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?

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.

Core Nursing Explanation Key Concept Analysis: This question tests the essential nursing skill of pediatric medication dosage calculation. The core principles involve calculating a weight-based dose and then converting that dose into a volume using the concentration of the available medication. The formula is: Key Point! (Weight in kg) × (Ordered mg/kg) = Total Dose in mg. Then, use the ratio (Available mg / Available mL) = (Total Dose mg / X mL) to solve for X.

Answer Rationale: Let's break it down step-by-step:

1. Calculate the total dose in milligrams (mg): The child weighs 20 kg, and the order is for 15 mg per kg. So, 20 kg × 15 mg/kg = 300 mg.
2. Determine the concentration of the available medication: The oral suspension is 160 mg per 5 mL. This means every 5 mL of liquid contains 160 mg of acetaminophen.
3. Set up a proportion to find the volume (mL):
   160 mg / 5 mL = 300 mg / X mL
   Cross-multiply: 160 mg × X mL = 300 mg × 5 mL
   160X = 1500
   X = 1500 / 160
   X = 9.375 mL
4. Round appropriately for safe administration: Using a standard oral syringe, we round to the nearest tenth: 9.4 mL. This is the correct volume the nurse should draw up.

Distractor Analysis:
Watch out for confusion!

• Option 1 (1.9 mL): This is likely a result of using the concentration incorrectly (e.g., 5 mL/160 mg) or a decimal place error.
• Option 2 (7.5 mL): This is a common error where the nurse might calculate 300 mg and then mistakenly use the concentration as "per 1 mL" (160 mg/mL) instead of "per 5 mL." 300 mg / 40 mg/mL (if misreading 160mg/5mL as 160mg/1mL) would give 7.5 mL.
• Option 4 (12.5 mL): This could result from forgetting the weight-based calculation and using the adult dose or a standard dose, or from an incorrect proportion setup (e.g., 5 mL/160 mg = X mL/300 mg).

Related Concepts: This calculation is fundamental for safe pediatric practice. Always remember the "rights" of medication administration: right patient, right drug, right dose, right route, right time, and right documentation. Double-checking your math is a critical part of the "right dose." For pediatric suspensions, always shake the bottle well to ensure uniform concentration before drawing up the dose.

Concept Summary

Step	Action	Example Calculation
1. Find Total Dose	Weight (kg) × Ordered dose (mg/kg)	20 kg × 15 mg/kg = 300 mg
2. Identify Concentration	Read drug label (Amount of drug / Volume)	160 mg / 5 mL
3. Set Up Proportion	(Available mg / Available mL) = (Total Dose mg / X mL)	160 mg / 5 mL = 300 mg / X mL
4. Solve for X (mL)	Cross-multiply and divide	X = (300 mg × 5 mL) / 160 mg = 9.375 mL
5. Round Safely	Use appropriate measuring device (oral syringe)	Round to 9.4 mL

Anatomy, Physiology & Pharmacology Points Acetaminophen (Tylenol): A common antipyretic (fever-reducer) and analgesic (pain-reliever). It works primarily in the central nervous system to inhibit prostaglandin synthesis. Key Point! Unlike NSAIDs (e.g., ibuprofen), it has minimal anti-inflammatory effects. The maximum daily dose for children is typically 75 mg/kg/day, not to exceed 4,000 mg/day for adults. Critical nursing consideration: Hepatotoxicity (liver damage) is the primary risk with overdose.

Memory Tips

• Dose Calc Mnemonic: "DDC" - Desired Dose, Divided by Concentration. In this case, Desired Dose = 300 mg. Concentration = 160 mg/5 mL = 32 mg/mL. 300 mg / 32 mg/mL = 9.375 mL.
• Double-Check Rule: Always have another nurse verify high-risk or calculated doses, especially for pediatric and IV medications.
• Unit Awareness: Write down units (kg, mg, mL) at every step to avoid mixing them up.

High-Frequency NCLEX Topics Pediatric dosage calculation is a must-know topic for the NCLEX-RN. Expect questions involving:

• Weight-based calculations (mg/kg).
• Liquid concentration conversions (mg/mL).
• IV drip rate calculations (mL/hr, gtt/min).
• Safe dose range checks (Is the ordered dose within the recommended range?).

Watch Out for Question Variations! The NCLEX can test this core skill in many ways:

• Priority Intervention: "After calculating the dose, which action should the nurse take first?" (Answer: Verify the calculation with another nurse or reference.)
• Safety: "The nurse calculates the dose as 9.4 mL. The parent states they usually give 'one teaspoonful.' What is the nurse's best response?" (Answer: Educate that 1 teaspoon (tsp) is approximately 5 mL, so 9.4 mL is nearly 2 teaspoons, and the dose must be measured accurately with the provided syringe.)
• Maximum Daily Dose: "The child receives this dose (15 mg/kg q6h). What is the total 24-hour dose in mg/kg, and is it safe?" (Calculate: 15 mg/kg × 4 doses = 60 mg/kg/day. Compare to safe range, e.g., 75 mg/kg/day – it is safe.)

Nursing Clinical Practice Guide Clinical Scenario: You are a nurse on a pediatric unit. A 6-year-old patient, Jamie, was admitted with pneumonia. Jamie's temperature is now 102.2°F (39°C), and they are uncomfortable. The physician's PRN order for acetaminophen is now indicated.

Nursing Intervention Strategy:

1. Assessment: Confirm the patient's identity using two identifiers. Assess current temperature, pain level, weight (verify the 20 kg in the chart is current), and any history of liver problems or allergies.
2. Planning: Calculate the dose as practiced (9.4 mL). Plan to use an oral syringe for precise measurement.
3. Implementation:
   • Shake the acetaminophen oral suspension bottle well for at least 15 seconds.
   • Draw up 9.4 mL into an oral syringe.
   • Administer the medication, ensuring the child swallows it. You may mix it with a small amount of juice or applesauce if approved and if the child will take the full dose.
   • Document the time, dose, route, and reason for administration (fever >101°F).
4. Evaluation: Reassess the patient's temperature and comfort level in 30-60 minutes. Document the effectiveness.

Patient Safety and Precautions:

• Hepatotoxicity Risk: Educate parents/caregivers that acetaminophen is in many cold/cough medicines. Never combine medications without checking labels to avoid accidental overdose.
• Accurate Measurement: Stress that kitchen spoons (teaspoons, tablespoons) are not accurate. Always use the measuring device (syringe, cup) provided with the medication.
• Contraindications: Do not administer if the child has severe liver disease or a known allergy to acetaminophen.

Nursing Procedure & Medication Flow Administering Pediatric Oral Liquids:

1. Perform hand hygiene.
2. Verify the "Rights" of Medication Administration.
3. Calculate dose and have a second nurse verify if required by policy.
4. Shake the suspension.
5. Draw up the correct volume, removing air bubbles.
6. Place the child in an upright or semi-Fowler's position to prevent aspiration.
7. Administer the medication slowly, allowing the child to swallow.
8. Offer a sip of water or preferred drink afterward if allowed.
9. Document immediately.

A Word from Your Senior Nurse "Medication math can feel stressful, but it's one of the most concrete ways we protect our patients. In the real world, you'll often use a calculator or dose-calculation software, but understanding the underlying math is your safety net. Always ask yourself, 'Does this number make sense?' For a 20 kg child, 9.4 mL of a common suspension is a reasonable volume. If you calculated 1.9 mL or 12.5 mL, that should trigger a mental alarm to recalculate. This critical thinking, linking numbers to real-world expectations, is what separates a good nurse from a great one. You've got this!"