Hypoxic Ischaemic Encephalopathy

Question 1

Pathology of hypoxic ischaemic encephalopathy

Answer 1

perinatal asphyxia>hypoxia, hypercapnia, acidosis>decreased CO>decreased brain and tissue perfusion>hypoxic ischaemic injury to brain and other organs

Question 2

Causes of HIE (5)

Answer 2

impaired placental gas exchange:

• prolonged contractions
• placental abruption
• uterine rupture

interrupted umbilical cord flow:

• cord compression
• cord prolapse

foetal compromise:

• anaemia
• IUGR

inadequate maternal placental perfusion:
-maternal hypotension/HTN

failure of cardiorespiratory adaptation at birth

Question 3

Features and prognosis of mild HIE (5)

Answer 3

irritability

staring into eyes

poor feeding

hyperventilation

should make full recovery

Question 4

Features and prognosis of moderate HIE (5)

Answer 4

abnormal tone and movement

poor feeding

may have seizures

if feeding by 2wks, should make full recovery

if problem persists, full recovery unlikely

Question 5

Features and prognosis of severe HIE (6)

Answer 5

no normal spontaneous movements/response to pain

may fluctuate between hypo/hypertonia

seizures: prolonged and refractory

multi-organ failure

30-40% mortality rate

80% will have neurodevelopmental disorders esp. cerebral palsy

(neuronal death can be primary-immediate-or secondary-delayed)

Question 6

Mx of HIE (2)

Answer 6

resuscitate at birth

therapeutic hypothermia

Question 7

Resuscitation of a neonate with HIE (5)

Answer 7

insert IV line +/- arterial line

assess eligibility for therapeutic hypothermia

start cerebral functioning analysis monitoring (like EEG to monitor background activity)

fluid restrict-due to transient renal impairment

check for hypoglycaemia and electrolyte imbalances

Question 8

Criteria for therapeutic hypothermia (4)

Answer 8

A-Term infant >1.8kg and <6hrs old plus:

• APGAR =/<5 or continued need to resuscitate for 10mins
• cord acidosis: pH<7

B-altered level of consciousness plus 1 of:

• hypotonia
• clinical seizures
• abnormal reflexes

If A and B are met then begin CFAM. if this shows abnormal background activity/seizures, then the criteria are met

if A and B are met but CFAM isn’t available then consult w. seniors

Question 9

Process of therapeutic cooling (4)

Answer 9

cool to 34-35 degrees C w/i 6hrs

maintain for 72hrs before warming up

monitor rectal temperature

also monitor via:

• cranial USS
• blood gases
• ventilator

Question 10

Prognosis of HIE w/o cooling (6)

Answer 10

spastic quadriplegia

dyskinetic cerebral palsy

cortical blindness

severely impaired IQ

hearing loss

epilepsy