Autologous platelet sequestration in patients undergoing coronary artery bypass grafting

Blood conservation remains an important issue for patients undergoing cardiac surgery with cardiopulmonary bypass. Platelet sequestration (PSQ) is an aggressive autologous blood conservation method, whose effectiveness is still debated. The main objective of the present study was to evaluate whether PSQ reduces postoperative blood transfusion requirements in patients undergoing coronary artery bypass grafting (CABG) and to determine if PSQ is a cost-effective blood conservation method.

All adult patients admitted for CABG entered the study. Exclusion criteria were: recent blood transfusion (<7 days), a platelet count of 150x10(3)/microl or less, hematocrit less than 35% and body weight 50 kg or less. The sequestration was aim 20% or more of the total platelet plasma volume. The sequestration protocol was three sequestration cycles performed just prior to surgery. The concentrated platelet portion was reinfused after weaning from the cardiopulmonary bypass. Hundred seven parameters/patients were recorded. Sixty patients entered the study; 30 in the PSQ group and 30 controls (CTR).

Patient characteristics, operation data, preoperative hematology and coagulation parameters did not differ between the groups. In the PSQ group a mean of 433+/-34 ml concentrated platelet portion was collected. The mean platelet count in the concentrated platelet portion was 749+/-157x10(3)/microl, resulting in a platelet yield of 28+/-6% (2040%). The average total chest tube blood loss was 423 ml (PSQ) compared to 858 ml (CTR), p<0.001. A greater number of CTR patients required blood transfusion postoperatively (23) compared to PSQ (3), P<0.001, and fluid requirements were also significantly increased in the control group, P<0.001. No statistical differences in hematology and coagulation parameters between the groups were observed. The hospital mortality was low and the incidence of postoperative complications was few and without group differences. Post-extubation gas exchange was better in PSQ patients compared to CTR.

A preoperative PSQ of a minimum 20% of the total platelet plasma volume resulted in significantly lower postoperative blood loss and fluid and blood transfusion requirements compared to controls. Post-extubation gas exchange was also better after PSQ. Only one patient did not tolerate the sequestration. No other adverse effects of the procedure were observed.