Validation of electrode placement in neonatal electrogastrography

Electrogastrography (EGG) is the transcutaneous measurement of gastric elec trical activity. The aims of this study were to validate the electrode plac ement position in neonatal electrogastrography using ultrasonography to loc alise the stomach, and to describe the observed EGG frequency characteristi cs. Fifteen neonates with no known abdominal disorder were studied. Two bip olar EGG recordings were obtained from each subject, the first from electro des placed at sites localized by ultrasound and the second from electrodes placed at the currently recommended sites. Paired sample t tests were used to compare electrode positioning and electrogastrographic data. There were 15 subjects with a mean age of 36 days (range 1-95). While there was a sign ificant difference in the position of electrodes at each site, the EGG reco rdings did not differ. The 3-cycle/minute (2.6-3.7cpm) activity ranged from 30% to 84% of recorded time (mean at sites localized with ultrasound was 5 3%, and at currently recommended sites it was 50%; difference not significa nt, P = 0.155). Bradygastria (<2.6 cpm) was observed in the range of 2-29% of recorded time (mean at sites localised with ultrasound was 12.9%, and at currently recommended sites it was 11.7%; difference not significant, P = 0.40). Tachygastria (3.2-10 cpm) was shown to be in the range of 10-58% of recorded time (mean at sites localized with ultrasound was 33.3%, and at cu rrently recommended sites it was 38.7%; difference not significant; P = 0.0 44). In conclusion, there was no significant difference between EGG recordi ngs taken from electrode sites localized by ultrasound and those recommende d by manufacturers of the electrogastrogram, thus confirming the validity o f the manufacturer's recommended electrode positioning. The pattern of elec trical control activity in the normal neonatal stomach appears to be differ ent from that demonstrated in adults. Bradygastria and tachygastria are see n more frequently, with fewer periods of 3 cpm activity.