blood-brain barrier
Selective barrier protecting the brain from toxins and infections, immature in newborns affecting drug penetration and infection risk.
Full Definition
The blood-brain barrier (BBB) is a highly selective semipermeable membrane barrier that separates circulating blood from the brain and extracellular fluid in the central nervous system. In neonates, particularly preterm infants, the blood-brain barrier is immature and more permeable than in older children and adults. This immaturity has significant clinical implications: it increases vulnerability to central nervous system infections and allows certain medications and toxins to cross more readily into brain tissue. The increased permeability also contributes to the risk of bilirubin crossing into brain tissue, potentially causing kernicterus. Understanding BBB development is crucial for medication dosing and infection management in neonatal care.
Usage
Usage note: Important concept for understanding medication pharmacokinetics and infection patterns in neonates. Often abbreviated as BBB.
In Context
- "The immature blood-brain barrier in preterm infants increases susceptibility to meningitis." — Infection control protocol
- "Antibiotic selection considered the enhanced blood-brain barrier penetration in neonates." — Pharmacology consultation