Fellow University of Texas at Austin Dell Medical School Austin, Texas, United States
Background: A continuous measure of pulmonary vascular resistance would be of value in guiding cardiorespiratory care in neonates. Arterial catheters are widely used in neonatal care for blood draws and for monitoring the systemic circulation. In the presence of a patent ductus arteriosus (PDA) systemic blood pressures also reflect pulmonary vascular resistance (e.g. a wide systemic pulse pressure in infants with hemodynamically significant PDA). Objective: Establish a proof of concept for systemic blood pressure waveform analysis acting as a continuous measure of pulmonary vascular resistance we will compare systemic arterial waveform characteristics before and after start of inhaled nitric oxide. Design/Methods: A retrospective analysis will be performed on continuous arterial blood pressure monitoring data taken from clinically indicated umbilical arterial catheters. All bedside data is available in a third-party server (SickBay, MIC, Houston TX) in native temporal resolution (240Hz) for all infants admitted to one of our two study NICUs since January 2021. We will analyze each blood pressure beat for two hours before and after initiation of nitric oxide for a change in systolic maximum, diastolic minimum, pulse pressure, and slope of the line between the systolic and diastolic pressures. Inclusion criteria will be infants admitted to the NICU by 24 hours postnatal age in whom nitric oxide therapy was initiated by the clinical team. Infants with structural congenital heart disease (other than PFO/PDA) or congenital diaphragmatic hernia will be excluded. A planned subgroup analysis will be performed in infants with gestational ages above and below 34+0 weeks.
Data Analysis/Timeline: Work for this project has already been approved by our local IRB. Data collation is underway and is expected to be complete by December 2023. A customized processing algorithm to analyze arterial waveform data within the Matlab environment is expected to be completed by February 2024. Software implementation and data analysis is expected to be complete by March 2024.
