NR 226 Week 1 MED Calculation and Sample Questions

1 milligram (mg) = 1000 micrograms (mcg) Grains (gr.) 15 = 1 Gram (g) or 1000 milligrams (mg) To convert gram. to grain multiply by 15 To convert grain to gram divide by 15. 1 Grain (gr.) = 60 Milligrams (mg) To convert gr. to mg multiply gr. by 60 To convert mg to gr. divide mg. by 60 1 ml = 1 cc 1 ounce = 30 ml 1 tablespoon (T or tbsp) = 15 ml 1 teaspoon (t or tsp) = 5 ml 2.2 lbs. = 1 kg To convert pounds to kg divide pounds by 2.2 To convert kg to pounds multiply by 2.2 Know the formula: D/H x QD D = Desired Dose Q = Quantity of Solution H = Strength on Hand X = Unknown quantity of Drug IV Calculations • [amount of fluid to be infused] x [drop factor] ÷ minutes to infuse = gtts/min Example : Dr. Abe orders your patient to receive 125 ml of D5W an hour for the next 8 hours. The nursing unit uses tubing with a drop factor of 10. What is the drip rate per minute? Solution: STEP 1 Convert 1 hour to 60 minutes STEP 2 125 x 10 gtts ÷ 60 minutes = 20.83 or 21 gtts/min Answer: 21 gtts/min If the answer is less than 5 the number remain :If it is over you round it up Example Dr. Ben orders a liter of D5W to run this 8-hour shift. The drop factor is 15. What is the drip rate per minute? Solution: 1 liter = 1000 cc of solution, next convert 8 hours to minutes (8 X 60 minutes) = 480 minutes 1000 cc x 15 gtts ÷ 480 minutes = 31.25 or 31 gtts/min Answer: 31 gtts/min STEP 4: Should the nurse convert the units of measurement? No STEP 5: Set up an equation and solve for X. Volume (mL)/Time (hr) = X mL/hr 3,000 mL/24 hr = X mL/hr X = 125/hr STEP 6: Round if necessary. STEP 7: Reassess to determine whether the amount to administer makes sense. If the prescription reads 3,000 24 hr, it makes sense to administer 125 mL/hr. The nurse should set the IV pump to deliver 125 mL/hr. The “7 Rights” of Medication Administration Right Patient Right Drug Right Dose Right Route Right Time Right Documentation Right to Refuse A nurse is preparing to administer dextrose 5% in water (D5W) 1,200 mL IV to infuse over 24 hr. The drop factor of the manual IV tubing is 15 gtt/mL. The nurse should set the manual IV infusion to deliver how many gtt/min? (Round to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.) Answer= 13 gtt/min Correct Rationale: STEP 1: What is the unit of measurement the nurse should calculate? gtt/hr STEP 2: What is the volume the nurse should infuse? 1,200 mL What is the unit of measurement the nurse should calculate? mL STEP 2: What