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Changes in mechanical fragility and free hemoglobin levels after processing salvaged cardiopulmonary bypass circuit
Sarah K Harm1, Jonathan H Waters, Pamela Lynn
1Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
Abstract:
Modified ultrafiltration (MUF) is available for the salvage of post-cardiopulmonary bypass circuit blood. This study evaluated the extent of hemolysis, the mechanical fragility index (MFI), and the amount of plasma free hemoglobin (PFHb) created after processing with the MUF device. Several RBC parameters were measured on pre- and post-MUF device processed samples of blood from 12 patients undergoing cardiac surgery. The MFI and total amount of PFHb did not change significantly between the pre- and post-processing samples: MFI, pre: .19 +/- .06 versus post: .19 +/- .06, p = .76; total amount of PFHb, pre: .24 +/- .21 g versus post: .20 +/- .12 g, p = .42. There was significantly more hemolysis in the post-processing samples compared with the pre-processing samples, .33 +/- .24% versus .96 +/- .48%, respectively, p < .001. Although percent hemolysis was increased following processing with the MUF device, the total amount of PFHb and RBC sublethal injury were not increased. The clinical significance of these findings needs to be determined.
Insights
Modified ultrafiltration (MUF) processing of post-cardiac surgery blood did not increase plasma free hemoglobin or red blood cell (RBC) injury. However, the study found a significant increase in hemolysis after MUF treatment.
Area of Science:
- Cardiovascular Surgery
- Biomedical Engineering
- Hematology
Background:
- Modified ultrafiltration (MUF) is utilized to salvage blood from cardiopulmonary bypass circuits.
- Assessing the impact of MUF on blood components is crucial for patient safety.
Purpose of the Study:
- To evaluate the extent of hemolysis, mechanical fragility index (MFI), and plasma free hemoglobin (PFHb) after MUF processing.
- To determine the effects of MUF on red blood cell (RBC) parameters post-cardiac surgery.
Main Methods:
- Blood samples from 12 cardiac surgery patients were analyzed pre- and post-MUF processing.
- Key parameters measured included RBC parameters, MFI, and PFHb levels.
Main Results:
- No significant changes were observed in MFI or total PFHb levels post-MUF.
- A significant increase in percent hemolysis was detected after MUF processing (0.33% pre vs. 0.96% post, p < 0.001).
Conclusions:
- While MUF processing increases hemolysis, it does not significantly elevate plasma free hemoglobin or cause sublethal RBC injury.
- Further clinical investigation is needed to determine the significance of increased hemolysis following MUF treatment.
