Just for the purpose of recall.(Cochrane 2013, Jacobs)
Evidence of peripartum asphyxia, with each enrolled infant satisfying at least one of the following criteria:
i) Apgar score of 5 or less at 10 minutes;
ii) mechanical ventilation or resuscitation at 10 minutes;
iii) cord pH < 7.1, or an arterial pH < 7.1 or base deficit of 12 or more within 60 minutes of birth.
Evidence of encephalopathy according to Sarnat staging (Sarnat 1976; Finer 1981):
i) Stage 1 (mild): hyperalertness, hyper-reflexia, dilated pupils, tachycardia, absence of seizures;
ii) Stage 2 (moderate): lethargy, hyper-reflexia, miosis, bradycardia, seizures, hypotonia with weak suck and Moro;
iii) Stage 3 (severe): stupor, flaccidity, small to mid position pupils that react poorly to light, decreased stretch reflexes, hypothermia and absent Moro.
AND abnormal standard EEG or aEEG findings(this in addition to above as in NeoNeuro Network RCT by Simburner, Germany).
Laptook etal. Effect of therapeutic hypothermia initiated after 6hours of age on death or disability among newborns with Hypoxic-ischemic encephalopathy, Jama 2017 October 24;318(16): 1550-1560.
•Randomized clinical trial
•April 2008 –june 2016
•Moderate or severe HIE enrolled at 6-24 hours after birth.
•Twenty one US neonatal research network centers
•There were 168 participants and 83 were randomly assigned to hypothermia and 85 to noncooling.
76% probability of any reduction in death or disability.(Biasian Statistics and analysis)
64% probability of at least 2% less death or disability at 18 to 22 months. Hypothermia initiated at 6 to 24 hours after birth may have benefit but there is uncertainty in its effectiveness.
Gist: TH can be tried for its benefit though not greater than that of starting early but with due consideration of parents participation and Consultant in decision making.