Hypoxic-Ischemic Encephalopathy rev1.pptx

1. Hypothermia Therapy in
Hypoxic-Ischemic Encephalopathy
Ramadan Abouelhassan Mahmoud
Assistant Prof of Pediatrics and Neonatology
Sohag University
Egypt

2. Hypoxic-Ischemic Encephalopathy
• Hypoxic ischemic encephalopathy (HIE) is a type of brain dysfunction
that occurs when the brain doesn't receive enough oxygen or blood
flow for a period of time.
• Hypoxic means not enough oxygen;
• Anoxia no oxygen delivered to the tissue
• Ischemic means not enough blood flow; and
• Encephalopathy means brain disorder.

3. The incidence of HIE
• The incidence of HIE is 1.5 per 1000 live births in developed countries
and varies between 2.3-26.5 per 1000 live births in developing
countries

4. Guidelines from for diagnosis of HIE
• History of a sentinel event, e.g. abruption or uterine rupture.
• History of fetal/intrapartum distress or acidosis.
• Profound metabolic or mixed acidemia (pH < 7) in an umbilical artery blood sample, if obtained or
Capillary, arterial, BG within 1 hours. (?7.1)
• Persistence of an Apgar score of less than 5 at 10 minutes.
• The need for positive pressure ventilation more than 10 minutes.
• Symptoms or signs of encephalopathy (eg, seizures, coma, hypotonia).
• Multiple organ involvements (e.g, kidney, lungs, liver, heart, intestines).
• Exclusion of other likely causes of encephalopathy.
• Neonatal neurologic sequelae.

6. the modified Sarnat scoring system
• In scoring system described below, from 0 to and a maximum score is
22 which signifies the worst possible status of HIE.
• a score of 0 is normal Infants
• a score of 1–10 are considered to have mild HIE,
• a score of 11–14 have moderate HIE and
• a score of 15–22 are considered to have severe HIE.

7. Online assess the degree using Sarnate Score
• https://www.cpqcc.org/resources/hie-calculator-cool-tool

8. • NB: When prognosis very poor as in following conditions:
• ∙ need for prolonged resuscitation at birth.
• ∙ evidence of severe asphyxia
• ∙ multi-organ failure
• ∙ intractable seizures

9. Management of HIE
• HYPOTHERMIA THERAPY
• ADJUVANT TREATMENT

10. How does therapeutic hypothermia work?
Lowering the body's temperature slows the metabolic rate and allows cells
more time to recover from neurological damage.

11. HYPOTHERMIA THERAPY
Criteria A
• At least ONE of the following:
• Apgar score ≤5 at 10 min after birth.
• Continued need for resuscitation, including endotracheal or mask
ventilation at 10 min after birth (does not include those receiving PEEP or
CPAP alone).
• Acidosis ≤ 7.0 in umbilical cord blood gas or any blood gas sample
(arterial, venous, or capillary) within 60 min of birth.
• Base deficit ≥16 mmol/L in in umbilical cord blood gas or any blood gas
sample (arterial, venous, or capillary) within 60 min of birth.

12. HYPOTHERMIA THERAPY
Criteria B
• Moderate-to-severe encephalopathy (according to Sarnate Stage) ,
consisting of :
• altered state of consciousness (lethargy, stupor, or coma)
• AND at least one of the following:
• ∙ hypotonia.
• ∙ abnormal reflexes including oculomotor or pupillary abnormalities.
• ∙ absent or weak suck.
• ∙ clinical seizures.
Criteria C
• abnormal aEEG if available

13. NB: Neonatal encephalopathy evolves with time, so babies who meet
Criterion A but are neurologically normal at the time of assessment
should be reassessed several times during the first 6 hours of life.

14. Exclusion Criteria:
• Birth weight less than 1800 g
• Gestational age less than 35 weeks
• Inability to initiate cooling by 6 h of age
• Suspected coagulopathy
• Life-threatening abnormalities of the cardiovascular or respiratory systems
such as complex congenital heart disease and persistent pulmonary
hypertension of the newborn (PPHN)
• Major congenital malformations, imperforate anus, suspected
neuromuscular disorders, or presence of known lethal chromosomal
anomaly
• Death appears inevitable

15. Cooling Mild HIE
• A meta-analysis of infants with mild HIE who had received
hypothermia compared with those who were not cooled in
randomized and quasi-RCTs noted that current evidence was
insufficient to recommend cooling for infants with mild HIE and
significant benefits or harm could not be excluded.
Is It Time for a Randomized Controlled Trial of Hypothermia for Mild Hypoxic-Ischemic
Encephalopathy?
Sanjay Chawla, MD, Sara V. Bates, MD, Seetha Shankaran, MD
Published:January 14, 2020, DOI:https://doi.org/10.1016/j.jpeds.2019.11.030

16. Passive cooling with cooling mattress
• By switching off overhead heater and active heating in incubator.
• If baby nursed in an incubator, open portholes.
• Nurse baby naked apart from a nappy.
• Use servo controlled total body cooling mattress (if available).
• Use fans or gloves filled with cold water only if continuous rectal
temperature monitoring is in place.
• Never use ice filled gloves to cool a baby as this can bring the
temperature down to dangerously low and uncontrolled levels.

17. Active cooling with cooling mattress
Obtain the following labs before start cooling at zero time
• CBC,
• RFT,
• LFT, Glucose,
• Coagulation tests ( PT, PTT, INR),
• CBG with Lactate.
• Insert Central line UVC.
• CBC, LFT, Bilirubin and Coagulation test's daily.
• Blood glucose every 6hours

18. Active cooling with cooling mattress
• Place continuous rectal temperature probe under supervision of
medical providers
• Place cardio-respiratory leads on the infant.
• Document time when cooling was initiated on Neonatal
Body Cooling Worksheet. This will serve as hour 0.
• Cooling will continue for 72 hours.

19. Active cooling with cooling mattress
• Desired temperature of the infant is 33.5 C.
• Target rectal temperature 33–34°C
• Vital signs monitoring during procedures
• Note: Shivering is not unusual in these infants. Medications will not be
used to stop the shivering.
• Heart Rate, Blood Pressure, Respirations
• Lower limit of HR monitor changed to 90 bpm will be tolerated as long as
the infant has a normal sinus rhythm, stable BP and saturation.
• Record measurements Vital sign hourly in the first 6 hours of cooling then
every 3hours.

20. Expectations During Body Cooling
a. Decreased heart rate.
b. Increased blood pressure initially due to increases in peripheral vasoconstriction.
c. Increased in urine output initially due to shunting of blood to the internal organs, cold, and diuresis
d. Decreased in platelet count, Calcium, Magnesium, Phosphorus and Potassium.
e. Labile glucose due to relative insulin resistance decreased metabolic rate, and shivering.
During Rewarming expect:
• a. Increased in heart rate.
• b. Decreased in blood pressure due to decreased in peripheral vascular resistance.
• c. Decreased in urine output due to increases in third spacing and shunting of blood to the periphery.
• d. Electrolytes shifts, as renal and liver clearance rate changes.
Active cooling with cooling mattress

21. Sedation during cooling therapy
• Morphine represents current standard of care with a history of
utilization and extensive pharmacokinetic data to guide safe and
effective dosing. 20 microgram/kg/hr and the aim for heart rate is
100 bpm
• Fentanyl 2 microgram/kg/hr is used in neonatal care for severe
procedural pain and prolonged pain and during mechanical
ventilation
• Paracetamol 10 mg/kg/dose every 6 hours… is a non-opioid, central-
acting analgesic used in the treatment of mild to moderate pain in
neonatal care

22. ADJUVANT TREATMENT
Fluid balance
• Restrict total fluids to 50 mL/kg/day initially
• Asphyxiated babies are at increased risk of hypocalcaemia, so regular check
for total and ionised ca levels
• Treat with calcium gluconate when serum corrected calcium <1.7 mmol/L
or if ionized calcium <0.8 mmol/L.
• Maintain serum magnesium >1 mmol/L.
• Keep glucose within normal range (target > 47 mg/dl).
• Avoid hypoglycaemia below 47 mg/l, so in presence of fluid restriction
higher concentrations of glucose may be required to maintain satisfactory
blood glucose.

23. ADJUVANT TREATMENT
GIT and nutrition:
Restrict total fluids to 50 mL/kg/day initially
• Feeding:
• a. in mild and moderate cases with no ongoing organ dysfunction
or poor perfusion, offer trophic breast milk.
• b. Term babies who suffer a severe asphyxial insult are at risk of
developing NEC, so better to kept NPO.
• Observe for SIADH and avoid severe hyponatremia (suggested by low
serum osmolarity and low serum sodium, associated with high urine
sodium and high urine osmolality)

24. ADJUVANT TREATMENT
Neurologically:
• Close follow up for abnormal movements.
• abrupt changes in blood pressure, SpO2 and heart rate can indicate
seizures.
• For aEEG monitoring if available.
• Consider treating seizures with antiepileptic drugs, particularly if
associated with physiological disturbance, prolonged (>3 min) or
frequent (>3/hr).
• Anticonvulsant, phenobarbital, phenytoin, Diazepam, levetiracetam
always used for one to two week if convulsion not repeated…

25. Cardiovascular
• Aim for heart rate of 100 bpm.
• Faster rates may be a sign of distress, in which case increase sedation.
• Maintain mean arterial blood pressure at >45 mmHg.
• If cardiac output is poor (e.g. poor perfusion (prolonged capillary refill time )
as blood pressure is a poor predictor of cardiac output) use inotropes.
• Avoid volume replacement unless evidence of hypovolaemia.
• systemic hypertension and volume overload, which can worsen cerebral
edema, should be avoided.
• If possible, insert umbilical arterial and venous catheters.
ADJUVANT TREATMENT

26. Respiratory
• Aim to maintain arterial PaCO2 of 45–60 mmHg.
• Aim to maintain PaO2 75–90 mmHg and SpO2 >94%.
• Hypoventilation leading to hypercapnia >60 mmHg is an indication for mechanical
ventilation.
• high frequency ventilation, inhaled nitric oxide, or extracorporeal membrane
oxygenation therapies, as available, for infants with persistent pulmonary
hypertension to maintain oxygenation.
• Acidosis will normally correct itself once adequate respiratory and circulatory
support provided.
• Sodium bicarbonate correction is almost not required and it is better to allow
spontaneous correction.
ADJUVANT TREATMENT

27. Infection:
• Almost we start antibiotics ampicillin and cefotaxime for 48-72hours
if blood culture verbally negative.
ADJUVANT TREATMENT

28. Stop active cooling measures when:
• the rectal temperature persistent falls below 33°C
• the infant has persistent hypoxemia on 100% oxygen
• there is life-threatening coagulopathy
• Persistent electrolyte imbalance: hypokalaemia, hypo magnesia,
hypophosphatemia
• There is an arrhythmia requiring medical treatment. Use re-warming
procedure

29. RE-WARMING PROCEDURE
• After completion of 72 h of total body cooling, the goal is to increase the
rectal temperature to 36.5-37°C at a rate not to exceed 0.5°C per hour.
• Re-warm by stopping any active cooling strategies and increasing the
incubator temperature by 1°C per hour
• The final temperature goal is 36.5°C and should take about 6 h to achieve.
• Record rectal temperatures every 30 min until temperature goal is
achieved
• Record HR, respiratory rate (RR), oxygen saturation, and BP (every 30 min
for the first 2 h, then hourly until re-warmed)
• Document vital signs every 3 h once the temperature goal is achieved and
continue rectal temperature monitoring for another 24 h

30. Imaging:
• Cranial ultrasound to be done within 12 -24 hr to rule out other
causes of encephalopathy.
• MRI to be done between day 5–7).
•

31. Thank you