381 - Pilot Study to Evaluate Doses of Mechanical Stimulus on the Effectiveness of Preterm Breathing

Publication Number: 381.6471

Paulina A. Toso, Pontificia Universidad Catolica de Chile, Santiago, Region Metropolitana, Chile; Stephanie Campbell, Pontificia Universidad Católica de Chile, Santiago, Region Metropolitana, Chile; Miriam E. Faunes, Pontificia Universidad Católica de Chile, Santiago Chile, Region Metropolitana, Chile; María Jesús Álvarez, Pontificia Universidad Católica de Chile, Santiago, Region Metropolitana, Chile; Alvaro J. Gonzalez, Universidad Catolica de Chile, Santiago, Region Metropolitana, Chile

Background: Apnea of Prematurity affects 90% of infants born ≤34 weeks of gestation. Despite current treatments, they often experience intermittent hypoxia events, leaving room for improvement. Kinesthetic stimulation, such as dorsal and extremity movements, is commonly used to activate the infant's own respiratory efforts. Although clinical studies have shown that continous or reactive stimulation can reduce apnea frequency and improve oxygen saturation, inconsistent results have been observed with various stimulation methods and mechanisms.

Objective: To compare the effects of nine different doses of dorsal mechanical stimulation in healthy preterm infants in a CPAP-like simulated scenario.

Design/Methods: A crossover pilot study of 24-34 weeks of gestational age healthy preterms. Infants were randomly assigned to baseline and nine continuous dorsal mechanical stimulation protocols, which involved different combinations of lifting amplitudes and frequencies, using a specially designed shirt with an inflating-deflating actuator on its back. Continuous cardiorespiratory monitoring and tidal volumes (measured using a mask with 5 cm H2O PEEP and a pneumotachograph connected to a Florian processor) were recorded for 1 minute or 20 quiet respirations for analysis. Repeated measures ANOVA was used to assess the impact of each dose on respiratory performance (NCT06639581).

Results: Ten of twelve preterms completed the study (Table 1). Preemies synchronized their breathing with the dorsal stimulus in 78% of the time, while they were calm and asleep, regardless of the dose. No differences were observed in heart rate , respiratory rate , or oxygen saturation during the interventions. Baseline tidal volumes (Vt) varied considerably between patients (Figure 1). Pairwise comparisons of each intervention with baseline revealed significant differences (p < 0.00001). A slight trend was observed, indicating that mean Vt increased with higher displacement and frequency of dorsal stimulation, showing a linear trend ranging from 0.001 to 0.290 (Figure 2). Three patients experienced apneas during resting periods between interventions; all apneas resolved with the application of the subsequent stimulation protocol .

Conclusion(s): Continuous dorsal mechanical stimulation increased Vt in healthy preterm infants in a simulating CPAP-like scenario, and effectively terminated apnea episodes during resting periods. These findings suggest that tailored dorsal mechanical stimulation has the potential to enhance respiratory function in preterm infants and lay the groundwork for larger studies to determine optimal stimulation parameters.

Table 1. Patient Characteristics


Figure 1. Basal Tidal Volumes of study patients


Figure 2. Mean tidal Volumes for each patient (P), basal and during nine back's stimulation protocols (SP)