Evaluation of the suitability and clinical applicability of different electrodes for aEEG/cEEG monitoring in the extremely premature infant

Introduction: Monitoring of brain function using continuous electroencephalography (aEEG/cEEG) is an essential tool in the standard care of the term infant, and its use is growing in the premature infant as a biomarker of lesion and brain maturity. However, the placing of the electrodes is a great challenge, particularly in the extremely premature infant, which often discourages neuromonitoring. The aim of this study is to assess the different electrodes available, to select the one that best suits the peculiarities of the extremely premature infant, and evaluate its applicability in clinical practice.

Population and methods: With the aim of designing a neuromonitoring study protocol using aEEG/cEEG in <28 weeks premature infants, an analysis was made of our experience with the type of electrodes available. The electrode that was considered most suitable for this population was chosen by assessing: the need of preparing the scalp, speed in positioning the electrodes, if the application was invasive or not, the possibility of repositioning, risk of skin injuries, sterility of the technique, and durability. The electrode chosen was used for continuous electroencephalographic monitoring started in the first 24 h of life, and maintained until at least 72 h of life.

Results: The electrodes evaluated were: subdermal needles, silver cups, and 2 types of self-adhesive electrodes (solid hydrogel and wet gel). The wet gel electrodes were chosen. They were used on 41 neonates with a mean gestational age of 25.8 ± 1.1 weeks. Good stable impedance was rapidly obtained, without the need of excessive manipulations, and no skin injuries were observed. The satisfaction of the staff involved in positioning them was very high.

Conclusion: The self-adhesive disposable electrodes with wet gel and integrated cable enabled the electrodes to be positioned rapidly and provided continuous non-invasive and good quality aEEG/cEEG monitoring in the extremely premature infant.