Hyperbilirubinemia (Neonatal Jaundice) Nursing Care Plans

Hyperbilirubinemia is a high serum bilirubin from hemolysis of RBCs and reabsorption of unconjugated bilirubin from the small intestine. The newborn liver is immature and cannot clear the bile pigments left over from normal postnatal red cell breakdown, so the skin and sclera yellow. The higher the level climbs, the deeper the jaundice and the bigger the risk of neurologic damage. Your job on the floor is to sort benign from dangerous, drive the level down, and protect the brain.

Know the three patterns cold, because timing tells you which one you are dealing with. Physiological jaundice is the most common, unconjugated, shows up after 24 hours of life, and can last through the first week. Pathological jaundice appears in the first 24 hours of life and is the one that scares you: serum bilirubin rising greater than 5 mg/dl/day, conjugated bilirubin levels 20% or more of total, peak levels above the normal range, or clinical jaundice lasting longer than two weeks. Breast milk jaundice starts between the first and third day, peaks by day 5 to 15, and declines by the third week of life.

Most hemolytic disease used to come from Rh incompatibility. Because Rh antibody prevention has been available for almost 50 years, ABO incompatibility is now the more common cause. Either way the mother carries a different blood type than the fetus, builds antibodies against fetal red cells, and drives hemolysis, anemia, and hyperbilirubinemia.

Nursing Care Plans and Management

The plan is straightforward: prevent injury and progression, support and inform the family, hold physiologic homeostasis while bilirubin falls, and head off complications.

Nursing Problem Priorities

Monitor bilirubin levels to gauge severity. Identify the underlying cause to guide treatment. Start and manage phototherapy. Consider exchange transfusion in severe cases. Do a thorough neonatal assessment. Teach parents the causes, the management, the red flags, and the value of followup. Check liver function for contributing disorders, coordinate with pediatric specialists, support breastfeeding to aid bilirubin elimination, and plan long-term followup to confirm resolution.

Nursing Goals

The mother will verbalize the cause, treatment, and possible outcomes, identify signs that need prompt provider notification, and demonstrate appropriate infant care. The neonate will show indirect bilirubin below 12 mg/dl in term infants at three days of age, jaundice resolved by the end of the first week of life, no CNS involvement, an exchange transfusion completed without complications, steadily decreasing serum bilirubin, body temperature and fluid balance within normal limits, intact skin and tissue, and expected interaction patterns.

Nursing Interventions and Actions

1. Patient Education and Health Teaching

Neonatal jaundice is the leading reason newborns get readmitted from home, often at or around day five with extreme hyperbilirubinemia or bilirubin encephalopathy after being discharged as healthy. The peak usually hits when the baby is already home, so detecting severe hyperbilirubinemia and judging whether breastfeeding is working falls largely on the parents and community services. Teach with that in mind.

Assess the family situation and support systems. Parents need guidance through the hospitalization, and the mother is often discharged without her infant, which strains attachment and bonding. Bring her into diapering, bathing, and feeding when she is ready.

Assess what the parents and family already understand. This pinpoints specific needs and lets you correct earlier information, especially around the diagnosis and coping with an unexpected, drawn out recovery.

Give parents written instructions for home phototherapy covering technique, potential problems, and safety precautions. Vague written instructions are a major reason families skip early community followup for jaundice. Spell out the real dangers of hyperbilirubinemia so the reason for followup lands.

Explain home monitoring: periodic recording of the infant's weight, feedings, intake and output, stools, and temperature, plus how to report status. Home phototherapy is recommended only for full-term infants after the first 48 hr of life whose serum bilirubin is between 14 and 18 mg/dl with no rise in direct reacting bilirubin. It keeps mother and infant together and continues care at home.

Explain the types of jaundice, the pathophysiology, and the future implications. Invite questions and reinforce as needed. This corrects misconceptions and eases guilt and fear. Tell parents why their infant needs phototherapy. Risk from the procedure appears minimal as long as the eyes stay covered and the infant does not get dehydrated from increased insensible water loss.

Teach home management of mild or moderate physiological jaundice: more frequent feedings, diffuse sunlight exposure (checking the infant often), and a followup serum testing program. Direct sunlight is contraindicated, because an infant's tender skin burns easily. Even without evidence that phototherapy raises skin cancer risk, apply sunscreen when the infant is in the sun and do followup skin assessments in coming years.

Show the mother how to maintain her milk supply with a breast pump and restart breastfeeding once jaundice forces an interruption. Infants weighing more than 1500 g (3.3 lb) may bottle feed if a small, soft, large-hole nipple is used to cut the effort of sucking. Breast milk can be hand expressed and bottled for a preterm infant.

Teach parents to assess for rising bilirubin: blanch the skin with digital pressure to reveal color, monitor weight, and watch for behavioral changes, especially with early discharge. Check skin, sclera, and mucous membranes. Jaundice that progresses from the face down to the abdomen and feet signals a climbing level and needs reporting.

Give parents a 24-hr emergency number and a contact name, and stress reporting increased jaundice. Early recognition and referral cut the complications of jaundice.

Review the rationale for hospital procedures and changes in bilirubin levels, especially when the neonate stays for treatment while the mother is discharged. Intensive phototherapy with hydration and close bilirubin monitoring has sharply reduced the need for exchange transfusion. Exchange transfusion lowers indirect bilirubin and can prevent heart failure in infants with severe anemia or polycythemia.

Discuss the long-term effects and the need for continued assessment and early intervention. Kernicterus comes from a high bilirubin level spreading into the brain, causing lasting damage: cerebral palsy, intellectual disability, sensory deficits, delayed speech, poor muscle coordination, learning difficulties, enamel hypoplasia or yellowish-green staining of teeth, and even death.

Discuss Rh immune globulin (RhIg) within 72 hours of delivery for an Rh-negative mother with an Rh-positive infant not previously sensitized. RhIg (RhoGAM) halts maternal antibody formation, prevents sensitization, and helps prevent erythroblastosis fetalis in later pregnancies.

Arrange followup serum bilirubin testing at the same lab. Treatment stops once serum bilirubin falls below 14 mg/dl, but recheck in 12 to 24 hr to catch rebound hyperbilirubinemia. Phototherapy prevents a rise but does not fix the underlying cause; if it cannot hold the total serum bilirubin low enough to prevent kernicterus, exchange transfusion may be needed.

Refer to a home phototherapy program when appropriate. Limited support or education may call for visiting nurses to monitor it. The pediatrician bases the referral on the newborn's health, bilirubin levels (generally between 10 to 14 mg/dL), evidence of jaundice, and the family's ability to comply. Parents can use a phototherapy blanket or fiberoptic pad, which lets them hold the infant and reduces eye-damage risk. They keep a daily record of temperature, weight, intake and output, stools, and feedings, keep the infant's eyes covered under the lights to protect the retina, and place a small diaper over the gonad area to shield the ovaries or testes.

2. Preventing Injury and Complications

Mitigating the risks of elevated bilirubin means strict phototherapy protocols, eye protection, vital sign and hydration monitoring, close watch for neurotoxicity or kernicterus, prompt response to concerning symptoms, parent teaching on safe handling, and tight team coordination.

Assess infant and maternal blood group and type. ABO incompatibility affects 20% of all pregnancies, most often when the mother has type O blood and her anti-A and anti-B antibodies cross into fetal circulation, causing RBC agglutination and hemolysis. In Rh-negative women previously sensitized by Rh-positive infants, maternal antibodies cross the placenta, attach to fetal RBCs, and raise the risk of hemolysis.

Assess the infant in daylight to avoid color distortion from artificial light. Most infants do not look jaundiced at birth, because maternal circulation has cleared the rising indirect bilirubin. Progressive jaundice within the first 24 hours of life points to a hemolytic process in both Rh and ABO incompatibility.

Review the infant's condition at birth, noting need for resuscitation, excessive ecchymosis or petechiae, cold stress, asphyxia, or acidosis. Asphyxia and acidosis reduce bilirubin's affinity for albumin, though acidosis from asphyxia is usually corrected soon after birth before significant hyperbilirubinemia develops in preterm infants.

Review intrapartum records for risk factors: low birth weight (LBW), intrauterine growth restriction (IUGR), prematurity, abnormal metabolic processes, vascular injuries, abnormal circulation, sepsis, or polycythemia. Some conditions can reverse the blood-brain barrier and let bound bilirubin separate, raising the risk of CNS involvement.

Inspect the sclera, oral mucosa, and skin (yellowing right after blanching) across body parts. In dark-skinned newborns, check oral mucosa, the posterior hard palate, and conjunctival sacs. The yellow comes from accumulating unconjugated bilirubin and first shows on the face and forehead. Clinical jaundice is evident at bilirubin levels greater than 7 to 8 mg/dl in full-term infants. A yellow underlying pigment may be normal in dark-skinned infants.

Evaluate maternal and prenatal nutrition and watch for neonatal hypoproteinemia, especially in preterm infants. One gram of albumin carries 16 mg of unconjugated bilirubin. Too little albumin leaves more unbound indirect bilirubin to cross the blood-brain barrier. Albumin also buffers acid-base balance.

Note the age at onset and differentiate the type of jaundice. Physiological jaundice appears between the 2nd and 3rd days of life as excess fetal RBCs are hemolyzed and release bilirubin. Breast milk jaundice appears between the 4th and 6th days, affecting only 1% to 2% of breastfed infants, and is thought to involve an enzyme (pregnanediol) that inhibits glucuronyl transferase or free fatty acids that inhibit conjugation. Pathological jaundice appears within the first 24 hr of life and is the most likely to cause kernicterus and bilirubin encephalopathy.

Assess for progression of signs and behavioral changes. Excessive unconjugated bilirubin has an affinity for extravascular tissue, including the basal ganglia. Kernicterus behavior usually shows between the 3rd and 10th days of life and rarely before 36 hours. Classic findings include athetoid cerebral palsy, paralysis of upward gaze, and hearing disorders.

Evaluate for pallor, edema, or hepatosplenomegaly. These can mark hydrops fetalis, Rh incompatibility, and in utero hemolysis. With Rh incompatibility the infant may not look pale at birth, because accelerated red cell production late in gestation partly offsets the destruction. The liver and spleen enlarge from clearing damaged cells. If red cells drop enough, vascular blood turns hypotonic to interstitial fluid and water shifts outward by osmosis, causing extreme edema. Hydrops fetalis means a pathologic fluid collection in two or more fetal cavities.

Assess bilirubin blood levels regularly; phototherapy success is judged by frequent serum measurement. Almost every newborn develops an unconjugated bilirubin above 1.8 mg/dL during the first week of life. Significant jaundice levels off at 14 mg/dL at four days in preterm infants and 17 mg/dL in term infants.

Assess for hypoglycemia. Low glucose forces fat stores to release fatty acids that compete with bilirubin for albumin binding sites. In one report, 70.8% of late preterm and 29.1% of term neonates had at least one morbidity such as jaundice, hypoglycemia, respiratory problems, or sepsis; jaundice requiring phototherapy occurred in 55.1% of late preterm neonates and hypoglycemia in 8.8%.

Start early oral feedings within 4 to 6 hours of birth, especially for breastfed infants. Feeding establishes intestinal flora that reduce bilirubin to urobilinogen, cuts enterohepatic circulation, and clears bilirubin from the bowel by promoting passage of meconium. Delayed enteral feeding limits intestinal motility and bacterial colonization and slows bilirubin clearance.

Keep the infant warm and dry and monitor skin and core temperature often. Cold stress releases fatty acids that compete for albumin binding sites and raise free unbound bilirubin. A neutral thermal environment holds a normal core temperature with minimum oxygen consumption and caloric expenditure. Preterm infants cannot shiver and lie in an extended posture from poor muscle tone.

Apply a transcutaneous jaundice meter. Visual assessment is unreliable, so guidelines recommend screening every newborn at or beyond 35 weeks of gestation by total serum bilirubin (SB) or transcutaneous bilirubin (TcB). TcB measures bilirubin subcutaneously and is not the same value as SB, though current meters are designed to track SB closely.

Discontinue breastfeeding for 24 to 48 hr if indicated, and help the mother pump and reestablish breastfeeding. Formula increases GI motility and excretion of stool and bile pigment, and serum bilirubin starts to fall within 48 hours of stopping breastfeeding. Breast milk beta-glucuronidase can uncouple bilirubin from glucuronic acid and make it available for reabsorption.

Monitor laboratory studies as indicated. See Diagnostic and Laboratory Procedures.

Calculate the plasma bilirubin-albumin binding capacity to judge kernicterus risk and treatment need. When total bilirubin divided by total serum protein is less than 3.7, the kernicterus risk is very low. Risk still depends on degree of prematurity, hypoxia or acidosis, and drugs such as sulfonamides and chloramphenicol.

Start phototherapy per protocol using fluorescent bulbs above the infant or a bili blanket, except for newborns with Rh disease. Phototherapy photooxidizes bilirubin in subcutaneous tissue, raising its water solubility for rapid excretion in stool and urine. Discontinue when the bilirubin level steadily declines to 14 mg/dL.

Administer an enzyme induction agent (phenobarbital, ethanol) when appropriate. Medications are not routine in physiologic neonatal jaundice, but phenobarbital induces hepatic bilirubin metabolism and has been shown to reduce mean serum bilirubin during the first week of life.

Exchange Transfusion

Assist with preparation and administration of exchange transfusion. It treats blood incompatibility by removing roughly 85% of sensitized red cells, lowers indirect bilirubin, and can prevent heart failure in infants with severe anemia or polycythemia. Use O Rh-negative blood even if the infant types positive; Rh-positive or type A or B blood would be destroyed by maternal antibodies in the infant's circulation and the transfusion would fail.

Note the cord condition before transfusion if the umbilical vein is the access. If the cord is dry, apply saline soaks for 30 to 60 min to soften the cord and vein and ease catheter passage. Umbilical vein access is the recommended route, though some reports flag it as relatively high risk.

Verify the infant's and mother's blood type and Rh factor, and the type and Rh of the blood to be exchanged. Exchange transfusions are most often tied to Rh incompatibility, and Rho(D)-positive blood would only worsen hemolysis and raise bilirubin.

Weigh the infant before transfusion and track changes. Adverse events are more frequent in lower gestation, lower birth weight, and sicker infants, who carry multiple comorbidities. Weight gain also flags fluid overload, which can cause respiratory and cardiac complications.

Assess for neurologic changes. Irritability, twitching, convulsions, or seizures signal neurotoxicity. A bilirubin above 20 mg/dL in a term infant, and perhaps as low as 12 mg/dL in a preterm infant, becomes dangerous because bilirubin-induced neurologic dysfunction (BIND) ranges from mild dysfunction to acute bilirubin encephalopathy (ABE) as bilirubin invades brain cells.

Assess for excessive bleeding from the IV site after transfusion. Heparinized blood, or citrated blood without calcium replacement, alters coagulation for 4 to 6 hr and may cause bleeding. Thrombocytopenia occurred in 57.4% of neonates after exchange transfusion, with the platelet count reaching a nadir at 24 hours and full recovery at or after 72 hours.

Monitor venous pressure, pulse, color, and respiratory rate and ease before, during, and after transfusion, and suction as needed. This sets baselines, catches instability such as apnea or cardiac dysrhythmia and arrest, and keeps the airway open. Exchange transfusion carries an estimated 5% morbidity and up to 0.5% mortality; common adverse events are apnea, bradycardia, cyanosis, vasospasm, and hypothermia with metabolic abnormalities. Bradycardia can occur if calcium is injected too fast.

Monitor for electrolyte imbalance: lethargy, seizure activity, apnea, hyperreflexia, bradycardia, or diarrhea. Hypocalcemia and hyperkalemia can develop during and after exchange transfusion. Hypocalcemia is among the most frequent events, with incidence reported from 22.5% to 98%, driven by citrate in the donor blood chelating calcium.

Assess for congenital disease such as other hemolytic disorders and cardiac failure. An infant born with cardiac failure and edema from hemolytic disease needs immediate exchange transfusion with fresh whole blood.

Maintain temperature before, during, and after the procedure; place the infant under a radiant warmer with servomechanism. A warm field through a lengthy procedure prevents energy expenditure, prevents vasospasm, lowers the risk of ventricular fibrillation, and decreases blood viscosity.

Warm the blood before infusion in a blood warmer. Donor blood must be at room temperature or hypothermia results. Use only commercial blood warmers, never hot towels or a radiant warmer, to avoid destroying red cells.

Ensure the blood is fresh (not more than two days old), with heparinized blood preferred. Older blood is more likely to hemolyze and raise bilirubin and carries higher leukocyte-secreted cytokines that raise the risk of non-hemolytic febrile reactions. Heparinized blood is always fresh but must be discarded if not used within 24 hr, and it avoids citrate toxicity.

Avoid overheating the blood. Excess heat promotes hemolysis and potassium release, causing hyperkalemia. Blood should ideally be heated to a body temperature of 37°C (98.6°F); any temperature between 32°C (89.6°F) and 37°C (98.6°F) is acceptable.

Ensure resuscitative equipment is available. Exchange transfusion can cause life-threatening bleeding, sepsis, cardiac arrhythmias, and death, on top of transient hypocalcemia, hyperkalemia, bradycardia, and thrombocytopenia.

Keep the infant NPO for 4 hr before the procedure, or aspirate gastric contents. Pass an oro-nasogastric tube, aspirate the stomach, and leave the tube on free drainage throughout to reduce regurgitation and aspiration risk.

Document events during transfusion, recording blood withdrawn and injected (usually 7 to 20 ml at a time). The total exchanged is about 170 ml/kg of body weight, and a double-volume exchange replaces 75% to 90% of circulating RBCs. It is slow and labor-intensive but remains the definitive treatment to prevent kernicterus.

Administer albumin before transfusion if indicated. It may increase albumin available for bilirubin binding and lower free serum bilirubin, though synthetic albumin is not thought to add binding sites. Because it pulls bilirubin into plasma, albumin invalidates total plasma bilirubin as a measure of neurotoxicity risk.

Administer medications as indicated. See Pharmacologic Management.

Administer antibiotics as indicated to prevent or treat infection. After transfusion, watch the cord site for inflammation that suggests infection.

Assist with intravenous immunoglobulin (IVIG) as indicated. IVIG reduces the need for exchange transfusion in hemolytic disease from Rh or ABO incompatibility, with a number needed to treat of 2.7 to prevent one exchange transfusion. A retrospective review reported an almost 30-times increased risk of necrotizing enterocolitis in late preterm and term infants.

Phototherapy Safety

Note any biliary or intestinal obstruction. Phototherapy is contraindicated here, because the bilirubin photoisomers made in skin and subcutaneous tissue cannot be readily excreted. Accelerated upper mesenteric artery flow after phototherapy may signal mesenteric vascular changes and ischemia, a possible cause of intestinal obstruction in premature infants.

Monitor skin and core temperature every two hours, or more often until stable, and regulate the incubator or isolette. Body temperature swings with light exposure, radiation, and convection, and exposed skin under blue phototherapy often drives those shifts.

Note color and frequency of stools and urine. Frequent, greenish, loose stools and greenish urine show phototherapy is breaking down and excreting bilirubin. Distinguish these photodegradation stools from true diarrhea.

Monitor intake and output and weigh the infant twice a day. Watch for dehydration: reduced urine output, depressed fontanels, dry or warm skin with poor turgor, and sunken eyes. Skin moisture loss rose 26.4% during phototherapy in one study, greatest at the elbow, groin, and back. The infant may sleep longer under phototherapy, so keep a frequent feeding schedule.

Inspect skin and urine for a brownish-black color. A rare side effect, bronze baby syndrome, can appear if conjugated bilirubin levels rise. The pigment changes may last 2 to 4 months and carry no harmful sequelae.

Note deteriorating behavior: lethargy, hypotonia, hypertonicity, or extrapyramidal signs. These can mark bile pigment deposition in the basal ganglia and developing kernicterus. After phototherapy, total free calcium often drops, more so in premature than full-term infants.

Assess for rash and petechiae. Some infants develop petechiae and rashes that fade once phototherapy stops. Petechiae may reflect light-induced thrombocytopenia, so monitor the platelet count closely. A few infants with cholestatic jaundice develop a purpuric rash and bullous eruptions.

Note fussiness, increased crying, and irritability. Infants under phototherapy cry more often than untreated infants, possibly from disrupted circadian rhythm.

Document the lamp type, hours since bulb replacement, and the measured lamp-to-infant distance. Light output decays over time. Position the infant about 18 to 20 in (45 cm) from the source for maximum benefit. A fiberoptic blanket connected to an illuminator lets the infant be wrapped in therapeutic light, held, and fed without interrupting therapy or risking the corneas.

Measure the photon energy of the bulbs (white or blue) with a photometer flush against the infant's abdomen; it should register between 8 and 10 mW/cm2/nm. Blue and special blue light beat white light for breaking down bilirubin but make cyanosis harder to spot. Standard phototherapy is 8 to 10 mW/cm2 per nm and intensive phototherapy is more than 30 mW/cm2 per nm in the 430 to 490 nm band.

Cover the testes and penis of a male infant. Undress the infant except for a diaper to expose maximum skin and shield the ovaries or testes. Phototherapy may affect reproductive and embryonic development through light penetration, with thinner seminiferous tubule diameters reported in animal studies.

Patch closed eyes and inspect them every two hours when patches come off for feedings; check placement often. Retinal damage is a real risk, since light-sensitive retinas absorb blue-light photons readily and prolonged blue light raises retinal cell death. Many centers also use lubricating eye drops.

Cleanse the infant's eyes with sterile or normal saline. Conjunctivitis is more common in infants who wear eye masks for prolonged periods, so clean secretions and surrounding skin with saline cotton balls.

Reposition every two hours for equal skin exposure, to prevent overexposing any one part, and to limit pressure areas.

Wash the perianal area after each stool and inspect for irritation or breakdown. Stools under bilirubin lights are often bright green, loose, and irritating, so early skin care prevents excoriation.

Encourage increased oral fluid intake. Phototherapy raises water loss, so replace water and electrolytes as needed. Conventional phototherapy increases water loss from the body surface; LED phototherapy, now widely used, causes less.

Bring the infant to parents for feedings and encourage stroking, cuddling, eye contact, and talking, plus interaction in the nursery between feedings. This supports attachment that phototherapy separation can delay and helps the infant overcome sensory deprivation. Intermittent phototherapy does not harm photooxidation, and depending on the infant and hospital policy, phototherapy may run alongside rooming-in.

Shield the infant's chest during phototherapy. In one report, 50% of premature infants under phototherapy were diagnosed with patent ductus arteriosus, possibly from blue light penetrating the chest wall and relaxing cardiovascular smooth muscle; appropriate chest shielding may lower that incidence.

3. Pharmacologic Management

10% calcium gluconate. Give 2 to 4 ml after every 100 ml of blood infusion to correct hypocalcemia and reduce cardiac irritability. Giving IV calcium during exchange transfusion is common but still debated, and tetany, convulsions, and death have been reported with adenine-citrate-dextrose (ACD) blood despite IV calcium.

Sodium bicarbonate corrects acidosis. A higher serum pH tracks with higher bicarbonate in freshly CPDA-treated blood, which starts to fall after three days of storage.

Protamine sulfate counteracts the anticoagulant effect of heparinized blood. Use it if overheparinization is suspected during or after transfusion, with extra caution in hemostatically unstable neonates (hemophilia, thrombocytopenia, DIC, or vitamin K deficiency).

Enteral or parenteral fluid as indicated. Fluids cover insensible and intestinal losses and supply nutrients when feedings are withheld during phototherapy for severe hyperbilirubinemia. Increase maintenance fluid by 10 ml/kg/day in premature infants under conventional phototherapy.

4. Diagnostic and Laboratory Procedures

Direct and indirect bilirubin. Direct (conjugated) bilirubin is processed by glucuronyl transferase; indirect (unconjugated) bilirubin runs free in blood or bound to albumin. Indirect bilirubin best predicts kernicterus potential, and levels of 18 to 20 mg/dl in the full-term infant or 13 to 15 mg/dl in preterm or sick infants are significant.

Total serum bilirubin level. Often the only test needed in an infant with moderate jaundice presenting on the typical second or third day of life with no history or findings suggesting a pathologic process.

Direct and indirect Coombs' test on cord blood. A positive indirect Coombs shows antibodies (Rh-positive or anti-A, anti-B) in the mother's and newborn's blood; a positive direct Coombs shows sensitized RBCs in the neonate.

CO2-combining power, reticulocyte count, and peripheral smear. A decrease fits hemolysis. Excess hemolysis raises the reticulocyte count, and the smear identifies abnormal or immature RBCs. The reticulocyte count shows whether anemia comes from inadequate RBC production or accelerated loss.

Hemoglobin and hematocrit (Hb/Hct). Elevated levels (Hb 22 g/dl, Hct 65%) indicate polycythemia from delayed cord clamping, maternal-fetal or twin-to-twin transfusion, maternal diabetes, or chronic intrauterine stress and hypoxia. Hemolysis raises bilirubin, with 1 g of Hb yielding 35 mg of bilirubin. Low Hb (14 mg/dl) may reflect hydrops fetalis or in utero Rh incompatibility causing hemolysis, edema, and pallor.

Total serum protein or serum albumin. Low serum protein (3.0 g/dl) means reduced bilirubin binding. Albumin binds bilirubin 1:1 at the primary high-affinity site, making it a useful adjunct for assessing toxicity risk.

Serum calcium and potassium. Measure urea and electrolytes regularly until stable. Citrate anticoagulant binds calcium and lowers serum calcium, and blood more than two days old releases potassium from RBC breakdown, risking hyperkalemia and cardiac arrest.

Glucose. Check immediately post-procedure, then hourly until stable. Post-exchange glucose rises from high dextrose in donor blood and anticoagulants; watch for rebound hypoglycemia in the early hours even when the 12-hour mean looks normal.

Serum pH. Donor blood pH is typically 6.8 or less. Acidosis follows when blood is not fresh and the infant's liver cannot metabolize citrate, or when donor blood continues anaerobic glycolysis. Low post-exchange potassium coincides with higher serum pH, which shifts potassium into cells.

Platelets and WBCs. Thrombocytopenia during phototherapy has been reported, and a WBC decrease suggests an effect on peripheral lymphocytes. The platelet drop tracks with longer phototherapy duration and lower gestational age.

Riboflavin levels. Blue light absorbs at a wavelength close to bilirubin, so riboflavin breaks down alongside bilirubin during therapy. The resulting riboflavin deficiency impairs erythrocyte hydrogen delivery and glutathione reductase activity, which can worsen hemolysis.