Changes in Respiratory Function Before and After Cardiopulmonary Bypass in Children with Congenital Heart Disease with Increased or Decreased Pulmonary Blood Flow.

Objective: Cardiopulmonary bypass (CPB) is a fundamental approach for managing complex congenital heart diseases (CHD). This study aims to examine the changes in respiratory function before and after CPB in children under 12 years diagnosed with CHD with different types of shunts.

Methods: A retrospective analysis was conducted on the clinical data of 60 pediatric patients with CHD admitted to the hospital between January 2022 and December 2023. Based on shunt type, the patients were divided into Group A (increased pulmonary blood flow, n = 30) and Group B (decreased pulmonary blood flow, n = 30). Changes in the diameters of the pulmonary artery and aorta, as well as respiratory mechanics before and 24 hours after CPB, were assessed in both groups.

Results: There were no significant differences in general characteristics between the two groups (p > 0.05). The external diameter of the pulmonary artery among patients in Group A was significantly larger than that in Group B (2.50±0.38 vs 1.31±0.29 cm, p < 0.05), while the external diameter of the aorta was significantly smaller in those in Group A compared to Group B (1.60±0.26 vs 1.91±0.37, p < 0.05). Significant differences were observed in the respiratory mechanics indexes before and after CPB within and between the two groups, including peak airway pressure, plateau airway pressure, inspiratory resistance, expiratory resistance, and lung-thorax compliance (p < 0.05).

Conclusions: Significant differences in the diameters of the pulmonary artery and aorta were observed among pediatric patients with CHD, depending on the type of shunt used. Dynamic monitoring of respiratory mechanics before and after CPB is essential for optimizing clinical respiratory management to facilitate timely adjustments in respiratory support strategies.