Weight based heparin dosing nomogram
| Initial dose | Bolus 80 U/kg, then 18 U/kg/h |
| aPTT < 35 s (< 1.2 × control) | Bolus 80 U/kg, increase infusion by 4 U/kg/h |
| aPTT 35–45 s (1.2–1.5 × control) | Bolus 40 U/kg, increase infusion by 2 U/kg/h |
| aPTT 46–70 s (1.5–2.3 × control) | No change |
| aPTT 71–90 s (2.3–3 × control) | Decrease infusion rate by 2 U/kg/h |
| aPTT > 90 s (> 3 × control) | Hold infusion 1 hour, then decrease rate by 3 U/kg/h |
aPTT is measured 6 hours after change of dosage, or at least once daily. Data from Raschke et al. Ann Intern Med1993;119:874.