title: Spindle activity in children during cardiac surgery and hypothermic cardiopulmonary bypass.
abstract: Hypothermia has marked effects on the electrical activity of the brain, which has been shown in animals as well as in humans. The aim of this study was to investigate EEG spindle activity in children during cardiac surgery and hypothermic cardiopulmonary bypass. The authors obtained intraoperative 21-channel EEG recordings in 36 children (mean age, 22 months; range, 6 days to 69 months) with congenital heart disease. Bipolar EEG derivations were analyzed visually for rhythmic spindle activity based on morphology, frequency, duration, and amplitude. Linear regression analysis for duration, frequency, and amplitude versus rectal temperature was performed in each individual. Spindle activity was observed in 17 children (16 children < 12 months of age). Progressive slowing of spindle frequency with decreasing rectal temperature was found (mean decrease, 0.54 +/- 0.31 Hz/ degrees C). Spindle duration increased on average by 0.69 +/- 0.39 second/ degrees C during cooling procedures. Spindle amplitude did not show any correlation to changes in rectal temperature. The current study demonstrates spindle activity during hypothermic cardiopulmonary bypass with temperature-dependent spindle modifications of frequency and duration. Although the temperature-dependent changes in this study confirm temperature coefficients of other EEG studies, the reasons for the clear age relationship and the "nature" of these spindles remain unknown.
authors.affiliation: University Children's Hospital, University Hospital, University of Zürich, Switzerland. bernhard.schmitt@kispi.unizh.ch
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schmitt
authors.forename: Oskar G
authors.initials: OG
authors.lastname: Jenni
authors.forename: Urs
authors.initials: U
authors.lastname: Bauersfeld
authors.forename: Rolf
authors.initials: R
authors.lastname: Schüpbach
authors.forename: Edith R
authors.initials: ER
authors.lastname: Schmid
mesh_terms: D001831:Body Temperature; D001921:Brain / Q000503:physiopathology; D001931:Brain Mapping; D002315:Cardiopulmonary Bypass; D004569:Electroencephalography; D006330:Heart Defects, Congenital / Q000503:physiopathology* / Q000601:surgery*; D006801:Humans; D007036:Hypothermia, Induced; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D016343:Monitoring, Intraoperative / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic