An observational study in Infant,Premature, sponsored by University of Miami. Completed at 1 site in United States. Per ClinicalTrials.gov, last updated 2025-03-18.
Sponsored by University of Miami · Observational
Premature infants present with significant oxygenation instability in the form of frequent spontaneous episodes of hypoxemia during the first weeks after birth. These infants are also exposed to hyperoxemia.
The objective of this study is to determine the extent to which exposure to frequent episodes of hypoxemia and hyperoxemia in extreme premature infants during the early stages of their evolving lung disease is associated with altered maturation and function of their respiratory control system.
This study is part of the Prematurity-Related Ventilatory Control (Pre-Vent): Role in Respiratory Outcomes Clinical Research Centers (CRC) (U01) cooperative program of the National Heart Lung and Blood Institute (NHLBI) of the National Institutes of Health (NIH).
Most extreme premature infants present with respiratory failure due to altered lung function compounded by breathing instability due to an immature respiratory control function.
Premature infants present with significant oxygenation instability in the form of frequent spontaneous episodes of hypoxemia during the first weeks after birth. As a result, these infants receive oxygen supplementation but this is often excessive and these infants are also exposed to hyperoxemia. The extent to which these episodes of hypoxemia or the exposure to hyperoxemia impact on the maturation and function of the control of breathing system in extreme premature infants during the evolving stages of their respiratory disease is unknown. This is a prospective study that will systematically evaluate such association in extreme premature infants.
The main objective of this study is to determine the extent to which exposure to frequent episodes of hypoxemia and hyperoxemia in extreme premature infants during the early stages of their evolving lung disease is associated with altered maturation and function of their respiratory control system.
This study is part of the Prematurity-Related Ventilatory Control (Pre-Vent): Role in Respiratory Outcomes Clinical Research Centers (CRC) (U01) cooperative program of the National Heart Lung and Blood Institute (NHLBI) of the National Institutes of Health (NIH).
Preterm infants admitted to the neonatal intensive care unit will be screened and will be considered eligible for inclusion if they fulfill all of the following inclusion and none of the exclusion criteria.
Exclusion Criteria:
Recordings of SpO2 and heart rate will be analyzed by dedicated software to obtain frequency, duration and severity of episodes of hypoxemia and hyperoxemia.
Recordings of SpO2, heart rate, esophageal pressure, tidal volume, minute volume, respiratory rate and transcutaneous PCO2 will be analyzed to determine the prevalence, severity and duration of hypoxemia episodes produced by the different mechanisms.
Recordings of tidal volume, minute volume and respiratory rate will be analyzed to determine frequency of apnea, periodic breathing, distribution of inter-breath intervals.
In mechanically ventilated infants the apneic threshold of CO2 will be measured by transcutaneous PCO2 following a step wise increase in ventilator rate until spontaneous breathing ceases transiently. In spontaneously breathing infants the apnea threshold of CO2 will be measured during episodes central apnea.
The Dejours test will be used to assess peripheral chemoreceptor function by measuring the immediate ventilatory response to high-inspired oxygen.
Also known as: Dejours test
Central chemo-receptor function will be assessed by measuring the ventilatory response to inspired CO2.
Also known as: Ventilatory response to CO2
Peripheral chemoreceptor control of breathing function
Ventilatory response to oxygen (Dejours test)
Time frame: at 32 weeks corrected postmenstrual age
Peripheral chemoreceptor control of breathing function
Ventilatory response to oxygen (Dejours test)
Time frame: at 36 weeks corrected postmenstrual age
Central chemoreceptor control of breathing function
Ventilatory response to carbon dioxide
Time frame: at 32 weeks corrected postmenstrual age
Central chemoreceptor control of breathing function
Ventilatory response to carbon dioxide
Time frame: at 36 weeks corrected postmenstrual age
Change in peripheral chemoreceptor control of breathing function
Ventilatory response to oxygen (Dejours test)
Time frame: Change from 32 to 36 weeks postmenstrual age
Change in central chemoreceptor control of breathing function
Ventilatory response to carbon dioxide
Time frame: Change from 32 to 36 weeks postmenstrual age
Ventilatory stability - Apnea frequency
Frequency of apnea episodes per hour
Time frame: at 32 and 36 weeks corrected postmenstrual age
Ventilatory stability - Periodic breathing density
Percent of time with periodic breathing
Time frame: at 32 and 36 weeks corrected postmenstrual age
Ventilatory stability - Time series analysis of inter-breath interval
Tail slope of the log-scaled probability density function of the inter-breath time series
Time frame: at 32 and 36 weeks corrected postmenstrual age
Mechanisms of episodic hypoxemia
Classify etiology of episodes of hypoxemia as central, obstructive, or mixed apnea or active exhalation based on measurements of respiratory inductance plethysmography, esophageal pressure
Time frame: at 32 and 36 weeks corrected postmenstrual age
Apneic CO2 threshold in central apnea
Carbon dioxide level change at onset of central apnea
Time frame: at 32 and 36 weeks corrected postmenstrual age
Apneic CO2 threshold during mechanical ventilation
Carbon dioxide level change at onset of central apnea with stepwise increase in ventilator rate
Time frame: at 32 and 36 weeks corrected postmenstrual age
Plan to share: No
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University of Miami