Levels of complement factor C3 and its activated product, C3a, in operatively salvaged blood

Hemolytic reaction in the washed salvaged blood of a patient with paroxysmal nocturnal hemoglobinuria

Background

In patients with paroxysmal nocturnal hemoglobinuria (PNH), the membrane-attack complex (MAC) formed on red blood cells (RBCs) causes hemolysis due to the patient’s own activated complement system by an infection, inflammation, or surgical stress. The efficacy of transfusion therapy for patients with PNH has been documented, but no studies have focused on the perioperative use of salvaged autologous blood in patients with PNH.

Case presentation

A 71-year-old man underwent total hip replacement surgery. An autologous blood salvage device was put in place due to the large bleeding volume and the existence of an irregular antibody. The potassium concentration in the transfer bag of salvaged RBCs after the wash process was high at 6.2 mmol/L, although the washing generally removes > 90% of the potassium from the blood. This may have been caused by continued hemolysis even after the wash process. Once activated, the complement in patients with PNH forms the MAC on the RBCs, and the hemolytic reaction may not be stopped even with RBC washing.

Conclusions

Packed RBCs, instead of salvaged autologous RBCs, should be used for transfusions in patients with PNH. The use of salvaged autologous RBCs in patients with PNH should be limited to critical situations, such as massive bleeding. Physicians should note that the hemolytic reaction may be present inside the transfer bag even after the wash process.

An economic analysis of costs associated with development of a cell salvage program

BACKGROUND

The increasing cost of blood products and associated risks of transfusion have lead to a heightened interest in techniques which reduce or replace allogeneic blood transfusion. The use of cell salvage is being explored in a number of institutions. We present financial information which may be useful to institutions that are considering the addition of a cell salvage service.

METHODS

A review of the cell salvage data from 2328 patients was used to estimate the average cost of a packed red blood cell unit equivalent processed by cell salvage equipment. In addition, an analysis was performed to assess the break-even point of establishing a cell salvage service.

RESULTS

Initial capital outlay to establish a cell salvage service at this institution was $103,551. The annual fixed operating cost was $250,943. The average cost of transfusion of an allogeneic packed red blood cell unit was $200. For an equivalent cell salvage unit, the cost was $89.46. The payback period was 1.9 mo.

CONCLUSION

This analysis suggests that cell salvage can be significantly less expensive than allogeneic blood. The cost of cell salvage in other institutions will vary depending upon case volume, expected levels of blood loss per case, and initial investment costs. A step-by-step formula is provided to assist in the evaluation of a cell salvage service in hospitals of various sizes.

A review of leukofiltration in cardiac surgery: the time course of reperfusion injury may facilitate study design of anti-inflammatory effects

The systemic inflammatory response syndrome (SIRS) is a well-recognized phenomenon attending cardiopulmonary bypass (CPB) surgery. SIRS leads to costly complications and several strategies intended to ameliorate the symptoms have been studied, including leukocyte reduction using filtration. Although the body of work suggests that leukoreduction attenuates SIRS, discrepancies remain within the literature. The recent literature is reviewed, highlighting the areas where concordance is lacking. Investigations into many promising device-related technologies are often deterred by the high costs of clinical trials. Adding to costs is the fact that clinical end points generally require large sample sizes. An understanding, however, of the pathogenesis of reperfusion injury can guide the investigator to choose physiologic response measures that correlate well with clinical outcome, but feature low inherent variability, allowing for clinical trials with smaller sample sizes. With this goal in mind, a model for the pathogenesis of reperfusion injury is described. Using a model of reperfusion injury as underpinnings for the design of prospective pilot studies, we show that salvaged blood reinfused following CPB elicits time-dependent effects on pulmonary function as predicted by the model. Data are illustrative of principles that could expand the scope of clinical investigations designed to validate the use of physiologic response measures as correlates of clinical outcome. Such investigations would target surrogate markers of clinical outcome, measured at clinically relevant times. Once validated, these surrogate markers would, thereafter, become economical screening tools for clinical studies of device-related or pharmacological anti- inflammatory interventions.

Complement activation during major surgery: the effect of extracorporeal circuits and high-dose aprotinin

OBJECTIVE

To assess the in vivo contribution to complement activation of an extracorporeal circuit and the use of high-dose aprotinin during major surgery.

DESIGN

Sequential samples were obtained from 8 patients undergoing thoracic surgery, 20 patients undergoing orthotopic liver transplantation (OLT) using venovenous bypass, and 19 patients undergoing cardiac surgery using cardiopulmonary bypass (CPB).

INTERVENTION

The latter two groups were part of a randomized controlled trial of high-dose aprotinin.

MEASUREMENTS

Total complement activation was measured with the hemolytic complement activity and the C3 activation-specific marker, C3d antigen.

MAIN RESULTS

Complement activation did not occur during thoracic surgery. During OLT, C3d antigen levels, expressed as mean +/- standard deviation (SD), were elevated from baseline at skin closure (8.6 +/- 2.5 v 13.0 +/- 5.2 mg/L; p = 0.0082). During cardiac surgery, C3d antigen levels increased 10 minutes after the start of CPB (pre-CPB, 8.0 +/- 1.9 v 14.2 +/- 3.1 mg/L; p = 0.0001) and remained at greater than baseline values postoperatively (8.0 +/- 1.9 v 11.8 +/- 2.3 mg/L; p = 0.002). There was no difference in complement activation in those receiving high-dose aprotinin during OLT or cardiac surgery. Complement activation during cardiac surgery using extracorporeal circulation occurred to a greater extent than during OLT and thoracic surgery. Complement activation during cardiac surgery or OLT was not attenuated by the use of high-dose aprotinin.