Hypothermia's Effect on Hepatitis B Vaccination

Despite the current research on Hypoxic Ischemic Encephalopathy (HIE), and the known effects of hypothermia on acute immune response, the effect of the hypothermia protocol for HIE on the efficacy of the Hepatitis B vaccine is still unknown. We plan to measure anti-hepatitis B surface antibodies at intervals prior, during, and after the primary Hepatitis B vaccine schedule for individuals with HIE to see if there is any effect on efficacy due to the Hypothermia protocol.

Inclusion criteria

• > 34 weeks' gestation at birth as measured by best obstetrical estimates
• > 1500 grams birth weight
• Clinical signs of asphyxia or documented periods of hypoxic ischemia with no cyanotic cardiac malformations and no known congenital infections.
• Documented period of hypoxic ischemia:
• Venous Cord gas pH < 7.0 or initial newborn blood gas pH < 7.1
• Base deficit > 13 on venous cord gas or initial newborn blood gas
• Apgar score < 5 at 10 minutes
• Prolonged, sustained fetal bradycardia (HR <80) for > 15 minutes in utero by doppler or fetal heart rate monitoring
• Need for continued resuscitation after 5 minutes (bag-valve mask ventilation with/or without chest compressions) due to the absence of respiratory effort
• Documented postnatal oxygen saturation < 70% or PaO2 < 35 for > 20 minutes by 2 ABGs, not due to cyanotic heart disease, accompanied by hypotension (mean BP< 35), cardiac arrest with chest compressions, or hemorrhage (requiring 20cc/kg volume replacement)
• Parental willingness for infant to receive Hepatitis B vaccine.

Exclusion criteria

• Positive maternal Hepatitis B status during pregnancy