Therapeutic Hypothermia for Hypoxic-Ischaemic Encephalopathy (

8/3/2019 Therapeutic Hypothermia for Hypoxic-Ischaemic Encephalopathy (

1/19

Therapeutic hypothermia forhypoxic-ischaemic

encephalopathy (HIE)


2/19

Moderate or severe HIE

Complicates 1/1000 term live births:

Mortality: >25%

Major neurological sequelae: >25%

Cognitive impairments at school-age, evenwithout neuromotor deficitsAssociated behavioral and educational difficulties


3/19


4/19

Basic sciences

Neuronal death occurs in 2 phases

Severe insult Immediate neuronal death cellular hypoxia

and primary energy failure

Delayed neuronal death occurs at least 6

hours later; allows a therapeutic window


5/19

Basic sciences

Secondary phase accounts for a major

proportion of cell loss

Pathology hyperemia, cytotoxic oedema,mitochondrial failure, accumulation of

cytotoxins, apoptosis, nitric oxide synthesis,

free radical damage

Clinically encephalopathy, increased

seizures activity


6/19

Mechanism of protection by

hypothermia

Survival of cells otherwise destined to die

through apoptosis

Reduced metabolic rate Reduced release of excitatory amino acids

(glutamate, dopamine)

Lower production of nitric oxide and free

radicals


7/19

Methods of cooling newborns

Selective head cooling with mild systemic

hypothermia

Rationale: cool brain more than body Newborn brain produces 70% of total body heat

Minimized adverse effects of systemic cooling

Whole body hypothermia

Rationale: reduce systemic temperature to achievedeep brain cooling Core body temperature and deep brain temperature are similar

Mathematic modeling supports this


8/19

Potential adverse effects of cooling

Heart


9/19

Randomized control trial included

Term or near term newborns


10/19

RCTs intervention

Therapeutic hypothermia (whole body or

selective head cooling)

Or no cooling (standard care)Active (device) and/or passive cooling


11/19

RCTs outcome

Primary Death or long term (>18 months) major

neurodevelopmental disability Secondary

Death, neurodevelopmental disability, CP,neuromotor delay, intellectual impairment,

blindness, deafnessAdverse effects of cooling: CVS, FBC,

coagulation, hypoglycemia, renal, cultureproven sepsis


12/19

Large published RCTs


13/19

Large published RCTs


14/19

Systemic reviews and meta-

analyses

7 reviews published

Cochrane review cooling of newborns with

HIE updated July 2007 Updated to include 12 RCTs and 1504 term

newborns with moderate or severe HIE 7 trials of whole body cooling 5 trials of selective head cooling


15/19


16/19


17/19

Cochrane review summary

When used with strict protocols in tertiary NICUs,

therapeutic hypothermia is beneficial in to near-

term newborns with moderate or severe HIE Cooling reduces mortality and major disability

The benefits of cooling on survival and

neurodevelopment outweigh the short term adverse

effects (sinus bradycardia, thrombocytopenia) Whole body and selective head cooling both effective


18/19

Delivery room resuscitationDelivery room resuscitation

Initiate resuscitation targeted oxygen concentration (21-30%)Initiate resuscitation targeted oxygen concentration (21-30%) Set pulse oximeter pre-ductal immediately after birth.Set pulse oximeter pre-ductal immediately after birth.

Keep SpO2 (90-93%) avoiding hyperoxemia.Keep SpO2 (90-93%) avoiding hyperoxemia.

Avoid hyperventilationAvoid hyperventilation

Set rectal probe for temperature and disconnect radiant heaterSet rectal probe for temperature and disconnect radiant heaterafter resuscitation is accomplished.after resuscitation is accomplished.

Keep rectal temperature between 33.5-34.0C.Keep rectal temperature between 33.5-34.0C.

Perform cord blood gases and repeat as needed in the first 60Perform cord blood gases and repeat as needed in the first 60

min.min. Never correct acid-base status with IVSBNever correct acid-base status with IVSB

Evaluate neurologic status using clinical signs (tone,Evaluate neurologic status using clinical signs (tone,

response, heart rate, breathing) and use aEEG if possible.response, heart rate, breathing) and use aEEG if possible.


19/19

PRENATAL ALERT!

POSTNATAL ASSESSMENT

RESUSCITATION

CALL NEONATAL

TRANSPORT

DISCONNETC RADIANT

HEATERMONITOR

T, GLYCEMIA,

BG, ions,

Ca++, Mg++

AVOID!Hypoglycemia

Hypocalcemia

Hypomagnesemia

Hyperoxia

Hypocapnia

KEEP

TEMPERATURE

DURING TRANSPORT

INICIATE PROTOCOL

IN REFERRAL CENTER

AVOID!

Hypoglycemia

Hypocalcemia

Hypomagnesemia

Hyperoxia

Hypocapnia

Neurologic evaluation

aEEG

MRI

ULTRASOUND

Therapeutic Hypothermia for Hypoxic-Ischaemic Encephalopathy (

Documents

Transcript of Therapeutic Hypothermia for Hypoxic-Ischaemic Encephalopathy (