Hypocapnia in early hours of life is associated with brain injury in moderate to severe neonatal encephalopathy

J Perinatol. 2022 Jul;42(7):892-897. doi: 10.1038/s41372-022-01398-2. Epub 2022 Apr 23.


Objective: To evaluate the association between hypocapnia within the first 24 h of life and brain injury assessed by a detailed MRI scoring system in infants receiving therapeutic hypothermia (TH) for neonatal encephalopathy (NE) stratified by the stage of NE.

Study design: This retrospective cohort study included infants who received TH for mild to severe NE.

Results: 188 infants were included in the study with 48% having mild and 52% moderate-severe NE. Infants with moderate-severe NE spent more time in hypocapnia (PCO2 ≤ 35 mmHg) and presented with more severe brain injury on MRI compared to mild cases. The MRI injury score increased by 6% for each extra hour spent in hypocapnic range in infants with moderate-severe NE. There was no association between hypocapnia and injury scores in mild cases.

Conclusion: In infants with moderate-severe NE, the hours spent in hypocapnia was an independent predictor of brain injury.

MeSH terms

  • Brain Injuries* / complications
  • Brain Injuries* / diagnostic imaging
  • Humans
  • Hypocapnia / complications
  • Hypocapnia / therapy
  • Hypothermia, Induced*
  • Hypoxia-Ischemia, Brain* / complications
  • Hypoxia-Ischemia, Brain* / diagnostic imaging
  • Hypoxia-Ischemia, Brain* / therapy
  • Infant
  • Infant, Newborn
  • Infant, Newborn, Diseases* / therapy
  • Magnetic Resonance Imaging
  • Retrospective Studies