D. Dörffel et al.: J Extra Corpor Technol 2025, 57, 89 – 95 93
Figure 3. Histogram of the elimination of total protein. The black vertical line in the histogram represents the target value for total protein elimination of 90 %.
Figure 4. Scatterplot of the age of patients relative to the elimination of total protein in %.
Identifying the exact factors that contribute to noncompliance with target values for quality control during intraoperative use of cell salvage is not trivial. Various factors influence the course of the operation and, in turn, hematocrit quality and total protein elimination. To retrospectively determine possible causes, the senior physicians responsible for cell salvage at the Department of Anesthesiology and Intensive Care Medicine at the Campus Charité Mitte and the Campus Benjamin Franklin were interviewed.
The main factors that had a negative impact on compliance with both target values were:
1. the use of the cell saver emergency option in the event of massive blood loss and
2. a strong dilution of the collected blood.
The dilution of the collected blood is caused by a high proportion of rinsing fluid relative to a low collection volume, which can be further increased as rinsing fluid is added until the bowl is filled. This often occurs with the last bowl if it is not completely filled. If only a very small volume of collected blood is gathered overall, this also leads to dilution in the first bowl. If the collected blood has fewer red blood cells due to a low collection volume and the remainder of the bowl is filled with rinsing fluid, the processed blood will have a lower hematocrit than undiluted collected blood, despite potentially higher red blood cell yield. Alternatively, processed blood can be taken from the retransfusion bag to fill the remaining bowl and start the centrifugation process. However, the study protocol does not specify which wash cycles this was used for. Therefore, cycles with incompletely filled bowls cannot be