Nasopharyngeal suctioning does not produce a salivary cortisol reaction in preterm infants

To investigate whether nasopharyngeal suctioning produces a physiological and behavioural stress reaction in preterm infants and if a possible reaction can be dampened by sweet solution.

Eleven preterm infants were randomly assigned to receive either 30% oral glucose or nothing prior to morning nasopharyngeal suctioning; the procedure was reversed in the afternoon. The study included a total of 44 samples from preterm infants evaluated with salivary cortisol, pain score (Visual Analogue Scale), heart rate, oxygen saturation and recovery time through the Newborn Individualized Developmental Care and Assessment Program. For reference, 44 samples from eleven full-term infants were evaluated for salivary cortisol.

Regardless of whether or not preterm infants received glucose before nasopharyngeal suctioning, no statistically significant difference was found in salivary cortisol reactivity, pain score, heart rate, oxygen saturation or recovery time. Nor were any statistically significant differences between salivary cortisol baseline and response values found in full-term infants after nasopharyngeal suctioning.

In the present setting, nasopharyngeal suctioning was not stressful enough to increase salivary cortisol or pain score. Oral glucose did not alter salivary cortisol levels.