Search

PURPOSE Neonatal seizures are a common neurologic diagnosis in neonatal intensive care units, occurring in approximately 14,000 newborns annually in the United States. Although the only reliable means of detecting and treating neonatal seizures is with an electroencephalography (EEG) recording, many neonates do not receive an EEG or experience delays in getting them. Barriers to obtaining neonatal EEGs include (1) lack of skilled EEG technologists to apply conventional wet electrodes to delicate neonatal skin, (2) poor signal quality because of improper skin preparation and artifact, and (3) extensive time needed to apply electrodes. Dry sensors have the potential to overcome these obstacles but have not previously been evaluated on neonates. METHODS Sequential and simultaneous recordings with wet and dry sensors were performed for 1 hour on 27 neonates from 35 to 42.5 weeks postmenstrual age. Recordings were analyzed for correlation and amplitude and were reviewed by neurophysiologists. Performance of dry sensors on simulated vernix was examined. RESULTS Analysis of dry and wet signals showed good time-domain correlation (reaching >0.8), given the nonsuperimposed sensor positions and similar power spectral density curves. Neurophysiologist reviews showed no statistically significant difference between dry and wet data on most clinically relevant EEG background and seizure patterns. There was no skin injury after 1 hour of dry sensor recordings. In contrast to wet electrodes, impedance and electrical artifact of dry sensors were largely unaffected by simulated vernix. CONCLUSIONS Dry sensors evaluated in this study have the potential to provide high-quality, timely EEG recordings on neonates with less risk of skin injury.

THE bispectral index (BIS®, Aspect Medical Systems Inc., Newton, MA) is a processed electroencephalographic variable which correlates with depth of hypnosis in adult patients during general anesthesia, 1,2 It has also been used clinically to guide anesthetic drug administration, 3 and to quantify the pharmacodynamic action of anesthetic drugs in the laboratory setting. 4 HIS has previously been shown to decrease following hypovolemic cardiac arrest, lagging behind the decrease in blood pressure by approximately 2 min. 5 We report a case of unrecognized venous hemorrhage with a fatal outcome during total intravenous anesthesia (TIVA) for elective abdominal aortic aneurysm repair, where the BIS score began to decrease well before other monitored variables suggested clinical deterioration, and we propose that BIS-derived data may provide early insights into altered drug pharmacokinetics due to hemorrhage.