Postoperative suction wound drainage after joint replacement is largely sanguinous. In fact hemoglobin levels in this drainage are in the range 22-25%. After complex reconstructions and particularly bilateral procedures wound drainage can be considerable and reinfusion of this drainage may lessen the need for transfusion. There is considerable controversy if this fluid should be washed or unwashed and reinfused through filtration systems alone. Clinical experience at HSS has demonstrated significant hypotensive events when unwashed drainage is reinfused. Cytokines have been implicated as a possible source of these hypotensive episodes. Cytokine levels in washed and unwashed drainage are being evaluated and serum levels in the patient are being studied to determine the safety of this drainage material and whether it should be washed or unwashed.