Kernicterus

Continuing Education Activity

• Definition: Kernicterus, or bilirubin encephalopathy, is neurological damage due to bilirubin, commonly in infants.
• Causes: High levels of unconjugated (indirect) bilirubin (>25 mg/dL) in the blood due to reduced elimination or increased production.
• Mechanism: Lipid-soluble bilirubin crosses the blood-brain barrier, depositing in brain tissue, mainly the basal ganglia.
• Objective: Evaluation and management of kernicterus with interprofessional team coordination.

Objectives

1. Identify the etiology of kernicterus.
2. Outline the evaluation components.
3. Summarize management options.
4. Interprofessional strategies for care improvement.

Introduction

• Occurrence: Seen when unconjugated bilirubin crosses the blood-brain barrier causing deposits in the brain tissue.
• Impact: Leads to neurotoxicity affecting neurologic functions.

Etiology

Increased Production of Bilirubin

• Polycythemia
• Hemolysis: Erythroblastosis fetalis, hemolytic disease, red cell abnormalities, hemoglobinopathies.
• Birth Injuries: Cephalohematoma, hemorrhage.

Decreased Excretion of Bilirubin

• Hypoalbuminemia
• Hereditary Defects: Crigler-Najjar, Gilbert syndrome.
• Biliary System Disruption
• Breast Milk Jaundice

Statistics

• Various causes identified in US registry, yet 43.4% idiopathic cases.

Epidemiology

• Demographics: Predominantly affects children, higher in African Americans, South Asians, and males.
• Risk: More prevalent in preterm infants and certain ethnicities.

Pathophysiology

• Process: Unconjugated bilirubin crosses the blood-brain barrier, damaging brain structures like the globus pallidus and hippocampus.
• Effects: Impairs neuronal function, mitochondrial damage, induces apoptosis.

History and Physical

History

• Onset & Duration: Jaundice onset within 24 hours is pathological.
• Family History: Check for genetic disorders.
• Social & Birth History: Maternal habits and birth injuries.
• Postnatal History: Congenital infections, maternal diabetes.

Physical Examination

• Neurological Signs: Assess consciousness, icterus, and vital signs.
• BIND: Classify as acute and chronic bilirubin encephalopathy.

Evaluation

Hematologic Studies

• Total and direct bilirubin, reticulocyte count, blood type, Coomb test.
• Imaging: Ultrasound, CT, MRI for inconclusive cases.
• Hearing Tests: Brainstem evoked auditory response.

Treatment/Management

• Exchange Transfusion Therapy: Removes bilirubin.
• Phototherapy: Converts bilirubin for excretion.
• IV Immunoglobulins: For blood group incompatibilities.
• Fluid Supplementation: Reduces exchange transfusion needs.

Differential Diagnosis

• Consider: Cerebral palsy, neonatal sepsis, congenital infections.

Pertinent Studies and Ongoing Trials

• Trials on constipation management, prebiotics, enzyme inhibition, and new therapies.

Prognosis

• Outcome: Depends on early detection and management.

Complications

• Hearing loss, extrapyramidal symptoms, visual abnormalities.

Deterrence and Patient Education

• Prevention: Antenatal care, AAP guidelines, parental education.

Enhancing Healthcare Team Outcomes

• Nursing Care: Early detection and intervention.
• Diet: Nutrition intervention as needed.

• References: A comprehensive list of studies and sources provided for further reading.