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Updated: Apr 18, 2026
The Hypoxic Ischemic Encephalopathy Model of Perinatal Ischemia
Published on: November 19, 2008
CoolCuddle and Autonomic Regulation in Infants With Hypoxic-Ischaemic Encephalopathy: An Intervention Study
Ela Chakkarapani1,2, Satomi Okano2, David Odd3
1Centre for Academic Child Health, Bristol Medical School, University of Bristol, Bristol, UK.
Insights
Parental cuddling during therapeutic hypothermia for hypoxic-ischaemic encephalopathy did not significantly alter heart rate variability (HRV). However, autonomic responses varied based on infant severity and parental presence.
Area of Science:
- Neonatal Medicine
- Cardiology
- Developmental Pediatrics
Background:
- Hypoxic-ischaemic encephalopathy (HIE) is a serious birth complication requiring therapeutic hypothermia.
- Heart rate variability (HRV) is a key indicator of autonomic nervous system function in infants.
- Parental presence and touch can influence physiological responses in neonates.
Purpose of the Study:
- To evaluate the impact of 'CoolCuddle', a parental cuddling intervention, on HRV during therapeutic hypothermia for HIE.
- To assess how infant severity and parental presence modulate HRV responses during the intervention.
Main Methods:
- Prospective, single-group, interventional study involving infants undergoing therapeutic hypothermia.
- Time-domain HRV was measured before, during, and after parental cuddling sessions.
- Primary outcomes included heart rate, mean RR interval (ANN), and RMSSD, analyzed in relation to infant Apgar scores and aEEG findings.
Main Results:
- Overall, CoolCuddle did not significantly alter HRV. However, infants with lower Apgar scores or abnormal EEG showed reduced HRV parameters during and after cuddling compared to controls.
- Infants with higher Apgar scores or normal EEG exhibited increased HRV parameters post-cuddle.
- Maternal cuddling was associated with higher post-cuddle RMSSD compared to paternal cuddling (p=0.04).
Conclusions:
- CoolCuddle has a minimal overall effect on HRV in infants undergoing therapeutic hypothermia.
- Autonomic responses to cuddling are modulated by the severity of HIE and the specific parent involved.
- These findings suggest a potential for tailored parental involvement to support vulnerable infants during critical care.
Aim:
We evaluated the impact of 'CoolCuddle', parental cuddling during therapeutic hypothermia intervention for hypoxic-ischaemic encephalopathy, on heart rate variability (HRV).
Methods:
In this prospective, single-group, interventional study with repeated measures, we included infants ≥ 36 weeks' gestation undergoing hypothermia and CoolCuddle with HRV data. Time-domain HRV was assessed before, during, and after each cuddle. Primary outcomes were heart rate, mean RR interval (ANN), standard deviation of normal RR intervals, and root mean square of successive differences (RMSSD).
Results:
In 65 CoolCuddles from 26 infants, CoolCuddle did not significantly alter HRV. However, infants with a 1-min Apgar < 7 had increased heart rates during (+2.33 bpm) and after (+3.27 bpm) cuddling, whereas those with higher Apgar scores showed decreases (-1.43 and -8.21 bpm) compared with pre-cuddle. Infants with Apgar < 7 or abnormal aEEG had reduced ANN during (-11.96 ms, -12.75 ms) and after (-19.89 ms, -19.00 ms), while those with higher Apgar or normal aEEG showed increases (+15.32 ms, +23.33 ms(during-cuddle); +63.94 ms, +55.06 ms (post-cuddle)). Maternal cuddling was associated with higher post-cuddle RMSSD (+1.06 ms) than paternal cuddling (-0.73 ms), (p = 0.04).
Conclusion:
While CoolCuddle had little overall effect on HRV, autonomic responses varied by asphyxia and encephalopathy severity and parent, suggesting differential modulation in vulnerable infants.
