The goal of this randomized controlled trial is to learn if different head-elevated prone positioning angles can optimize cardiopulmonary function and enteral nutrition tolerance in infants and children after congenital heart disease (CHD) surgery. The main questions it aims to answer are:
1. Do specific prone positioning angles (10°, 30°, or 45°) lead to better improvements in cardiopulmonary recovery, specifically regarding oxygenation, lung compliance, airway resistance, and hemodynamic stability?
2. Does increasing the elevation angle improve the tolerance of enteral nutrition (tube feeding) while maintaining patient safety?
Researchers will compare three different head-of-bed elevation angles (10°, 30°, and 45°) to see if a specific angle offers superior heart and lung support and nutritional benefits during the early postoperative period.
Participants will:
1. Be randomly assigned to one of three groups: 10°, 30°, or 45° head-elevated prone position.
2. Maintain the assigned prone position for at least 12 hours daily.
3. Undergo monitoring of cardiopulmonary indicators (including oxygen levels, ventilator parameters, blood pressure, and central venous pressure) and digestive function (gastric residual volume) at scheduled intervals (0, 4, 6, and 12 hours).