Hypoxic-ischaemic encephalopathy (HIE)

Overview

Brain injury from a perinatal hypoxic-ischaemic insult (birth asphyxia) in the TERM infant — from cord/placental problems, shoulder dystocia, etc. Presents with a depressed, encephalopathic newborn (poor tone, poor feeding, reduced consciousness, seizures). Graded (Sarnat I-III). THERAPEUTIC HYPOTHERMIA (cooling) within 6 hours of birth is the key neuroprotective treatment for moderate-severe HIE.

Recognise

• Term infant after a sentinel hypoxic event: low Apgars, needing resuscitation, cord/early blood gas with metabolic acidosis
• Encephalopathy: altered tone/consciousness, poor feeding, abnormal primitive reflexes, SEIZURES (Sarnat staging I mild → III severe)
• Multi-organ effects (renal, hepatic, cardiac); MRI later for prognosis

Differentials & how to tell them apart

Investigations

Cord/early blood gas (metabolic acidosis), Apgars, clinical Sarnat staging; aEEG/EEG (seizures); MRI brain (prognosis); monitor organ function.

Management

Therapeutic hypothermia (within 6 h) for moderate-severe HIE + supportive care

1. 1Recognise the encephalopathic term infant after a hypoxic event; stage severity. Start THERAPEUTIC HYPOTHERMIA within 6 hours for moderate-severe HIE; supportive intensive care, treat seizures, exclude sepsis.Gate: Cooling must begin within the 6-HOUR therapeutic window to be neuroprotective — recognise and refer promptly; cover for sepsis (a mimic) and manage seizures/multi-organ effects
2. 272 hours of cooling then rewarming; MRI for prognosis; neurodevelopmental follow-up; family support.

Monitor & prognosis

Sarnat stage, aEEG/seizures, organ function; MRI.

Cooling improves outcome; severe HIE has high morbidity.