Background: Neurally adjusted ventilatory assist (NAVA) is an emerging
mode of respiratory support that uses the electrical activity of the
diaphragm (Edi) to provide synchronised inspiratory pressure support,
proportional to an infant’s changing inspiratory effort. Data on Edi
reference values for neonates are limited. The objective of this study
was to establish reference Edi values for preterm and term neonates.
Methods: This was a prospective observational study of newborn infants
breathing spontaneously in room air. The Edi signal was monitored by a
specialised intragastric feeding tube with embedded electrodes
positioned at the level of the diaphragm. Edi minimums and peaks were
recorded continuously for four hours. Results: 24 newborn infants (16
preterm [<37 weeks’ gestation]; 8 term) were studied. All
infants were breathing comfortably in room air at the time of study. Edi
data were successfully captured in all infants. The mean (±SD) Edi
minimum was 3.02 (±0.94) µV and the mean Edi peak was 10.13 (±3.50) µV.
In preterm infants the mean (±SD) Edi minimum was 3.05 (±0.91) µV and
the mean Edi peak was 9.36 (±2.13) µV. In term infants the mean (±SD)
Edi minimum was 2.97 (±1.05) µV and the mean Edi peak was 11.66 (±5.14)
µV. Conclusion: Reference Edi values were established for both preterm
and term neonates. These values can be used as a guide when using
diaphragm-triggered modes on respiratory support in newborn infants.