PLATELET-RICH PLASMAPHERESIS IN CARDIAC-SURGERY - A METAANALYSIS OF THE EFFECT ON TRANSFUSION REQUIREMENTS

Objective: Our purpose was to determine whether intraoperative platele t-rich plasmapheresis in cardiac surgery is effective in reducing the proportion of patients exposed to allogeneic red cell transfusions. Me thods: A systematic search for prospective, randomized trials of plate let-rich plasmapheresis in cardiac surgery, using MEDLINE, HEALTHSTAR, Current Contents, ''Biological Abstracts,'' and EMBASE/Excerpta Medic a up to August 1997, was completed. Trials were included if they repor ted either the proportion of patients exposed to allogeneic red cells or the units of allogeneic red cells transfused, Trials were abstracte d by 2 independent investigators and the quality of trial design was a ssessed with the use of a validated scale. Results: Seventeen referenc es met the inclusion criteria (1369 patients [675 control: 694 platele t-rich plasma-pheresis]). Platelet-rich plasmapheresis reduced the lik elihood of exposure to allogeneic red cells in cardiac surgery (odds r atio 0.44; 95% confidence interval 0.27, 0.72, P =.001), Platelet-rich plasmapheresis had a small but statistically significant effect on bo th the volume of blood lost in the first 24 hours (weighted mean diffe rence -102 mL; 95% confidence interval -148, -55 mL, P<.0001) and the mean units transfused (weighted mean difference -0.33 units; 95% confi dence interval -0.43, -0.23, P <.0001), However, platelet-rich plasmap heresis was only marginally effective (odds ratio 0.83, 95% confidence interval 0.34, 2.01, P =.68) for ''good'' quality trials, whereas it appeared very effective in trials with poor methodologic quality (odds ratio 0.33, 95% confidence interval 0.17, 0.62, P=.0007), Conclusions : Although platelet-rich plasmapheresis appeared effective in decreasi ng the proportion of patients receiving transfusions after cardiac ope rations, the quality of most of the supporting trials was Low and the benefit was small in trials of good quality, Further clinical trials s hould be completed.