Abstract
AIM: To assess whether early prone positioning is associated with differences in gas-exchange indices at prespecified postoperative time points after complete tetralogy of Fallot (TOF) repair in children, without evidence of hemodynamic instability. We also explored associations between early respiratory indices and short-term outcomes. METHODS: This was a single-center retrospective cohort study of patients aged <18 years undergoing complete TOF repair. Groups were defined by positioning during the first 12 postoperative hours: prone (n = 44) or supine (n = 43). PaO₂, PaCO₂, and PaO₂/FiO₂ were measured at 1, 4, 8, and 12 h; hemodynamics were recorded over 24 h; short-term outcomes within 60 days were ascertained, and postoperative mortality was assessed during in-hospital follow-up and at 3 months. Group comparisons, Pearson correlations, and receiver operating characteristic analyses were performed. RESULTS: Prone positioning was associated with higher oxygenation indices vs. supine (higher PaO₂ at 1, 4, 8, 12 h; higher PaO₂/FiO₂ at 4, 8, 12 h) and with lower PaCO₂ at 8 and 12 h (all P ≤ 0.05). Hemodynamics were similar between groups, and no maneuver-related adverse events were documented. Short-term clinical outcomes did not differ. No in-hospital deaths occurred in either group, and no deaths were identified at the 3-month postoperative follow-up. Within the prone group, PaO₂/FiO₂ at 12 h correlated inversely with hospital stay (r = -0.33, P = 0.03). PaCO₂ at 8 h showed modest discrimination for ventilator-associated pneumonia (AUC 0.73; sensitivity 92.86%, specificity 31.25). CONCLUSIONS: Early short-duration prone positioning was associated with differences in gas-exchange indices at prespecified time points without evidence of hemodynamic instability after pediatric TOF repair, while short-term outcomes were similar. Findings support feasibility and warrant prospective multicenter evaluation to define optimal timing and duration.