To determine if pre-operative high-flow nasal cannula (flow >
2 L per minute) or mechanical ventilation impact post-operative outcomes after the superior cavopulmonary connection. A single-center retrospective review of single-ventricle patients who underwent the superior cavopulmonary connection procedure at a tertiary care center over a 10-year period. Patients who underwent the procedure at greater than 2 years of age were excluded. The groups of interest were those who were on mechanical ventilation or high-flow nasal cannula. Patients in room air or on nasal cannula oxygen served as the control group. A total of 269 consecutive patients were included, of which 44 required high-flow nasal cannula and 17 required mechanical ventilation prior to the superior cavopulmonary connection procedure. Thirty-day post-operative survival was high, with 1 death in both the high-flow nasal cannula and the mechanical ventilation groups. At 1-year post-procedure, the transplant-free survival was lower in the mechanically ventilated group when compared to the high-flow nasal cannula and room air groups (46% vs. 84% vs. 95%, p value <
0.01). The same trend was seen at 5 years (20% vs 78% vs 90%, p value <
0.01). These groups also had worse overall survival, longer post-operative lengths of stay, and longer post-operative intubation durations. Pre-operative respiratory support with high-flow nasal cannula or mechanical ventilation is associated with decreased overall survival and reduced transplant-free survival at 1- and 5-year post-superior cavopulmonary connection.