Category 1D-dimer < 3.0 μg/mL FEU Standard prophylaxis | Category 2D-dimer ≥ 3.0 μg/mL FEU High-intensity prophylaxis | Category 3Confirmed VTE Full anticoagulation | |

Standard | Enoxaparin 40 mg subcutaneously every 24 hours | Enoxaparin 40 mg subcutaneously every 12 hours | IV heparin per DVT/PE nomogram or enoxaparin 1 mg/kg subcutaneously every 12 hours |

Renal failure | CrCl 10–30 mL/min:Enoxaparin 30 mg subcutaneously every 24 hours CrCl < 10 mL/min or AKI^{a}:Unfractionated heparin 5,000 U subcutaneously every 12 hours CRRT:Unfractionated heparin 500 U/hour through circuit Circuit clotting:IV heparin per ACS nomogram ^{a} | CrCl < 30 mL/min or AKI:Enoxaparin 40 mg subcutaneously every 24 hours CrCl < 10 mL/min or AKI^{a}:Unfractionated heparin 7,500 U subcutaneously every 12 hours CRRT:Unfractionated heparin 500 U/hour through circuit Circuit clotting:IV heparin per ACS nomogram ^{a} | IV heparin per DVT/VTE nomogram |

Obesity | |||

Standard | > 100 kg:Enoxaparin 40 mg subcutaneously every 12 hours > 120 kg:Enoxaparin 60 mg subcutaneously every 12 hours | > 100 kg:Enoxaparin 60 mg subcutaneously every 12 hours > 120 kg:Enoxaparin 80 mg subcutaneously every 12 hours | IV heparin per DVT/PE nomogram or Enoxaparin 1 mg/kg subcutaneously every 12 hours, up to 150 mg Above 150 kg use unfractionated heparin |

Renal failureCrCl < 30 mL/min or AKI ^{b} | ≤ 120 kg: 7,500 U every 12 hours> 120 kg: 10,000 U every 12 hoursCRRT:500 U/h through circuit Circuit clotting:IV heparin per ACS nomogram ^{a} | ≤ 120 kg: 7,500 U every 8 hours> 120 kg: 10,000 U every 8 hoursCRRT:500 U/h through circuit Circuit clotting:IV heparin per ACS nomogram ^{a} | IV heparin per DVT/PE nomogram |

↵a IV heparin ACS nomogram: initial dose 60-U/kg bolus, then 12 U/kg/hour; target aPTT 49–67 seconds; target heparin anti-Xa 0.2–0.5 units/mL.

↵b AKI definition: doubling of creatinine in 48 hours or anuria.

ACS = acute coronary syndrome; AKI = acute kidney injury; aPTT = activated partial thromboplastin time; CrCl = creatinine clearance; CRRT = continuous renal replacement therapy; DVT = deep vein thrombosis; FEU = fibrinogen equivalent units; IV = intravenous; PE = pulmonary embolism; VTE = venous thromboembolism