Vtht 1349 - Medical Calculations Week 5 MULTIPLE CHOICE 1. How many milligrams of drug should be given to a patient who who weighs 22 lb if the dose is 0.2mg/kg? a. 2 c. 4.4 b. 20 d. 44 (22 lb / 2.2 lb/kg) * 0.2 mg/kg = 2 mg 2. A 75-lb dog must be dewormed. If the daily dose of the dewormer is 1 tsp/25 lb of body weight for 3 days, approximately how much should be given each day? a. 3 tbs c. 1 tbs b. 5 tsp d. 1 tsp 1 tbs = 3 tsp 3. A cat on intravenous fluids must receive 30ml/hr normal saline. If this cat has a drip set that provides 60 drops/ml, what should the drip rate be? a. 1 drop/2 sec c. 3 drops/sec b. 1 drop/6sec d. 16 drops/sec (30ml/hr) * (60 drop/sec) / (3600 sec/hr) = 0.5 drop/sec or 1 drop/2sec 4. The concentration of furosemide (Lasix) is 5%. How many milligrams are in 0.5 ml? a. 150 c. 25 b. 2.5 d. 50 5% = 50mg/ml = 25 mg/ 0.5 ml 1
5. How many milliliters of a drug with a concentration of 100mg/ml should be given to a 75-lb dog at a dose of 1 mg/lb? a. 75 c. 0.75 b. 100 d. 0.34 (75 lb * 1mg/lb) / 100mg/ml = 0.75ml 6. A prescription in which 3 ml of lactulose are given orally twice daily will require how many ounces to last for at least 30 days? a. 3 c. 90 b. 6 d. 180 30 mls is 1 ounce (oz). (3 ml * 2/day) * 30 days = 180 ml / 30ml/oz = 6 oz 7. A commercial dog food is 420Kcal/cup. A dog weighing 60 lb fed at a rate 70kcal/lb/day should be fed how many cups at each meal if you feed him twice a day? a. 5 c. 2 b. 10 d. 1 ((60lb) * (70 kcal/lb/day)) / (420kcal/cup)) / 2 feedings/day = 5 cups 8. A cockatiel needs 100mg/kg piperacillin via intramuscular injection. If the bird weighs 80 g, and the concentration of piperacillin is 100mg/ml, how many milliliters should be given? a. 0.08 c. 80 b. 0.8 d. 1.6 ((80g/1000g/kg) * 100 mg/ml) / 100mg/ml = 0.08ml 9. A rabbit needs 300 µg/kg of a 1% ivermectin solution. If the rabbit weighs 8 lb, how many milliliters of ivermectin should be given? a. 8 c. 0.1 b. 10 d. 0.8 ((8 lb / 2.2 lb/kg) * 300µg/kg) / 1000 µg/mg ) / 10 mg/ml = 0.1 2
10. How many milliliters of a 50% dextrose solution is needed to make 1000 ml of a 5% dextrose solution? a. 1 c. 50 b. 10 d. 100 V s x C s = V d x C d 50% * X = 5% * 1000 mls X = 100 mls 11. Six 12-oz puppies need deworming medication. If the dose is 1ml/lb, how many milliliters do you dispense? a. 12 c. 6 b. 4.5 d. 3 1 lb is 16 ounces (12 oz / 16 oz/lb) * 1 ml/lb * 6 puppies = 4.5 mls 12. To make a solution with a concentration of 15mg/ml, how many milliliters of sterile water should be added to 30 g of powdered drug? a. 5 c. 150 b. 200 d. 2000 (30 g * 1000 mg/g) / 15 mg/ ml = 2000 ml 13. How many tablets would you dispense for a 30-day supply of a drug with a dose of one and one-half tablets three times daily? a. 500 c. 135 b. 45 d. 90 1.5 tablets/dose * 3 doses/day * 30 days = 135 tablets 14. One gram of powdered drug diluted with how many milliliters of sterile water will make a concentration of 20 mg/ml? a. 0.05 c. 100 b. 0.2 d. 50 (1 g * 1000 mg/ml) / 20 mg/ml = 50 ml 3
15. You regularly order six 10-ml vials per month of a drug that has a concentration of 50mg/ml. Now that same drug is available in only 20-ml vials of 10mg/ml. How many vials should you order this month to get the same total amount? a. 150 c. 10 b. 60 d. 15 6 vials * 10 ml * 50mg/ml = 3000 mg 20 ml * 10 mg/ml = 200 mg 3000 mg / 200 mg = 15 vials 16. If a dog that receives fluids at a rate of 120 ml/hr has a rate reduction of 20%, what would be the new rate in milliliters per hour? a. 1.6 c. 24 b. 0.4 d. 96 80% * 120 ml/hr = 0.8 * 120 ml/hr = 96 ml/hr 17. A cat that weighs 5 kg is given 0.1 ml of a drug with a concentration of 10 mg/ml. What does this cat receive? a. 0.05 mg/kg c. 2 mg/kg b. 0.2 mg/kg d. 25 mg/kg 0.1 ml / 5 kg * 10 mg/ml = 0.2 mg/kg 18. You give 5 mg of a drug to a 10-kg animal. What is the dose of the drug in mg/kg? a. 2 c. 0.5 b. 10 d. 50 5 mg / 10 kg = 0.5 mg/kg 19. A bird that weighs 50 g requires a particular drug at 4 mg/kg divided twice a day. What is the morning dose? a. 1 mg c. 0.1 mg b. 4 mg d. 100 mg (50 g / 1000 g/kg) * 4 mg/kg = 0.2 mg /2 = 0.1 mg 4
20. How long will it take to give a whole blood transfusion of 60 ml at a rate of 2 ml/min? a. 30 hours c. 1/2 hour b. 3 hours d. 1.8 hours (60 ml / 2 ml/min) / 60 min/hr = 1/2 hour 21. If a prescription calls for one tablet to be given for 3 days bid, then one tablet for 5 days sid, then one-half tablet given every other day for 2 weeks, how many tablets should be dispensed? a. 15 c. 20 b. 18 d. 11 (3 * 2) + 5 + (7 * 0.5) + 14.5 22. Fifty milliliters of a solution of 50% dextrose is added to a liter of 0.45% NaCl with 2.5% dextrose to yield a solution with a final dextrose concentration of what percent? a. 3% c. 5% b. 4.8% d. 10% (500 mg/ml * 50 ml) + (25 mg/ml * 1000 ml) = (50,000 mg) / 1050 ml = 47.6 mg/ml = 4.76% 23. A dog consumes five bowls of water in a 24-hour period. Each bowl contained exactly 100 ml. If you collect 475 ml of urine over the same 24-hour period, approximately how many milliliters constitute insensible loss? a. 475 c. 25 b. 500 d. 5 500-475 = 25 24. If you measure an animal and set the x-ray machine at 70 kvp and 1/60 second and the resulting radiograph is 20% too light, what should the new kvp be increased to? a. 84 c. 90 b. 87 d. 114 kvp = peak kilovoltage 70 kvp * (120/100) = 84 5
25. Tidal volume for a dog is 15ml/kg. If a 10-kg male dog is taking 10 breaths per minute, what is his minute volume? a. 150 ml/min c. 15 ml/min b. 1500 ml/min d. 10 ml/min (15 ml/breath) * 10 kg = (150 ml/breath) * 10 breaths/min = 1500 ml/min 26. An anesthesia machine is set to deliver 1 L/min oxygen and 3% isoflurane. Approximately how many milliliters of isoflurane will be used for a 1-hour procedure? a. 30 c. 2400 b. 180 d. 1800 3 % = (30 ml / 1000 ml) * 1000 ml/min * 60 min/hr 27. Five tonometer readings in milliliters of mercury are 14, 15, 19, 14 and 18. What is the average (mean) reading? a. 17 c. 16 b. 18 d. 15 (14+15+19+14+18)/5 = 16 28. You have just administered one tablet of 64.8 mg of phenobarbital. How many grains of drug did you deliver? a. 0.25 c. 0.6 b. 0.5 d. 1 Technically 1 gr = 64.9 mg but still 1 gr = 60 mg is also used. 64.8 mg / 64.9 mg/grain = 1 29. What will the units of your final answer be for the following problem: How much of a 5% solution can be prepared from 100 ml of a 10% solution? a. g (grams) c. ml (mililiters) b. % (percent) d. g/ml 6
30. If 480 ml of 0.9% sodium chloride is to be infused intravenously over 24 hours, what is the correct infusion rate if the set delivers 60 drops/ml? a. 20 drops/min c. 480 drops/min b. 200 drops/min d. 1200 drops/min (60 drops/ml * 480 ml) / (24 hours * 60 minutes/hr) = 20 drops/min 7