A pediatric nurse is preparing to administer acetaminophen to a 6-year-old child weighing 20 kg. The physician's order states "acetaminophen 15 mg/kg PO q6h PRN for fever >101°F." The available medication is acetaminophen oral suspension 160 mg/5 mL. How many milliliters should the nurse administer per dose?
11.9 mL
27.5 mL
39.4 mL✓ 정답
412.5 mL
해설
Calculate total dose: 20 kg × 15 mg/kg = 300 mg. Using concentration 160 mg/5 mL, set proportion: 160 mg/5 mL = 300 mg/X mL → X = 9.375 mL ≈ 9.4 mL. Other options result from incorrect weight or concentration calculations.
Clinical Judgment
This question assesses your ability to perform weight-based pediatric drug calculations. The key is accurate two-step calculation. First, multiply the patient's weight (20 kg) by the prescribed mg/kg dose (15 mg/kg) to find the total required dose. Next, use the available drug concentration (160 mg/5 mL) to calculate the volume (mL) corresponding to that dose. In pediatric nursing, drug dosages are almost always weight-based, unlike in adults, and calculation errors can lead to treatment failure or toxicity, making accuracy critically important.
Memory Tip: Remember pediatric drug calculations in the WDV order: Weight → Dose (total dose) → Volume (volume to administer). 1) Weight (kg) × mg/kg = total mg, 2) (total mg / concentration mg) × concentration mL = mL to administer.
KR vs US: In Korea, acetaminophen is commercially available in various concentrations such as 100 mg/mL and 150 mg/5 mL, but US NCLEX questions primarily feature the 160 mg/5 mL (Children's Tylenol) concentration. The calculation principle is the same, but it is necessary to develop the habit of accurately checking the available concentration in the question.
임상 시나리오
Clinical Practice Guide
Acetaminophen is most commonly used as an antipyretic and analgesic for children. The maximum daily dose should generally not exceed 75 mg/kg/day (or 4,000 mg), and hepatotoxicity must be monitored. After weight-based calculation, always verify that the calculated dose falls within the typical dosage range for that age/weight.
Caution: In SATA (Select All That Apply) questions, each step of the calculation process may appear as an individual option. For example, "What is the total required dose?" (300 mg) and "How many mL to administer?" (9.4 mL) may be presented together, so you must be able to accurately calculate each step independently. Additionally, "q6h PRN" means a maximum of 4 doses can be given within 24 hours, which may be linked to calculating the total daily amount.
핵심 개념
Acetaminophen — A nonsteroidal drug with antipyretic and analgesic effects. Since it is metabolized in the liver, caution is required as overdose can cause hepatotoxicity.
Weight-Based Dosing — The standard method for determining drug dosage, especially in children and infants. The total dose is calculated by multiplying the required amount of medication (mg) by the patient's weight (kg).
Oral Suspension — Oral suspension. Solid drug particles are dispersed in a liquid, so it must be shaken well before use to ensure a uniform concentration.
PRN (Pro Re Nata) — Latin for "as needed." Administer whenever the patient experiences specific symptoms (e.g., fever, pain), while adhering to the prescribed maximum dosing interval and daily limit.
Medication Calculation — A nurse's core skill of determining the exact dosage using weight, volume, concentration, etc. Double-checking is essential, and the use of standardized formulas for safety is recommended.