Bilirubin encephalopathy

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Classification according to ICD-10
P57 Kernicterus
ICD-10 online (WHO version 2019)

Under bilirubin encephalopathy (synonym: kernicterus ) refers to a severe damage to the central nervous system ( CNS ) in newborns caused by an excessive increase of bilirubin in the blood (hyperbilirubinemia).

frequency

In the western world, kernicterus is found in 0.4 to 2.7 cases per 100,000 live births (and after the 34th week of gestation). In some developing countries, however , the incidence is up to 100 times higher.

Cause (pathogenesis)

Unconjugated bilirubin is very soluble in fat, but hardly soluble in water. For this reason it is mainly bound to the blood protein albumin for transport to the liver . However, if the amount of bilirubin exceeds its transport capacity, the excess free bilirubin can cross the blood-brain barrier and penetrate into the core areas of the brain . There it inhibits oxidative phosphorylation processes, which leads to cell death. The so-called basal ganglia (the globus pallidus , putamen and the caudate nucleus ) are particularly badly affected, which is why the term kernicterus was coined. Severe encephalopathy is fatal.

Risk factors

On the one hand, all conditions that are associated with increased bilirubin formation increase the risk of kernicterus. This includes increased blood dissolution ( haemolysis ), in particular Rhesus incompatibility and other blood group incompatibilities. On the other hand, the blood-brain barrier can also be impaired, so that bilirubin can penetrate the brain even at a lower concentration. This is the case, for example, in the case of a lack of oxygen ( hypoxia ), aggravated by the resulting acidosis in the blood, low blood sugar ( hypoglycemia ) or hypothermia ( hypothermia ). Finally, a reduction in the concentration of albumin ( hypoalbuminemia ) leads to less bilirubin being bound in the blood and the relatively increased free bilirubin being able to enter the central nervous system more easily. Drugs that displace bilirubin from protein binding also lead to an increased proportion of free bilirubin. These include ceftriaxone , sulfonamides , furosemide , digoxin, and diazepam .

Congenital glucose-6-phosphate dehydrogenase deficiency also increases the risk of bilirubin neurotoxicity.

Symptoms

Acute bilirubin encephalopathy

Acute symptoms of bilirubin encephalopathy can be divided into three stages. In the initial phase , there is a reluctance to drink, sleepiness, flaccid muscle tension (muscular hypotension) and a sedentary lifestyle. In the intermediate phase there is shrill screaming, increasing clouding of consciousness ( stupor ), irritability and increased muscle tension with overstretching of the neck (retrocollis) and spine ( opisthotonus ). In the advanced phase , the stupor can turn into a coma, muscle tension continues to increase and eventually cramps can occur. A fatal outcome is also possible.

Chronic bilirubin encephalopathy

If the acute phase is survived, central deafness , so-called extrapyramidal motor disorders in the form of an athetoid cerebral palsy and a psychomotor development delay , can develop as the long-term consequences .

therapy

In order to prevent potentially irreversible bilirubin encephalopathy, mature, healthy newborns from 72 hours of age in hyperbilirubinemia with unconjugated bilirubin values ​​above 20 mg / dl are given phototherapy with blue light (425–475 nm). If bilirubin levels are above 30 mg / dl, these children should be given blood exchange transfusions . In the case of special risk factors, therapy must of course start earlier.

literature

Individual evidence

  1. ↑ M. Berns: Hyperbilirubinemia in the mature newborn - limits of intervention. In: Monthly Pediatrics. 2006; 154 (published online on July 22, 2006).
  2. ↑ C. Bührer et al.: Hyperbilirubinemia of the newborn - diagnosis and therapy. AWMF guideline. AWMF, Düsseldorf 2015.