A prescriber orders enoxaparin 0.5 mg/kg for a client weighing 132 pounds. The prefed syringe reads 60 mg/0.6 mL. How many milliliters should be given? (Round to the nearest tenth)

A prescriber orders enoxaparin 0.5 mg/kg for a client weighing 132 pounds. The prefed syringe reads 60 mg/0.6 mL. How many milliliters should be given? (Round to the nearest tenth)

• A. 0.3 mL
• B. 0.6 mL
• C. 1.2 mL
• D. 0.1 mL

Answer: (B)

Focus on converting weight to the right units, then use the syringe’s concentration to convert mg to mL. First, convert the patient’s weight: 132 lb ÷ 2.2 lb/kg ≈ 60 kg. The ordered dose is 0.5 mg per kg, so 0.5 × 60 = 30 mg to be given. The prefed syringe is labeled 60 mg in 0.6 mL, which means the concentration is 60 mg / 0.6 mL = 100 mg per mL. To find the volume that delivers 30 mg, use volume = dose ÷ (mg per mL) = 30 mg ÷ 100 mg/mL = 0.3 mL. Rounded to the nearest tenth, that’s 0.3 mL. So the correct amount to administer is 0.3 mL.

Focus on converting weight to the right units, then use the syringe’s concentration to convert mg to mL.

First, convert the patient’s weight: 132 lb ÷ 2.2 lb/kg ≈ 60 kg. The ordered dose is 0.5 mg per kg, so 0.5 × 60 = 30 mg to be given.

The prefed syringe is labeled 60 mg in 0.6 mL, which means the concentration is 60 mg / 0.6 mL = 100 mg per mL. To find the volume that delivers 30 mg, use volume = dose ÷ (mg per mL) = 30 mg ÷ 100 mg/mL = 0.3 mL. Rounded to the nearest tenth, that’s 0.3 mL.

So the correct amount to administer is 0.3 mL.