Cerebral desaturation in cystic fibrosis patients undergoing Double lung transplantation

Perioperative cerebral oximetry is widely used during cardiopulmonary bypass (CPB) to monitor cerebral perfusion and guide intraoperative management. However, standard thresholds may not account for disease-specific physiology. In cystic fibrosis (CF), chronic hypoxia and hypercapnia may influence baseline cerebral oxygenation and intraoperative responses.

This retrospective cohort study included adults who underwent bilateral lung transplantation with intraoperative CPB between January 2014 and February 2022 at a single academic center. Patients with CF (n = 18) were compared with non-CF controls (n = 128). Bilateral near-infrared spectroscopy (NIRS) was used to monitor cerebral oxygenation, with desaturation defined as a ≥20% decline from baseline. Arterial blood gases (ABGs) were collected during CPB, and postoperative neurologic outcomes were assessed through clinical documentation during the index hospitalization.

CF patients demonstrated significantly lower intraoperative cerebral oximetry values and higher PaCO₂ compared with controls. Prior to CPB and during bypass, model-based mean rSO₂ values were significantly lower in CF patients (62.0% vs. 69.1%, p = 0.04; 42.6% vs. 57.0%, p < 0.001; and 40.3% vs 53.9%, p = 0.0001), with a significant group × time interaction (p = 0.002). Imaging-confirmed stroke was infrequent and did not differ significantly between groups (5.6% vs 3.1%, p = 0.487).

CF patients exhibit lower cerebral oxygen saturation and distinct carbon dioxide physiology during CPB, yet similar short-term neurologic outcomes compared with non-CF patients. Cerebral oximetry values in CF should be interpreted in the context of chronic pulmonary physiology rather than uniform desaturation thresholds.