KERNICTERUS MEDICAL CARE TREATMENT
Category: Child Health
Abstract : kernicterus medical care: The cornerstone of management of
hyperbilirubinemia is prevention of neurotoxicity. The definitive method of
removing bilirubin from the blood is via exchange transfusion. This is currently
the indicated approach in the presence of clinical bilirubin encephalopathy when
the bilirubin level has reached dangerous levels despite preventive efforts.
Phototherapy
kernicterus medical care:
The cornerstone of management of
hyperbilirubinemia is prevention of neurotoxicity. The definitive method of
removing bilirubin from the blood is via exchange transfusion. This is currently
the indicated approach in the presence of clinical bilirubin encephalopathy when
the bilirubin level has reached dangerous levels despite preventive efforts.
Phototherapy is the most common method aimed at prevention of bilirubin
toxicity. Current clinical research is evaluating the use of metalloporphyrins
to block bilirubin formation by competing with the enzyme heme
oxygenase.
• Exchange transfusion: This definitive therapy is used to
mechanically remove already-formed bilirubin from the blood. It is indicated
whenever clinical signs of acute bilirubin encephalopathy exist in patients who
present with critically high serum bilirubin (eg, >25 mg/dL) and dehydration
or when the serum bilirubin level continues to rise despite attempts to reduce
it. In the presence of Rh isoimmunization, a cord bilirubin level greater than 5
mg/dL or a rate of rise in serum bilirubin greater than 0.5-1 mg/dL/h has been
shown to be predictive of the ultimate need for exchange transfusion. This
relationship has not been demonstrated in hyperbilirubinemia of other
etiologies. This procedure is not without risk.
o Technique: The
procedure involves removing the baby's native blood and replacing it with CPD
(citrate phosphate dextrose) banked blood that does not contain bilirubin.
Obviously, this must be performed gradually. Using an estimate of 80-90 cc/kg
total blood volume, usually double this amount is removed and replaced
sequentially in 10-15 cc aliquots over several hours. This approach, called a
double volume exchange transfusion, harvests the most efficient amount of
bilirubin from the blood for the amount of intervention and results in a
decrease in total serum bilirubin levels by about 40%. Because of ongoing
pathology and equilibrium between the intravascular and extravascular spaces,
having to repeat the procedure at least once is not uncommon. Using O negative
blood rather than the baby's blood type is important because not all circulating
antibodies may be removed. Packed RBCs resuspended in fresh frozen plasma must
be used for this procedure.
o Risks
This procedure carries both
inherent risks and iatrogenic ones and should be carefully performed. The
reported overall mortality rate is about 3:1000; the risk of significant
morbidity has been reported at about 5:100. In very ill babies, the risks are
higher. One series of 25 ill infants reported a mortality rate of 20%.
Transfusing with banked blood products carries a risk of infection. Currently,
the risk of infection with known pathogens is exceedingly small. However, a risk
of infection with pathogens that have not yet been discovered (ie, most recently
hepatitis C) continues.
During the procedure, continually monitor for
attendant physiologic aberrations, such as hypoglycemia, thrombocytopenia,
hyperkalemia (particularly if the banked blood is older than 5 d), and
hypocalcemia (if ethylenediamine tetra-acetic acid [EDTA] preservative is used
in the banked blood).
Mechanical issues can contribute to the overall
mortality and morbidity of the procedure. The need for central access, catheter-
and infusion-related problems, and human error during infusion are all areas
that can pose potentially significant risk. Since the advent of phototherapy
and obstetric treatment of Rh disease, the need for exchange transfusion has
diminished.
o Indicated bilirubin levels
As mentioned above, no
clear-cut level of bilirubin exists above which encephalopathy is assured and
below which neurologic safety exists. Birthweight, gestational age, and
chronologic age are all important, as are a baby's systemic condition, fluid and
nutritional status, acid-base status, and the presence or absence of known
pathology. In 1994, the American Academy of Pediatrics (AAP) published practice
parameters for the management of hyperbilirubinemia in the healthy term infant.
In this document, the AAP recommended exchange transfusion for serum bilirubin
levels greater than 20-25 mg/dL, depending on the chronologic age of the infant.
Some have criticized these parameters as being too aggressive.
Studies
have reported neurologically normal outcomes in healthy term infants with
histories of serum bilirubin levels as high as 46 mg/dL. However, the recent
resurgence in kernicterus has been reported to occur exclusively in near-term
infants with serum bilirubin levels greater than 30 mg/dL. The level at which to
intervene is a clinical question that remains to be answered. The procedure
should be highly considered in babies with significant risk factors predisposing
for kernicterus (eg, sepsis, acidosis, hemolytic disease) if the bilirubin level
has approached the 20- to 25-mg/dL range.
• Agar: Enteral administration
of agar has been tried in an attempt to decrease the enterohepatic recirculation
of conjugated bilirubin. It has not proved to be clinically useful and may cause
intestinal obstruction.
• Sn-mesoporphyrin: Experimental therapy with
Sn-mesoporphyrin inhibits bilirubin production by interfering with
heme-oxygenase, an essential enzyme in the catabolic pathway of hemoglobin. This
therapy is in clinical trials but has not been approved for use by the Food and
Drug Administration (FDA). Consultations: Obtaining input from a pediatric
neurologist during the acute presentation of bilirubin encephalopathy may be
useful. However, the history and clinical presentation may make the diagnosis
apparent. In the chronic phase, involving neurodevelopmental specialists in the
care and evaluation of the infant is important. Developmental potential can be
maximized by early identification of and intervention for neurologic deficits.
If the patient develops hydrocephalus, consultation with a neurosurgeon is
recommended.
Diet: Depending on the degree of neurologic impairment,
infants or children may have limitations in their ability to eat normally. Diet
and nutrition must be individualized with the help of the neurodevelopmental
team caring for the patient. Activity: Some neurologic deficits typically appear
during the phase of motor skill acquisition by the infant. Motor deficits should
be identified early, and appropriate intervention should be initiated to
maximize the infant's ability in this critical area.
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