Association Between Intraoperative Alveolar Dead Space Fraction and Early Extubation After Glenn and Fontan...

To evaluate the association between intraoperative alveolar dead space fraction (AVDSF) and early extubation in patients undergoing Glenn and Fontan procedures.

Retrospective observational study.

Single tertiary care center.

Ninety-two patients who underwent Glenn (n = 44) or Fontan (n = 48) procedures between 2019 and 2024.

None.

Arterial blood gas and end-tidal CO₂ were measured simultaneously at procedure start, cardiopulmonary bypass (CPB) weaning, and procedure end. Postoperative outcomes were also assessed. Patients extubated ≤24 hours and >24 hours postoperatively comprised the early extubation (E) (n = 79) and prolonged ventilation (P) (n = 13) groups, respectively. Median AVDSF values (E v P) were 0.13 versus 0.11 at the start (p = 0.67), 0.18 versus 0.29 at CPB weaning (p = 0.01), and 0.12 versus 0.26 at the end (p = 0.02). The area under the curve for AVDSF at procedure end associated with early extubation was 0.70 (95% confidence interval: 0.53-0.86; cutoff: 0.19; sensitivity: 69.2%; specificity: 73.4%). The E group had significantly better mean postoperative outcomes compared with the P group, including ventilation duration (6.00 v 72.00 hours, p < 0.001), intensive care unit length of stay (5.00 v 23.00 days, p < 0.001), hospital length of stay (20.00 v 44.00 days, p < 0.001), cardiovascular reintervention rate (10.1% v 61.5%, p < 0.001), and in-hospital mortality (0.0% v 15.4%, p = 0.02).

AVDSF measured at CPB weaning and the end of the procedure was significantly lower in patients extubated within 24 hours, suggesting that intraoperative AVDSF is associated with early extubation after Glenn or Fontan procedures.