Removal of activated complement from shed blood: comparison of high- and low-dilutional haemofiltration.
BACKGROUND
Perioperative blood salvage is associated with release of inflammatory mediators. Depending on type of processing, the complement system is activated to some extent in the final blood product. The aim of the present study was to evaluate a haemofiltration technique concerning complement system activation and whether the volume of added saline will have an influence on the elimination of activated complement during processing.


METHODS
Sixteen patients undergoing total hip arthroplasty received wound blood salvaged intraoperatively with a haemofiltration technique. Saline was added to the reservoir for washing in a ratio of 1:1 or 5:1 of estimated blood volume. Samples for determination of the anaphylatoxins C3a and C5a, and the terminal SC5b-9 complement complex (TCC) were drawn from the patients, the collected blood, the ultrafiltrate and the processed blood.


RESULTS
Increased concentrations of C3a, C5a and TCC were found in aspirated and processed blood. Haemofiltration did not reduce the concentrations of these factors, except that of C3a in the group where saline was added in a ratio of 5:1. There were no increased concentrations of C3a, C5a or TCC in the patient plasma after reinfusion. No differences in blood pressure, heart rate, pH, arterial oxygen tension, arterial carbon dioxide tension, or base excess were found in association with reinfusion of the blood.


CONCLUSIONS
Collected shed blood washed through haemofiltration contained moderately elevated concentrations of C3a, C5a and TCC. Reinfusion of the blood neither led to increased systemic concentrations of complement activation products, nor to disturbances in haemodynamic or biochemical parameters.
Arnestad
J P
JP
Department of Anaesthesiology & Intensive Care, Sahlgrenska University Hospital, Göteborg, Sweden.
Hyllner
M
M
Bengtson
J P
JP
Tylman
M
M
Mollnes
T E
TE
Bengtsson
A
A
D000136:Acid-Base Equilibrium; D000368:Aged; D000706:Anaphylatoxins / Q000032:analysis; D019644:Arthroplasty, Replacement, Hip; D016063:Blood Loss, Surgical; D001794:Blood Pressure / Q000502:physiology; D001804:Blood Transfusion, Autologous; D001810:Blood Volume; D002245:Carbon Dioxide / Q000097:blood; D003167:Complement Activation; D015926:Complement C3a / Q000032:analysis; D015936:Complement C5a / Q000032:analysis; D015938:Complement Membrane Attack Complex; D003165:Complement System Proteins / Q000032:analysis*; D005069:Evaluation Studies as Topic; D005260:Female; D006023:Glycoproteins / Q000032:analysis; D006339:Heart Rate / Q000502:physiology; D006440:Hemofiltration / Q000379:methods*; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood; D007430:Intraoperative Care; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010949:Plasma; D012965:Sodium Chloride / Q000008:administration & dosage
D000706:Anaphylatoxins; D015938:Complement Membrane Attack Complex; D006023:Glycoproteins; D018836:Inflammation Mediators; C047610:SC5b-9 protein complex; D002245:Carbon Dioxide; D012965:Sodium Chloride; D015926:Complement C3a; D015936:Complement C5a; D003165:Complement System Proteins; D010100:Oxygen