Question

One general guideline for the maintenance dosing of heparin in pediatric patients is 100 units/kg every 4 hours, or 20,000 units/m²/24 hour administered continuously. The available injection for use by intravenous infusion contains 1000 USP Heparin Units/mL. For a 44-lb child, measuring 42 inches in height, calculate the difference between the quantities of heparin administered over a 24-hour period in (a) heparin units, (b) in milligrams of heparin (sodium), and (c) in milliliters of heparin injection.

Answer 1

Given data

Maintanace dosing of heparin = 100 units/kg every 4 hours, or 20,000 units/m²/24 hour

Availability = 1000 USP Heparin Units/mL

Child weight = 44-lb = 20 kg

Child height = 42 inch = 107 cm

Body Surface Area = (height (cm) x  weight (kg))/3600

= (107 cm x 20 kg)/3600

= 2140/3600

= 0.59

= 0.768 m²

(a). Heparin administered over a 24-hour period in units = 20,000 units/m²

= 20,000 units x 0.768

= 15360 units

The answer is Heparin administered over a 24-hour period in units = 15360 units

(b). Heparin administered over a 24-hour period in milligrams of heparin (sodium)

1 unit of heparin = 0.002 mg of heparin

Heparin administered over a 24-hour period in units = 15360 units

So, Heparin administered over a 24-hour period in milligrams of heparin = 15360 x 0.002 mg

   = 30.72 mg

The answer is Heparin administered over a 24-hour period in milligrams of heparin = 30.72 mg

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(c). Heparin administered over a 24-hour period in milliliters (mL) of heparin

mL of heparin = (Heraprin required for 24 hr in units / herapin availabe in units ) x availability in mL

= 15360 units x 1000 units x 1 mL

= 15. 36 mL = approx. 15 mL

The answer is Heparin administered over a 24-hour period in milliliters (mL) of heparin= 15 mL