Medical Dosage Calculations A Dimensional Analysis Approach Eleventh Edition Chapter 12 Pediatric Dosages

Learning Objectives (1 of 2) 12.1 Determine if a pediatric dose is within the safe dose range. 12.2 Calculate pediatric oral and parenteral dosages based on body weight. 12.3 Calculate pediatric oral and parenteral dosages based on body surface area.

Learning Objectives (2 of 2) 12.4 Perform calculations necessary for administering medications using a volume control chamber. 12.5 Calculate daily fluid maintenance.

Figure 12.1 A bottle of oral medication and a measuring spoon.

Figure 12.2 Liquid medication administration devices: Two droppers, an oral syringe, and a measuring spoon.

Dosages Based on Body Size Example 12.1 (1 of 2) Order: erythromycin 30 mg/kg po q6h. Read the label below. The child weighs 38 kilograms. How many milliliters of the drug will you administer to this child?

Dosages Based on Body Size Example 12.1 (2 of 2) Start with the size of the patient.

Determining Safe Dosage Range Example 12.2 (1 of 4) A drug is ordered: 0.045 mg IM stat. The child weighs 40 kilograms, and the recommended dose is (0.001-0.002) milligram per kilogram. Is this ordered dose safe for this child?

Determining Safe Dosage Range Example 12.2 (2 of 4) Using the minimum recommended dose of 0.001 mg/kg, find the minimum recommended dose in mg for this child.

Determining Safe Dosage Range Example 12.2 (3 of 4) Using the maximum recommended dose of 0.002 mg/kg, find the maximum recommended dose in mg for this child.

Determining Safe Dosage Range Example 12.2 (4 of 4) So, the safe dose range for this child is (0.04–0.08) mg. Because the prescribed dose of 0.045 mg is in this range, it is a safe dose for this child.

Figure 12.8 Volume control chamber.

Pediatric Daily Fluid Maintenance Formula For the first 10 kg of body weight 100 mL /kg For the next 10 kg of body weight 50 mL /kg For each kg above 20 kg of body weight 20 mL /kg

Calculating Daily Fluid Maintenance Example 12.3 (1 of 3) The order is maintenance for a child who weighs 35 kg. At what rate should the pump be set in mL/h? Divide the child’s weight (35 kg) into three portions as follows: 35 kg = 10 kg + 10 kg + 15 kg

Calculating Daily Fluid Maintenance Example 12.3 (2 of 3)

Calculating Daily Fluid Maintenance Example 12.3 (3 of 3) The daily “maintenance” was determined to be 1,800 mL per day.

Chapter Summary (1 of 3) Taking shortcuts in pediatric medication administration can be fatal to the child. Check to see if the order is in the safe dose range. Consult a reliable source when in doubt about a pediatric medical order. Question the order or check your calculations if the ordered dose differs from the recommended dose. Pediatric dosages are sometimes rounded down (truncated) to avoid the danger of an overdose.

Chapter Summary (2 of 3) IV bags of no more than 500 mL should be hung for pediatric patients. No more that 2 mL should be given IM to a pediatric patient. Because accuracy is crucial in pediatric infusions, electronic control devices or volume control chambers should always be used. For a volume control chamber, a flush is always used to clear the tubing after a medication is infused.

Chapter Summary (3 of 3) Know the facility policy regarding the inclusion of medication volume as part of the total infusion volume. Minimal and maximal dilution volumes for some IV drugs are recommended in order to prevent fluid overload, minimize irritation to veins, and reduce toxic effects. When preparing IV drug solutions, the smallest added volume (minimal dilution) results in the strongest concentration; the largest added volume (maximal dilution), results in the weakest concentration. Daily fluid maintenance depends on the weight of the child and includes both oral and parenteral fluids.