Skip Ribbon Commands
Skip to main content

Prescriptive Patient Extracorporeal Circuit and Oxygenator Sizing Reduces Hemodilution and Allogeneic Blood Product Transfusion during Adult Cardiac Surgery

8/07/2022 -  


The goal of this cardiopulmonary bypass (CPB) quality improvement initiative was to maximize hemoglobin (Hgb) nadir concentration by minimizing hemodilution and, in turn, eliminating allogeneic blood product transfusion.

Results / Methods

The effects of transitioning from "one-size-fits-all" to "right-sized" oxygenators, reservoirs, and arterial-venous tubing loops were evaluated through a 2-year retrospective review of 3852 patient perfusion records. Using a sizing algorithm, derived from manufacturers' recommendations, we were able to create individualized "right-sized" extracorporeal circuits based on patient body surface area, cardiac index, and target blood flows. Use of this algorithm led to an increase in the percent of algorithm-recommended smaller oxygenators being used from 39% to 63% (p < .01) and an increase in average hemoglobin nadir from 8.38 to 8.76 g/dL (p < .01). Decreased priming volumes led to increased hemoglobin nadir and decreases in allogeneic blood transfusion (p = .048). Patients with similar body surface areas who previously were exposed to larger oxygenators, reservoirs, and arterial-venous loops were now supported with smaller circuits as a result of the use of the right-sized algorithm. Adjustments to the algorithm were made for unique patients and procedural situations including age, gender, and length and type of procedure. Larger heat exchanger surface area oxygenators were used for circulatory arrest procedures as a result of the need for increased heat exchange capability. Despite the generally higher costs of smaller circuits, reduced transfusion-related expenditures and decreased exposure risks justify the use of smaller circuit components. This quality improvement initiative demonstrated that as an integral part of a multidisciplinary, multimodal blood conservation effort, the use of the "right-sized" circuit algorithm can help to elevate hemoglobin nadir during CPB and eliminate allogeneic blood transfusions to patients undergoing CPB.


In conclusion, by "right-sizing" patient extracorporeal circuits and using other methods to eliminate allogeneic blood use, dilutional anemia is reduced, thereby increasing Hgb nadir. These techniques contribute to the elimination of allogeneic blood product transfusion and transfusion-related complications and expenditures.


"Key Takeaways"

  • Increased use of the CAPIOX FX15 oxygenator and R30 reservoir circuit components was associated with decreased prime volumes and contributed to less hemodilutional anemia as shown by the rise in average Hgb nadir.
  • The Mayo clinic was able to demonstrate a significant increase in the percent of patients with no transfusion from 49% to 56%.


cardiopulmonary bypass, oxygenator, perfusion index, extracorporeal circuit, hemodilution.

The opinions expressed by Bronson SL et al. are their own. Unattributed data, device selection and procedural guidance is a matter of physician preference and opinion derived from the clinicians’ own observations and experience.