Monitoring interactions between spontaneous respiration and mechanical inflations in preterm neonates

Area of Science:

• Neonatology
• Respiratory Physiology
• Medical Device Technology

Background:

• Preterm infants often require mechanical ventilation, necessitating careful monitoring of respiratory function.
• Assessing the interaction between spontaneous breathing efforts and ventilator support is crucial for optimal respiratory management.
• Existing methods for monitoring patient-ventilator synchrony can be complex and lack continuous, easily interpretable data.

Purpose of the Study:

• To evaluate a novel bedside monitor's capability in assessing patient-ventilator interactions in preterm infants.
• To continuously monitor patient-ventilator synchrony and spontaneous respiratory effort stability across different ventilation modes.
• To assess the monitor's utility in response to routine care procedures in the neonatal intensive care unit.

Main Methods:

• A prospective, observational study involving 31 preterm infants on conventional mandatory ventilation and 22 on patient-triggered ventilation.
• Continuous recording of physiologic variables, including spontaneous respiration and ventilator inflations, using a computerized monitoring system.
• Application of the Frequency Tracking Locus method to derive an 'interaction Score' quantifying respiratory synchrony.

Main Results:

• The monitor successfully quantified patient-ventilator synchrony using the interaction Score, distinguishing 1:1 interaction, non-1:1 interaction, and passive infant response.
• During conventional mandatory ventilation, only 27.4% of epochs showed a 1:1 interaction, with a median interaction Score of 1.2 for 1:1 and 2.2 for non-1:1 interactions.
• Patient-triggered ventilation showed better synchrony (19.5% ideal triggering), but autotriggering was frequent in infants ≤28 weeks gestation, with a median interaction Score of 1.14 for ideal triggering and 1.74 for non-1:1 interactions.

Conclusions:

• A new bedside monitor provides a continuous and easily interpretable measure of patient-ventilator interaction in preterm infants.
• This monitor has significant potential for widespread application in neonatal intensive care units to optimize ventilation strategies.
• The device can help clinicians determine optimal ventilatory settings and manage potential physiologic instability caused by respiratory asynchrony.