Washing blood-saturated surgical swabs shown to boost the recovery of erythrocytes by Andrea Galliano, Ivan Kalmukov and colleagues at Fitzpatrick Referrals

Findings of a BSAVA PetSavers-funded study published in the November 2022 issue of Veterinary Surgery showed that a cell salvage device was efficient at recovering canine erythrocytes in an ex vivo setting. Access the paper here.

Building on this work, further study published in the July 2022 issue of the American Journal of Veterinary Research (AJVR) compared red blood cell recovery using a cell salvage device between swab-washing by manual agitation or filtration and found no significant difference between the two. The high red blood cell mass recovered using both methods (>83%) suggests that both techniques are highly efficient, while the potential for the automation of filtration swab-washing could have benefits in a clinical setting.

Haemorrhages are a major complication of surgery, with blood transfusions the gold standard of treatment. In human surgery, intraoperative cell salvage collects and filters suctioned blood and bloody fluid, before cells are washed, concentrated, and delivered to the patient. The washing of blood-soaked swabs can improve red blood cell recovery, but manual washing is labour intensive and time-consuming. Little is known about such techniques in veterinary medicine.

In the paper titled “Intraoperative cell salvaging: ex vivo evaluation of two swab-washing methods”, red blood cell recovery by manual swab washing was compared with that achieved with a newly devised filtration apparatus based on a mesh basket and pan that function like a colander.

Twelve recently expired units of canine packed red blood cells underwent quality analysis before being volume-expanded with anticoagulant and divided into two equal aliquots that were used to soak surgical swabs. One set of swabs was processed using manual agitation in saline solution while the other underwent gravity-aided filtration with saline washing using the mesh apparatus. The resulting bloody fluid was processed using the Cell Saver Elite Autotransfusion System (Haemonetics).

The volume, manual packed cell volume, complete blood count, and red blood cell mass, calculated as the product of the volume and packed cell volume, were measured before and after salvaging. Red blood cell mass recovery was then recorded as a percentage. The red blood cell mass recovered by manual agitation and filtration averaged 85.73% and 83.99%, respectively, which was not significantly different.

This work has the potential to improve the recovery of red blood cells during haemorrhage, which can then be transfused back to aid recovery of the patient.

The full article, which is open access, can be found in the July issue of the American Journal of Veterinary Research (AJVR), and can be read online here: https://doi.org/10.2460/ajvr.22.03.0061