Kernicterus
Kernicterus is a chronic neurological disease caused by the neurotoxic effects of bilirubin on neonatal brain tissue. This happens when bilirubin, a byproduct of the breakdown of red blood cells, is abnormally high in the newborn’s body. Kernicterus is preventable because jaundice (the term used to describe the clinical manifestations of yellow skin and the sclera of the eye) can be treated. In addition, risk factors for developing this devastating neurological disorder can be identified, and serum total bilirubin levels should be closely monitored in an infant at risk of developing one of the acute clinical stages of neurological impairment, including the following complex sign. Bilirubin-induced neurological dysfunction.
Kernicterus is a relatively rare cause of lifelong severe disability in otherwise normal infants, but it is preventable. Severe or extreme levels of bilirubin in serum can lead to encephalopathy, and bilirubin has long been thought to be a neurotoxin that causes brain cell death and destruction.
acute bilirubin encephalopathy
Acute bilirubin encephalopathy is characterized by elevated bilirubin across the blood-brain barrier. Once clinically diagnosed, symptoms range widely and include feeding problems, lethargy, hypotonia or hypertonia, opistonia, fever, seizures, loud crying, and spastic torticollis.
Acute bilirubin encephalopathy has three clinical stages, each with distinct features. The first stage occurs a few days after birth and symptoms include coma, hypotonia, and poor sucking. The second stage is characterized by hypertonia, an arching of the torso (reverse arching of the horns) or a posterior arching, that is, the neck arching back. Babies who reach this stage develop chronic bilirubin encephalopathy. The third stage occurs after a week and the hypertonia disappears. Muscle stiffness, upward gaze paralysis, periodic ocular crises, prominent end-stage respiratory irregularities. In this third stage, 4% of affected infants die.
chronic bilirubin encephalopathy
Chronic bilirubin encephalopathy is also known as kernicterus. The term refers to lifelong disability due to neurological dysfunction caused by bilirubin. Kernicterus is characterized by poor feeding in the first year. A high-pitched cry is another characteristic of kernicterus.
Babies with kernicterus have hypotonia but retain good deep tendon reflexes. Tonic neck reflex and righting reflex are present. Motor skills are delayed, and some children can walk by age 5.
In the first year of life, prominent clinical features of children with chronic bilirubin encephalopathy include extrapyramidal disorders such as tremor, dysarthria, athetosis, and shell shock. Damage to the cochlear nucleus in the brainstem results in hearing loss, and there is often limitation of upward gaze. Athetosis usually occurs between 18 months and 8 years of age. Some children have only hearing loss and no other symptoms.
Imaging studies in the diagnosis of kernicterus
When kernicterus is checked, high serum bilirubin levels are present in most cases. The most useful imaging test is MRI. In magnetic resonance imaging, the signal intensity in the globus pallidus is usually increased.
How common is kernicterus?
In the United States, there is a voluntary kernicterus registry, with 90 cases reported from 1984 to 2001. Since not all cases are reported, the true incidence is not known.
Kernicterus is preventable
Kernicterus is very preventable when closely monitored and aggressively treated in high-risk infants. However, if left untreated, jaundice caused by elevated bilirubin can lead to permanent brain damage, which may result in cerebral palsy, enamel hypoplasia, and mental retardation in some children. Unfortunately, while neonatal jaundice is common, extreme hyperbilirubinemia is uncommon, and the evaluation of this condition is often inadequate.
Recommendations by JCAHO in its 2001 Sentinal Event Alert
JCAHO is the Joint Commission on Accreditation of Medical Institutions, and in April 2001, they issued a “Sentinel Incident Alert” on Kernicterus. They compiled a root cause analysis and identified four patient care processes that failed in the cases that led to the development of kernicterus. These include:
– Patient assessment
– Continuing care
– Patient and family education
– treat
Regarding patient assessment, the JCAHO noted the failure to measure bilirubin levels in infants with jaundice within the first 24 hours, the failure to identify jaundice or its severity based on visual assessment, and the unreliable visual assessment of jaundice in dark-skinned neonates. In the case of discharge before 48 hours and no follow-up within 1 to 2 days, continuous care is insufficient, especially for infants less than 38 weeks’ gestation. Failure to perform early follow-up and physical assessment of infants with jaundice prior to discharge, and failure to provide ongoing lactation support to maintain adequate intake of breastfed neonates were also identified as problems in the continuum of care. Inadequate patient and family education was found when parents were not provided with appropriate information about jaundice, and when physicians failed to respond to parental concerns about jaundiced newborns, lactation problems, or changes in newborn activity and behavior. Treatment failure was due to failure to identify, assess, and treat rapidly rising total bilirubin levels, as well as failure to aggressively and rapidly treat severe hyperbilirubinemia with intensive phototherapy or exchange transfusion.
Recommendations from the American Academy of Pediatrics
The Clinical Practice Guideline Management of Neonatal Hyperbilirubinemia at 35 Weeks of Pregnancy or More was published in Pediatrics in 2004, with key recommendations including support for successful breastfeeding, establishment of hyperbilirubinemia in the nursery identification and assessment protocols, measuring total serum bilirubin or transcutaneous bilirubin levels in infants with jaundice within 24 hours of life, and recognizing that visual assessment is inadequate. In addition, the college recommends the use of a nomogram to interpret all bilirubin levels, which allows interpretation based on hours of life, and that infants born before 38 weeks of gestation are at higher risk for severe hyperbilirubinemia, and Those infants with severe hyperbilirubinemia who are breastfed are at higher risk. The college recommends that all infants be systematically evaluated before discharge to determine the risk of severe hyperbilirubinemia and provide parents with written and verbal information about neonatal jaundice. Follow-up and risk assessment should be arranged at the time of discharge. When there are obvious indications for treatment, phototherapy or exchange transfusion should be performed on the neonate in time.
in conclusion
Adherence to these clinical practice guidelines can prevent lifelong disability, and although kernicterus is relatively rare, neonatal jaundice is common and should be thoroughly evaluated based on risk factors and measurements of serum total or transcutaneous bilirubin. Prompt treatment is essential.