Article Review – ‘Cooling neonates who do not fulfill the standard cooling criteria – short-and long-term outcomes’

I received a phone call this last week about a baby who had an acute event while in the mother’s room. The baby required CPR and fulfilled the criteria for hypothermia (metabolic acidosis, acute event less than 6 hours, gestational age).  Because of the call, this week’s blog will focus on an article entitled: Cooling neonates who do not fulfill the standard cooling criteria- short- and long-term outcomes (

Brief Background:

  • Therapeutic hypothermia has become standard treatment for neonates with HIE in the developed world.
  • The question of whether to cool infants with postnatal collapse is currently not being investigated in a trial setting.
  • The authors present a case series of 36 infants not fulfilling the original cooling entry criteria as set out in CoolCap and TOBY who underwent hypothermia over a 6-year period and compare their clinical course and 18-month outcome to 129 infants who were cooled fulfilling all standard cooling entry criteria.

Materials and methods:

  • All neonates who underwent hypothermia at St. Michael’s Hospital in Bristol UK between December 2006 and December 2012 had their data entered into a data repository.


  • The database was used for the study.
  • Neonates who met the standard criteria for hypothermia were included. These criteria included.
    • (i) infants ≥36 weeks’ gestation with at least one of the following: Apgar score ≤5 at 10 min, continued need for resuscitation at 10 min after birth, acidosis (pH <7.0) within 60 min of birth in umbilical cord blood or any arterial, venous or capillary blood sample, base deficit ≥16 mmol/L
    • in any sample within 60 min of birth,
    • (ii) moderate to severe encephalopathy as evidenced by altered state of conscious-ness and at least one of the following: hypotonia, abnormal reflexes, absent or weak suck, clinical seizures and
    • (iii) at least 30 min of aEEG (12) that showed one of the following: normal background with some electrical seizures (>5 min), moderately abnormal background activity, suppressed activity or definite seizure activity.
  • The standard group was compared to a group which did not fulfill the standard criteria. This group included:
    • infants cooled after 6 h
    • infants with postnatal collapse
    • infants <36 weeks GA
    • infants with cardiac or surgical conditions
    • infants with major cranial hemorrhage.
  • Infants from both groups were followed up at 2years of age and underwent Bayley testing.


  • A total of 165 babies were cooled. Of the 165, 36 did not meet the standard criteria.
  • Of the 36, 11 were cooled beyond 6 hours, 6 were lower than 36 weeks (between 34-35 weeks), 5 had intracranial hemorrhages, 10 had postnatal collapse, 2 had a postnatal diagnosed cardiac condition and 2 had surgical conditions.
  • The complication rates overall were similar between the two groups. Neonates with major intracranial hemorrhages had a higher rate of coagulopathies and the length of stay was higher in the group not fulfilling the standard criteria (Most likely due to the surgical patients).
  • Neonates with postnatal collapse had a 100% survival and 38% had an MDI/PDI less than 70 at 2 years.


  • This was a retrospective review.   It is interesting since it examined follow-up data. Most other studies have been small case series.
  • It appears safe to cool patients with postnatal collapse.
  • We have been cooling babies who have had postnatal events. In each case an extensive evaluation was undertaken to determine the etiology.
  • Do other centers cool babies with postnatal collapse?
  • Should we as a group think about developing guidelines for postnatal collapse?
  • If your center does cool these babies, I think we should include them in our registry. We can then develop data and analyze.

~Mike Weiss