What is the Raschke weight-based heparin nomogram?

Bolus 80 units/kg, initial infusion 18 units/kg/hour; aPTT 90: hold 1h + decrease 3 U/kg/h.

What is the therapeutic aPTT range for heparin?

Therapeutic aPTT is typically 60-100 seconds or 1.5-2.5x normal control value; anti-Xa 0.3-0.7 IU/mL (for VTE) is increasingly used as it is not affected by lupus anticoagulant or clotting factor deficiencies.

When should anti-Xa level monitoring replace aPTT?

Anti-Xa is preferred when aPTT is unreliable: lupus anticoagulant, elevated factor VIII, heparin resistance, and supratherapeutic factor levels causing baseline prolonged aPTT without therapeutic anticoagulation.

What is heparin resistance and how is it managed?

Heparin resistance is defined as heparin requirements >35,000 U/day without therapeutic aPTT; causes: antithrombin deficiency, elevated factor VIII, active thrombosis consuming heparin; switch to direct thrombin inhibitors or argatroban.

How should heparin be reversed with protamine?

Protamine 1 mg neutralizes 100 units heparin; for IV heparin infusion: only count heparin in last 2-3 hours (due to short half-life); max protamine 50 mg; monitor for hypotension, bradycardia, and anaphylaxis (fish allergy risk).

Unfractionated Heparin Infusion Dosing and aPTT Adjustment Calculator

Calculates weight-based unfractionated heparin infusion dosing per Raschke nomogram, aPTT-guided dose adjustments, and anti-Xa target monitoring for DVT/PE treatment and ACS.

Use the full interactive calculator below, or

Related Calculators

Warfarin Dosing

Medical Calculators

Renal Drug Dosing

Medical Calculators

Vancomycin Dosing

Medical Calculators

Unfractionated Heparin Infusion Dosing and aPTT Adjustment Calculator

Related Calculators

Frequently Asked Questions

What is the Raschke weight-based heparin nomogram?

What is the therapeutic aPTT range for heparin?

When should anti-Xa level monitoring replace aPTT?

What is heparin resistance and how is it managed?

How should heparin be reversed with protamine?