Influence of a cell salvage washing system and leukocyte reduction filtration on bacterial contamination of canine whole blood ex vivo.

OBJECTIVE

To determine the ability of cell salvage washing and leukoreduction filtration to remove bacterial contamination from canine whole blood.

STUDY DESIGN

Ex vivo nested cohort study.

SAMPLE POPULATION

Commercially purchased fresh canine whole blood (n = 33 units).

METHODS

Commercially obtained canine whole blood was inoculated with known concentrations of one of three species of bacteria, Escherichia coli (ATCC 25922), Staphylococcus pseudintermedius (quality control strain; Texas A&M University), or Pseudomonas aeruginosa (ATCC 27853). Negative controls were inoculated with sterile saline. The inoculated blood was processed through a cell salvage system and filtered through a series of two leukocyte reduction filters. Samples were aseptically collected at five points during processing (inoculum, prewash, postwash, post-first filtration, and post-second filtration) for bacterial enumeration.

RESULTS

Bacterial concentrations were reduced by 85.2%, 91.5%, and 93.9% for E coli, S pseudintermedius, and P aeruginosa, respectively, after washing (P < .0001), and bacterial concentrations were reduced by 99.9%, 100%, and 100%, respectively, after the first filtration (P < .0001). After the second filtration, none of the three species of bacteria could be isolated (100% reduction). No bacterial growth was obtained from negative controls throughout the study. The type of bacteria (P = .29) did not allow prediction of bacterial reduction.

CONCLUSION

Cell salvage washing combined with leukoreduction filtration eliminated bacterial contamination of whole dog blood (P < .0001).

CLINICAL SIGNIFICANCE

Cell salvage washing and leukoreduction filtration could be applied to intraoperative autotransfusion in clinical animals, especially those treated for trauma or hemorrhage with concurrent bacterial contamination.