Question

1. A 150 lb adult is prescribed a heparin infusion at 18units/kg/hr. The heparin is supplied in a concentration of 25,000 units in a 500 ml. What rate should the IV pump be set at?

2. A child weighs 6 kg and 110 cm in height. Calculate the child’s BSA.

3. The child weighs 40 lb and is 40 in. in height. Calculate the child’s BSA.

4. The child’s BSA is .5 m2 and the adult recommended dose is 100 mg. Calculate the appropriate dose for this child.

5. A provider prescribes oral ampicillin to a child weighing 22 lbs. The recommended oral dosage for ampicillin in children is 50-100 mg/kg/24 hours divided every 6 hours. Calculate the maximum individual dose for ampicillin that can be given to this child?

6. Physician's order: Acetaminophen 210 mg po q4-6h for a child weighing 39 lbs. The recommended dose is 10-15 mg/kg/dose q 4-6 hours. Acetaminophen is supplied as 160mg/5ml. Is the ordered dose safe? Calculate the dose to be given in ml. (Round the final answer to the nearest tenth decimal place.)

Answer 1

Sol:-

Here wt. Of patient= 150lb = 68 kg

Prescribed infusion rate= 18 units/kg/hr

Concentration of Heparin= 25000 units in 500 ml

So, the starting unit = 18units × 68kg. =1224 units/hr.

Now the rate of IV pump should be =

Total units in IV bag ÷ Total volume (in ml) = units/hr ÷ x (ml/hr)

25000 units ÷ 500ml = 1224 units/hr ÷ x (ml/hr) [x stands for the rate]

25000 × x (ml/hr) = 1224 units/hr × 500ml

X ml/hr = 612000 ÷ 25000

X= 24.48 ml/hr.

b) Sol:- In order to calculate the Body Surface area we use the Mosteller formula which is the simplest one-

BSA = √ {height (in cm) × weight (in kg) / 3600

Here height = 110cm

Weight= 6 kg

BSA =√110 cm × 6 kg /3600

= √660 / 3600

= . 42 m^2.

^{c) Sol:-}

^{Here weight = 40 lb = 40 × . 45 kg = 18 kg}

^{Height = 40 inch = 40 × 2.54 cm = 101.6 cm}

^{Similarly going by the Mosteller Formula for BSA.}

^{BSA = √ Height ( in cm) × weight (in kg) / 3600}

^{= √ 101.6 cm × 18 kg / 3600}

^{= √ 1828.8 / 3600}

^{= . 71 m2}

d) Sol :- In the above mentioned question the BSA of the child is already given

BSA = . 5m²

Adult dose= 100mg

So, we can calculate the recomended dose for the child using the formula:-

= BSA of the Child / 1.73 × Adult dose.

= . 5m²  / 1.73 m² × 100 mg

= 28 mg.

So, the recomended dose is 28mg.