Calculating Subcutaneous Heparin Dosages

• Use– Proportion method– Dimensional analysis– Formula method– As well as the ABC’s of dosage calculation

• Step A Convert• Step B Calculate• Step C Think!....Is It Reasonable?

Calculating Subcutaneous Heparin Dosages

Find the amount to administer:

Ordered: Heparin 2500 units subcut

On hand: Heparin 5000 ISP units/mL

Step A Both dose ordered and dose on hand are in units.

No conversion is necessary.

ExampleExample

Calculating Subcutaneous Heparin Dosages – Proportion Method

Step B Calculate

5000 units:1mL= 2500 units: A

1 mL x 2500 = 5000 x A

2500 mL/5000 = 5000A/5000

A = ½ mL

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Calculating Subcutaneous Heparin Dosages

Step C Think!....Is It Reasonable?

Since 2500 units is half of 5000 units, the amount to administer should also be half of 1 mL, so the answer is reasonable.

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Practice

Ordered: Heparin 7500 units subcut

On hand: Heparin 20,000 units/mL

Find the amount to administer.

Answer: 0.4 mL