CALCULATIONS PRACTICE TEST

Transcription

1 RED RIVER COLLEGE NURSING SKILLS LABORATORY CALCULATIONS PRACTICE TEST 1. Please read questions carefully. 2. Show your work for each answer. Be sure to: change all fractions to decimals round off to 2 decimal points for ml, mg and kg (where appropriate) for IV drip rates (gtt/ min) and flow rates (ml/ hr) round off to the nearest whole number when applicable state the unit of measurement in each answer 3. There are a total of 20 marks. 4. The pass grade is 90% (18/20).

2 1. GENTAMYCIN For I.V. use 40mg/mL Usual Dosage: Adults: 250mg in divided daily doses dispensing without prescription. Each vial contains equivalent of 400mg Gentamycin. Dilution not required. Discard open solution after 24 hours at room temperature or 96 hours under refrigeration. See enclosure for prescribing information. The physician s order reads: Gentamycin 60 mg IV q8h How many mls are required for one dose? 2. PHENOBARBITOL For I.V. use only 1g/ 2mL Usual Dosage: Adults: 100 mg IV Vial contains Phenobarbitol equivalent to 5g. Keep from freezing. Protect from light. Discard open solution. Read accompanying circular. The physician s order reads: Phenobarbitol 100 mg IV daily X3 How many mls are required for one dose? 3. THIAMINE HYDROCHLORIDE For I.V. injection 100mg/mL Usual Dosage: Adults: 250 IV daily Vial contains equivalent of 1g Thiamine hydrochloride. Dilution not required. Discard open solution after 24 hours at room temperature or 96 hours under refrigeration. See enclosure for prescribing information. The physician s order reads: Thiamine hydrochloride 75mg IV tid for 2 weeks How many mls are required for one dose?

3 4. ADENOSINE For I.V. use only 3mg/2mL Usual Dosage: Adults: 6mg IV; may repeat for a maximum of 2 times Each vial contains 30mL. Keep from freezing. Discard open solution after 8 hours at room temperature or 72 hours under refrigeration. Read accompanying circular. The physician s order reads: Adenosine 6 mg IV stat How many mls are required for one dose? 5. TAZIDIME For I.V. use 500mg Add 5mL of sterile water for a final concentration of 500mg/5mL Stable for 24 hours at room temperature or 3 days in the refrigerator. Read accompanying circular. The physician s order reads: Tazidime 200 mg IV q6h a) How many mls are required for one dose? b) If there is medication left after you prepare your dose, how should you label the vial?

4 6. TOBRAMYCIN For I.V. use only 300mg For a FINAL Concentration of: 10mg/ ml 50mg/ ml 100mg/ ml Add sterile NS: 30 ml 6 ml 3 ml Stable for 48 hours at room temperature or 7 days in the refrigerator. Read accompanying circular. The physician s order reads: Tobramycin 75mg IV q8h a) Considering the information given above, how many ml of NS would you use to reconstitute the medication? (give only one answer) b) Based on how you answered 6a above, how many mls are required for one dose? 7. The physician s order reads: Oxacillin 300 mg IV q6h The patient weighs 43.5 kg. The nursing drug guide recommends a maximum of mg/kg/dose. a) What is the maximum safe dose for this patient? b) Is the ordered dose for your patient safe? (show your work to support how you arrived at your answer) 8. The physician s order reads: Ticar 35 mg IV q4h The patient weighs 14 lb. The nursing drug guide recommends a maximum of mg/kg/day. a) What is the maximum safe individual dose for this patient? b) Is the ordered dose for your patient safe? (show your work to support how you arrived at your answer)

5 9. The physician s order reads: 2 L of D5NS to infuse over 14 hours a) How many ml/ h will the IV need to run at in order to deliver the solution as ordered? b) The drop factor of the IV tubing is 10 gtt/ml. What should you set the drip rate (gtt/min) at in order to deliver the solution as ordered? 10. The physician s order reads: 100mL of NS to infuse over 30 min a) How many ml/ h will the IV need to run at in order to deliver the solution as ordered? b) The drop factor of the IV tubing is 60 gtt/ml. What should you set the drip rate (gtt/min) at in order to deliver the solution as ordered? 11. The physician s order reads: 1000mL of NS to infuse over 6 hours a) How many ml/ h will the IV need to run at in order to deliver the solution as ordered? b) The drop factor of the IV tubing is 20 gtt/ml. What should you set the drip rate (gtt/min) at in order to deliver the solution as ordered?

6 12. 1 L of D5W is to run over 10 hours. After 4 hours, there are 400 ml remaining in the bag. a) Is the IV ahead or behind? (show your work to support how you arrived at your answer) b) Recalculate a new flow rate (ml/ h) in order to finish the IV on time. c) Does the new flow rate fit with acceptable practice? Explain your answer ml of NS is to run over 4 hours. After 2 hours, there are 350 ml remaining in the bag. a) Is the IV ahead or behind? (show your work to support how you arrived at your answer) b) Recalculate a new flow rate (ml/ h) in order to finish the IV on time. c) Does the new flow rate fit with acceptable practice? Explain your answer.

7 14. PRONESTYL For I.V. use 1mg/mL Usual Dosage: Adults: 5mg per day for days Contains the equivalent of 10mg Pronestyl. Dilution not required. Discard open solution immediately. See enclosure for prescribing information. The physician s order reads: Pronestyl 8 mg IV stat You decide to give this by the direct IV method. The drug monograph states that IV infusion is not to exceed 6 mg/ min. a) How many mls are required for one dose? b) Over what period of time will you administer this dose? (if applicable, show your work to support that the time period you select is safe) c) Based on how you answered 14b above, how many mls is that q15seconds? 15. The physician s order reads: Aminophylline 80 mg/ h IV The drug is supplied in a bag containing 500 mg of Aminophylline in 50 ml of solution. a) What is the concentration (mg/ per 1 ml) of Aminophylline in the bag? b) At what rate (ml/ h) would you deliver the medication? 16. The physician s order reads: Regular Insulin 1 unit/ h IV The drug is supplied in a bag containing 10 units of Regular Insulin in 100 ml of solution. a) What is the concentration (units/ per 1 ml) of Regular Insulin in the bag? b) At what rate (ml/ h) would you deliver the medication?

8 DOSAGE CALCULATIONS PRACTICE TEST ANSWER KEY mg X 1 ml = 40 mg mg X 2 ml = 1000 mg mg X 1 ml = 100 mg 4. 6 mg X 2 ml = 3 mg 5a. 200 mg X 5 ml = 500 mg 1.5 ml 0.2 ml 0.75 ml 4 ml 2 ml 5b. TAZIDIME 500 mg/ 5mL 05/05/ h km 6a. 3 ml is the best choice because the final concentration matches the dose that you need to give. However, it would also be acceptable to use 6 ml or 30 ml. 6b. If you picked 3 ml for previous answer then: 75 mg X 1 ml = 100 mg 0.75 ml If you picked 6 ml for previous answer then: 75 mg X 1 ml = 50 mg 1.5 ml If you picked 30 ml for previous answer then: 75 mg X 1 ml = 10 mg 7.5 ml 7a. 7.5 mg X 43.5 kg = mg/ dose 7b. The maximum safe dose is mg/ dose. The patient is to receive 300 mg so YES the ordered dose is safe.

9 8a. 14 lb = 6.36 kg mg X 6.36 kg = mg/ day 8b. The maximum safe dose is 189 mg/ day. The patient is to receive 35 mg X 6 doses = 210 mg/ day so NO the ordered dose is not safe. 9a ml = 14 h 143 ml/ h 9b. 143 ml X 10 gtt/ml = 60 min 24 gtt/ min 10a. 100 ml = X 30 min 60 min X = 200 ml/ h 10b. 200 ml X 60 gtt/ml = 60 min 200 gtt/ min 11a ml = X 6 h 60 min X = 167 ml/ h 11b. 167 ml X 20 gtt/ml = 60 min 56 gtt/ min 12a ml = X X = 100 ml/ h 10 h 1 h 100 ml/ h X 4h = 400 ml should be infused out of a 1000 ml bag so there should be 600 ml left in the bag. But there is 400 ml left so IV is AHEAD (so IV needs to be slowed down) 12b. 400 ml = X 6h 1h X = 67 ml/ h 12c. It is usually acceptable practice to slow an IV, even to TKO YES, the new flow rate is acceptable.

10 13a. 500 ml = X X = 125 ml/ h 4 h 1 h 125 ml/ h X 2h = 250 ml should be infused out of a 500 ml bag so there should be 250 ml left in the bag. But there is 350 ml left so IV is BEHIND (so IV needs to be speeded up) 13b. 350 ml = X 2h 1h 13c. Ordered rate is 125 ml/h. 25% of 125 ml is 31 ml. Therefore could safely flow rate by 31 ml to 156 ml/h 14a. 8 mg X 1 ml = 8 ml 1 mg X = 175 ml/ h New rate = 175 ml/ h which is more than the acceptable 156 ml/h NO, the new flow rate is not acceptable. 14b. Maximum rate is 6 mg/ min so 6 mg = 8 mg min X 14c. 2 min = 8 15 sec blocks so 8 ml = 8 blocks X = 1.33 min NOTE: Students are generally required to give an IV medication over a minimum of 2 minutes so you should bump this answer up to 2 minutes. Because the drug monograph gives you only a minimum time for administering the med, it is acceptable for you to decide to do this. 1 ml/ 15 sec 15a. 500 mg = 50 ml 10 mg/ ml 15b. 80 mg X 1 ml = 10 mg 16a. 10 units = 100 ml 16b. 1 unit X 1 ml = 0.1 unit 8 ml/h 0.1 units/ ml 10 ml/h