**Weight- Based Heparin Orders
For Deep venous Thrombosis (DVT) and Pulmonary Embolism (PE)**

**Obtain PTT, INR, CBC prior to initiating heparin.
Notify physician if platelet count is less than 100 K , hemoglobin drops by
more than 1 gram from baseline, or other abnormal values.**

Dosing Weight = Actual Body Weight = ___________ kilograms

Initial heparin dosing:

(1) Give a bolus of 80 IU per kilogram =____________

(2) Start an infusion of 18 IU per kilogram per hour= ___________

(3) Order an aPTT 6 hours after heparin bolus given.

Initial heparin bolus (at 80 units/kg rounded to the nearest 100 units) =
________

Adjusting Infusion based on aPTT

aPTT(Seconds) |
Bolus Dose IV |
Hold
Infusion (minutes) |
Rate Change |

< 35 s (<1.2 X control) |
80 units/ kg
=___________ |
0 | 4 units/kg/hr = ________ |

35 to 45 s (1.2 to 1.5 X control) |
40 units/ kg =_________ |
0 | 2 units/kg/hr =________ |

46 to 70 s (1.5 to 2.3 X control) |
0 | 0 | No change |

71 to 90 s (2.3 to 3 X control) |
0 | 0 | Decrease infusion
rate by 2 u/kg/hr =________ |

> 90 s (> 3 X control) |
0 | 60 | Decrease infusion
rate by 3 u/kg/hr =________ |

Ongoing monitoring:

(1) Order an aPTT 6 hours after any dosage change.

(This interval approximates^{ }four half-lives of heparin, the time
required to achieve steady-state^{ }kinetics.)

(2) Once 2 consecutive aPTTs are within the therapeutic range, monitor the aPTT every 24 hours and adjust infusion accordingly.

REFERENCE: Raschke RA, Reilly BM, et al., The weight-based heparin dosing
nomogram compared with a "standard care" nomogram. A randomized controlled
trial. Ann Intern Med. 1993 Nov 1;119(9):874-81.
PMID:8214998