Detection of CardioRespiratory Events Using Acoustic Monitoring in Preterm Infants on CPAP

Study Overview
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Brief Summary
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This is an observational, proof-of-concept, feasibility study where 50 preterm infants with gestational age < 32+0 weeks will be recruited from the neonatal intensive care unit (NICU) at the Montreal Children's Hospital. The study's primary objective is to describe the relationship between respiratory acoustics and airflow and determine the reliability of a novel respiratory acoustic sensor at detecting breathing sounds in preterm infants. The study's secondary objectives are: To compare transthoracic impedance, respiratory inductive plethysmography and an inertial measurement unit for the detection of respiratory efforts in preterm infants. To evaluate the feasibility and accuracy of a novel, non-invasive method for continuously detecting and differentiating cardiorespiratory events in preterm infants on CPAP by integrating measurements of respiratory effort with respiratory acoustic monitoring.

Detailed Description
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Cardiorespiratory events, defined by the occurrence of apneas, bradycardias, and desaturations, are almost ubiquitous in very preterm infants and are associated with numerous complications. Unfortunately, the current standard for monitoring cardiorespiratory events in the NICU, transthoracic impedance (TTI), does not permit for accurate differentiation of the different types of cardiorespiratory events; TTI cannot detect airflow and has low accuracy for detecting respiratory efforts. As a result, TTI does not detect obstructive apneas and may not reliably capture all central apneas. Respiratory sounds are an attractive surrogate measure of airflow, and can be captured using respiratory acoustic technology (akin to a miniaturized electronic stethoscope). We hypothesize that respiratory acoustic monitoring can provide a continuous, non-invasive, and accurate representation of airflow and breathing sounds in preterm infants. Altogether, we conjecture that the combination of respiratory acoustic monitoring with measurements of respiratory effort will improve the ability to differentiate and describe the nature of cardiorespiratory events in preterm infants.

Official Title
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Detection of CardioRespiratory Events Using Acoustic Monitoring in Preterm Infants on Continuous Positive Airway Pressure: the DREAM Pilot Project

Conditions
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Apnea of Prematurity

Intervention / Treatment
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* Device: Respiratory Acoustic Sensors
* Device: Nasal thermistor
* Device: Respiratory Inductive Plethysmography
* Device: Pneumotachometer


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria for all infants: Gestational age < 32+0 weeks Postmenstrual age between 28+0 and 36+6 weeks. Additional inclusion criteria for Groups 1 and 2: Off any respiratory support and breathing in-room air Less than 3 clinically significant cardiorespiratory events per calendar day Additional inclusion criteria for Group 3: On the bubble CPAP device with the binasal prongs interface Receiving CPAP levels of 5 to 7 cm H2O with gas flows not exceeding 10L/min At least 3 clinically significant cardiorespiratory events per calendar day Exclusion Criteria: Major known congenital abnormalities Known congenital heart disorders Known neuromuscular disease Known diaphragmatic paralysis or a diagnosed phrenic nerve injury History of esophageal perforation in the 7 days preceding the study History of pneumothorax requiring chest tube insertion in the 7 days preceding the study Receiving inotropes, narcotics, or sedative agents at the time of study recording Additional exclusions at the time of the study recording: Infants receiving ventilator-derived CPAP Infants receiving CPAP via a nasal mask interface. Infants receiving inotropes, narcotics or sedative agents Infants deemed clinically unstable for the study by the attending neonatologist.

Ages Eligible for Study
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Minimum Age: 72 Hours

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| (1) 10 preterm infants spontaneously breathing in-room air with no respiratory support<br>Group 1 will consist of 10 preterm infants spontaneously breathing in room air, with no respiratory support, in whom respiratory acoustic signals from the acoustic sensor will be compared with airflow measurements obtained using a pneumotachometer, i.e. the gold standard. Data will be acquired for 10 minutes. | Device: Respiratory Acoustic Sensors<br>* Wireless sensor that contains a dual microphone and an inertial measurement unit (IMU) will capture the breathing sound and respiratory effect. Two wireless sensors will be used, with one placed on the suprasternal notch and the other placed on the right upper chest of the infant, in order to determine the sensor placement yielding the best respiratory signal. Data will be transmitted in real-time to a research-dedicated tablet using the Bluetooth Communication Controller (ISP1807, Insight SIP) and stored on the same device for future analysis.<br>Device: Pneumotachometer<br>* The pneumotachometer is a pressure-differential based flow sensor that is used to measure respiratory flow. It will be connected to a standard face mask that is gently applied to cover the infant's mouth and nose. The face mask will be similar to the masks used as part of standard of care in the NICU for infants who require continuous positive pressure, with or without ventilation. The flow measurements will be recorded using the Power Lab data acquisition system and stored for later analysis.<br>* Other names: Hans Rudolph, Inc, Shawnee, KS;|
| (2) 20 preterm infants spontaneously breathing in-room air with no respiratory support<br>Group 2 will consist of 20 preterm infants spontaneously breathing in room air, with no respiratory support, in whom respiratory acoustic signals from the acoustic sensor will be compared with airflow measurements obtained using a nasal temperature sensor. In addition, measurements of respiratory efforts will be obtained using the Respiratory Inductance Plethysmography (RIP), an inertial measurement unit (IMU) integrated within the acoustic sensor, and the Transthoracic Impedance (TTI) from the bedside monitor. Data will be continuously recorded for 3 hours. | Device: Respiratory Acoustic Sensors<br>* Wireless sensor that contains a dual microphone and an inertial measurement unit (IMU) will capture the breathing sound and respiratory effect. Two wireless sensors will be used, with one placed on the suprasternal notch and the other placed on the right upper chest of the infant, in order to determine the sensor placement yielding the best respiratory signal. Data will be transmitted in real-time to a research-dedicated tablet using the Bluetooth Communication Controller (ISP1807, Insight SIP) and stored on the same device for future analysis.<br>Device: Nasal thermistor<br>* The nasal temperature probe that detects changes in temperature between inhaled and exhaled gases allows for the surrogate measure of airflow. It will be placed in one naris and secured with tape at the upper lip or cheek. The nasal temperature signal will be acquired using the Power Lab analog-digital acquisition system and stored for later analysis.<br>* Other names: MLT415/A®, ADInstruments®, Bella Vista, Australia;Device: Respiratory Inductive Plethysmography<br>* Two respiratory bands will be placed circumferentially around the infant's chest (at the level of nipple line) and around the abdomen (just above the level of the umbilicus) in order to measure chest and abdominal wall movements, respectively. These movements will be recorded using Respiratory Inductive Plethysmography (Respitrace QDC®, Viasys® Healthcare, USA). The Respitrace® signals will be acquired using the Power Lab data acquisition system and stored for later analysis.<br>* Other names: SleepSense®, Scientific Laboratory Products, Elgin, USA;|
| (3) 20 preterm infants on continuous positive airway pressure (CPAP) with cardiorespiratory events<br>Group 3 will consist of 10 preterm infants on CPAP with established cardiorespiratory events, in whom respiratory acoustic signals from the acoustic sensor will be continuously measured for 3 hours. In addition, measurements of respiratory efforts will be obtained using the Respiratory Inductance Plethysmography (RIP), an inertial measurement unit (IMU) integrated within the acoustic sensor, and the Transthoracic Impedance (TTI). Data will be continuously recorded for 3 hours. | Device: Respiratory Acoustic Sensors<br>* Wireless sensor that contains a dual microphone and an inertial measurement unit (IMU) will capture the breathing sound and respiratory effect. Two wireless sensors will be used, with one placed on the suprasternal notch and the other placed on the right upper chest of the infant, in order to determine the sensor placement yielding the best respiratory signal. Data will be transmitted in real-time to a research-dedicated tablet using the Bluetooth Communication Controller (ISP1807, Insight SIP) and stored on the same device for future analysis.<br>Device: Respiratory Inductive Plethysmography<br>* Two respiratory bands will be placed circumferentially around the infant's chest (at the level of nipple line) and around the abdomen (just above the level of the umbilicus) in order to measure chest and abdominal wall movements, respectively. These movements will be recorded using Respiratory Inductive Plethysmography (Respitrace QDC®, Viasys® Healthcare, USA). The Respitrace® signals will be acquired using the Power Lab data acquisition system and stored for later analysis.<br>* Other names: SleepSense®, Scientific Laboratory Products, Elgin, USA;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reliability of respiratory acoustics at detecting airflow compared to airflow measurements obtained from a pneumotachometer. | The airflow signal derived from the respiratory acoustic sensor will be compared with the airflow signal derived from the pneumotachometer. | 10 minutes (group 1) or 3 hours (groups 2 and 3) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reliability of the inertial measurement unit (IMU) at detecting respiratory efforts compared to Respiratory Inductance Plethysmography (RIP). | The chest wall movement signal derived from the respiratory acoustic sensor will be compared with the chest wall movement signal derived from RIP. | 3 hours (groups 2 and 3 only) | 
| Reliability of the inertial measurement unit (IMU) at detecting respiratory efforts compared to Transthoracic Impedance (TTI). | The chest wall movement signal derived from the respiratory acoustic sensor will be compared with the chest wall movement signal derived from TTI. | 3 hours (groups 2 and 3 only) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Preterm infants, Respiratory acoustics, Prematurity, CPAP, Acoustic monitoring, Airflow, Apnea, Cardiorespiratory events, Monitoring, Neonatal Intensive Care