Performance of a new-generation continuous autotransfusion device including fat removal and consequences for quality controls

Blood clot formation in reinfusion bag with CATSmart: Two case reports

Autologous blood cell salvage reduces the need for postoperative allogeneic blood transfusion and alleviates immunologic reactions, so the technique is commonly used in cardiac surgery. The continuous autotransfusion system is a type of blood cell salvage device. Although the processing program of continuous autotransfusion system includes filtering of several materials from suctioned blood, such as clots, leukocytes, cytokines, and complement, we identified some unexpected blood clots in the reinfusion bag. Pathologic examination revealed that the clots were composed of fibrin, red blood cell aggregates, and histiocytes. We report two cases of these abnormal findings during the use of CATSmart in cardiac surgery.

[Cell salvage : Scientific evidence, clinical practice and legal framework]

Cell salvage is an efficient method to reduce the transfusion of homologous banked blood, as documented by several meta-analyses detected in a systematic literature search. Cell salvage is widely used in orthopedics, trauma surgery, cardiovascular and abdominal transplantation surgery. The retransfusion of unwashed shed blood from wounds or drainage is not permitted according to German regulations. Following irradiation of wound blood, salvaged blood can also be used in tumor surgery. Cell salvage makes a valuable contribution to providing sufficient compatible blood for transfusions in cases of massive blood loss. Certain surgical procedures for Jehovah's Witnesses are only possible with the use of cell salvage. Another possible use is the washing of homologous banked blood, e. g. to prevent potassium-induced arrhythmia or sequestration of autologous platelets. Other advantages besides a good compatibility are the high vitality and functionality of the unstored autologous red blood cells. These have been declared a pharmaceutical product by the German transfusion task force in 2014, so that the autologous red blood cells are now under the control of the Pharmaceutical Products Act (AMG). The new hemotherapy guidelines, however, tolerate cell salvage only under strict rules, whereby the production of autologous blood during or after surgery is still possible without additional special permits. The new guidelines now require the introduction of a quality management system for cell salvage and regular quality controls. These quality controls include a control of the product hematocrit for every application, monthly controls of the protein and albumin elimination rates and the erythrocyte recovery rate for each cell salvage device. Testing for infection markers is not required. The application of cell salvage has to be reported to the appropriate authorities.

Quality evaluation of the emergency program of three contemporary cell-washing machines

This study evaluates the efficiency of emergency programs used by three contemporary cell washers. Both time necessary to process a given amount of blood and quality of the processed blood are investigated. The Fresenius Kabi Smart, Haemonetics Elite and LivaNova Xtra were validated using bovine blood, with a starting hematocrit of 13% or 21%. For all devices, the pre-programmed emergency program was used. The total volume processed in the 13% hematocrit group was 358 ± 68 mL for Fresenius, 375 ± 308 mL for Haemonetics and 497 ± 87 mL for LivaNova. In the 21% hematocrit group, the volumes were 533 ± 60 mL, 713 ± 142 mL and 798 ± 96 mL, respectively, showing a statistical difference between the Fresenius and LivaNova (p = 0.02). In the 13% hematocrit group, the Fresenius processed 45 ± 15 mL blood/min, the Haemonetics 62 ± 8 mL blood/min and the LivaNova 66 ± 1.5 mL blood/min. The difference between the Fresenius and LivaNova was statistically significant (p = 0.04). In the 21% hematocrit group, the processing speed was 69 ± 4 mL blood/min, 62 ± 8 mL blood/min and 77 ± 5 mL blood/min for the Fresenius, LivaNova and Haemonetics, respectively (p = 0.25). No major differences in the elimination of potassium, albumin and total protein or in hemolytic index were observed. No major differences were observed between discontinuous and continuous systems with respect to processing speed and wash quality with a starting hematocrit of 21%. Minor differences in processing speed were observed with a starting hematocrit of 13%.

Cell salvage using the continuous autotransfusion device CATSmart - an observational bicenter technical evaluation

BACKGROUND

The use of cell salvage and autologous blood transfusion has become an important method of blood conservation. So far, there are no clinical data about the performance of the continuous autotransfusion device CATSmart.

METHODS

In total, 74 patients undergoing either cardiac or orthopedic surgery were included in this prospective, bicenter and observational technical evaluation to validate red cell separation process and washout quality of CATSmart. The target of red cell separation process was defined as a hematocrit value in the packed red cell unit of 55-75% and of washout quality of 80-100% removal ratio.

RESULTS

Hematocrit values measured by CATSmart and laboratory analysis were 78.5% [71.3%; 84.0%] and 73.7% [67.5%; 75.5%], respectively. Removal ratios for platelets 94.7% [88.2%; 96.7%], free hemoglobin 89.3% [85.2%; 94.9%], albumin 97.9% [96.6%; 98.5%], heparin 99.9% [99.9%; 100.0%], and potassium 92.5% [90.8%; 95.0%] were within the target range while removal of white blood cells was slightly worse 72.4% [57.9%; 87.3%].

CONCLUSION

The new autotransfusion device enables sufficient red cell separation and washout quality.