mg / dl, premature infant bilirubin more than 12 ~ 15mg / dl should be alert to the occurrence of bilirubin encephalopathy. It begins to manifest as atrophy, sucking reflex and hug reflex, and low muscle tone. It lasts for half a day to one day. If the disease progresses, fever, binocular gaze, increased muscle tone, convulsions, angulation, etc., may be due to respiratory failure. Or lung bleeding died. Newborns and infants with anemia who need to be examined. Precautions Requirements for examination: arterial blood, it is difficult for newborns to smoke, it is best to pump arterial blood, carefully touch, the syringe enters the artery vertically, the blood is bright red, after the blood is drawn, the artery is pressed to prevent bleeding. Inspection process 1, hematological examination: red blood cells and hemoglobin are mostly in the normal range, hemoglobin is only about 5% of 100g / L or less, reticulocytes often increase, heavy cases have nuclear red blood cells up to 10%. The morphology of red blood cells is characterized by the appearance of spherical red blood cells, and the osmotic fragility and autolysis of red blood cell saline are increased. 2, serological examination (1) Determination of bilirubin: Because the degree of ABO hemolytic disease is quite different, the degree of serum bilirubin is also inconsistent, and serum total bilirubin exceeds 342 μmol/L (20 mg/dl) or more and accounts for about 1/4. In short, the degree of jaundice in ABO hemolytic disease is relatively mild. The bilirubin value of 86 cases of AO hemolytic disease was counted. The average value was (131.7±83.8) μmol/L [(7.7±4.9) mg/dl], and 66 cases of BO hemolytic disease newborns, the average bilirubin. The value was (126.5 ± 71.8) μmol / L [(7.4 ± 4.2) mg / dl]. In serum bilirubin, the increase in unconjugated bilirubin is dominant. (2) Antibody assay: The detection of blood group antibodies against its own red blood cells in neonatal red blood cells or serum is the main experimental basis for the diagnosis of ABO hemolytic disease. Three tests are generally performed: the first is the modified Coombs test, which uses the "optimal dilution" of anti-human globulin serum to detect antibodies attached to the erythrocytes of the child, and the second is the antibody release test, which is used. The method of heating is to release the antibodies on the red blood cells of the child, and then check the antibodies in the release solution. Any of these two tests can be diagnosed as ABO hemolytic disease, and the positive rate of antibody release test is higher. The third is the plasma free antibody assay, which is to check the antibody in the serum of the child. If only the free antibody is positive, it only indicates that the patient has antibodies in the body, which does not mean that it has been sensitized, so it can only be suspected as ABO hemolytic disease. Other auxiliary examinations: routine X-ray, B-ultrasound examination, brain CT examination if necessary. Not suitable for the crowd Special diseases: Patients with hematopoietic dysfunction, such as leukemia, various anemia, myelodysplastic syndrome, etc., unless the examination is essential, try to draw less blood. Adverse reactions and risks 1, subcutaneous hemorrhage: due to pressing time less than 5 minutes or blood draw technology is not enough, etc. can cause subcutaneous bleeding. 2, discomfort: the puncture site may appear pain, swelling, tenderness, subcutaneous ecchymosis visible to the naked eye. 3, dizzy or fainting: in the blood draw, due to emotional overstress, fear, reflex caused by vagus nerve excitement, blood pressure decreased, etc. caused by insufficient blood supply to the brain caused by fainting or dizziness. 4. Risk of infection: If you use an unclean needle, you may be at risk of infection.

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