Oxygenator oxygen transfer performance during cardiopulmonary bypass of the Sorin^® Inspire 6F^©

BackgroundOxygenator oxygen transfer performance is typically measured by manufacturers under standardized, static laboratory conditions. However, these parameters do not adequately reflect the dynamic environment of clinical cardiopulmonary bypass (CPB). To align with modern goal-directed perfusion standards - specifically the maintenance of physiological PaO2 levels to reduce oxidative stress - perfusionists require a reliable tool to titrate FiO2 based on real-time oxygen demand. This study aimed to develop a clinical oxygen transfer function for the Sorin® Inspire 6F© oxygenator.MethodsWe retrospectively analyzed 420 blood gas samples and hemodynamic parameters from 54 adult patients undergoing CPB with the Sorin® Inspire 6F©. Oxygen transfer (VO2) was calculated via the Fick principle. Using the methodology established by Hamilton et al., a validation subset (n = 57) of samples within a target PaO2 range of 150 ± 5 mmHg was used to derive a specific correlation function between FiO2 and VO2 via linear regression analysis.ResultsA significant correlation was observed between FiO2 and oxygen transfer. For the validation subset, the derived oxygen transfer function for the Sorin® Inspire 6F© was VO₂ = 284.34 x FiO2 (R² = 0.6185). In contrast, the correlation for the entire clinical dataset (n = 420) yielded an R² of 0.4583. Comparison with existing literature indicates that the Inspire 6F© has a lower transfer capacity compared to larger membrane surface area oxygenators, as expected.ConclusionsThe newly developed oxygen transfer function provides a practical, evidence-based tool for the clinical setting. It allows perfusionists to adjust the FiO2 accurately to meet patient-specific oxygen requirements and maintain desired PaO2 levels. Implementing this function in routine practice can enhance standardization and improve patient safety by preventing hyperoxygenation.