A study of autologous blood collected after joint replacement surgery

Blood from the surgical drains of 11 patients undergoing joint replacement was collected in the Solcotrans Orthopaedic autologous transfusion device and analysed for microparticulate matter before and after micro-aggregate filtration and for its effect on the coagulation of paired venous blood samples. An average of 165 ml (range 0-260 ml) was collected into the Solcotrans during the first hour. Using a Coulter Counter Zm particle counter, particulate matter of diameter 10-20 microns was found in only 2 of 10 collections at an average concentration of 33 x 10(3)/l. All units contained acoagulable blood [kaolin partial thromboplastin time (KPTT) greater than 600 s] but when mixed with paired post-operative venous samples exhibited the ability to shorten the KPTT by an average of 4.3 s inspite of the marked dilutional effect of mixing. Retransfusion of blood collected in the Solcotrans Orthopaedic device appears to be a suitable method to supplement or substitute pre-deposit and reduce exposure to homologous blood. Given the low incidence and concentration of microparticles detected, retransfusion of shed blood by this method is unlikely to cause significant pulmonary vascular occlusion resulting directly from deposition of microparticles.