ATI Detailed Answer Key Math Practice

1. A nurse is preparing to administer digoxin 12 mcg/kg/day PO to divide equally every 12 hr to a school-age child who weighs 66 lb. Available is digoxin elixir 0.05 mg/mL. How many mL should the nurse administer per dose? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.) 3.6 mL Correct Rationale: Follow these steps for the preliminary conversions: Step 1: What is the unit of measurement the nurse should calculate? kg Step 2: Set up an equation and solve for X. 2.2 lb/1 kg = Client's weight in lb/ X kg 2.2 lb/1 kg = 66 lb/X kg X = 30 Step 3: Round if necessary. Step 4: Reassess to determine whether the conversion to kg makes sense. If 1 kg = 2.2 lb, it makes sense that 66 lb = 30 kg. Step 5: What is the unit of measurement the nurse should calculate? mcg Step 6: Set up an equation and solve for X. mcg x kg/day = X 12 mcg X 30 kg = 360 mcg Step 7: Should the nurse convert the units of measurement? Yes (mcg is not equal to mg) 1 mg = 1,000 mcg (1 x 1,000) 360 mcg = 0.36 mg (360/1,000) Step 8: Round if necessary. Step 9: Reassess to determine whether the amount makes sense. If the prescription reads 12 mcg/kg/day to divide equally every 12 hr and the school-age child weighs 30 kg, it makes sense to give 0.36 mg/day or 0.18 mg every 12 hr. The nurse should administer digoxin 0.18 mg PO twice a day. Ratio and Proportion STEP 10: What is the unit of measurement the nurse should calculate? mL STEP 11: What is the dose the nurse should administer? Dose to administer= Desired 0.18 mg STEP 12: What is the dose available? Dose available = Have 0.05 mg STEP 13: Should the nurse convert the units of measurement? No STEP 14: What is the quantity of the dose available? 1 mL STEP 15: Set up an equation and solve for X. Have/Quantity = Desired/X 0.05 mg/1 mL = 0.18 mg/X mL X = 3.6 STEP 16: Round if necessary. STEP 17: Reassess to determine whether the amount to give makes sense. If there is 0.05 mg/1 mL and the prescription reads 12 mcg/kg/day, it makes sense to give 3.6 mL twice a day. The nurse should administer digoxin elixir 3.6 mL PO every 12 hr. Desired Over Have STEP 10: What is the unit of measurement the nurse should calculate? mL STEP 11: What is the dose the nurse should administer? Dose to administer= Desired 0.18 mg STEP 12: What is the dose available? Dose available = Have 0.05 mg STEP 13: Should the nurse convert the units of measurement? No STEP 14: What is the quantity of the dose available? 1 mL STEP 15: Set up an equation and solve for X. Desired x Quantity/Have = X 0.18 mg x 1 mL/0.05 mg = X mL 3.6 = X STEP 16: Round if necessary. STEP 17: Reassess to determine whether the amount to give makes sense. If there is 0.05 mg/1 mL and the prescription reads 12 mcg/kg/day, it makes sense to give 3.6 mL twice a day. The nurse should administer digoxin elixir 3.6 mL PO every 12 hr. Dimensional Analysis STEP 10: What is the unit of measurement the nurse should calculate? mL STEP 11: What is the quantity of the dose available? 1 mL STEP 12: What is the dose available? Dose available = Have 0.05 mg STEP 13: What is the dose the nurse should administer? Dose to administer= Desired 0.18 mg STEP 14: Should the nurse convert the units of measurement? No STEP 15: Set up an equation and solve for X. X = Quantity/Have x Conversion (Have)/Conversion(Desired) x Desired/ X mL = 1 mL/0.05 mg x 0.18 g/ X = 3.6 STEP 16: Round if necessary. STEP 17: Reassess to determine whether the amount to give makes sense. If there is 0.05 mg/1 mL and the prescription reads 12 mcg/kg/day, it makes sense to give 3.6 mL twice a day. The nurse should administer digoxin elixir 3.6 mL PO every 12 hr. InCorrect Rationale: Follow these steps for the preliminary conversions: Step 1: What is the unit of measurement the nurse should calculate? kg Step 2: Set up an equation and solve for X. 2.2 lb/1 kg = Client's weight in lb/ X kg 2.2 lb/1 kg = 66 lb/X kg X = 30 Step 3: Round if necessary. Step 4: Reassess to determine whether the conversion to kg makes sense. If 1 kg = 2.2 lb, it makes sense that 66 lb = 30 kg. Step 5: What is the unit of measurement the nurse should calculate? mcg Step 6: Set up an equation and solve for X. mcg x kg/day = X 12 mcg X 30 kg = 360 mcg Step 7: Should the nurse convert the units of measurement? Yes (mcg is not equal to mg) 1 mg = 1,000 mcg (1 x 1,000) 360 mcg = 0.36 mg (360/1,000) Step 8: Round if necessary. Step 9: Reassess to determine whether the amount makes sense. If the prescription reads 12 mcg/kg/day to divide equally every 12 hr and the school-age child weighs 30 kg, it makes sense to give 0.36 mg/day or 0.18 mg every 12 hr. The nurse should administer digoxin 0.18 mg PO twice a day. Ratio and Proportion STEP 10: What is the unit of measurement the nurse should calculate? mL STEP 11: What is the dose the nurse should administer? Dose to administer= Desired 0.18 mg STEP 12: What is the dose available? Dose available = Have 0.05 mg STEP 13: Should the nurse convert the units of measurement? No STEP 14: What is the quantity of the dose available? 1 mL STEP 15: Set up an equation and solve for X. Have/Quantity = Desired/X 0.05 mg/1 mL = 0.18 mg/X mL X = 3.6 STEP 16: Round if necessary. STEP 17: Reassess to determine whether the amount to give makes sense. If there is 0.05 mg/1 mL and the prescription reads 12 mcg/kg/day, it makes sense to give 3.6 mL twice a day. The nurse should administer digoxin elixir 3.6 mL PO every 12 hr. Desired Over Have STEP 10: What is the unit of measurement the nurse should calculate? mL STEP 11: What is the dose the nurse should administer? Dose to administer= Desired 0.18 mg STEP 12: What is the dose available? Dose available = Have 0.05 mg STEP 13: Should the nurse convert the units of measurement? No STEP 14: What is the quantity of the dose available? 1 mL STEP 15: Set up an equation and solve for X. Desired x Quantity/Have = X 0.18 mg x 1 mL/0.05 mg = X mL 3.6 = X STEP 16: Round if necessary. STEP 17: Reassess to determine whether the amount to give makes sense. If there is 0.05 mg/1 mL and the prescription reads 12 mcg/kg/day, it makes sense to give 3.6 mL twice a day. The nurse should administer digoxin elixir 3.6 mL PO every 12 hr. Dimensional Analysis STEP 10: What is the unit of measurement the nurse should calculate? mL STEP 11: What is the quantity of the dose available? 1 mL STEP 12: What is the dose available? Dose available = Have 0.05 mg STEP 13: What is the dose the nurse should administer? Dose to administer= Desired 0.18 mg STEP 14: Should the nurse convert the units of measurement? No STEP 15: Set up an equation and solve for X. X = Quantity/Have x Conversion (Have)/Conversion(Desired) x Desired/ X mL = 1 mL/0.05 mg x 0.18 g/ X = 3.6 STEP 16: Round if necessary. STEP 17: Reassess to determine whether the amount to give makes sense. If there is 0.05 mg/1 mL and the prescription reads 12 mcg/kg/day, it makes sense to give 3.6 mL twice a day. The nurse should administer digoxin elixir 3.6 mL PO every 12 hr.