Perinatal asphyxia is an insult to the fetus or the newborn due to lack of oxygen (hypoxia) and or a lack of perfusion (ischemia) to various organs. Hypoxia ischemia remains a significant cause of neonatal mortality and morbidity and adverse neurodevelopmental outcome. Therapeutic hypothermia found to improve neurodevelopmental outcome in asphyxiated babies.

2. PRESENTED BY
DR. SYED KAMRUL HASAN
MEDICAL OFFICER
NEONATAL INTENSIVE CARE UNIT
SWMCH, SYLHET

3. Introduction
Perinatal asphyxia is an insult to the fetus or the
newborn due to lack of oxygen (hypoxia) and or a
lack of perfusion (ischemia) to various organs.
Hypoxia ischemia remains a significant cause of
neonatal mortality and morbidity and adverse
neurodevelopmental outcome. Therapeutic
hypothermia found to improve neurodevelopmental
outcome in asphyxiated babies.

5. History of Therapeutic Hypothermia
• Hippocrates use snow and ice packing to reduce
haemorrhage in the wound.
• In 1800s Russian patient’s with arrest would be
covered in snow with the hopes of return of
spontaneous circulation.
• Napoleon’s Forces used it for the preservation of
amputated limbs.

6. • In 1937 Fay cooled a patient to 32°c to prevent
cancer cells from spreading.
• In 1959 it was being used for CNS injury.
• Up to 1980’s concept of therapeutic hypothermia
using in cardiac arrest and traumatic brain injury in
adults probable benefit in neurological outcome.

7. • Marianne Thoresen (Researcher on cerebral
perfusion) Intrigued by stories of children who fell
through norwegian ice and suffered prolonged
drowning in iced water emerged with preserved
cerebral function.
• Data from animal study show beneficial effect.
• In 2000s using evidence based practice from prior
researcher trials.

8. Mechanism of Hypoxic Ischemic
Encephalopathy (HIE)
In Hypoxic Ischemic Encephalopathy (HIE) biphasic
nature of cell death occurs. Primary neuronal death
(cell hypoxia/ Primary energy failure) followed by
latent period at least 6 hours than secondary phase
or delayed neuronal death (secondary energy failure)
begins. So therapeutic window of 6 hours.

9. Mechanism of Ischemic Brain Injury
Hypoxia
Ischemia
Primary
Neuronal
Death
Cytotoxic
Mechanism
Delayed
Neuronal
Death
Birth 1 hour 6 hours Days
Hypothermia

10. Secondary Energy Failure
Hypoxia-ischemia
Anaerobic Glycolysis
Decrease ATP
Adenosin Increase Glutamate Increase Lactate
Hypoxanthine Increase intracellular calcium
activates lipases
Xanthine
Increase FFA activate NOs
Free radicals free radicals NO
Xanthin
oxidase

11. How Hypothermia prevent HIE damage
• Decrease cerebral blood flow and thus decrease
metabolic rate of brain.
• Slows depolarization of brain cells.
• Decrease accumulation of excitatory neurotransmitters.
• Decrease release of free radicals.
• Keeps integrity of brain cell membrane.
• Decrease apoptosis.

12. Types of Therapeutic Hypothermia
1. Selective head cooling.
Example: Olympic cool cap
2. Whole body cooling.
Example: Tecotherm, Blaketrol,
Phase changing materials (Miracradle)

13. Candidate for Therapeutic Hypothermia
Infants ≥36 weeks gestation, birth weight ≥1800gm
with at least one of the following:
• Apgar Score of 5 or less at 10 minutes after birth
• Need for assisted ventilation including endotracheal
or bag mask ventilation at 10 minutes after birth.
• Acidosis PH<7, Base deficit >16mmol/L or more
within 1 hour of birth.
And
• Moderate to severe encephalopathy or seizure
(clinical or electrical)

14. Newborn infants ≥36 weeks gestation and birth weight ≥1800gm
Meet both Physiologic and Neurologic criteria,
Physiologic Criteria
Cord or baby ABG <1 hour
No gas <1 hour
Or
PH 7.01-7.15 or BD 10-15.9
A major perinatal event : cord
prolapsed, uterine rupture
And
APGAR Score <5 at 10 minutes
Or PPV ≥10 minutes
PH≤7
or
BD≥16
Meet
Physiologic
Criteria
Cooling
Plus
Neurologic Criteria
Moderate Encephalopathy
3 of 6
Severe Encephalopathy
3 of 6
seizure
(clinical or
electrical)
Meet
Neurologic
Criteria
AND
Or
Or

15. Criteria for defining moderate & severe encephalopathy
(modified Sarnat’s staging)
Category Moderate Encephalopathy Severe Encephalopathy
1. Level of Consciousness Lethargic Stupor or coma
2. Spontaneous activity Decrease No activity
3. Posture Distal flexion
Complete extension
Decerebrate
4. Tone Hypotonia Flaccid
5. Primitive reflexes
Suck weak absent
Moro Incomplete absent
6.Autonomic system
Pupils Constricted Deviated, dilated or
nonreactive to light
Heart rate Bradycardia variable
Respiration Periodic breathing Apnoea

16. Contraindication of Therapeutic Hypothermia
• The baby appears moribund
• Severe ongoing hypoxaemia
• Severe coagulopathy or evidence of bleeding
• Major congenital or genetic abnormalities
• PPHN
• Intracranial Haemorrhage
• Shock which is catecholamine resistant

17. Types of equipments
• Servo controlled cooling devices:
-Blanketrol
-Criticool,
-Tecotherm,
- Cool cap.
• Frozen Ice Gel Packs.
• Phase Changing Materials: Miracradle.

18. Prerequisites
Prior to initiating Therapeutic hypothermia:
• A written informed consent from parents/ legal guardian.
• The neonate’s cardio-respiratory status should be stable.
• Patient in NICU.
• Access to bedside USG, CT, MRI, EEG.
• Have 1:1 nurse: patient ratio if non servo controlled
devices.
• Secure at least 2 intravenous line.

19. Preferred Method of Providing TH
• Servo- controlled devices ( head cooling, Whole
body cooling) are to be preferred to non servo
controlled device ( ice gels & phase change material
devices).
• Whole body cooling preferred to selective head
cooling.

20. (Servo controlled Device)
Tecotherm Neo

21. Equipment
Hyper-hypothermia machine
(Tecotherm Neo)

22. Reusable or Disposable Mattress
Disposable Rectal Probe & Rectal Probe Cable

23. Disposable Skin
Temperature Probe
Skin Temperature Probe
Cable

24. Drainage hose
Fill-up set filled with
sterile water

25. Infant radiant warmer bed with warming capability

26. Procedure
• Confirm eligibility for hypothermia therapy.
• Gather equipment require for the procedure.
• Pre cool the blanket to 5°c for whole body cooling to
maintain an esophageal or rectal temperature of
33.5°c ± 0.5°c.Lay infant supine on the precooled
mattress with occiput resting on the mattress. A single
layer thin blanket may be placed between the infant
and the cooling mattress to prevent soiling of
equipment.

27. • Insert the esophageal temperature probe into an
external naris. Probe should be positioned in the lower
third of the esophagus ( desired length = distance from
nares to ear to the mid sternum minus 2 cm). Secure
the probe by adhesive tap to the side of the nose.
Connect the probe to the cooling unit. Confirm probe
placement with a radiograph. In case of Rectal
temperature sensor measure and mark the sensor,
lubricate the tip, insert the rectal probe 5 to 6 cm into
the rectum, and secure to the buttocks with tape.

28. • Use an open radiant warmer bed for optimal
monitoring. Skin temperature will be monitored by
skin temperature probe on the lower abdomen
attached to the radiant warmer. The radiant warmer is
on manual mode with the heat turned off.
• Operate the cooling unit in automatic mode with a
core temperature goal of 33.5°c ± 0.5°c

29. • The infant’s esophageal or rectal temperature will
begin to decrease soon after the initiation of the
cooling therapy. The cooling system adjust
automatically to achieve 33.5°c by approximately 90 to
120 minutes. Temperature should not fluctuate more
than ±0.5°c . Total period of cooling 72 hours.

30. Tecotherm Neo Menu and Mode

31. • Gradual rewarming is done over 6 hours after
completion of 72 hour cooling period. At a rate of
0.5°c/hour over 6 to 10 hours up to maximum set
point of 36.5°c.
• When normothermia is achieved, turn off hyper-
hypothermia unit and remove cooling mattress and
probe.

32. • During the cooling and rewarming process monitor and
record esophageal/rectal, skin and water temperature
as well as vital signs HR,RR,BP, Spo2, urine output at
regular intervals. Daily review for evidence of infection.
• Blood investigation: RBS, ABG, S.Electrolyte, LFT, CBC,
Coagulation profile.

33. Supportive care during TH
• Sedative/ Analgesic: Morphine/Fentanyl
• Enteral feed : Minimal enteral feeding if
hemodynamically stable.
• No prophylactic antibiotic
• AED: if convulsion present clinical or electrical
• Platelet transfusion: if platelet count <1lac.

34. Setup of Tecotherm Neo

36. Phase Changing Materials
• PCMs are passive heating and cooling substances,
usually made of a salt hydride, fatty acid and ester or
paraffin such as octadene.
• PCMs are solid at room temperature but when in
contact with warmer objects they liquefy and absorb
and store heat.
• Liquid PCMs can solidify and give off heat.
• Temperature Monitoring required additional blanket
if low temperature, or additional PCM if temperature
high outside therapeutic range.

37. Miracradle

39. Miracradle

40. Temperature maintenance in Miracradle
• Rectal temperature >33.8°c : Introduce FS 21 PCM
• Temperature <33.2°c: Introduce folded piece of cloth
under the newborn and cover the baby.
• Switch on warmer in manual mode and grade up the
temperature up to 10-20%.

41. Do’s & Don’ts in Miracradle
• Do not keep FS 21 & FS 29 in deep freezer.
• Avoid direct contact of PCM with the newborn.
• Do not bend/ distort or fold.
• Once a month cross check the temperature on the
charged FS 21 & 29.
• For cleaning the surface soap water solution,
isopropyl alcohol or any other new born friendly
cleaning solution.
• Sanitize before and after each use.

42. Frozen Ice Gel Packs
Equipments:
• 4 cold packs in fridge
temperature at 10°C
• Disposable rectal probe and
cable
• Cotton cover the cold packs

43. Temperature maintenance in Frozen Ice Gel Packs
Temperature
Ranges
Number of cold
packs applied
Area to be applied
>37°C 4 Head, Shoulders ,Neck,
Trunk
36.1°C-37°C 3 Shoulders, Neck, Trunk
35.1°C-36°C 2 Shoulders, Trunk
34.1°C-35°C 1 Trunk
33°C-34°C 0 Nil

44. Advantage of Therapeutic Hypothermia
• Therapeutic hypothermia is now the gold standard
treatment for infants with moderate to severe
Hypoxic Ischemic Encephalopathy (HIE).
• Therapeutic hypothermia reduce the mortality and
morbidity.
• Improve the Neurodevelopmental outcome at 18 -24
months about 24% compare to baby who are not
undergoes therapeutic hypothermia.

45. Adverse effect of Therapeutic Hypothermia
• Hypotension.
• Cardiac arrhythmia (mainly sinus bradycardia).
• Thromobocytopenia.
• Coagulopathy.
• Pulmonary hypertension.
• Persistent acidosis.
• Altered glucose metabolism.
• Skin breakdown.
• Subcutaneous fat necrosis.

46. Cooling trials
• Cool cap study
• NICHD Trial
• TOBY Trial
• ICE Trial

47. TOBY Trial
The TOBY trial based in the UK during 2007 using
Tecotherm Neo. Result shows cooling increases
infants chance of surviving without neurological
deficits at 18 months and reduces
neurodevelopmental impairment in survival.

48. Deficiencies in evidences
• Long term neurological outcome at 18 months early
to diagnosed CP and cognitive deficiency.
• Best method of temperature monitoring rectal
versus esophageal.
• Does temperature fluctuations causes any adverse
outcome.

49. Reference
• Neonatology Management , Procedure, On call
Problems, Diseases and drugs- Tricia Lacy Gomella 8th
Edition.
• The Science of Paediatrics – Dr. Tom Lissaure
• Illustrated Textbook of Paediatrics- 6th Edition
• New England Journal of Medicine.
• AIIMS Protocol in Neonatology-2nd Edition

50. • The LANCET Global Health.
• https://pubmed.ncbi.nlm.nih.gov/24982721/
• www.resarchgate.net
• https://thejns.org/view/journals/j-
neurosurg/130/3/article-p1006.xml
• https://www.frontiersin.org/articles/10.3389/fnins.
2019.00586/full