In recent years, blood transfusion has become a greatly debated health care issue. Considerations have included the
concerns regarding blood safety from the 1980’s and 1990’s  (Human Immunodeficiency Virus, Hepatitis C Virus) as well
as emerging pathogens (West Nile Virus, variant Creutzfeldt-Jakob disease) and transfusion reactions related to incorrect
blood/component transfused, bacterial contamination, and TRALI (transfusion related acute lung injury).  Current issues of
blood supply shortages and the financial resources required to produce the safest possible product have also become the
focus of attention.  In response to these considerations, perioperative blood conservation strategies, such as pre-operative
autologous donation, erythropoietin therapy, antifibrinolytic medications, acute normovolemic hemodilution, hypotensive
anesthetic, intra-operative cell salvage, and review of transfusion triggers and practices are being implemented with increasing
frequency. This discussion will be limited to the process of intra-operative cell salvage as a strategy to reduce the need for
allogenic blood transfusion.

Intra-operative cell salvage is the process whereby shed surgical field blood is collected, filtered, and washed to produce
autologous red blood cells for transfusion to the patient.  Red blood cells processed by cell salvage and stored at room
temperature can be safely transfused up to 6 hours following collection.  During the surgical procedure, wall suction is not
utilized to clear the operative field; the cell salvage suction pressure can be regulated if the field needs to be cleared quickly.
Heparinized normal saline or citrate anticoagulant is added as the shed blood is collected. Filtering and washing remove
contaminants such as cell fragments, fat globules, bone chips, and potassium leaked from hemolysis.  The final washing
steps utilize only normal saline to produce red blood cells (no functional platelets or clotting factors) suspended in saline
for transfusion to the patient.

The technology of cell salvage has evolved since its initial implementation in the 1970’s. In the early days, cell salvage was
limited to simply filtering by gravity.  Subsequently, washing techniques involved “bowl technology”, centrifugation within a
constrained bowl, with a full bowl mandatory for effective, efficient washing.  The most advanced technology utilizes “coil
technology”, with the shed blood directed into a continuous washing chamber, allowing for continuous processing.   This
technology avoids wasting partially filled bowls of shed blood and allows for a readily available product to be transfused to
the patient.  The computerized process of the cell salvage equipment facilitates the role of the perfusionist in balancing the
suction pressure, the washing chamber fill rate, and the wash cycle flow rate to the priority of the patient’s physiological need
for red blood cell transfusion.

As with all health care technology, the relative advantages and limitations of intra-operative cell salvage must be weighed up
in the clinical setting.  Intra-operative cell salvage is most effective in major surgical blood loss (1000 ml or greater) procedures
and especially effective for patients with adequate pre-operative hemoglobin.  Cell salvage is an advantageous blood conservation
strategy in that a 3 to 4 week pre-operative time frame is not a requirement, as is with pre-operative autologous donation or
erythropoietin therapy.  Contamination of the surgical site, ongoing infectious processes, use of topical antibiotics or
anticoagulants, potential presence of amniotic fluid or cancer cells in the surgical field is controversial when considering
intra-operative cell salvage.  If 1 to 1 ½ times the patient’s blood volume is shed, close monitoring for signs of coagulopathy
becomes essential.  Financial aspects to bear in mind include the cell salvage device itself, the disposables required for each
patient, the availability of skilled operators (perfusionists), and the frequency of surgical cases where cell salvage is applicable.

The Canadian Standards Association (CSA) draft standards for blood have specified recommendations governing perioperative
collection (Canadian Standards Association Draft Z902 Blood and Blood Components; Section 12.5: Perioperative Collection). 
Policies and procedures with established quality control programs, recording of the collection procedures utilized and explicit
labeling of the collected shed blood are outlined in these recommendations.

Intra-operative cell salvage can be effectively utilized for elective and emergency abdominal aortic aneurysm and spinal fusion/instrumentation procedures. A committed multi-disciplinary team approach involving surgeons, anesthesiologists,
perfusionists and nurses is essential to provide the benefits of intra-operative cell salvage to patients.  Implementation of
intra-operative cell salvage as well as other blood conservation strategies will continue to evolve as physicians and their
patients balance the benefits and risks of allogenic transfusion in the perioperative care setting.

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