The effect of nasal olfactory stimulation on apnea of prematurity: a randomized cross-over trial
Kaylen Gähwiler1, Christoph M Rüegger1, Coralie Dirler1
1Newborn Research, Department of Neonatology, University Hospital and University of Zurich, Zurich, Switzerland.
Background:
Olfactory stimulation may enhance respiratory drive in preterm infants without respiratory support. The aim of this study was to assess the efficacy of olfactory stimulation on apnea of prematurity (AOP) in preterm infants receiving nasal continuous positive pressure (nCPAP).
Methods:
This randomized, placebo-controlled, double-blind cross-over study enrolled preterm infants born between 23 0/7 and 31 6/7 weeks of gestation receiving nCPAP and treatment with caffeine citrate. Vanilla or strawberry odor, or an odorless placebo solution, was applied to the nCPAP masks with an odor pen. The primary outcome was the number of desaturation and bradycardia episodes. Secondary outcomes included physiological parameters and feeding tolerance.
Results:
Eighty preterm infants completed the study. The median (interquartile range) number of events during the 12-hour study period was 10 (3-27) in the intervention group and 14 (3-29) in the control group (p = 0.82). No significant differences were observed in any secondary outcome measures with either vanilla or strawberry odor.
Conclusion:
This study did not demonstrate an effect of olfactory stimulation on the number of desaturation and bradycardia episodes in very preterm infants receiving nCPAP. Future research may focus on optimizing methods for delivering olfactory stimuli to infants on non-invasive respiratory support.
Impact:
Clinical trials have demonstrated that olfactory stimulation, using odors such as vanilla, may reduce the frequency of apnea and desaturation episodes in spontaneously breathing preterm infants. This study evaluates the effect of olfactory stimulation with vanilla and strawberry odor on the respiratory drive of preterm infants receiving nasal continuous positive pressure support - the population most severely affected by the apnea of prematurity. In this population, olfactory stimulation did not significantly reduce the number of desaturations and bradycardia. Future research may focus on optimizing delivery methods to ensure that olfactory stimuli are effectively perceived by infants on non-invasive respiratory support.
