Optimal Cardiopulmonary Bypass and Anticoagulation Management Strategies in Obese Patients Undergoing Cardiac Surgery

Optimal Cardiopulmonary Bypass and Anticoagulation Management Strategies in Obese Patients Undergoing Cardiac Surgery

Standard Heparin management, based on total body weight, is not well established for obese patients undergoing cardiac surgery with cardiopulmonary bypass (CPB).

The purpose of this study is to assess the safety and efficacy of using lean body mass (LBM) to determine pump flow rate and/or Heparin dosage in obese patients undergoing CPB.

Inclusion Criteria:

• Obese patients (BMI ≥ 30kg/m2)
• Planned cardiac surgery
• Age ≥ 18 years

Exclusion Criteria:

• Permanent pacemaker
• Known intolerance to protamine
• Known or suspected allergy to the used antifibrinolytic agent
• Refusal to receive blood products
• Planned off pump coronary artery bypass
• Planned peri-operative use of desmopressin
• Known Heparin-induced thrombocytopenia
• Known deficiency in protein C, protein S, antithrombin or homozygous factor V Leiden
• Known congenital bleeding disorders
• Current endocarditis
• Planned hypothermic circulatory arrest (<28C)
• Two or more cardiac surgery procedures
• Emergency cardiac surgery procedures (medically required within 24hours of presenting with acute symptoms)
• Planned CPB priming with red blood cells
• Any known autoimmune disease
• Any history of stroke or non-coronary thrombotic disorders including deep venous thrombosis and pulmonary embolism
• Significant (≥50%) carotid artery stenosis
• Patient dosed with low molecular weight Heparin less than 24h before surgery
• Females of childbearing potential who are pregnant, breast-feeding or intend to become pregnant or are not using adequate contraceptive methods
• Confirmed ST elevation myocardial infarction (STEMI) within 7 days
• Pre-operative platelet count <100,000/microliter
• Anaemia (Hematocrit <32% for females, <35%for males)
• Dosed with clopidogrel or ticagrelor within the last 5 days prior to surgery, or prasugrel within 7 days
• Dosed with GPIIb/IIIa receptor blockers (Abciximab, Tirofiban, Eptifibatide) ≤ 24 hours prior to surgery
• International ratio (INR) >1.5 on the day of surgery in patients treated with vitamin K antagonist
• Liver dysfunction (aspartate aminotransferase (AST) or alanine aminotransferase (ALT) increased ≥ 2-fold above the upper limit of local laboratory normal ranges)
• Renal failure (creatinine ≥ 175 micromol/L or dialysis)
• Current thromboembolic disease other than myocardial infarct
• Patients who have pre-donated autologous blood
• Patient presenting with a resistance to Heparin