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Carbon Dioxide and Glucose Affect Electrocortical Background in Extremely Preterm Infants
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health, Pediatrics. (Perinatal, neonatal och barnkardiologisk forskning/Hellströml-Westas)
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2011 (English)In: Pediatrics, ISSN 0031-4005, Vol. 127, no 4, e1028-e1034 p.Article in journal (Refereed) Published
Abstract [en]


To investigate if Paco(2) and plasma glucose levels affect electrocortical activity.


Ours was an observational study of 32 infants with a gestational age of 22 to 27 weeks. We performed simultaneous single-channel electroencephalogram (EEG) and repeated blood gas/plasma glucose analyses during the first 3 days (n = 247 blood samples with corresponding EEG). Interburst intervals (IBIs) and EEG power were averaged at the time of each blood sample.


There was a linear relationship between Paco(2) and IBI; increasing Paco(2) was associated with longer IBIs. One day after birth, a 1-kPa increase in Paco(2) was associated with a 16% increase in IBI in infants who survived the first week without severe brain injury. EEG power was highest at a Paco(2) value of 5.1 kPa and was attenuated both at higher and lower Paco(2) values. Corrected for carbon dioxide effects, plasma glucose was also associated with IBI. Lowest IBI appeared at a plasma glucose level of 4.0 mmol/L, and there was a U-shaped relationship between plasma glucose level and EEG with increasing discontinuity at glucose concentrations above and below 4.0 mmol/L.


Both carbon dioxide and plasma glucose level influenced EEG activity in extremely preterm infants, and values considered to be within normal physiologic ranges were associated with the best EEG background. Increasing EEG discontinuity occurred at carbon dioxide levels frequently applied in lung-protection strategies; in addition, moderate hyperglycemia was associated with measurable EEG changes. The long-term effects of changes in carbon dioxide and glucose on brain function are not known.

Place, publisher, year, edition, pages
2011. Vol. 127, no 4, e1028-e1034 p.
National Category
URN: urn:nbn:se:uu:diva-142722DOI: 10.1542/peds.2010-2755ISI: 000289074800023PubMedID: 21444592OAI: oai:DiVA.org:uu-142722DiVA: diva2:387964
Available from: 2011-01-16 Created: 2011-01-16 Last updated: 2015-08-13Bibliographically approved
In thesis
1. Background aEEG/EEG measures in very preterm infants: Relation to physiology and outcome
Open this publication in new window or tab >>Background aEEG/EEG measures in very preterm infants: Relation to physiology and outcome
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The overall aim of this thesis was to characterize single-channel aEEG/EEG, recorded during the first postnatal days in preterm infants, in relation to brain function and two-year outcome.

Study I investigated if aEEG/EEG was associated with neonatal brain injury, inflammation and outcome in 16 very preterm (VPT) infants. The interburst interval (IBI) was prolonged, and aEEG amplitudes were lower in infants with brain injury, and in infants developing handicap. Cord blood TNF-α correlated with IBI.

Study II investigated inter-rater agreement of visual burst detection, as compared to automated burst detection based on a non-linear energy operator (NLEO) in an EEG data set from 12 extremely preterm (EPT) and 6 VPT infants. The sensitivity of the NLEO was 64 % and 69 % (EPT and VPT infants, respectively) and the specificity 96 % and 88 %. The algorithm was then modified to further improve the accuracy.

Study III investigated if arterial carbon dioxide and plasma glucose is associated with EEG continuity. In 247 sets of samples (PaCO2, plasma glucose, IBI) from 32 EPT infants there was a positive association between PaCO2 and IBI; higher PaCO2 was associated with longer IBI. Corrected for carbon dioxide, plasma glucose had a U-shaped association with IBI in infants with good outcome.

Study IV investigated the predictive value of aEEG/EEG in 41 EPT and 8 VPT infants. All VPT infants had good outcome. Predictors of outcome in EPT infants included presence or absence of burst-suppression, continuous activity and cyclicity, median IBI and interburst%. Seizures were associated with neonatal brain damage but not with outcome.

Improved preterm brain monitoring may in the future be used for early identification of infants at high risk of brain damage and adverse outcome, which may have implications for direction of care and for early intervention.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2011. 74 p.
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine, ISSN 1651-6206 ; 647
Electroencephalography, brain damage, prediction, interburst interval, Neurodevelopmental impairment
National Category
urn:nbn:se:uu:diva-146737 (URN)978-91-554-8010-3 (ISBN)
Public defence
2011-04-04, Rosensalen, Akademiska sjukhuset, ing. 95, Uppsala, 13:15 (English)
Available from: 2011-03-14 Created: 2011-02-19 Last updated: 2011-05-04Bibliographically approved

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