The effect of preoperative aspirin-free interval on red blood cell transfusion requirements in cardiac surgical patients.

OBJECTIVE

To compare red blood cell transfusion in first-time coronary artery surgery patients who stopped taking aspirin < or = 2 days, 3 to 7 days, or >7 days preoperatively.

DESIGN

Observational study.

SETTING

University-affiliated teaching hospital.

PARTICIPANTS

Adult patients (n = 797) undergoing first-time coronary artery surgery on cardiopulmonary bypass who were not receiving other anticoagulant or antiplatelet drugs before surgery.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN

RESULTS

Patients were divided into 4 groups based on days since last ingestion of aspirin. Blood products transfused in the groups were (aspirin < or =2 days) (n = 140) 2.2 +/- 4 U of red cell concentrate (RCC) (mean +/- SD), 1.4 +/- 3 U of fresh frozen plasma (FFP), and 2.7 +/- 6 U of platelets; (aspirin 3 to 5 days) (n = 255), 1.5 +/- 2 U of RCC, 0.8 +/- 2 U of FFP, and 1.6 +/- 4 U of platelets; (aspirin 6 to 7 days) (n = 215), 1.6 +/- 3 U of RCC, 0.9 +/- 3 U of FFP, and 1.5 +/- 3 U of platelets; and (aspirin >7 days) (n = 187), 1.3 +/- 2 U of RCC; 0.6 +/- 2 U of FFP, and 0.9 +/- 2 U of platelets.

CONCLUSION

Patients who stop taking aspirin < or =2 s preoperatively have increased allogenic red blood cell transfusion requirements perioperatively. Patients who stop taking aspirin 3 to 7 days preoperatively have little or no increased requirement for allogenic red blood cell transfusion.