Blood Conservation

Drugs that inhibit the platelet P2Y12 receptor should be discontinued before operative coronary revascularization (either on pump or off pump), if possible. The interval between drug discontinuation and operation varies depending on the drug pharmacodynamics, but may be as short as 3 days for irreversible inhibitors of the P2Y12 platelet receptor. (B, Class I)

Point-of-care testing for platelet adenosine diphosphate responsiveness might be reasonable to identify clopidogrel nonresponders who are candidates for early operative coronary revascularization and who may not require a preoperative waiting period after clopidogrel discontinuation. (C, Class IIb)

Routine addition of P2Y12 inhibitors to aspirin therapy early after coronary artery bypass graft (CABG) may increase the risk of reexploration and subsequent operation and is not indicated based on available evidence except in those patients who satisfy criteria for ACC/AHA guideline-recommended dual antiplatelet therapy (eg, patients presenting with acute coronary syndromes or those receiving recent drug eluting coronary stents). (B, Class III)

It is reasonable to use preoperative erythropoietin (EPO) plus iron, given several days before cardiac operation, to increase red cell mass in patients with preoperative anemia, in candidates for operation who refuse transfusion (eg, Jehovah’s Witness), or in patients who are at high risk for postoperative anemia. However, chronic use of EPO is associated with thrombotic cardiovascular events in renal failure patients suggesting caution for this therapy in individuals at risk for such events (eg, coronary revascularization patients with unstable symptoms). (B, Class IIa)

Recombinant human erythropoietin (EPO) may be considered to restore red blood cell volume in patients also undergoing autologous preoperative blood donation before cardiac procedures. However, no largescale safety studies for use of this agent in cardiac surgical patients are available, and must be balanced with the potential risk of thrombotic cardiovascular events (eg, coronary revascularization patients with unstable symptoms). (A, Class IIb)

Preoperative identification of high-risk patients (advanced age, preoperative anemia, small body size, noncoronary artery bypass graft or urgent operation, preoperative antithrombotic drugs, acquired or congenital coagulation/clotting abnormalities and multiple patient comorbidities) should be performed, and all available preoperative and perioperative measures of blood conservation should be undertaken in this group as they account for the majority of blood products transfused. (A, Class I)

Preoperative hematocrit and platelet count are indicated for risk prediction and abnormalities in these variables are amenable to intervention (A, Class I)

Preoperative screening of the intrinsic coagulation system is not recommended unless there is a clinical history of bleeding diathesis. (B, Class III)

Patients who have thrombocytopenia (50,000/mm²), who are hyperresponsive to aspirin or other antiplatelet drugs as manifested by abnormal platelet function tests or prolonged bleeding time, or who have known qualitative platelet defects represent a high-risk group for bleeding. Maximum blood conservation interventions during cardiac procedures are reasonable in these high-risk patients. (B, Class IIa)

It is reasonable to discontinue low-intensity antiplatelet drugs (eg, aspirin) only in purely elective patients without acute coronary syndromes before operation with the expectation that blood transfusion will be reduced. (A, Class IIa)

Most high-intensity antithrombotic and antiplatelet drugs (including adenosine diphosphate-receptor inhibitors, direct thrombin inhibitors, low molecular weight heparins, platelet glycoprotein inhibitors, tissue-type plasminogen activator, streptokinase) are associated with increased bleeding after cardiac operations. Discontinuation of these medications before operation may be considered to decrease minor and major bleeding events. The timing of discontinuation depends on the pharmacodynamic half-life for each agent as well as the potential lack of reversibility. Unfractionated heparin is the notable exception to this recommendation and is the only agent which either requires discontinuation shortly before operation or not at all. (C, Class IIb)

Alternatives to laboratory blood sampling (eg, oximetry instead of arterial blood gasses) are reasonable means of blood conservation before operation. (B, Class IIa)

Screening preoperative bleeding time may be considered in high-risk patients, especially those who receive preoperative antiplatelet drugs. (B, Class IIb)

Devices aimed at obtaining direct hemostasis at catheterization access sites may be considered for blood conservation if operation is planned within 24 hours. (C, Class IIb)