Bradykinin and cysteinyl leukotriene concentrations in cell-salvaged blood before and after passage through negatively charged filters during clinical use in cancer patients: a pilot study.

It has been suggested that giving cell-salvaged blood through a leucocyte depletion filter can cause hypotension due to bradykinin released when factor XII and platelets are activated by the negatively charged surface of the filter. We measured the concentration of bradykinin and cysteinyl leukotrienes in cell-salvaged blood sampled before and after passage through a negatively charged leucodepletion filter in 24 consecutive patients with gynaecological or bowel cancer undergoing elective surgery with cell salvage. In no case was an increase in bradykinin concentration observed after passage through the filter; in 23 patients the post-filtration bradykinin concentration was zero (p = 0.007). The change in the concentration of cysteinyl leukotrienes detected during passage across the filter was not statistically significant (p = 0.1). Our findings do not support the suggestion that either bradykinin or cysteinyl leukotrienes are generated in cell-salvaged blood during passage through leucodepletion filters.

Use of a leucocyte filter to remove tumour cells from intra-operative cell salvage blood.

SUMMARY: The intra-operative blood loss of 50 consecutive gynae-oncology patients undergoing surgery for endometrial, cervical or ovarian cancer was cell salvaged and filtered. In each case blood samples were taken from the effluent tumour vein, a central venous line, the cell saver reservoir, the cell salvage re-transfusion bag after processing but before filtration and from the cell salvage re-transfusion bag after processing and filtration. Samples were examined using immunohistochemical monoclonal antibody markers for epithelial cell lines. Viable, nucleated malignant cells were detected in 2/50 central venous samples, 34/50 reservoir samples and 31/50 unfiltered cell salvaged samples. After passage through a Pall RS leucocyte depletion filter no remaining viable, nucleated malignant cells were detected in any sample. The clinical risks of cell salvage in these circumstances should be reviewed in the light of the risks of allogeneic blood transfusion.

Blood conservation techniques in obstetrics: a UK perspective.

In the UK, maternal mortality due to haemorrhage appears to be rising, with obstetric haemorrhage accounting for 3-4% of the red cells transfused. Allogeneic blood transfusion carries risks such as administration errors, transmitted infections and immunological reactions. The supply of blood is decreasing, partly due to the exclusion of donors who have themselves received a blood transfusion since 1980, in order to stop transmission of variant-Creutzfeldt-Jakob disease. The cost of blood is significantly increasing, partly because it is now leucocyte-depleted to minimize viral transmission. Various blood conservation techniques can reduce exposure to allogeneic blood thereby reducing risk and conserving the blood supply. These include preoperative autologous donation, acute normovolaemic haemodilution and intra-operative cell salvage. Preoperative autologous donation may produce anaemia, does not eliminate transfusion risk, cannot be used in an emergency and is not acceptable to Jehovah's Witnesses. It should be reserved for exceptional circumstances (rare blood type or unusual antibodies). Acute normovolaemic haemodilution may induce anaemia and cardiac failure and cannot be used in an emergency. It may have a limited role in combination with other techniques. Intra-operative cell salvage is more effective and useful in obstetrics than the other techniques, overcomes their shortcomings and is endorsed by CEMACH, OAA/AAGBI Guidelines, the National Blood Service and NICE.