Abstracts

Rationale: In some instances evaluation of seizure activity in the neonate may require continuous EEG monitoring over a period of days. During this time, the neonatal skin is continuously exposed to chemical irritation from the electrolyte paste and as well as other environmental factors. Although irritation from EEG electrode placement is well known, we were concerned that the thermoregulatory environment unique to the neonatal intensive care environment may pose additional hazards to the fragile neonatal skin. Hypothesis: Thermal radiation from overhead warmers could create localized heat islands under exposed EEG electrodes filled with electrolyte paste. Methods: On the forehead of a plastic manikin placed under an infant warmer (Hill Rom), an EEG electrode was attached using electrolyte gel and a thermocouple placed through the top hole of the electrode. A second thermocouple was affixed in a vertical position adjacent to the EEG electrode using a small amount of electrolyte paste. Temperature readings from each thermocouple were obtained after manually increasing the output of the radiant warmer. The experiment was repeated in an isolette with temperatures varied using the air temp control mode.Results: Temperatures inside the EEG electrode were consistently higher than the control site. At maximum heater output the temperature within the EEG electrode exceeded 108 F versus the control temp of 99 F. Loss of heat following removal of the radiant heater was significantly delayed in the EEG electrode. Changes in isolette heating had no significant effect on electrode versus control temperaturesConclusions: Temperatures within EEG electrodes filled with conductive paste can reach temperatures associated with thermal dermal injury. Repetitive thermal cycling and decreased skin perfusion are conditions typically found in the neonatal environment and may lower the threshold for thermal injury (Moritz and Henrique, Am. J. Pathol. 1947: 23(5); 695-720). The skin under EEG electrodes exposed to radiant warmers should be periodically evaluated and measures taken to limit exposure to external thermal sources