PhD Candidate The University of Texas at Austin Austin, Texas, United States
Background: Continuous monitoring of vital signs is fundamental to ensuring the safety of newborns admitted to the neonatal intensive care unit (NICU). Skin-mounted sensors can cause skin breakdown and suffer signal loss and inaccuracy from poor skin contact. Most NICU infants have a naso- or orogastric tube paced to provide milk feeds. An FDA-cleared 6Fr feeding tube with electrical sensors is already in clinical use to sense diaphragmatic activity and synchronize ventilatory support. (Edi catheter, Getinge, Germany). ECG signals have previously been extracted from Edi catheters in a small proof-of-concept study. Objective: The primary objective is to compare esophageal with skin-mounted ECG signals in preterm infants receiving respiratory support. Secondary objectives are to compare respiratory rate data with skin-mounted sensors and to quantify the magnitude of Edi signal in infants with and without respiratory distress as a potential metric of work of breathing. Design/Methods: Our study will enroll 30 stable ex-preterm infants, all above 32 weeks corrected gestational age and weighing over 1,500 grams. We'll divide these into three cohorts: unsupported, high-flow nasal therapy, and continuous positive airway pressure. During clinically indicated feeding tube insertions, an Edi catheter will be inserted for simultaneous standard feeding, ECG, and Edi monitoring over seven consecutive days, employing a high-resolution data capture system.
Approved by our IRB, we've initiated participant enrollment. Given that our two NICU study locations admit 1,000 infants annually, we anticipate concluding enrollment by February 2024, with data analysis finalized by the following month. Our primary measure is the cumulative duration of heart rate signal loss per participant when comparing esophageal and skin-mounted ECGs. Secondary measures include a Bland-Altman assessment of mean bias and agreement for heart and respiratory rates against skin-mounted sensors, alongside an Edi signal magnitude comparison across infants in ambient air versus those on respiratory support.
