Impact of Chest Wall Mechanics on Lung and Cardiovascular Function During Delayed Sternal Closure

This study aims to describe chest wall mechanics during delayed sternal closure (DSC) in neonates following cardiopulmonary bypass or palliation of congenital heart diseases.

This research study is being done so that investigators can understand the complex interactions between the heart, the lungs and the chest wall after heart surgery. Understanding this may guide future care that can help patients with their recovery from heart surgery. The heart and lungs work together to make sure the body has the oxygen-rich blood it needs to function properly. The chest wall protects the heart, lungs, and other important organs. Investigators would like to learn how a patient's chest wall contributes to the heart and lungs interaction when the chest is left open after heart surgery. Investigators will be using a device called an esophageal pressure catheter to estimate the pressure that is transmitted to the lungs and heart, called pleural pressure. Previous research has shown that this pressure measurement is used to adjust the breathing machine for patients with lung diseases. Measuring the pressure transmitted to the lungs and heart after heart surgery and delayed chest wall closure may help investigators understand how the chest wall contributes to the heart and lung interaction.

Palliation of Congenital Heart Diseases, Cardiopulmonary Bypass, Chest Wall Mechanics, Neonatal Delayed Sternal Closure

chest wall mechanics, congenital heart disease, neonates, delayed sternal closure, cardiopulmonary bypass

Participants will undergo placement of an esophageal manometry catheter before planned sternal closure. This catheter will be used to measure esophageal pressure which is a surrogate for pleural (intrathoracic) pressure. Esophageal pressure will then be used to estimate changes in respiratory system mechanics and hemodynamics following sternal closure and across different levels of positive end-expiratory pressure (PEEP) and tidal volumes.

Investigators hypothesize that successful esophageal catheter placement and measurement of Pes (full data set) will occur in ≥80% of enrolled subjects.

Inclusion Criteria: Informed consent provided by parent or primary guardian. Aged <28 days of life at the time of cardiac surgery. Undergone surgery using CPB for congenital heart disease. Undergoing DSC in CCCU. Exclusion Criteria: Gestational age < 37 weeks or weight < 2 kg at the time of surgery. Endotracheal tube leak >20%. Need of extracorporeal support (ECMO), inhaled nitric oxide. Pre-existing pulmonary disease (For example: Congenital diaphragmatic hernia). Pre-existing or new arrhythmia that can impact hemodynamic assessment. Severe coagulopathy or any other contraindication for the insertion of a nasogastric catheter (e.g., history of tracheo-esophageal fistula).

All de-identified individual participant data (IPD) that underlie results in a publication will be shared upon request. The study protocol, statistical analysis plan, informed consent form, and analytic code will be shared starting (6 months after publication or starting January 2023, whichever comes first) upon request in writing. Requests for IPD will be reviewed by the study PI and SickKids institute. IPD will be provided to researchers interested in furthering academia and research development only. IPD requests may also be subjected to SickKids' institutional agreements/contracts. IPD mechanism of sharing and types of analysis/data shared will be directed and determined by SickKids' institutional research contracts requirements.

Requests for IPD will be reviewed by the study PI and SickKids institute. IPD will be provided to researchers interested in furthering academia and research development only. IPD requests may also be subjected to SickKids' institutional agreements/contracts. IPD mechanism of sharing and types of analysis/data shared will be directed and determined by SickKids' institutional research contracts requirements.