Week 12 Flashcards
Physiological jaundice
Usually caused by increased red call mass caused by shortened lifespan of fetal Hgb. Decreased gut motility. Decreased gut flora. Leads to decreased excretion. Hangs around and is reabsorbed. Increased hepatic circulation of bile. Causes increased bili. Book lists causes as: (1) Increased red cell mass in the neonate combined with shortened life span of fetal hemoglobin leads to greater daily production of bilirubin than is seen in the adult. (2) Decreased activity of UDP glucuronyl transferase (UDPGT) that correlates with gestational age, leading to decreased conjugation and excretion of bilirubin. (3) Increased enterohepatic circulation due to lack of intestinal flora, decreased gut motility, and small enteral intake, all of which are seen in the first days of life.
o Bili levels rise around day 3. Decline by day 10-12. Don’t rise much above 5-7 mg/dL.
o Breastfeeding doesn’t need to be stopped. Increase feeds. May supplement with formula to help bili levels decrease (casein hydrolysate formula). This formula helps in a more rapid decline of serum bili. It inhibits the glucuronidase.
Pathological jaundice
Greater than 0.5 mg/dL/hr increase in bili levels. Appearance of jaundice earlier (in 1st 24 hours). Usually over 12 for bili level. Jaundice lasts longer. So, earlier, faster, higher, longer.
Causes of pathological:
Antibody-mediated hemolysis causes: ABO incompatibility, Rh incompatibility. Positive Coombs test indicates antibodies in serum. Antibodies on red blood cells. These can attack the system and cause erythroblastosis in the baby.
Non-antibody hemolysis causes: Changes in shapes of red blood cells such as red cell membrane defects (hereditary spherocytosis, elliptocytosis), red cell enzyme defects (G6PD deficiency, pyruvate kinase deficiency).
Non-hemolysis causes: Bruising, internal hemorrhage, polycythemia.
Indirect (unconjugated) is
bili in the bloodstream (reversibly bound to albumin).
Direct (conjugated) is
bili conjugated with glucuronide. It is water-soluble.
Breastfeeding jaundice
Physiological or pathological. If it persists (more than 3-4 weeks after birth) it is uncommon and is more likely to be pathological. Babies are feeding well and still persists: more serious pathological jaundice.
Signs of bili toxicity
Lethargy, hypotonia, fever, seizures, encephalopathy, poor suck, irritability, high pitched cry, backward arching of neck (retrocollis), opisthotonos (arching of trunk), kernicterus (25-30). Encephalopathy is a sudden toxicity that occurs during the first weeks of life. Kernicterus is chronic and permanent clinical sequelae of bili toxicity (cerebral palsy, auditory dysfunction, dental enamel dysplasia, paralysis of upward gaze, intellectual handicaps).
Risk factors for severe jaundice:
Family history risk factors include: significant hemolytic disease, anemia, inborn errors of metabolism, early/severe jaundice, ethnic or geographic origin associated with hemolytic anemia, hepatobiliary disease, previous sibling who received phototherapy, predischarge TSB or TCB in the high-risk zone. A personal history of these: ABO or Rh incompatibilities in previous pregnancies, sepsis risk for the infant (such as prolonged ROM), macrosomic infant of diabetic mother, cephalohematoma, significant bruising, exclusive BF that is not going well, East Asian race. Risk factors for pathologic jaundice include: appearance of jaundice in first 24 hours of life, rise of bilirubin greater than 0.5 mg/dL/hr, or conjugated bili greater than 2 mg/dL. Early or severe jaundice is esp concerning (first 24-36 hours of life). Early gestational age (35 weeks or earlier). Book states <38 weeks. Maternal age >25 yo. Male sex.
Decreased risk factors of jaundice include
African American, discharged from hospital after 72 hours of life, gestational age at 41 weeks or greater, exclusive breastfeeding that is going well or exclusive bottle feeding (asynch states bottle feeding), TSB or TCB in the low-risk zone.
Nonphysiological/pathological jaundice is
more severe.and requires more in-depth workup and look for risk factors. Most severe is early and severe jaundice. Greater than 0.5 mg/dL/hr rise of bili. Appearance in 1st 24 hours.
Treatment of jaundice
Continue to BF. Add casein hydrolysate formula. Phototherapy. Bilitool.org helps assess risk, interpret levels, and when to start treatment. Tool determines level based on age in hours and bili levels. Total serum bilirubin + hours of life. Tells if in high, intermediate, or low risk zones.
Key points about jaundice
Remember jaundice is observed most often during the 1st week of life in approximately 60% of all term infants. If bili levels rise early and persist long-term, it can be pathological instead of normal, physiological. Why breastfeeding causes jaundice? Starvation. Mechanism: Decreased enteral intake with increased enterohepatic circulation, analogous to starvation jaundice in adults. Note that jaundice may be an important indicator of inadequate breast milk supply or inadequate nursing and should prompt specific inquiries into this possibility.
Rule of thumbs for jaundice
Monitor all infants for jaundice. Use standard protocols. Interpret all levels by infant’s age in hours.
Newborn Weight
The infant may initially lose up to 5-8% of birthweight but should regain it within 10-14 days. Weight loss of 10% or more requires close monitoring and may require further evaluation. Weight gain after the initial loss averages 0.5-1 ounce/day or about 2 pounds/month.
When do you routinely encourage healthy newborns to see primary care provider after discharge?
48-72 hours after hospital discharge (around 3-5 days of age).
