Abstract:
Purpose: To investigate the utility of salivary cortisol as an objective
measure of stress in sick infants.
Participants: One hundred and forty four infants nursed in two neonatal intensive
care units in two children's hospitals in Australia.
Design: A prospective observational cohort study.
Methods: Infants' saliva was collected using a 3 mL syringe attached to a shortened
size 8 FG feeding tube. Salivary cortisol levels were measured using ELISA and
examined for associations with potential environmental stressors in the NICU.
Main outcome measures:
1. collection of saliva in sufficient volumes for analysis,
2. relationship between salivary cortisol levels and environmental factors
associated with stress.Results: Sufficient salivary cortisol samples were obtained from 49 infants (35%of
participants). In the samples obtained, there was no significant correlation
between salivary cortisol levels and any environmental stressfactors. However,
meancortisol levels were significantlyhigher(a two-fold increase)in those infants
who had been fed compared to those who were not fed (0.61± 0.41ug/dl, (SD)and
1.13± 0.97jlg/dL (SD),respectively).
Conclusion: Using the method of collection, sufficient volumes of saliva for analysis
were difficult to obtain in the majority of infants. Additional technical limitations
included possible milk contamination of the collected samples. Associations
between environmental stressors and infant cortisol levels were unable to be
determined.
