Hypoxic Ischemic Encephalopathy

Question 1

HIE

Answer 1

spectrum of neuro impairment associated with high neonatal mortality and neurologic morbidity

HIE = lack of oxygen and substrate delivery to the brain as a result of decreased blood flow which may occur from maternal, uteroplacental, or fetal complications.

Question 2

Causes

Answer 2

maternal cardiac arrest, placental abruption, and fetomaternal hemorrhage

Question 3

Incidence

Answer 3

.5-2 per 1000 live births

MRI is preferred imaging tool

Question 4

Clinical signs

Answer 4

moderate HIE = lethargy, decreased activity level, hypotonia, weak suck, incomplete moro reflex, constricted pupils, bradycardia, and periodic breathing

severe HIE = stupor or coma, no spontaneous activity, decerebrate posturing, flaccid tone, absent moro/suck reflexes, dilated or nonreactive pupils, variable heart rate, apnea

Question 5

Pattern of HIE

Answer 5

2 phases:

1. primary energy failure related to the specific insult, which causes lack of oxygen and glucose
2. Secondary or delayed brain injury phase = occurs some hours later with symptoms evolving over approx 72 hrs and is postulated to be due to delayed cell death
   - - delayed cell death is caused by cellular energy failure, acidosis, neurotoxicity, calcium, and nitric oxide release and accumulation from the early injury phase

Question 6

Treatment

Answer 6

hypothermia of head or whole body

increased risk of stroke